Honda Ridgeline Owners Club Forums banner

1 - 19 of 19 Posts

·
Super Moderator
2008 Ridgeline RTS in Billet Silver Metallic
Joined
·
22,895 Posts
Discussion Starter #1 (Edited)
Moderator note: I created this thread and moved the appropriate posts here from the 2nd gen RL discussion thread.

Yeah, I hope that unit can handle a substantial amount of torque (enough to move the entire vehicle). I was just out with my Friend in his (my old) Ridgeline last weekend and we accidentally found ourselves stuck in some mud at the hunting camp. The entire left side was spinning in real slick mud, I thought the current VTM4 system could do some degree of rear lock, but whatever it can do it wasn't enough to get out. Had to dig out a wheel and get some traction under it before it could free itself. Made me really long for a true real locker, hopefully this new VTM4 system can do that job very well.
Were you unable to get both rear wheels spinning in manual VTM-4 lock with VSA disabled?
 

·
Registered
Joined
·
782 Posts
Re: Next-Generation Ridgeline general comments...

Were you unable to get both rear wheels spinning in manual VTM-4 lock with VSA disabled?
We were not. The truck was in very slick mud on the entire driver's side, both driver's side wheels were spinning, neither passenger wheels would spin. We dug out both driver's side wheels and slid some sticks underneath for traction, then one pushed while the other drove and it managed to just barely pull itself out. I was under the impression that VTM4 would send some torque to the passenger rear wheel to get us out, but, at least in this situation with this truck, it was not able to do so.

It was definitely a pretty bad mud slick, I'm surprised we got it out at all. Thought we were going to have to walk back and get a tractor or Polaris to tug it out. I assume that a rear locker like an ARB would have been sufficient here, but I certainly don't know that for sure. Felt a little stupid for not having the come along with us.
 

·
Super Moderator
2008 Ridgeline RTS in Billet Silver Metallic
Joined
·
22,895 Posts
Discussion Starter #3
Re: Next-Generation Ridgeline general comments...

In that scenario, I would expect both rear wheels to spin IF:
1) gear position 1, 2 or R is selected and
2) manual VTM-4 lock is engaged and
3) VSA is disabled.

Else you may have a silent failure of the VTM-4 unit.
 

·
Registered
Joined
·
782 Posts
Re: Next-Generation Ridgeline general comments...

In that scenario, I would expect both rear wheels to spin IF:
1) gear position 1, 2 or R is selected and
2) manual VTM-4 lock is engaged and
3) VSA is disabled.

Else you may have a silent failure of the VTM-4 unit.
But if it were a silent failure I would not expect the rear driver's wheel to spin. I guess maybe clutches on one side could be in the process of failing and can only transmit a very low amount of torque. We worked through the entire process, tried to get out of it, shifted it into 2 and locked in VTM-4 and tried, next tried simultaneously depressing the brake and using the ebrake to trick the diffs into seeing more traction on one side, then disabled VSA. In the end it took clearing out some mud and putting down some sticks for traction on the slipping wheels and bracing against a tree and pushing it very hard. I don't know how much the pushing really helped, but that's what was happening when the truck broke free. It was a good experience for my friend, who now keeps better traction aids in the trunk. Nevertheless I hope that never happens again. When you stop going forward and start sliding sideways down a hill, because you hit slick mud you couldn't see, it gets a little scary.
 

·
Registered
Joined
·
5,620 Posts
Re: Next-Generation Ridgeline general comments...

We were not. The truck was in very slick mud on the entire driver's side, both driver's side wheels were spinning, neither passenger wheels would spin. We dug out both driver's side wheels and slid some sticks underneath for traction, then one pushed while the other drove and it managed to just barely pull itself out. I was under the impression that VTM4 would send some torque to the passenger rear wheel to get us out, but, at least in this situation with this truck, it was not able to do so.

It was definitely a pretty bad mud slick, I'm surprised we got it out at all. Thought we were going to have to walk back and get a tractor or Polaris to tug it out. I assume that a rear locker like an ARB would have been sufficient here, but I certainly don't know that for sure. Felt a little stupid for not having the come along with us.
In that scenario, I would expect both rear wheels to spin IF:
1) gear position 1, 2 or R is selected and
2) manual VTM-4 lock is engaged and
3) VSA is disabled.

Else you may have a silent failure of the VTM-4 unit.
But if it were a silent failure I would not expect the rear driver's wheel to spin. I guess maybe clutches on one side could be in the process of failing and can only transmit a very low amount of torque. We worked through the entire process, tried to get out of it, shifted it into 2 and locked in VTM-4 and tried, next tried simultaneously depressing the brake and using the ebrake to trick the diffs into seeing more traction on one side, then disabled VSA. In the end it took clearing out some mud and putting down some sticks for traction on the slipping wheels and bracing against a tree and pushing it very hard. I don't know how much the pushing really helped, but that's what was happening when the truck broke free. It was a good experience for my friend, who now keeps better traction aids in the trunk. Nevertheless I hope that never happens again. When you stop going forward and start sliding sideways down a hill, because you hit slick mud you couldn't see, it gets a little scary.
I agree with Speed's observations, and in my opinion, this truck was NOT functioning properly. There's no way that both wheels on one side should be not spinning ("neither passenger wheels would spin"), even if you did NOT have VTM4 locked and was in Drive.
But with VTM4 locked & VSA switched off (and in 1st or 2nd gear), you should have had 3 wheels spinning aggressively..... and if it HAD been functioning correctly, you might have even escaped your muddy morass! .... or not. Also, I'm thinking he should have disabled VSA from the get-go.... sounds like it was an after thought? In any case, that truck should be taken to the dealer for VTM4 diagnostics before attempting any further off-road adventures. I do agree that is has suffered a "silent failure" somewhere along the road (possibly prior misapplied VTM4 lock activity?).
I'm just sayin'..... :act039: :act018:
 

·
Super Moderator
2008 Ridgeline RTS in Billet Silver Metallic
Joined
·
22,895 Posts
Discussion Starter #6 (Edited)
Re: Next-Generation Ridgeline general comments...

But if it were a silent failure I would not expect the rear driver's wheel to spin. I guess maybe clutches on one side could be in the process of failing and can only transmit a very low amount of torque. We worked through the entire process, tried to get out of it, shifted it into 2 and locked in VTM-4 and tried, next tried simultaneously depressing the brake and using the ebrake to trick the diffs into seeing more traction on one side, then disabled VSA. In the end it took clearing out some mud and putting down some sticks for traction on the slipping wheels and bracing against a tree and pushing it very hard. I don't know how much the pushing really helped, but that's what was happening when the truck broke free. It was a good experience for my friend, who now keeps better traction aids in the trunk. Nevertheless I hope that never happens again. When you stop going forward and start sliding sideways down a hill, because you hit slick mud you couldn't see, it gets a little scary.
I cannot explain your observations short of some type of failure in the VTM-4 system. Maybe someone more knowledgeable will chime in with a solid explanation.

It has been my experience that neither the dealer nor the FSM has any procedure for checking the function of the VTM-4 locking function short of taking it to a slippery spot and trying it out. That seems a bit underwhelming in the service diagnostic category.

Just out of curiosity, did you try manual lock in gear 1 WITH VSA enabled? (the only benefit there that I can see is that it would allow traction to go to the passenger side front wheel). However, the disadvantage of power being cut due to wheelspin probably outweighs any potential benefit of having VSA enabled.
 

·
Administrator
Joined
·
17,297 Posts
Re: Next-Generation Ridgeline general comments...

It has been my experience that neither the dealer nor the FSM has any procedure for checking the function of the VTM-4 locking function short of taking it to a slippery spot and trying it out. That seems a bit underwhelming in the service diagnostic category.
Actually, there is a procedure. It involves manually applying voltage to each clutch and trying to turn each wheel.

"Mechanical Testing:

2WD: In 2WD, the clutches are NOT engaged and each wheel should spin freely by hand while on jack stands. The actual specification is 15 ft lbs of rotating force. If the wheels do not spin freely, check for a short to power by disconnecting the electrical connectors to the coil. If the wheels continue to have excessive turning resistance, check for mechanical binding in the associated clutch pack.

4WD: When activated, the electro-magnetic coils in the VTM-4 force the ramps in the thrust plate and pole piece to separate with considerable force when the wheel or ring gear carrier is rotated. To test the holding capacity of the clutches, use the following procedure:

Lift the vehicle and place on jack stands
Remove the rear wheels
The engine should be "OFF" and the transmission selector in "PARK"
The parking brake should be "RELEASED"
Disconnect the 2 pin and 6 pin connectors
To test the left clutch/coil, place full battery power to pin 1 of the 2-pin connector and ground to pin 2 of the 2-pin connector. NOTE: The VTM-4 controller typically Pulse Width Modulates current to the coils. Providing full battery voltage to the coils will get them HOT and could potentially cause damage to the coils if left "on" for too long. DO NOT energize the coils for more than 3-minutes
Set a click type torque wrench to 148 ft lbs and attempt to rotate the rear hubs in both directions. The torque wrench should click before the hub/axle rotates. If the Hub rotates before 148 ft lbs, the clutch pack is slipping
Repeat the procedure for the right side clutch pack
Place 12 volts on pin 6 of the 6-pin connector and ground on pin 3 of the 6-pin connector."

http://mypage.siu.edu/jeepster/vtm4.html
 

·
Super Moderator
2008 Ridgeline RTS in Billet Silver Metallic
Joined
·
22,895 Posts
Discussion Starter #8
Re: Next-Generation Ridgeline general comments...

Yes, I am aware of that. However, it is not in the FSM and my local dealer does not know of any way to test other than a practical application test. I don't think they can use unofficial testing procedures. I ran that very procedure by the service manager.

Do we know the source of that testing info?
 

·
Registered
Joined
·
782 Posts
Re: Next-Generation Ridgeline general comments...

I cannot explain your observations short of some type of failure in the VTM-4 system. Maybe someone more knowledgeable will chime in with a solid explanation.

It has been my experience that neither the dealer nor the FSM has any procedure for checking the function of the VTM-4 locking function short of taking it to a slippery spot and trying it out. That seems a bit underwhelming in the service diagnostic category.

Just out of curiosity, did you try manual lock in gear 1 WITH VSA enabled? (the only benefit there that I can see is that it would allow traction to go to the passenger side front wheel). However, the disadvantage of power being cut due to wheelspin probably outweighs any potential benefit of having VSA enabled.
We did not try manual lock in "1" at all. I told him to go to "2" because I figured the additional torque to the wheels in "1" would do more harm than good since we were spinning wheels anyway. In "2" we tried with both VSA enabled and disabled, and with and without applying some brake pressure to try and trick the differential into "seeing traction" on the driver's side. It seems that the stability control, at least in this case with this vehicle, is not sufficient to send torque to the side with traction. This was a particularly tough situation though, it wasn't just a little mud, we slid sideways down a hill and nearly crashed sideways into a treeline. The driver's side was probably close to a completely zero traction situation, like they get on those rollers you see on internet videos sometimes. We never would have gone that way if we had known what it was like, but the grass was relatively high and it hadn't rained in several days, it was one of those fluke situations where it came completely out of left field.

It certainly is possible that the VTM4 system in his truck is no longer fully functional, that would certainly be a bummer. But I guess it also depends on how much torque the current VTM4 can send to a single rear wheel with traction. I thought that the current VTM4 unit could lock all of the clutches so torque would be send to the rear axle, but then across the rear axle. I guess if the torque that can make it to/across the rear axle is limited to some relatively small number (perhaps due to a failed/failing unit) the passenger rear just couldn't get enough torque to turn and get the truck going. That certainly seems possible since with a little extra traction on the driver rear system and some pushing the truck fought its way out.

It would be nice to test the system out but even if we put it on 4 jack stands I'm not sure how we could simulate a load on one side and not the other. I guess this is one advantage of an "old fashioned" 4wd system and/or an air locker in the rear. It is very clear very quickly if it is working or not. Maybe something Honda can work on including in the next Ridgeline (G3?) is some sort of clever sensor to detect if the VTM4 system is functioning within parameters or if the clutches have worn down. I have no idea how they'd do it, but they're clever guys someone can probably come up with something.
 

·
Registered
Joined
·
782 Posts
Re: Next-Generation Ridgeline general comments...

Actually, there is a procedure. It involves manually applying voltage to each clutch and trying to turn each wheel.

"Mechanical Testing:

2WD: In 2WD, the clutches are NOT engaged and each wheel should spin freely by hand while on jack stands. The actual specification is 15 ft lbs of rotating force. If the wheels do not spin freely, check for a short to power by disconnecting the electrical connectors to the coil. If the wheels continue to have excessive turning resistance, check for mechanical binding in the associated clutch pack.

4WD: When activated, the electro-magnetic coils in the VTM-4 force the ramps in the thrust plate and pole piece to separate with considerable force when the wheel or ring gear carrier is rotated. To test the holding capacity of the clutches, use the following procedure:

Lift the vehicle and place on jack stands
Remove the rear wheels
The engine should be "OFF" and the transmission selector in "PARK"
The parking brake should be "RELEASED"
Disconnect the 2 pin and 6 pin connectors
To test the left clutch/coil, place full battery power to pin 1 of the 2-pin connector and ground to pin 2 of the 2-pin connector. NOTE: The VTM-4 controller typically Pulse Width Modulates current to the coils. Providing full battery voltage to the coils will get them HOT and could potentially cause damage to the coils if left "on" for too long. DO NOT energize the coils for more than 3-minutes
Set a click type torque wrench to 148 ft lbs and attempt to rotate the rear hubs in both directions. The torque wrench should click before the hub/axle rotates. If the Hub rotates before 148 ft lbs, the clutch pack is slipping
Repeat the procedure for the right side clutch pack
Place 12 volts on pin 6 of the 6-pin connector and ground on pin 3 of the 6-pin connector."

http://mypage.siu.edu/jeepster/vtm4.html
This is a really good idea. If the Ridgeline were still mine I would probably give this a try. Pretty sure my friend won't be interested though. So each wheel should be capable of putting down 148 ft lbs of torque when the system is fully engaged? Interesting.
 

·
Registered
Joined
·
5,620 Posts
Re: Next-Generation Ridgeline general comments...

......
It has been my experience that neither the dealer nor the FSM has any procedure for checking the function of the VTM-4 locking function short of taking it to a slippery spot and trying it out. That seems a bit underwhelming in the service diagnostic category..............
Actually, there is a procedure. It involves manually applying voltage to each clutch and trying to turn each wheel.
"Mechanical Testing: ............................
Yes, I am aware of that. However, it is not in the FSM and my local dealer does not know of any way to test other than a practical application test. I don't think they can use unofficial testing procedures. I ran that very procedure by the service manager.

Do we know the source of that testing info?
I'm not so sure Speed.... I might be missing something, but at section 15-45 in my 2006 Service Manual, I'm looking at "Differential Function Test", which utilizes the HDS diagnostic unit. It tests the electromagnetic coils in the rear diff + ??. The manual just says "follow the screen prompts", so I'm not sure exactly what the procedure is or what exactly gets tested. Result options are only "normal" or "abnormal" (in which case the solution is to replace the differential)!
If your dealer does not know about this you might want to point it out. If it's just that this will not detect certain defects/wear, then that's a different story with which I am unfamiliar. Are you aware of this diagnostic test?
 

·
Super Moderator
2008 Ridgeline RTS in Billet Silver Metallic
Joined
·
22,895 Posts
Discussion Starter #12
Re: Next-Generation Ridgeline general comments...

Dnick,

15-45 in my FSM relates to VTM-4 lock indicator light issues. However, 15-48 relates to a Rear Differential Function Test, which I what I think you are referring to. If so, I fail to see how this would test for a silent VTM-4 failure. It is not applying any torque to the rear wheels as the test that zroger posted does. Instead, it looks like it simply checks that the EM coils on the clutches work.

Rear Differential Function Test
NOTE: Before doing the Differential Function Test, the following conditions must be present.
• No DTCs detected
• Engine is OFF
• The VTM-4 control unit must be initialized
1. Connect the HDS to the data link connector (DLC).
2. Turn the ignition switch ON (II).
3. Make sure the HDS communicates with the VTM-4 control unit. If it doesn’t go to the DLC circuit troubleshooting
(see page 11-194).
4. Confirm that the temperature of the differential oil is between 68 °F (20 °C) and 140 °F (60 °C) with the HDS.
5. Turn the ignition switch OFF with the shift lever in P.
6. Raise the vehicle so all four wheels are off the ground, and make sure the vehicle is securely supported (see page
1-10).
7. Remove the rear wheels (see page 18-28).
8. Release the parking brake.
9. Turn the iginition switch ON (II).
10. Select MISCELLANEOUS TEST, then select the LEFT CLUTCH ELECTROMAGNETIC COIL TEST with the HDS, and
follow the screen prompts. If the results are NORMAL, the left clutch is OK, go to step 11. If the results are
ABNORMAL, replace the rear differential.
11. Select MISCELLANEOUS TEST, then select the RIGHT CLUTCH ELECTROMAGNETIC COIL TEST with the HDS,
and follow the screen prompts. If the results are NORMAL, the right clutch is OK. If the results are ABNORMAL,
replace the rear differential.
 

·
Registered
Joined
·
5,620 Posts
Re: Next-Generation Ridgeline general comments...

Dnick,

15-45 in my FSM relates to VTM-4 lock indicator light issues. However, 15-48 relates to a Rear Differential Function Test, which I what I think you are referring to. If so, I fail to see how this would test for a silent VTM-4 failure. It is not applying any torque to the rear wheels as the test that zroger posted does. Instead, it looks like it simply checks that the EM coils on the clutches work.

Rear Differential Function Test
NOTE: Before doing the Differential Function Test, the following conditions must be present.
• No DTCs detected
• Engine is OFF
• The VTM-4 control unit must be initialized
1. Connect the HDS to the data link connector (DLC).
2. Turn the ignition switch ON (II).
3. Make sure the HDS communicates with the VTM-4 control unit. If it doesn’t go to the DLC circuit troubleshooting
(see page 11-194).
4. Confirm that the temperature of the differential oil is between 68 °F (20 °C) and 140 °F (60 °C) with the HDS.
5. Turn the ignition switch OFF with the shift lever in P.
6. Raise the vehicle so all four wheels are off the ground, and make sure the vehicle is securely supported (see page
1-10).
7. Remove the rear wheels (see page 18-28).
8. Release the parking brake.
9. Turn the iginition switch ON (II).
10. Select MISCELLANEOUS TEST, then select the LEFT CLUTCH ELECTROMAGNETIC COIL TEST with the HDS, and
follow the screen prompts
. If the results are NORMAL, the left clutch is OK, go to step 11. If the results are
ABNORMAL, replace the rear differential.
11. Select MISCELLANEOUS TEST, then select the RIGHT CLUTCH ELECTROMAGNETIC COIL TEST with the HDS,
and follow the screen prompts. If the results are NORMAL, the right clutch is OK. If the results are ABNORMAL,
replace the rear differential.
Yeah, it was the "follow the screen prompts" part that left me unsure what they were actually doing during the test (which might have tested for ???). I guess I'm granting too much benefit of the doubt. (Yes, that's the test I was referring to)

.... and I guess our SMs are different editions; mine is 2006 Service Manual, bought from way back when... "First Edition 05/2005".... and it's on 15-45. Yours may be newer?
 

·
Super Moderator
2008 Ridgeline RTS in Billet Silver Metallic
Joined
·
22,895 Posts
Discussion Starter #14
When I reread the original problem post after moving the thread, it dawned on me that only one side of the truck was in slippery mud. Ergo, I assume the passenger side had traction. This leads me to believe there may be another possibility for the failure of the passenger side rear wheel to turn: the torque applied was greater than the holding ability of the clutches and the clutches simply slipped on that side.

This is exactly what I found when I did my VTM-4 lock test several years ago:
http://www.ridgelineownersclub.com/forums/showpost.php?p=471230&postcount=257

I duplicated these results on our 2006 Pilot (4wd) as well. I have since verified that (at least for the RL) both rear wheels spin when locked in snow. So I think my clutches are still good.

The only conclusion I could draw from my experience was that the clutches did not have the grip capability to spin the heavily loaded right rear wheel (the only one with traction) and so the clutches simply slipped. I have to admit this was rather disappointing.

That being said, I suspect my old 4x4 T100 (no lockers) would not have fared any better since it would have only had 1 wheel driven per axle as well. The only saving grace there is that it may have had more articulation and may not have lost as much traction on the downslope side as my RL (which was basically teetering on the diagonal between the front left and right rear wheels).
 

·
Registered
Joined
·
75 Posts
It might be nice to see a selection of videos showing the various results with different VTM-4 & VSA setting so those who suspect a problem have an idea of what it looks like. Although I understand it is dependant on having a Ridge with everything working right, but even one with a known 'silent' fail showing how it responds would be nice to see. I may have to try and find some flat mud areas and try it out.

I guess the challenge is you need a couple of people watching / video from either side to know if all is working as it should. I have never had to use my VTM-4, so for all I know it could have had a silent fail since I bought it used....hhmmm???
 

·
Super Moderator
2008 Ridgeline RTS in Billet Silver Metallic
Joined
·
22,895 Posts
Discussion Starter #16
Just for accuracy, when you say you've never had to use your VTM-4, you mean you've never had to use your manual VTM-4 lock. (VTM-4 is in constant use automatically).

I imagine there may be varying degrees of silent failure... all the way from complete failure (no power to the rear wheel(s)) to partial failure (both L&R clutches partially failed or fully failed on one side only).

Clutches that have partly failed may provide some power to the rear wheels, but not the full amount of power per the design specs. (I'm assuming the clutches can still provide some power transfer in varying stages of wear.. or perhaps it's all or nothing?).
 

·
Registered
Joined
·
5,620 Posts
Just for accuracy, when you say you've never had to use your VTM-4, you mean you've never had to use your manual VTM-4 lock. (VTM-4 is in constant use automatically).

I imagine there may be varying degrees of silent failure... all the way from complete failure (no power to the rear wheel(s)) to partial failure (both L&R clutches partially failed or fully failed on one side only).

Clutches that have partly failed may provide some power to the rear wheels, but not the full amount of power per the design specs. (I'm assuming the clutches can still provide some power transfer in varying stages of wear.. or perhaps it's all or nothing?).
That last uncertainty is the troubling part of trying to understand/diagnose what's going on with VTM-4 in various reported situations!

IOW; exactly how much torque is being applied to any given wheel when VTM-4 is engaged, locked or otherwise? We've seen the "% of total to the rear" figures, but I'd especially like to know the answer to this with respect to minimum applied under lock to which wheels.

Between 0-6MPH, we should see 100% of the system's capacity to send power to the rear... but what does that mean? 70% of total power train torque??? And if so, then what is the limit of the clutches at the rear axles to deliver that torque..... will resisting force (e.g. braking action or impossibly steep incline) first defeat the clutches in the rear diff, or the transmission?? Ideally, the rear diff clutches should be able to withstand any amount of torque the transmission is able to deliver to it. The absence of real data on this bothers the heck out of me. Especially when we see a truck with only 2 wheels turning.....

Bottom line however, is that if I understand the system correctly the following would be true:
If VSA is disabled
If VTM4 lock is engaged
If truck is in 1st gear (for example)
If one of the rear wheels is spinning due to loss of traction (never mind the front wheels)
..... THEN
The other rear wheel should be spinning as well, correct??????
......And (for good measure)
If it's off the ground & not spinning this would HAVE to indicate a TOTAL 100% failure of the VTM4 system to deliver ANY torque to that side (clutches 'gone', etc.).
If it's NOT off the ground, then it's possible that the clutches have just failed to the point that they cannot overcome whatever resisting force is being applied (partial failure as Speed referenced).
Am I perceiving the operation of the system correctly in the above example?
 

·
Registered
Joined
·
75 Posts
Just for accuracy, when you say you've never had to use your VTM-4, you mean you've never had to use your manual VTM-4 lock. (VTM-4 is in constant use automatically).

I imagine there may be varying degrees of silent failure... all the way from complete failure (no power to the rear wheel(s)) to partial failure (both L&R clutches partially failed or fully failed on one side only).

Clutches that have partly failed may provide some power to the rear wheels, but not the full amount of power per the design specs. (I'm assuming the clutches can still provide some power transfer in varying stages of wear.. or perhaps it's all or nothing?).
Yes, Sorry I wasn't clear. I have never manually engaged the VTM-4 lock. My bad
 

·
Super Moderator
2008 Ridgeline RTS in Billet Silver Metallic
Joined
·
22,895 Posts
Discussion Starter #19
Bottom line however, is that if I understand the system correctly the following would be true:
If VSA is disabled
If VTM4 lock is engaged
If truck is in 1st gear (for example)
If one of the rear wheels is spinning due to loss of traction (never mind the front wheels)
..... THEN
The other rear wheel should be spinning as well, correct??????
......And (for good measure)
If it's off the ground & not spinning this would HAVE to indicate a TOTAL 100% failure of the VTM4 system to deliver ANY torque to that side (clutches 'gone', etc.).
If it's NOT off the ground, then it's possible that the clutches have just failed to the point that they cannot overcome whatever resisting force is being applied (partial failure as Speed referenced).
Am I perceiving the operation of the system correctly in the above example?
That is pretty much my understanding. And in addition, if the wheel with traction is not turning (in a perfectly functional system), that would indicate the clutches in the VTM-4 unit are slipping on that side and do not have sufficient ability to transfer power to the wheel above a certain (undefined) torque limit. IE, traction exceeds the amount of torque the system can handle.

The question then becomes how much has the system been compromised (if any) due to wear on the clutches due to the slippage. Surely Honda has some defined limits/specs in this regard. But if so, they are unknown to the general public. The only hint we have is that link that zroger posted with specifics. However, that source is not officially recognized, to the best of my knowledge.

The main thing about using manual VTM-4 lock (IMO) is that you get the maximum amount of power to the rear wheels without having to engage the other parameters to effect power transfer to the rear (as in the automatic mode).

On a separate note, I've never understood by what mechanism Honda gets up to 70% power transfer to the rear wheels.

"When the clutches are energized and engaged by the VTM-4® electronic control unit, up to 70% of the engine's power is diverted to the rear wheels so they can work with the front wheels to provide 4-wheel drive."

http://automobiles.honda.com/certified-pre-owned/ridgeline/2014/performance.aspx

IE, what limits/determines that 70% value, instead of, say, 40%... or 100%?
 
1 - 19 of 19 Posts
Top