[speedlever]

For G2 owners who aren't familiar with the G1, the G1 had a "VTM-4 LOCK" mode that could "lock" the rear wheels to help get you unstuck. It would only work in 1st, 2nd, or reverse. Using it on dry pavement results in increased wear and likely damage to the VTM-4 unit.

Just to be clear about this, I view VTM-4 (I don't know enough about iVTM-4 yet) like a conventional, mechanical 4wd system. Only use it in slippery conditions so you don't get bind in the driveline that is not easily removed by a tire slipping on the terrain.

You can engage manual lock on the G1 and hear the slippage occurring when you back up and turn at the same time in gravel. If that slippage can't occur (as on dry pavement), the driveline will bind and something will give somewhere. Ergo the admonishment to not use 4wd/locked diffs on dry pavement or high traction surfaces.

That being said, I see no reason for any damage to occur if you use manual lock (or the G2 equivalent) on dry pavement as long as you go in a straight line and have equal tire pressures all around (so that all tires travel the same distance). Then again, I see no reason to engage it on dry pavement anyway (unless you are testing something)!

 

[zroger73]

That being said, I see no reason for any damage to occur if you use manual lock (or the G2 equivalent) on dry pavement as long as you go in a straight line and have equal tire pressures all around (so that all tires travel the same distance). Then again, I see no reason to engage it on dry pavement anyway (unless you testing something)!

Because iVTM-4 overdrives the rear wheels by 2.7%. I believe the VTM-4 also overdrives the wheels, but by 1.7%. So, even in a straight line with four tires with identical circumference driveline binding and/or clutch slippage will occur.

 

[speedlever]

Because both VTM-4 and iVTM-4 overdrive the rear wheels by 1.7% and 2.7%, respectively, so even in a straight line with four tires with identical circumference driveline binding and/or clutch slippage will occur.

Ahh. Good info! Do you have a reference for the overdrive specs?

On my older conventional 4wd vehicles, you were supposed to exercise the systems frequently. If I didn't have slippery surfaces convenient, I'd just drive briefly in a straight line with 4wd engaged to exercise them a bit. To the best of my knowledge, conventional 4wd doesn't overdrive anything.

 

[zroger73]

Ahh. Good info! Do you have a reference for the overdrive specs?

On my older conventional 4wd vehicles, you were supposed to exercise the systems frequently. If I didn't have slippery surfaces convenient, I'd just drive briefly in a straight line with 4wd engaged to exercise them a bit. To the best of my knowledge, conventional 4wd doesn't overdrive anything.

I edited my previous post because I'm not 100% certain the VTM-4 overdrives by 1.7%. Based on what I'm reading, the VTM-4 system may be similar to one of the Acura SH-AWD systems that overdrives the rear wheels by 1.7% since it may be based on the same hardware, but different logic.

Acura SH-AWD: A Comprehensive Analysis (Updated Jan.8, 2016) - YouWheel.com - Car News and Review

http://www.ridgelineownersclub.com/...eneration-ridgeline-general-comments-265.html

 

[Northriver]

I too am interested to hear real world experience with the sand mode. we have a drive on beach nearby where I'm looking forward to taking the truck and hoping it performs well.

 

[zroger73]

Because iVTM-4 overdrives the rear wheels by 2.7%. I believe the VTM-4 also overdrives the wheels, but by 1.7%. So, even in a straight line with four tires with identical circumference driveline binding and/or clutch slippage will occur.

Ahh. Good info! Do you have a reference for the overdrive specs?

On my older conventional 4wd vehicles, you were supposed to exercise the systems frequently. If I didn't have slippery surfaces convenient, I'd just drive briefly in a straight line with 4wd engaged to exercise them a bit. To the best of my knowledge, conventional 4wd doesn't overdrive anything.

I edited my previous post because I'm not 100% certain the VTM-4 overdrives by 1.7%. Based on what I'm reading, the VTM-4 system may be similar to one of the Acura SH-AWD systems that overdrives the rear wheels by 1.7% since it may be based on the same hardware, but different logic.

Acura SH-AWD: A Comprehensive Analysis (Updated Jan.8, 2016) - YouWheel.com - Car News and Review

http://www.ridgelineownersclub.com/...eneration-ridgeline-general-comments-265.html

"The Pilot's new, lightweight rear drive unit is 22 lbs. lighter than the previous generation Pilot unit and is constantly overdriven by 2.7 percent compared to 0.8 percent."

The final answer is:

The rear wheels on the iVTM-4 system are overdriven at 2.7% relative to the front wheels.

The rear wheels on the VTM-4 system are overdriven at 0.8% relative to the front wheels.

This information was found in the press release for the 2016 Pilot.

2016 Honda Pilot - Powertrain - Honda.com

 

[speedlever]

Thanks zrog. 0.8% overdrive for the RL. If I knew that, I'd forgotten it. That's quite a change from the VTM-4 to the iVTM-4 system. I wonder how that overdrive function works? Is that number driven by gear ratios?

So for the VTM-4 system, the rear wheels go 1.008 times the front wheels?

 

[Outahere]

...I wonder how that overdrive function works? Is that number driven by gear ratios?

So for the VTM-4 system, the rear wheels go 1.008 times the front wheels?

"...For a brief introduction of what is a planetary gear set, please refer to the Appendix 1 at the end of this article. For SH-AWD, there is a planetary gear set for each rear wheel. The Ring Gear is connected to the center drive shaft (via the hypoid gear); the Planet Gear Carrier is connected to the half rear axle (which drives the rear wheel); One group of the clutch plate is connected to the Sun Gear, and the other group of the clutch plates is fixed to the rear power unit casing and is completely stationary. The below image clearly shows how the clutch pack is constructed in the rear drive unit.

If the clutch pack is fully locked up (which means the Sun Gear is stationary), the different gear numbers between the Ring Gear and the Planet Gear will cause the Ring Gear (connected to the front wheel ultimately) and the Planet Gear Carrier (connected to the rear wheel) to spin at different speeds, thus the rear wheel will spin 1.7% faster (overdriven) than the front wheel…"

above excerpts from: Acura SH-AWD: A Comprehensive Analysis (Updated Jan.8, 2016) - YouWheel.com - Car News and Review


But in the i-VTM4, the planetary gear sets have been removed. I believe the 2.7% difference comes from different ring and pinion ratios between front and rear.
Honda published a paper describing this in more detail:
http://papers.sae.org/2015-01-1098/

 

[Outahere]

2017 Honda Ridgeline Press Kit - Powertrain - Ridgeline - Honda News

The Ridgeline AWD system is a fulltime system that requires no driver interaction or monitoring, thanks to a torque-transfer unit that is bolted directly to the front-mounted transaxle. The torque-transfer unit receives torque from a helical gear that is attached to the front differential's ring gear, and a short horizontal shaft and hypoid gear set within the torque-transfer unit's case send power to the rear propeller shaft, which in turn transfers power to the rear drive unit that has a 20-percent greater torque capacity.

"...The Ridgeline's new, lightweight rear drive unit is 22 lbs. (10 kg) lighter than the previous generation Ridgeline unit and is constantly overdriven by 2.7 percent. The resulting overdrive effect is regulated by left- and right-side clutch packs (located in the rear differential) that independently control the power delivered to each rear wheel. The significant overdrive percentage in the new Ridgeline means that the torque vectoring effect is pronounced and effective even in corners with a radius of as little as 49.2 feet (15 meters). This means that torque vectoring can be felt when accelerating aggressively through a typical corner.

Hydraulically operated clutch systems mounted on either side of the hypoid gear that drives the rear axles control the amount of torque sent to each rear wheel and provide a limited-slip differential function when needed. The clutches can be controlled as a pair to alter front/rear torque split or they can be controlled independently to allow 100 percent of available rear axle torque to go to just one rear wheel. A single electric motor powers a pair of hydraulic pumps—one for each clutch pack. An Electronic Control Unit (ECU) controlled linear solenoid valve selectively sends pressure to the clutch packs, which in turn control the amount of power sent to each rear wheel. The clutch packs and their friction material are carefully designed to withstand the small amount of continuous slip between front and rear axles created by the 2.7-percent speed differential—all while delivering the durability expected of a Honda product…"

Will be interesting to see how long those clutch packs really last, in the real world instead of the engineering lab.

 

[speedlever]

Great info Outahere. Thanks. I hope iVTM-4 is at least as durable as VTM-4. While there is some suspicion that there are many VTM-4 silent failures out there, I would think the failure wouldn't be as silent as postulated. I would think excessive torque steer and front wheel burnouts would be a pretty solid indicator of such a failure. ??

In that regard, I wonder how the FWD G2 RL drives relative to the AWD G2 RL? If they drive similarly, I wonder how Honda tamed torque steer and limited front wheel spin?

 

[Darksky]

Explanation of Snow, Mud, Sand modes

Does anyone have an accurate explanation of exaxtly how the snow, mud and sand modes work? What difference do each of these modes provide? Is there any Honda "factory" information available? Thanks!

 

[stevem5215]

Re: Explanation of Snow, Mud, Sand modes

This is the best description of it I've seen.

deadspin-quote-carrot-aligned-w-bgr-2

Steve

 

[njamesj]

Re: Explanation of Snow, Mud, Sand modes

The Powertrain Press Release link in the article is even more revealing. I bookmarked it so I can read it in it's entirety.

 

[johnson-rod]

Re: Explanation of Snow, Mud, Sand modes

I still need an explanation in English on how the different traction modes work. Charts always make me sleepy.

I need WHY the mud and sand modes put more traction to the rear wheels when they have less weight on them.

Is it a '4 wheeler' thing I don't understand?

 

[JoWoodburn]

Re: Explanation of Snow, Mud, Sand modes

I still need an explanation in English on how the different traction modes work. Charts always make me sleepy.

I need WHY the mud and sand modes put more traction to the rear wheels when they have less weight on them.

Is it a '4 wheeler' thing I don't understand?

It is kind of a lot of physics. You are trying to move something on a dry surface with good running shoes on (good traction), you push forward, just forward. It is a slippery surface you move your feet a bit, outward, trying to gather more traction to push forward? It does this with the front and rear wheels. It moves the power to where you will get the best traction, best forward propulsion.

Push a truck pull a truck

 

[Darksky]

Re: Explanation of Snow, Mud, Sand modes

​

This is the best description of it I've seen.

deadspin-quote-carrot-aligned-w-bgr-2

Steve

Thanks Steve. That's what I was looking for.

 

[Wellington]

Have any of you new owners tried out the sand mode or mud mode?
Would be interested in your experiences with it.

I just bought a rigeline RTL_E 2 week ago and I just tried it on the beach in the sand in the truth I was stuck for a few minutes but managed to get out, I came to the conclusion that I put some off road tires would be better for to be able to handle it in the sand in the dunes that was my experience only a few days ago

 

[longboat]

I just bought a rigeline RTL_E 2 week ago and I just tried it on the beach in the sand in the truth I was stuck for a few minutes but managed to get out, I came to the conclusion that I put some off road tires would be better for to be able to handle it in the sand in the dunes that was my experience only a few days ago

Or let half of the air out of the tires.

 

[olgzr]

I just bought a rigeline RTL_E 2 week ago and I just tried it on the beach in the sand in the truth I was stuck for a few minutes but managed to get out, I came to the conclusion that I put some off road tires would be better for to be able to handle it in the sand in the dunes that was my experience only a few days ago

I agree with Longboat above. Airing down to about 18 psi or so will do wonders in sand.

 

[hondopark]

11 psi for sand driving in my neck of the woods. Makes a world of difference