Hoping my VTM-4 system is not damaged

5513 Views 23 Replies 11 Participants Last post by dc2012, 3 mo ago

dc2012

Discussion Starter · Apr 2, 2016

Alright everyone, I could use some help here.

I was hauling my prelude on a trailer with my ridgeline.
For about an hour and a half everything was fine headed towards OKC on I40.

I turned on the music. About 30 minutes later I think I hear something. I turn off the music to hear a metal scraping noise coming from my ridge. I pull over.

I check the trailer, all is well. I check the ridge, looks fine, no serious leaking (although it did look like the tranny had a very minor leak)

I check the fluid levels for the oil and tranny and all is good.

I started it back up and went on my way. I couldn't reproduce the sound at first. Turned on the Cruise, and the sound came back. Diengaging the Cruise control did not stop it, but slowing down or speeding up did.

It only seemed to happen in top gear at around or just under 2k RPM.

I put it in D3 several times and in all but 1 occasion the noise stopped. On that one occasion, the truck downshifted and I heard the noise at 3K RPM.

Now in my paranoia, I can hear a very, very slight high pitched noise in top gear that I never noticed before.

Any Idea what this may be? I Was driving down to Austin and I have another 8 hour drive scheduled for this thing in a week.

Thanks everyone.

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ridged

· #2 · Apr 2, 2016

I would start troubleshooting by removing the trailer from the equation.

S.T.U.V

· #3 · Apr 2, 2016

^^^what he said^^

Rock stuck in the brakes somewhere... Same exact issue with a coworkers tc on thursday. He was freaking out. Said it would go away when he slowed down under a certain rpm and when he sped up it would stop when over a certain mph...I told him to check his backing plates and check for rocks. A stupid little pebble stuck in the caliper.

Carsmak

· #4 · Apr 2, 2016

+1 for both earlier posts...

Also recently on this forum a newer member posted about a rock or something in the driveline from the engine to the VTM unit.

jonesbb630

· #5 · Apr 3, 2016

dc2012 said:
I put it in D3 several times and in all but 1 occasion the noise stopped. On that one occasion, the truck downshifted and I heard the noise at 3K RPM.
Thanks everyone.

Did you drive on D3 only after the noise started as a troubleshoot or did you drive D3 for a long period prior?

dc2012

Discussion Starter · #6 · Apr 3, 2016

I only drove in D3 for testing. I unloaded the trailer and the noise stopped. However I now hear a higher pitched humming noise a lot when driving. Seems to be in around the same circumstances as the scraping. It's slight and could have been there before and I not notice.

Thanks for the feedback so far.

dc2012

Discussion Starter · #7 · Apr 4, 2016

So,

after driving it a bit more today, I can say that its definitely a new noise. Also, it looks like the rear dif is now leaking. This may not be fun =(.

Any other ideas guys? The truck was kind of squatting when pulling the car.

chiph

· #8 · Apr 4, 2016

With an unexplained noise and a rear diff leak, I think you need to get it trailered to the dealer.

Chip H.

dc2012

Discussion Starter · #9 · Apr 5, 2016 (Edited)

2

Chip H.

That was good advice, too little too late. I'm pretty sure I towed my prelude 8 hours on the highway with a completely dry VTM system.

Got under the ridge today to determine cause of small leak.I seemed to be coming from the drain plug. I opened the fill plug to find to the best of my knowledge an empty Dif. When going to find out for sure (removing the drain plug) The drain plug was not quite hand tight, and about a teaspoon a fluid came out along with the drain plug, and a lot of metal shavings.

Hopefully, this thread will save someone else from this. Although, in retrospect I would change the name of the thread. If I'm lucky, some fluid will fix the noise and all will be well, but I'm not holding my breath. I'll update later.

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speedlever

· #10 · Apr 5, 2016

Yeah, that's definitely not a normal looking rear diff mag plug. I rarely see anything on mine. Who did the last service on your rear diff? I assume you use OEM fluids?

I have to wonder if that rear diff has been leaking for a while. It holds about 3 quarts of VTM-4 fluid.

I can change the thread title if you want. What would you like it to be?

donuteater306

· #11 · Apr 5, 2016

OH NO! I'm sorry man, that's horrible!

Some years ago I had worked at a family owned, auto repair shop. A Civic was towed-in, customer was a college kid who was on her way back to school. She said that it just started making noise. It was a 5spd, and the transmission was toast. Turns out, her boyfriend had changed the "oil" before she started her drive back to school. No exaggeration, she made it a good 150 miles before she felt vibration and heard a scraping sound. We found the transmission empty, and the engine oil way over filled.

dc2012

Discussion Starter · #12 · Apr 5, 2016

speedlever said:
Yeah, that's definitely not a normal looking rear diff mag plug. I rarely see anything on mine. Who did the last service on your rear diff? I assume you use OEM fluids?

I have to wonder if that rear diff has been leaking for a while. It holds about 3 quarts of VTM-4 fluid.

I can change the thread title if you want. What would you like it to be?

I use OEM fluids and washers. It looked like the washer had not been crushed at all. I think the last service was at the dealership around 10k ago. The one in Fort Smith truly deserves the title of stealership. They did a timing belt for me once and 300 miles later the pulleys fell off. They weren't going to fix it until I threatened to call customer care.

Anyway, My guess is the extra pressure on the VTM system from the towing caused it to push the plug out? I really don't know how long its been leaking, but there were no spots on my driveway before I left for Texas, but after I got here there was a spot on the driveway.

Change the title to whatever you may think would make this easiest to find for someone in the same shoes. The sound doesn't seem like its coming from the rear. I thought it was the transmission because that's where you hear it from.

On good note:

I filled it with fluid. Drove it around a bit to mix it up and hopefully pick up some particulate. Sound was much quieter and seemed to be gone after about a minute. Going to change the fluid in it tomorrow again and see what the magnet picked up. If it's mostly clean I'm going to test out VTM and see my damage. If it's not then I will start again.

If the honda ends up running fine even after driving 600 miles on an empty dif while towing a car, people should use this as a freakin testimonial. Keeping fingers crossed and hopes high. :smile:

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48218

· #13 · Apr 5, 2016

dc2012 said:
If the honda ends up running fine even after driving 600 miles on an empty dif while towing a car, people should use this as a freakin testimonial. Keeping fingers crossed and hopes high. :smile:

No kidding!!

I hope it stays quiet and working well for you.

FWIW, the VTM box/diff is vented, so it _shouldn't_ have pressure build-up inside. See section 15 of the FSM (page 15-52 in my copy) for a diagram and description.

speedlever

· #14 · Apr 5, 2016

dc2012 said:
I use OEM fluids and washers. It looked like the washer had not been crushed at all. I think the last service was at the dealership around 10k ago. The one in Fort Smith truly deserves the title of stealership. They did a timing belt for me once and 300 miles later the pulleys fell off. They weren't going to fix it until I threatened to call customer care.

Anyway, My guess is the extra pressure on the VTM system from the towing caused it to push the plug out? I really don't know how long its been leaking, but there were no spots on my driveway before I left for Texas, but after I got here there was a spot on the driveway.

Change the title to whatever you may think would make this easiest to find for someone in the same shoes. The sound doesn't seem like its coming from the rear. I thought it was the transmission because that's where you hear it from.

On good note:

I filled it with fluid. Drove it around a bit to mix it up and hopefully pick up some particulate. Sound was much quieter and seemed to be gone after about a minute. Going to change the fluid in it tomorrow again and see what the magnet picked up. If it's mostly clean I'm going to test out VTM and see my damage. If it's not then I will start again.

If the honda ends up running fine even after driving 600 miles on an empty dif while towing a car, people should use this as a freakin testimonial. Keeping fingers crossed and hopes high. :smile:

Since you said the drain plug wasn't even finger tight, it sounds to me like the shop forgot to tighten it after the last service. But if it was leaking, I would hope you would have noticed the fluid drops. I doubt it dumped the fluid all at once, but ya never know.

I'd definitely flush the system by doing multiple drains and fills until the mag plug comes out clean after driving a week or so between changes.

I think a new rear diff is somewhere around $4k.

How do you plan to test out your VTM-4 system? If it fails, yours may be a prime example of a silent fail (although the symptoms weren't silent until you put fluid in there).

I'm wondering if a silent fail will show itself by torque steer and ease of spinning the front tires on an aggressive take-off.

But wow, if the shop left the drain plug loose, that's just another wake up call for DIY action. Even though it could be easy to do the same thing, at least there'd be no discussion as to who left it loose.

dc2012

Discussion Starter · #15 · Apr 8, 2016

I'm a big fan of DIY, but one of the reasons I was headed to texas was for a new job. The old one was regularly 70 hours a week or more. Meaning no time for me to do it.

I did do all of this DIY.

Here is what I've done so far and where I'm at now:

I refilled the system. Drove it for about 8 miles or so to mix up the fluid. I turned on VTM-4 in a dirt lot for all of 2 seconds during that.
I drained the system again and checked the plug. The plug came back still with particulate on it, but not near as bad as it was. (about half as much)
I refilled the system again.
I drove it for a day (around 40 miles,mostly highway) and then drained again.
The plug came back almost clean. See the pic.
I'm now going to drive on this for probably a week and go find a patch of dirt to test my vtm-4 system on or maybe a grass field. Whatever will produce the least amount of torque.

I want to see if activating VTM will increase the amount of particulate. I bought 3 gallons of fluid and crush washers from the dealer.
The parts guy looked at me funny after going back for the same thing on a third day.

I have enough for 1 more fill. (It takes just barely under 3 quarts every time) Hopefully I wont see any more particulate on this next drain or I'm back at the dealer. The stuff is 32 bucks or so a gallon so I'm ready to be done with it.

So bad news: I think I did do permanent damage. I still hear it, but just barely. Alternatively, I may be paranoid.
Good news : I think everything is working fine and it seems to be driving ok.

Will update when I know more.

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Carsmak

· #16 · Apr 8, 2016

DC, there are threads and descriptions on activating the VTM while all 4 wheels are off the ground and on jack stands. Alternately, if your not hearing front wheel spin and not feeling torque steer, my guess is the VTM system is working. If it was me I'd be inclined to test the system with the least amount of resistance, i.e. Snow or ice covered ground(which may be hard to do this time of year or where your located), a wet grass or wet mud area, or possibly off the ground. Be advised running the truck with all four corners off the ground may be a balancing act and should be done with as many precautions to not "LAUNCH" the RL. Once off the ground and running, forces of inertia come into play and one collapsed jack stand, or improper balance to a 4500 pound RL and many bad things could happen.

I'd say this for all the limits and bad things I've read over the years on the VTM system, I'd say here is another statement to just how good the actual unit is.

Good Luck and keep us posted.

chiph

· #17 · Apr 8, 2016

Oh man, that's bad (or was...)

Yeah, a new differential is $3800 list price. You can get an "internet price" of $2600 from online dealers (it may still be a reman unit, but won't be a junkyard pull).

Honda Automotive Parts

Even after your 3x change + drive process, I'd still put it on an accelerated fluid replacement schedule (can't hurt...), so maybe do it again in 1000 miles, then 5000 miles, then 15k miles and stay with 15k afterwards.

Chip H.

48218

· #18 · Apr 8, 2016

If you got 3 gallons, you should hopefully be able to fill the box 4 times: The initial (re-)fill, plus 3 subsequent drains & fills. If you're already down to very little drain plug debris after the second drain, I'd say you've probably accomplished the flush you needed. The third fill should be fine. I don't have a problem with a fourth drain and fill, but I also wouldn't sweat just running it.

The VTM box is a gearbox as well as a multi-plate wet clutch system. The FSM does not describe its inner workings, nor offer a rebuild procedure, but it does specify backlash limits. Basically, running a gearbox dry is bad (obviously) because it accelerates gear and bearing wear. IF the noise you're hearing is new, and if it's coming from the VTM-4 box, my own guess is that it's bearing and/or gear whine. Check backlash if you like, but otherwise I'd probably just run it until there's a bigger problem. I can't even remember how many tens (actually it may have been over a hundred) of thousands of miles a former neighbor ran his Nissan pickups with rear end whine. It got to be loud before he rebuilt or replaced.

If you want to check backlash, the FSM procedure is...
EDIT***
Carsmak has posted the link to the correct FSM page for this procedure and spec. Thanks!

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Carsmak

· #19 · Apr 8, 2016 (Edited)

2

Here is an image grab from the FSM, and I agree, I think I'd go further mileage before doing an additional DnF...

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IanRTL

· #20 · Apr 11, 2016

Wow. This is quite the story. For the four drains and fills I've done to my truck since I've owned it, I've had only a slight grey "coating" on the mag drain plug. This is obviously an interesting situation, but the amount of material that was on your plug in the pictures doesn't lead me to believe that the unit is now non-functional. The clutches may have a little less material than they used to, but it will still work fine. As long as there is fresh fluid in it and you aren't getting any terribly abnormal noises, driving feelings or anything like that, I think you should just drive it and monitor it. As was suggested, maybe do one more drain and fill in about 5000 miles or so just to check the mag plug one more time. Then every 15,000 miles after that should do.

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