Need Help: Drivetrain Whine, Slipping in tight turns

[bentcipher]

Hey everyone…

Got a little bit of a problem with my ’01 Vx with 95k miles in unfamiliar territory – searched the forum and it appears my issue is originating from within the drivetrain but I can’t get anything definitive.

SYMPTOMS:
The truck is “jumpy” in tight turns going slowly forward or backwards (whether left or right) – that is, when the steering wheel is locked in to the right or left, throttle pedal travel does not correspond to the usual rate of vehicle acceleration. It momentarily hesitates, as if you’re stepping on the brakes, then as it slightly lunges forward as if you release the brake, then brake again… so it’s rocking back and forth, and other times it feels like it “slipping” or similar sensation when ABS is kicking in. Feels very similar as if I had 4lo engaged and in tight turn but a bit more forceful in lunges which ruled traction-related issues out. Other than that, I don’t hear anything abnormal or hear/feel any grinding.

At the same time, I noticed another abnormality. The drivetrain (unsure where exactly noise is coming from) is A LOT louder than it used to be, especially as you’re coming to a stop. It’s exactly the same whine that you hear coming from your drivetrain except a lot louder. The vehicle does not feel different however, may slightly “heavier” if anything..

This may or may not be related but the Vx was towed about a month ago (this just started happening a week ago), which was done by a mistake and when the driver brought it back I asked him how he got the truck on his flat bed to which he replied that he used WD40 spray on the tires to drag it up from a asphalted parking lot onto a metal flatbed.

I’m looking for guidance on which component I need to start looking at (diffs, tranny, t/c, etc..) to resolve the jumping and the whine.

Also, I’d like to know if this is related to the “towing” method truck driver used few weeks before the problem surfaced.

Thank you all.

[circmand]

those threads sound similar to what you are describing. I hope this helps there are several suggestions

[4X4 UFO]

bentcipher,
I can't address all of your symptoms, but the whine on deceleration sounds a lot like the TOD does when all the tires are not the same circumference. I tried running rear tires that had about 3/32 less tread depth than the fronts, and it caused a loud driveline whine on deceleration. When I put an evenly worn set of tires on all the way around, the whine disappeared.

Randy

[bentcipher]

Thanks both for the reply... I checked the diesel sound search results... not it. I'll read it in more detail but so far the symptoms are different. The sound itself is an even whine that stays at about same pitch no matter what speed, acceleration, coasting, etc... also, this is not motor related. My gut tells me it's probably the differential but don't have enough experience to know for sure.

Oh, and it's definitely not the tires or traction related, same "whine" occurs whether I'm at 2 mph, 20mph, or 40mph... can't hear the rest due to wind noise.

As far as slipping/jumpiness in tight turns - I had this truck for about 3 years now and pretty familiar with its eccentricities and character traits, especially in tight turns, on/off pavement, good/bad tires. What I'm experiencing now is very dissimilar in a feel and sound.

Thank you both for the input.

[Solitude]

It is still an all wheel drive vehicle.... maybe your turn is a bit too tight for the speed

[bentcipher]

Well.. I think the culprit here is the front axle. For now, I'm ruling transmission and T/C out as I'm not able to establish a relationship between the symptoms and the transmission or gearing itself. The symptoms persist whether I'm in gear or coasting in neutral, forward or reverse, slow or fast, in 4lo or 2wd, etc..

I'm going to start with changing fluid both front and back and see where that takes me. Will post results as soon as I have them...

[tom4bren]

"Also, I’d like to know if this is related to the “towing” method truck driver used few weeks before the problem surfaced."

Entirely possible. I would definitely check with the company to see if they will have the VX evaluated at a garage of your choice (not theirs).

[MSHardeman]

I was actually thinking about the towing issue during my morning coffee (hey, it just popped in my head) and I wouldn't think that dragging ANY car across the asphalt would be good. It would put stress on all the gears along the drive line (transmission, transfer case, differentials) and could throw something out of whack.

[TheGanzman]

I was actually thinking about the towing issue during my morning coffee (hey, it just popped in my head) and I wouldn't think that dragging ANY car across the asphalt would be good. It would put stress on all the gears along the drive line (transmission, transfer case, differentials) and could throw something out of whack.

Agreed - kinda like throwing it in "Park" while you're still rolling 5mph...:(

[bentcipher]

Ehh, no go guys. I called the AAMCO shop here in town and they said it is actually a pretty common practice to drag up a vehicle on the flatbed whenever they cannot get it out of PARK. They said that it is very unlikely for it to affect anything and doesn't hurt gearing or anything else. They added that the only mechanism that could be affected, if any, is the Park mechanism within the transmission... so they said that if that doesn't work in any way (i.e. stuck in PARK, can't get into PARK, etc) then I might have something but other than that it is probably coincidental.

Now, as far as my symptoms, their rep stated that it could be just that I need to service my front axle. He said that in all wheel drive vehicles, there are "clutch disks" within the axle that compensate for wheel travel in turns as the total distance traveled by each of the front wheels is different (i.e. inside wheel travels less distance than the outside wheel in turns) and when you get low on gear oil, if it is broken down and is no longer able to properly lubricated axle components then you would get what he called "shudder" effect.

So boys and girls, I'm off to change that oil.... !

[bentcipher]

No cheese... looks like that didn't affect the noise, nor did it affect the "shudder"...

Did some more reading and starting to fear that this a little more serious than a fluid change :eek:

[etlsport]

try pulling the fuse for your ABS out and see if the problem occurs still (its the one show being pulled in this photo, dont mind the ghetto-rigged relay at the bottom ;))
http://www.vehicross.info/gallery/data/500/medium/brakes_079.jpg (http://www.vehicross.info/gallery/showphoto.php?photo=12376)

if it goes away with your abs disabled you can guess its related to the abs... not sure if that would be the issue, but its quick and easy and will help you rule out another possibility

[tom4bren]

"They said that it is very unlikely for it to affect anything"

I wouldn't have expected them to reply with anything less since they are potentially liable for some very expensive tranny work.

[bentcipher]

Alright, so changing gear oil didn't really do much. The truck feels livelier but still has the whine and shuddering in turns.

After doing some probing I noticed two things I didn't quite take into account before... not sure if that helps:
1. The whine comes through the gear shifter and can almost be felt if I have my hand resting on the shifter. Transfer Case maybe?


2. The shuddering is not constant... it's more timed, occuring as the turn is made almost as if something is turning and everytime it passes a particular spot it shudders - yeah, I know, sounds like pinion gear related.. crap

P.S.
Etl: I did pull the fuse - no change.
Tom: the tranny shop I thought was pretty unbiased but if you have another specialist I'd be willing to talk to them!

[tom4bren]

"if you have another specialist I'd be willing to talk to them!"

Not really - just hate the thought of dragging a vehicle across the ground, it's bound to cause problems.

"the Vx was towed about a month ago ... which was done by a mistake"

BTW, how do you accidentally tow a vehicle?:)

Have you checked your CV boots? CV troubles usually sound more like clicking & you mentioned whine/vibration (but anything is possible).

Tom

[bentcipher]

Tom,

I know what you're saying. When I first learned that they "dragged" it up the flatbed I was seriously considering injuring the tow truck driver. I still think something could easily snap using that method - but whether I can prove it as a viable cause is a different story.

The truck was towed by mistake while in the hotel parking lot. Luckily the hotel profusely apologized and had it brought back at no cost.

Oh and I just did the boots like 3 months ago - easy peasy works great!

[tom4bren]

"easy peasy"

If that translates to 'fingertips to armpits' in grease ... OK:)

[bentcipher]

Hehe... nah, it wasn't that bad. Got the independent4x kit which in my opinion is the only way to do it right (except if you're lifted) :grinb:

Had plenty of time and beer.... it was a good day :)

Got a small update: Took the truck to the local AAMCO, the guy kept saying that the only thing it may need is a full service on the front diffy with a nice positrac additive... Anyone did this?

Personally I'm not buying it - if the problem is with the fluid then it would shudder constantly when in turn instead of once every revolution (?). I also think that it would exhibit these symptoms when in 4lo, which it doesn't.

Out of desperation, I'm willing to try anything before driving to a dealer 50 miles away. I can try the K&W LSD additive in the front axle... can this be done safely? If so, should it be added on top of the Mobil 1 oil already in there or bled a bit first? Workshop Manual states that too much gear oil may produce a leak but no other adverse symptoms.

Also, K&W instructions call for adding the additive first, oil second. How critical is this?

[bentcipher]

Ok, so I took the truck to another shop that normally does my alignment and such... luckily, one of the guys was familiar with 4x4s so we took a quick spin to see if he could help pinpoint what the problem is...

According to him, my pinion gear is going out at the very least. He said no fluid change is going to help that. It feels like it's slipping because pinion gear is going bad and the whine is coming from (clutch disks) locked in and not releasing. He told me to get this thing into a shop that works on these or the dealer pronto.

Later, when we pulled back up to the shop and I brought up the fact that the truck was recently dragged on a flatbed both him and their service manager's eyes widened and they promptly confirmed that there is a 99% probability that this is the cause of my issue. They said that dragging the vehicle on the bed is one of the worst things you could do to your driveline and what's worse... they knew that this particular wrecker simply dry-drags the vehicles onto the flatbed. :eek:

I remember having that suspicion after the tow truck driver gave me that story because I didn't smell any wd40 anywhere on or around the truck when he brought it back... and purposely took some pictures at the time just in case. Guess what, a reviewed the pics, again, and I don't see any wd40 or oily residue on my tires, on the inside of my rims, on the rims, on the cladding, or inner wheel wells.

Oh yeah... and I almost forgot - I'm not covered by a powertrain warranty as I am a second owner of the vehicle so if the tow service gets out of this, looks like I'll be getting very familiar with the insides of my front axle. :mad:

[TheGanzman]

The defense rests...;)

[bentcipher]

Right! So! Uhmmm... I changed the t-case oil - no more slipping, no more shudder. I'm happy.

The old oil was filthy so I flushed it completely with a quart of fluid before filling it.

So if your truck is slipping in tight turns at all times, forward or reverse, in 2 or 4 wheel drive - REPLACE YOUR T-CASE OIL. It's easy, I did it on my lunch break.

And while at it, service your front and rear differentials!

P.S. I used Valvoline ATF fluid to fill the t-case and although it stopped the slipage/shudder the noisy whine continues. Can someone recommend a fluid that better deals with the whine?

It sounds /exactly/ like it sounds when it's in 4lo...

[enderg]

Hi all, long time no chat...

I was having a similar issue with the binding in turns but mine was only in very SHARP turns such as a U-turns. Well all of the sudden it started making harsh grinding noises and would barely make a 90 degree turn. I babied it to a transmission shop and had 4 technicians under the VX with stethoscopes, magnifying glasses, lights... they had no clue. Thank goodness it was the Friday before the holiday and they asked me to bring it back on Tuesday morning.

I was fearing the worst when I saw this thread, crossed my fingers and changed the transfer case oil while hoping for the best.

What a difference! Who knew something so simple could sound so bad. So the moral of the story is: Stay on top of those fluid changes!

!!!!Thanks for the information bentcipher!!!!

Regards,

ender

[bentcipher]

Glad I could help... Actually, I'm really glad your issues were fixed with the T/C oil change. I still remember that sinking feeling, thinking "****e, how much is this going to cost?" Keep those fluids changing at regular intervals and you should be good. If you recently got the Vx, change them all just to be safe!

Sweet! And let this be a lesson that most of the shops out there have no idea what to do with a Vx. Even when it comes to what seems like generally simple to diagnose issues. I let them do my wheels... everything else I do myself.

Good luck!