2500HD deceleration vibration??????
 

Anyone ever had this on there 2500HD??? I have a 2001 8.1/allison.

I'm getting a vibration upon deceleration. It's most prominent when slowing down/braking from 20mph down to a stop, but you can feel it slightly at highway speeds when you let off the gas and are going down a slight grade.

At first I thought it was brakes. Had it checked out at local brake/undercar place. They are pretty good. Front's at 75%, backs at 25%. Rotors all looked good. I had them replace the backs. They also rotated the the tires from front to back. No change in the vibration. They were stumped with the vibration and when it occurred and couldn't find anything that would cause it. Really can't tell if its coming from the front or the rear. Don't feel any shimmy in the steering wheel or any pulsating on the brake pedal.

Did some driving/testing to try and pinpoint the problem or at least the location.

On the highway at 60mph, take foot off the gas to slow down on a slight downhill grade--slight vibration like you are on rough textured pavement.

Normal driving 40 mph down to a stop-- Increasing vibration from 20mph to a stop.

Coasting in neutral 40 mph down to a stop--same result.

Coasting in neutral 40 mph, turn off engine, brake to a stop--same result.

Downshift 1st, coast to almost a stop--still have vibration, but not as much.

Its strange because at normal highway speeds, there is no vibration whatsoever. No clunking and no other stange noises at any time. Just the strange vibration during deceleration.

Re: 2500HD deceleration vibration??????
 

griff you might check at the diesel place. www. dieselplace.com for some extra info. Did you check u joints? trying to think of the obvious, along with shocks?

Re: 2500HD deceleration vibration??????
 

How are your u joints?

Re: 2500HD deceleration vibration??????
 

Ditto on the U-joints. Have someone check out the driveshaft. You have a two piece driveshaft and it is real common for the center bearing where the two halves are connected to wear out. Crawl under there and see if you can see any play by the center bearing.

How many miles??? Another thing might be a pinion bearing. I forget if it's front or rear on decel. Check out the driveshaft/cntr bearing and let me know. I have a good friend who is a Chevy truck Master technician. I can ask him for you.

Re: 2500HD deceleration vibration??????
 

there is a re-call on the driveshaft. Because of vibration ,they are going with a 2 piece shaft.

Re: 2500HD deceleration vibration??????
 

I have 2001 2500 duramax crew cab short bed 4x4 that I got 11/3/2000. Truck came with 2 piece shaft & chev changed it out to 1 big one. I just thought I had vibration when taking off & stoping but after they put new 1 piece on the vibration went away when stoping, starting & even crusing.

Re: 2500HD deceleration vibration??????
 

Griff- 2wd or 4wd? How many miles on vehicle? When did problem start? After a service event or hitting curb/pothole? Sounds like problem occurs on smooth roads. Is it worse on irregular roads? No pulsing in brake pedal,rotors 'look good' (was runout checked?). Any irregular wear pattern on tires? Were tires dynamically balanced to see if belts shifted,etc.? When was front end alignment checked? How many miles on shocks? I assume standard wheels/tires? Wheel bearings tight and in good shape? No noises making turns? Briefly, it's been a long while but I,ve seen some weird things like this. Key is the fact that you say you get the vibration without applying the brakes. I'd want to be sure that the caster and toe are in spec and that the shocks are in good shape. Those items give you your straight line stability. If out you could get the wheel/tire bouncing slightly and not be able to dampen out the vibration. Don't know what kind of steering you've got (Saginaw kind of box or rack and pinion) but I once had a vehicle with power steering where the stud that attaches to the Pitman arm was controlled by two opposing spring mounted ball seats that went bad. Unlikely in your case but my point is that anything could be suspect. Higher road speeds can smooth out many kinds of imbalances. Most of us don't realize how heavy the wheel/tire/spindle/brake assembly are. The shock/suspension design has a lot to do. The way sounds/vibrations can be transmitted, it's tough to tell which end the vibration is coming from. I'm sure there are foks with a lot more experience than me who could help. I just wanted to offer some thought starters to get the ball rolling to hopefully help ya out. Keep us posted.

Re: 2500HD deceleration vibration??????
 

I had a strange vibration in mine that ended up being an idler gear/bearing in the transfer case. I never did anything about it until I needed a whole new transfer case.

Re: 2500HD deceleration vibration??????
 

I've been over there for about an hour looking for info. Most everything I'm finding has to do with higher speed vibrations while running. Can't really find anything on a vibration that increase as you decelerate or brake at low speeds.

Re: 2500HD deceleration vibration??????
 

Thanks for all the quick replies.

2001 Chevy CC, 4WD, 61k. No services or big potholes.

Everything mentioned, I have pretty much thought of. Its just the symptoms point to varying things. I noticed a slight vibration over the past month or so and it has gotten slowly worse. I would almost prefer it continue that way until it blatantly obvious what the problem is, so I don't have to throw $$$$ at new stuff that wasn't causing the problem.

I don't know if they checked runout, but this is one of the best brake places in town and all other work I've had done by them has been perfect. The Owner has been there for 35 years and he was at a loss. He pulled up TSB's and couldn't find anything specific to my problem.

They checked the tires and said the fronts had a strange wear pattern and they first thought this was the problem after the service manager took a ride with me, he said he did not think the tires would cause that much vib decelerating without causing some at high at higher speeds. There is no vib while under even the slightest acceleration.

As far as the alignment, I have not had it checked. I've had a very slight pull to the right for a while and probably need an alignment. After they rotated the tires from Front to Back, I 've got about the same amount of pull to the left ????

I'm still doing some brainstormin, but this thing just doesn't make sense. I have read a lot over on dieselplace.com, but nothing quite matches what I have. Also a lot of the problems there have been fixed.

I'll call the place that checked the brakes and ask them if they checked the runout. More than likely it will be going to the dealer.

Re: 2500HD deceleration vibration??????
 

I did look under it with the rear end jacked up, running and in gear, and didn't see anything obvious. I could get very slight vibration to, but very little in comparison. I do have the 2 piece drive shaft and am leaning to it being a problem with that. There is a boot around what looks similar to a CV joint. The boot looks fine, but I'm not sure about what's inside. The u-joints appear fine when pushing the driveshaft and I don't see any slop.

I also thought of the rear end. The vibration gets worse as you slow down faster or brake harder, but I don't think its in the brakes. There is no pulsating in the pedal at all and the brakes feel normal.

Re: 2500HD deceleration vibration??????
 

HAD THE SAME PROBLOM ON MY 2001 F350, U JOINTS, REPLACED THEM AND NO MORE VIBRATION :drink:

Re: 2500HD deceleration vibration??????
 

I reeeeeeeeeally hope that is the case. Its going in Mon to get looked at by a real mechanic----not a "service technician"

Tires have been checked and although they have some minor flat spots, everyone seems to be in agreement that the tires would not cause the vibration I'm getting, or if they were, it would not be isolated to just deceleration.

Re: 2500HD deceleration vibration??????
 

My F-250 has done it since new. Sort of feels like a tire that's way out of balance. But it only happens during de-excelleration (braking or coast-down).
On F150online.com many members there complained of the same vibration on all Ford trucks. Ford has not been able to figure out what it is.
Truck has 120K on it now and I've grown used to it.

Re: 2500HD deceleration vibration??????
 

I have a 2002 2500HD 6.0 gas automatic. Does the recall apply to me?

Griff. This is the exact problem I have. Did you resolve this.?

Updating the truck to the hydraulic body mounts will help the problem, if it doesnt have them from the factory.

Dad had an 04 duramax with the same issue around 45, and the dealer put those body mounts (I think it was only the rear 2 mounts they did) and that helped a good bit, but it still did it. 95% of the time the truck was used to tow anyway, so when there was a load in it or behind it, it didnt do it.

Good luck

Sounds like a drive shaft vibration of some sort. Had the same symptoms with my 2010 dodge cummins mega cab turned out the two piece drive shaft was causing it. I installed a one piece large diameter drive shaft and is now super smooth. I don't know how your drive line is configured but if it's a cab and chassis I would imagine it has a two piece shaft with a carrier bearing and I would start there. Just noticed this thread is pretty old but hope this info helps someone.

I have had this happen on 2 of my fords and both times it was the front shock for the steering stabilizer. It's either lose or bad.

Holy old threads!!!

It was the U joints.

Griff, I was impressed you had a 2001 with 61k until I looked at the date of the original post :)

Are you in 4x4? I didn't read all the posts so don't attack me if posted already. Well just read the posts.........old shi t

You should check the U-joints.

Griff. Thank you. I love this truck and just aquired it last year at 80000 from a helicopter engineer friend. The famous clunk was in effect but now has subsided and is replaced by the shudder you described so perfectly in your old thread
I was just about to go the slip yoke route. And still may.
I will now include the u joints. Do you recall which and how many? If not all.
I will start my ujoint education now.
Thank you very much again
John

I had all the U joints replaced and the problem was solved.

I wish. I traded that truck in 2010 with about 140k for my current truck.
I have virtually the same truck in 2007 2500HD Classic 8100/allison and it has about 125k on it.
Never had any U joint issues with this one.