PDA

View Full Version : Vibration help requested!!!


comsigns
08-26-2013, 12:14 AM
:yell:
So my 05 T1N 158 with 120k miles and is doing weird things. Here's the history.
I started with the classic RSN vibration
New driveshaft that didn't help.
It was finally fixed by the darf repair (thank you Dr. A.)
Then I still had a drive shaft speed vibration starting at about 50 mph.
It does it in neutral with the engine off rolling downhill as well.
I had my new driveshaft turned at a driveline shop and they did some minor tweaking but said it was okay.
Then I took the old driveshaft and put it back in to see if that changed anything and it made the vibration much worse. Vibration started at about 35 mph
Put the "new" driveshaft back in- back to 50
After doing some reading I change the tranny fluid with the high-end Dodge Mercedes product. I noticed a slight improvement but nothing remarkable.
My thought now is to remove the driveshaft from the transmission and run it at about 55 mph and see if the vibration is still there to try to isolate the problem.
Any input would be appreciated! Thank you very much in advance.

coalminer
08-26-2013, 12:45 AM
:yell:
So my 05 T1N 158 with 120k miles and is doing weird things. Here's the history.
I started with the classic RSN vibration
New driveshaft that didn't help.
It was finally fixed by the darf repair (thank you Dr. A.)
Then I still had a drive shaft speed vibration starting at about 50 mph.
It does it in neutral with the engine off rolling downhill as well.
I had my new driveshaft turned at a driveline shop and they did some minor tweaking but said it was okay.
Then I took the old driveshaft and put it back in to see if that changed anything and it made the vibration much worse. Vibration started at about 35 mph
Put the "new" driveshaft back in- back to 50
After doing some reading I change the tranny fluid with the high-end Dodge Mercedes product. I noticed a slight improvement but nothing remarkable.
My thought now is to remove the driveshaft from the transmission and run it at about 55 mph and see if the vibration is still there to try to isolate the problem.
Any input would be appreciated! Thank you very much in advance.

If you grab the driveshaft where it attaches to the transmission, is there any play in it? I had the same 45-50 mph vibration, and the nut that holds the flange on the output shaft of the transmission had come off and was laying inside there. That happened to me 2 times, the second time I put it back together, I put red Loctite on it, so hopefully it does not come loose again. From the way it looks, that nut is supposed to be pounded into a recess onto the shaft, but it must take a special tool to do that with, since it is recessed inside the flange.

NelsonSprinter
08-26-2013, 01:33 AM
Since it does a vibration at 50mph with the engine off or in Neutral, I would think its an unbalanced tire vibrating the van, and giggling something loose like an aluminum heat shield above the exhaust pipe.

comsigns
08-28-2013, 01:23 AM
Hey coalminer - i'll check that nut! That sounds just like what it'd be. "ive grabbed that driveshavt and given it a good wiggle from one end to the other. Thanks for the advice on the wheel Nelson but it's a driveline speed not wheel speed vibration. Ive got two 158's so maybe I'll pull the other driveline and put it in the offending van. That'll isolate the problem somewhat.

surlyoldbill
08-28-2013, 01:56 AM
Tried swapping the front and rear rims?

comsigns
09-02-2013, 04:36 PM
Thanks BUT it's a driveline speed not a wheel speed vibration.

NelsonSprinter
09-02-2013, 04:59 PM
When you changed the driveshaft, did you put in a new hangar center bearing assembly?
A new one should absorb any vibration in the shaft, a worn one will have too much play.

riskydnb
09-02-2013, 07:22 PM
:yell:
So my 05 T1N 158 with 120k miles and is doing weird things. Here's the history.
I started with the classic RSN vibration
New driveshaft that didn't help.
It was finally fixed by the darf repair (thank you Dr. A.)
Then I still had a drive shaft speed vibration starting at about 50 mph.
It does it in neutral with the engine off rolling downhill as well.
I had my new driveshaft turned at a driveline shop and they did some minor tweaking but said it was okay.
Then I took the old driveshaft and put it back in to see if that changed anything and it made the vibration much worse. Vibration started at about 35 mph
Put the "new" driveshaft back in- back to 50
After doing some reading I change the tranny fluid with the high-end Dodge Mercedes product. I noticed a slight improvement but nothing remarkable.
My thought now is to remove the driveshaft from the transmission and run it at about 55 mph and see if the vibration is still there to try to isolate the problem.
Any input would be appreciated! Thank you very much in advance.

When you changed the tranny fluid were there a lot of metal shavings in the bottom of the pan or on the magnet?

Allantuttle1
07-10-2014, 06:26 PM
Hello, I've got a 2006 140" with 198000 on her. Similar vibration I think. I does go away when I let off accelerator. Seems to happen between 2200rpm and 2600 rpm. Which is about where it settles on the interstate. I don't go over 2200rpms while I'm trying to get to the bottom of this.

My question is, was this resolved? And was that nut the cause? Also, I have play at the transmission. I can wiggle the driveshaft but the only play I see is at the back of the tranny. Sounds like I am moving gears inside of it.

On the phone with two separate shops.....they say its usually the carrier bearing and both shops have never done a driveshaft.

Any ideas?

Allan

autostaretx
07-10-2014, 09:45 PM
Thanks BUT it's a driveline speed not a wheel speed vibration.
I don't understand that comment: the driveshaft spins at "the same" speed as the wheels (ignoring the differential's internal gear ratio).
The driveshaft does spin a little faster/slower than the individual rear tires during a turn, but if you're going straight the driveshaft and wheels will always be spinning at a proportional fixed ratio, irrespective of selected gear.
(3.73 to 1 on my 2500, 4.11 to 1 on some 3500's)
The clutch (which decouples the engine from the wheels) can be thought of as "between" the engine and tranny.

If you're trying to convey that the vibration is from the tranny, not the driveshaft (propeller shaft), then i could understand your comment.

Perhaps some time on a dyno would let you isolate the vibration?

An audio spectrum meter (or microphone in an oscilloscope) could perhaps yield the actual frequency of the vibration.
Using my 2500 as an example, at 60 mph my tires are spinning at (about) 760 rpm. (12.7 hertz)
The driveshaft is spinning at about 2835 rpm (47.25 hertz).
If the vibration was at either of those two frequencies, the guilty party would be targeted.
If the vibration was an integer harmonic of either, that would also be telling.

You didn't mention whether you've played with the hanger bearings.

--dick