Vibration - freeway speed

[MT12V]

Hang on, you said you had the front driveshaft out for a while and it still had the vibration? If the driveshaft was out the front output shaft by itself isn't going to cause any noticeable vibration.

Yes, that's what I remembered. I've been on this chase for a year & half & all fixes have failed so far. The reason the front output shaft is reputed to be bad is that that is the latest diagnosis when the truck was run up to speed on a lift by a dealer. I should get word from the TC reman shop in the next day or so as what they found, if anything. The repair history sequence has been after losing 4WD: 1) bad TC, replaced with reman unit, 2) all tires replaced & balanced, 3) rear DS, replaced u-joints, 4) front DS repaired, 5) front DS replaced, 6) rear DS carrier bearing replaced + "stub" end of DS replaced + DS rebalanced, 7) all tires re-balanced, front output shaft now named as suspect as they (dealer) said they could feel too much play there. ???...Thx for the info & suggestions, I'll post more data when available.

 

[MT12V]

The latest in this search for the problem indicates I have a bent RR wheel. Had the rear tires removed to
check the rims and this showed up. NOW, I am searching for a factory wheel replacement, tried a couple of
local junk yards and their rims indicated "bent" when spun on a tire balance machine. Any suggestions as where I might locate a 96 Dodge factory 16" X 6 1/2" 8 lug 5 "spoke" rim would be much appreciated.
Also, is there any rating applied to such a used part? Trying to save freight back & forth costs.

 

[GrantP]

As others have stated in this thread, tire vibration and driveshaft vibration feel very different.

Why not just replace the allegedly bent wheel with the spare and see if the vibration goes away?

 

[MT12V]

I plan on doing so,, if vibration does away, then on the search for another stock rim. Will indicate if spare use takes vibration away.
Thanks GrantP.

 

[JR]

Where are you located? I think I've still got a set of OEM gen 2 wheels stashed away in the back of one of my garages. I'd make you a deal too good to pass up if you are near NE Ohio!

 

[Joe Mc]

Is it possible shaft angle changed with reman t-case? New mount installed when reman t-case installed?

 

[Joe Mc]

MT12V, any update. Just wondering if you figured out yet and what it was/is?

 

[MT12V]

Where are you located? I think I've still got a set of OEM gen 2 wheels stashed away in the back of one of my garages. I'd make you a deal too good to pass up if you are near NE Ohio!

Hello JR,, am in Montana, located an oem rim from S Cal, waiting to receive, hope it is in pristine shape. I'll
pursue your offer if this rim fails the spin test.

 

[MT12V]

MT12V, any update. Just wondering if you figured out yet and what it was/is?

I will update when I replace the bent rim & road test.

 

[rotohead]

I remember reading a thread by a long timer on this site that had pretty much the same vibration. He finally found the root cause after he accidently had the rear on some jack stands and was running it in drive about 45 mph on the speedo. It was the rear hubs. They were defective from the get go and took a few years of driving for the vibration to fully show itself. Can't remember if he replaced or found a way to balance. I have a similar situation but on a much smaller scale. I can live with it for the most part. If I ever find a set of new hubs for a Dana 70 I might buy them. The originator of that find is a mod on this page I believe, Steve St. Laurent I think?

 

[Joe Mc]

Rotohead, your post reminded me that back when I still had the infamous stock chrome “potato chip” wheels I had a vibration on the right rear at highway speeds - it was a constant sort of annoying thing would change frequency from hardly noticeable to a “what the heck is that” and work itself back to hardly noticeable and back up again. I rotated the wheels and the vibration still came from the right rear. I read the post you were speaking of (back then = must have been back in 02-ish??) and set my truck up on 4 stands, had a buddy run it up to 60 mph with the wheels on and then did the same with wheels off (note: at that time I hadn’t converted to rear discs yet. IMPORTANT NOTE: if you have drums “make sure” you put at least 4 lug nuts on so the drums don’t “fly” off and kill someone) the vibration actually seemed to be coming from the axle. I pulled the right shaft and set it up on rollers one at the splined end and the other at the hub end using a dial indicator there appeared to be a slight bend of sorts in the middle. Took it to a machine shop specializing in differential/drivelines and the main Machinest told me “that is typical, he’s seen much worse ones that didn’t create vibrations”. He said he could try to do something with it but whatever he was able to do would most likely make things (the slight bend) worse. He told me to focus on the bearings, races and proper amount of torque/play. I installed new “Timkin” bearings & races, set up play/torque per spec. and it was better. I dealt with it for years until I “snaggle toothed” (long story - search for “Snaggle Tooth Ring Gear”) the ring gear and came about a D70 with an L/S for a “song”. I swapped the whole housing, converted to rear discs and the vibration was gone.

 

[MT12V]

I remember reading a thread by a long timer on this site that had pretty much the same vibration. He finally found the root cause after he accidently had the rear on some jack stands and was running it in drive about 45 mph on the speedo. It was the rear hubs. They were defective from the get go and took a few years of driving for the vibration to fully show itself. Can't remember if he replaced or found a way to balance. I have a similar situation but on a much smaller scale. I can live with it for the most part. If I ever find a set of new hubs for a Dana 70 I might buy them. The originator of that find is a mod on this page I believe, Steve St. Laurent I think?

The "latest" from here (Montana) is that 1) replaced the bent RR rim,, vibration continued, "then" that tire shop indicated that "that" tire (only ~1200 miles on the set of tires) was defective - not able to balance! Tire replaced! Vibration continues, although reduced somewhat. At this point I have decided to stop chasing this and live with this honorable 300,000 mile truck, engine & running gear appear fine,, and I'll not need to put a lot more miles on using the freeway, as we have a good used car now.

 

[JR]

I'm sorry you haven't been able to find an amicable solution to this....

 

[JMcCoy]

Just throwing this out there, maybe a worn harmonic balancer or loose or cracked flywheel. They usually show up at certain RPMs and different speeds.

You probably have a bad set of tires though.

 

[KATOOM]

I chased a highway vibration for years. I knew it was tires and had them re-balanced multiple times for about a year. The shop eventually chalked the rims/tires to see if the tires were possibly spinning on the rims. Eventually it was discovered that the tires were separating internally and would never balance correctly. New tires and the truck drove like glass for 8 years until I had to replace them...
That said, those crappy tires were D rated and the smooth set was E rated. I think D's are too light for these heavy trucks.

 

[JMcCoy]

I think D's are too light for these heavy trucks.

I agree 100% i had numerous BFG KM2s break belts and go egg shaped. I finally had to stop running them since BFG doesn't make an E rated 35x12.5R-17 (or metric equivalent) km2. I no longer break belts, but I did lose fuel mileage going to the E rates tires.