Vibrations

[nitroxsteve]

I have a vibration I can't get rid of and would like to know if there is anything I'm forgetting. I have an 88 4.0 5 speed. I am currently converting to 4wd and have installed the front axle no t-case yet. I don't know if it had the vibration before installing the front axle as I never drove it at any speed with 2wd axle. The front axle was installed with a rusty's 3" coils with new shocks track bar and controll arm bushings. The rear AAL only raised the rear 1" so I don't think the rear driveline angle is a problem. I have had the front end aligned and it drives nice and straight and tight. I have replaced the engine mounts the trans mount is still in one piece and looks ok, I didnt want to replace it untill t-case install. I have replaced the rear u-joints and the axle joints. when installing new tires I found two bent rims and replace the rims with a set of stock steal wrangler wheels. I have had the tires balanced but also had the exact same vibration with old tires. The vibration is a high freqency and starts at around 60 and gets worse as fast as you can stand to drive. All the things I have replaced seem to help but it never goes away. I am going to look at the rear wheel bearings tomarrow but i am not sure what else to do. How smooth is your truck at 75mph?

[JeffN]

Mine does the same thing, new wheels/tires and a new alignment. It is not the death wobble people have, just a vibration over 60.

I am thinking i may have a ujoint or bent driveshaft issue. I am hoping to check it out today and will report back

[Pete M]

check your driveshaft u-joints for sure. :thumbsup:

[87Warrior]

That definitely sounds like drive line vibes.

[txjeeptx]

I had a similar vibe problem with my 2wd MJ. Turns out the rear driveshaft on mine had a rubber sleeve in between two pieces of tubing that made up factory the driveshaft. I tried replacing the u-joints twice to get rid of the vibe, then gave up and took the shaft to have it balanced. The drivshaft shop said it needed to be replaced with a new shaft. I do a lot of business with this shop for my other Heeps, so I trusted what they were tellin me, and they were right. After the new shaft, which doesn't have any rubber damper BS parts to it, the vibe was gone.

 

Does yours look like it has an inner and outer tube with rubber sandwiched in between, pretty much the whole length of the shaft? If so, then that's likely the cause of the vibration - the rubber is dried out/worn out.

[nitroxsteve]

I had a similar vibe problem with my 2wd MJ. Turns out the rear driveshaft on mine had a rubber sleeve in between two pieces of tubing that made up factory the driveshaft. I tried replacing the u-joints twice to get rid of the vibe, then gave up and took the shaft to have it balanced. The drivshaft shop said it needed to be replaced with a new shaft. I do a lot of business with this shop for my other Heeps, so I trusted what they were tellin me, and they were right. After the new shaft, which doesn't have any rubber damper BS parts to it, the vibe was gone.

 

Does yours look like it has an inner and outer tube with rubber sandwiched in between, pretty much the whole length of the shaft? If so, then that's likely the cause of the vibration - the rubber is dried out/worn out.

 

 

Yep it has the rubber in one end. I checked to see if the ends are lined up and it looks ok but who knows my eye balls may be crooked. I think I will go ahead and install the t-case and new drive shaft and see what happens.

[nitroxsteve]

New (used) Drive shaft fixed it.