Intermittent vibration around 70mph Driveline or Trans?

[Rmck85]

Ok, I thought I had the problem solved and I was wrong. I've been searching for the solution and no luck. I get an intermittent vibration around 70. Whole truck is shaking. Sometimes it's more violent than others, and sometimes it is completely smooth. I have replaced front axle u-joints, front hub bearings, front brake system, rear wheel cylinders, drums, lines, balanced tires, checked alignment, checked front end, everything is tight. I have checked front shaft u-joints and rear shaft u-joints, they are in good shape from what I can tell. I have replaced trans mount.

I notice when I start from a stop, I sometimes feel a little hopping. Thinking that may be in the trans? Could it be my transmission or my transfer case?

Thinking back, my brother and I went to the poconos to do some atv riding. I'm not pulling a lot of weight, a single axle trailer under 1500 lbs and a 500 lb atv in the bed. I was running in OD. The OD off light came on, smoke started blowing out from truck. The atf was blowing out vent tube to exhaust and dipstick was high. I let truck cool down, drove rest of trip with OD off and was fine.

I just replaced plenum gasket, intake gaskets, valve cover gaskets, complete tune up, water pump, tensioner, idler, radiator, and hoses. I'm towing my 1500 lb trailer, empty bed, and I have my scanner monitoring trans. Running in OD, my trans temp climbed to 220 so I turned off OD. Truck at 70 running at 3000 rpms but got temp to drop down to 174. When I bought truck back 2 years ago the gov press switch and solenoid were bad so replaced them. Trans left limp mode and shifts since I did that. Sometimes it feels like it downshifts too soon, sometimes not soon enough. The scanner shows target pressure and actual, and they don't seem to be matching when I check. Not sure if that is normal. I used mopar parts, atf4, and filter.

I see many people have had this vibration issue, and many pages I have come across do not have the fix. I'm worried about whatever it is causing a catastrophic event or leaving me stranded. I need to solve it.

So before I spend thousands sending out my transmission, transfer case, and drive shafts, can anyone tell me if they were able to solve this problem and what was causing it? Could it be the torque converter or clutches slipping? If I floor it on a straight away I don't feel any slippage and shifts are tight. Is there something I'm overlooking?

 

[dudeman2009]

Does the vibration only occur while hitting turns of any angle when at speed? If it only occurs during turns but never on a straightaway, i'd start to pull the rear diff cover if you have the limited slip.

It may not be related to the trans, but it might be. Does the vibration feel like its the body moving up and down or would you describe it as more of a forward and backward vibration, like the trans was starting to slip and grab right away?

 

[Rmck85]

Sorry for late reply. Couldn't find my log in info. Bookmarked this time.

So vibration is felt from 55+ mph. It gets strong and weak. Sometimes almost seems it totally clears up, and a few minutes later gets strong again.

List of things I have just replaced:

All 4 shocks, front axle UV joints, front sway bar links/bushings, ball joints, control arms/bushings, and trans mount. Front is completely tight. I had tire balance checked. Also tried a different set of wheels/tires. Vibration remains. Last year I replaced leaf spring shackles.

I checked front and rear drive shafts, no missing weights and UV joints are not showing signs of play or extreme wear. I am going to replace rear shaft UV joints this weekend. It's a straight shaft reg cab 8' bed. Although they seem ok, I'm going to eliminate that from the list of possibilities and check the angles to make sure rear matches the trans. If not I'll get shims to correct that. Also going to pull the diff covers and inspect.

I did verify my front vacuum actuator is not sticking and is in proper working order.

I also will be replacing trans cooler lines for i suspect a bad check valve, another issue I've been trying to diagnose on trans overheating.

I put the rear axle on jack stands and at same speed range I notice vibration, not as bad as highway but it is there.

I also just ordered new steering shaft, mine has excessive play and I ordered motor mounts. Origionals are 20 yrs old with 177k on them. I feel a slight hopping when in gear at idle or light acceleration from a stop.

Truck just got new plenum gasket, intake gaskets, water pump, hoses, complete tune up, throttle body cleaned, radiator, and injectors cleaned.

I feel loss of power, so I'm suspecting the cat may be culprit due to excessive oil burning while plenum gasket was leaking. I'd average a quart of oil per tank of gas, now I've got 600 miles and no oil loss.

 

[dapepper9]

If it does it jacked up its something rotational. Could be rear end, trans, or even engine misfires the pcm isn't catching

 

[Buzz]

Watchin this one closely.

 

[Rmck85]

Ok, today is the day. I opened the rear diff and noticed some of the gears in the carrier are pitted and there is a ton of play, more than I've seen in other videos I've watched. Also I see wear on inside of the ring gear so I'm thinking that the pinion and ring gear are not properly aligned. I have more to investigate there. I'll be back later with updates.

 

[Rmck85]

Ok guys, I just pulled the drive shaft. The u-joints seem ok. I noticed some wiggle in the output off the transfer case. I took an angle gauge and compared the pinion to the transfer case and there is a 4* difference. I have a straight shaft, only 2 u-joints, no carrier. So I know that can cause vibration at highway speed. I have new motor mounts so I'm going to do them now. I looked at the mounts as they are now and where they bolt to the frame there is a slotted channel. One side is bolted at top of the channel, other side is dropped all the way down. So I'm thinking that may be why my angle could be off, and the root of my vibration issue.

 

[Rmck85]

Motor mounts installed. Passenger side was a bear to do. I don't think the body shop ever got the frame true years ago when I had an accident. I thought one mount was dropped lower than the other. It's just the passenger side has a deeper slot. Optical illusion.

I rechecked the angles, they are now matching. The u-joints have been replaced and are good, except something I didn't notice when I've looked them over initially and on removal. Where you bolt the rear u-joint on to the pinion, there is a set of clips with a retaining spring. One of the clips had rotted. They lock the caps in place. So I am wondering if the cap was starting to walk out and that was my vibration. Now I need to go get the right u-joint. Can't believe I didn't catch that when I took it out.

 

[Rmck85]

So this is a pic of the retainers, one is broken. I can't find this same style ujoint.u so I'm hoping the replacement with regular c clips works.

 

[Rmck85]

I can't give an update. The control arms are kicking my butt, the new trans lines have a slight leak, I think my park switch may be leaking considering electrical connector was soaked with atf, and I still have to finish the driveshaft.

 

[SportRam00]

Interested in this thread as well. Good stuff here. I have a slight vibration between 40 and 50mph. I think my driveshaft is slightly bent though since I noticed that one of the UV joint retainers on the rear side of the drive shaft was damaged...

 

[Rmck85]

Ok. Now that suspension, steering, engine/trans mounts and u-joints are replaced, the truck feels much tighter. I definitely need an alignment, wheel is off now that the 4 inches of play is gone. Vibration........ remains. It's not as bad in the sense that everything is tighter but still not tolerable. So I'm going to swap the tires onto a different set of wheels and see what happens. When I had it up on jack spinning in place, the vibes were definitely coming from back of truck. I switched tires and still had a vibe, not as bad. The bad one I put up front and it feels like it is in steering. Mind you I have had these tires balanced 3 times in under 10k miles, that was the first thing I tried to get rid of vibes.

 

[Rmck85]

SportRam00 I overlooked the driveshaft u-joints 3 times. It wasn't until I was inspecting the rear and pulled the shaft that I found that the retaining clip on one of the caps that bolts to pinion was broken. I figured it may have walked enough that it was causing vibes. Wishful thinking.

 

[SportRam00]

If you switch your tires and the vibration moved, I think you found the issue. I hear that some tires are so out of balance, they can not ever be perfect...

I looked back through the previous posts and noticed you replaced all your front end components except the track bar. Did you check for play in that?

Does the vibration only happen when the wheels are moving?

 

[Rmck85]

The track bar has been replaced and doesn't seem to have play. Same goes for tie rods.

Back to tires, I ran 2 on the back jacked up in place. The rr which spins most on open rear had heavy vibe. I took them off, put the other two from the front on the back. Still had vibration but not as bad. So when all was said and done, I moved the worst to the front and driving today I feel it in the wheel. So what I'm going to do today is stop at the shop and swap the steel wheels they are on to the alloy ones (I have 2 sets of wheels/tires) and see if it goes away after a remount and balance.

I've balanced these tires so many times and problem still existed which is why I believed it was mechanical. Granted the parts were old and worn, so it wasn't wasted money. I'm restoring the truck, it was my dads last new truck before he died and was his toy. It was sold a long time ago and I just got it back 2 years ago. Sentimental project, so I want it to be right.

 

[Rmck85]

The vibe was 55-70mph, intermittent in intensity. It would get really intense, then lighten up. You could see the whole truck shuttering in the mirrors.

 

[SportRam00]

Wow. Glad you're restoring the truck in memory of your dad. Definitely do it right. You sound like your on the right track. Who knows, maybe the alloy rims are shot or got bent somehow.

 

[Rmck85]

Well I was actually running on the steel rims. I just switched the tires to the set of alloy rims I have. Still vibrating. So at this point I'm going to have to say it's either in trans, transfer case, the driveshaft itself or the diff. I'm just going to have to drive it until whatever it is goes. Just hopefully not when I'm on a trip upstate.

On the bright side, the steering, suspension, and brakes are all new. So now it's time to start focusing on the body.

 

[Rmck85]

Bad u-joint which was replaced. Was binding and causing the shaft to hop. Replaced it and shaft is spinning smooth. All that's left is tire vibration which General won't warranty due to LT tires and time, they are only 2 1/2 years old with 10k miles on them, 9/32 tread left.

 

[Shadow_Death]

If it does it jacked up its something rotational. Could be rear end, trans, or even engine misfires the pcm isn't catching

and they seem to be bad about not catching them. lol