Vibration at high RPM and high torque (1 Viewer)

[zhloea]

Maybe not relevant to the vibration but I can see your point if it was shudder that you pointed to.

How many miles (over 200k?) Could be ujoints, but that vibe will present more pronounced as speed increases- less noticeable under 45 mph

could be drive shaft balance, worn CV axles, etc

read up on diagnosis here:

Pulsing/droning vibration at highway speeds

This diff bushing won't cure driveline vibes. Even brand new the bushing flex's quite a bit. Replacing that may help cure a portion of the D-N-R clunk but thats about it. Driveline vibes are hard to isolate with out removing prop shafts one at a time and test driving with CDL locked. Once you...

forum.ih8mud.com

Strongly agree, I think any symptom could possibly be related to many issues when the car gets to this age and particularly for the people who buy used one and don't know the history of the maintenance clearly like me. Before that, I always try to find a solution for truth when I facing an issue with my LC, but after many DIY repairs I start to understand the only thing true is "the car is an old car and when you got it, it already that old", then there is no idea that doing a single thing can entirely cure the issue...So I just try to start somewhere when I found an issue now, and maybe fix some other issue accidentally...For example, I got the “shaking when red light" issue a couple of months ago, I have no idea what to do. then I start to replace my brake pads because the pads are worn, then the caliper because the caliper freeze, then the brake booster assembly because it can not pass the pump timing test, I never expect it will resolve the shaking issue, but the issue is finally gone after all of these repairs...

 

[WreckDiver1321]

Will directly replace both shafts resolve this? how about this?
Watched some video of change U-joint, kind of tricky...and they said the balance of the shaft also could lead vibration means even though change the U-joint only will not kill this symptom. And order two new shafts put it on seems will 100% sure resolve this if this really caused by u-joint and shaft.

Completely replacing both driveshafts is totally unnecessary and more money than you should be spending.

In my experience, driveshaft vibrations caused by an unbalanced shaft are pretty rare. I've changed every u-joint in every truck I've ever owned and I've never introduced a driveshaft vibe, so I wouldn't let that stop you. If changing out the u-joints yourself looks tricky, get some u-joints, pull the shafts, and take them to a shop to get replaced. Call around too, you'll likely have a driveshaft or clutch specialist nearby who can not only swap the joints, but also check to make sure the shafts are balanced and balance them if necessary.

However, before you go through all this work, do these two tests:

1. Chock the wheels, put the transmission in neutral, and climb under the truck. Locate the forward-most u-joint on the front driveshaft, then grab the driveshaft near that joint and push the shaft up and down, then side to side. Any play in the u-joint will be pretty obvious and will make a clunking sound. Then move on to the rear u-joint, then repeat the process on the rear driveshaft.
2. If you can't confirm the problem this way, pull the rear driveshaft and lock the center differential. Drive the truck in the situation that would normally cause the vibration. If it's gone, you know the problem is likely to be a bad u-joint in the rear driveshaft. If not, repeat the process with the front driveshaft.

If neither of those two tests work, your problem is elsewhere.

 

[dosruedas]

I just dropped my 2000 back at the shop this morning as my truck developed this exactly (and most noticeable around 3500 rpm going around 70 up the pass) after* having my CV’s and drive flange replaced last week (for unrelated issue of sheared teeth). I thought it might be tire related (maybe swapped during repair) so had those rotated and balanced earlier this week but no improvement coming back up the canyon.

 

[Hake]

Anybody have any luck resolving their vibration issues? Just bought a 2000 LX a few days ago and just joined here. Been searching this forum and seeing several posts with similar type vibrations. Mine too has terrible vibration only when accelerating at 50-60mph range. It stops vibrating when I lift off the accelerator. Or when at a speed above or below that range. I thought for sure it was U-joints. I just had a mechanic put it on the lift yesterday, drop both driveshafts and carefully check all U-joints. They were all fine. We were both scratching our head on this one. I know CVs are a possibility, but the previous owner replaced those about 3 years ago (have receipts) with minimal mileage since then. Could be a cheap aftermarket CV? Bearings don't seem loose. 295 tires are brand new this week and balanced. It does have a OME lift kit with heavy springs that was installed long time ago. So I know stock geometry is a bit stretched. Anyways, I say all that for background info on my situation. Following this thread, and a few others, hoping to learn more and search for a new clue on this issue. Thanks!

 

[overlandish]

Any updates on this? I have a 1998 LX that has the same issue regarding higher speed acceleration and dropping a gear to go up hill. I have new CVs and a fresh diff drop. The issue was there before those, and is still there. Thank you!

 

[JohnnyMackerel]

No updates on my end still have it going on tho pretty slight… I was chalking it down to the 2.5” lift maybe??? Anyone have any thoughts on that ??