Shaking over 60, how can I tell if my u joints are off?
Just rebuilt the zj 5.2 1996 from a blown head gasket, and had to take off the drive shaft tow it. It sat for 3 years before I picked it up, then I drove it for about a month before it started overheating. Found tranny fluid in the engine, swapped the radiator and of course all new gaskets. Now, while I drove it the first month, it never shook once.
Now that I've sewn everything back together, it's running fine but once I'm going above about 62mph, I get shakes which increase with speed and stop only when I drop below the 62mph mark. If my U joints were off (although I marked the drive shaft before removal to assure it was put back right) could this be the cause? I would have said alignment/rotate and balance, but it never shook until I rebuilt it, so it seems to me that that's got to be the cause. Any thoughts?
My 93 shook all kinds of crazy with the front drive shaft in when I first got it. Turned out to be all 4 front control arm bushings were completely dry rotted. The upper bushings are the ones that seemed to cause the most shake in mine.
I agree about the u joints; it seems like it would shake the whole time. See, that's the thing, I never touched anything to do with the frame, axles, or cv joints. For it to start shaking now, only and immediately after the rebuild, it seems strange that it would be caused by something else. I had it up on a jack overnight, and for some extended time during the job, maybe that threw it out of whack?
As to your questions, I didn't rebuild the shaft joints, I'm pretty sure it's all u-joints, and haven't even looked at the wheel bearings.
@ratmonkey, I'd agree that it could use new tires if it sat for that long, only it didn't shake for a whole month of driving before the rebuild, which indicates to me that it wasn't a pre-existing condition. They look good, plenty of tread, and no "squaring", btw.
New tires. old ones are probably dry rotted.. I also found replacing my lower control arms recently reduced my vibrations at 60-70mph by like 70%, and replacing my transmission mount did the same. It could just be rotted bushings.
2013 6.2 V8 Camaro SS 9k miles
1998 5.9 V8 ZJ 180k miles
1998 4.0 I6 Laredo ZJ 227k miles
94 stock zj and a 95 zj with a 5.5" lift with 35" bfg km2 a rear currie 9in with 4.56 gears an arb and 35spine axle shafts and 4.56 gears in the front Hp30 super30 kit arb 4.1 low range transfercase
My experience is I've had that twice on mine and i could only feel the shake over 60 .both times it was one of the u-joints at the diff .1 front and 1 rear .
Just slide under and push up on the drive shafts at either end closer to the u-joints .They should be tight as a drum .As little as 1/16 -1/8 " movement and it's probably time to change . Also check the cv or cardian in the front D.S .
Oh , and make sure there's no mud or anything like that slumped on the inside of the rims , that'll throw the ballance off too .but i do agree with bad tires as option as well . If the tires/tread are still good , it may be worth it to you to get them load ballanced .That should tell the story there if there's de-laminating going on .