Hey, i have an 8 inch lift by iron rock offroad in my 2001 cherokee and i have a hack n tap on my 242 case as well as a tom woods front and rear drive shaft. I feel vibes past 40 mph and it only gets worse. It's coming from the rear and they stop when i take my foot off the gas. Could it just be a bad u-joint or could it be that the angle is still too much and its still causing vibes? any thoughts are appreciated

 

bump

 

Are you sure the tires are balanced properly? Also that you don't have a bent or warped wheel? I know it's basic but maybe?

 

Sounds like a u joint to me. Get under and see if there's any play in your drive shaft. And 8inches is a lot lol...what's your d shaft's angle look like? You'll probably need to add shims on the rear axle if you don't already have them

 

It's a buddy of mine's that i'm thinking about buying. Everything has less than 1,000 miles and the wheels and tires are brand new. I don't think it's aligned though (it's close enough). and the drive shafts are brand new also. next time i see it i'll take a look at the u joints because i figured it was that too. I'm just wondering if they could've been defective or broke before they were put in. Also i was thinkin of putting shims in to see if that could help it out. Last time i looked at the drive line it didn't seem horrid. Theyre double cardon shafts (And yea its a huge lift)

 

If it has a lift kit he will need to install spacers on the tranny mounts. I had the exact problem with my 3.5" lift and the spacers stopped it cold.

 

You can't drop the tranny or transfer case, they're resting on the crossmember. The rear axle is shimmed. Its got a hack n tap on the 242 and a double cardan drive shaft. Is it possible that it can still get vibes with all this?

 

The driveshaft might just need to be rebalanced. Mines was out of balance and it caused bad vibes. I just swapped it with my front shaft and its been all good since then.

 

Could possibly be front driveshaft also check the angles