I'm brand new to the jeep world. I purchased a 98 Cherokee and dove right in. After blowing the stock transfer case I re-upped on a 231j from a junk yard and installed a SYE and a 3.5" lift. Now that I have finished the install I'm not so sure I did it right. There is a fairly loud thumping when I put the jeep into drive/reverse that increases as I accelerate (noise level stays about the same). This thumping also occurs while going in reverse, 4WD H and L.

Any suggestions on where to start trouble shooting?

Thanks in advance.

 

How's the trans mount ? can something be hitting around there ? does it make the noise when it is off the ground on jack stands ?

 

If it is a low speed thump, I agree with the motor/trans mount idea. But to be sure, was the chain tight after the install of the SYE and what brand did you get. Was it a hackntap or full SYE? What did you use for a driveline? Was it new or used?

 

I havent tried putting it on jack stands and engaging the train yet. I will probably give that a go tomorrow

 

The chain seemed tight after install. The SYE I got was Rough Country. Quickly learning there is a reason Rough Country is affordable. I believe it was a full SYE. The front drive shaft is stock the rear drive shaft was purchased.

Rear drive shaft Rough Country 5076.1 Rear CV Drive Shaft for 84-01 Jeep Cherokee XJ

 

Did you change the bearings in your junk yard transfer case, run it before the mods or just assume it was good to begin with ?? The rough country SYE I'm looking at on the site looks like a rebranded advance adapters kit.. If so it's a good kit.. So tell us what you ended up with for driveshaft angles for completion of your SYE install??

 

Is it when you accelerate or engage the transmission? If when accelerating, it could be a u joint