After Lift...Grinding noise

First of all, lets get it out of the way that Im going to need an SYE... I am one of the unlucky suckers....

So I installed my lift this weekend, in which I peiced together on ebay for much cheaper than one would pay for an entire lift. Anyway the Brand new 3" Rough country leaves that I bought only turned out to give me about 1.5" of lift over the sagging rear springs...which I am really pissed about...but anyway, with this 1.5" over where it was sitting before, going down the road, usually at about 45 or faster, when I let off the gas there is a grinding noise. I can stop the grinding noise by giving it a little bit of gas. I understand its something driveline related, however I would like to know what exact it is that is doing the grinding? Pinion Bearing?

Thanks, Derek

try checking your u-joints. Also, i had a 89 pioneer with a 6" tomken lift and when I gave it gas it would alleviate a grinding noise but when I slammed on the brakes I would hear a slight grind clunk noise and it was the tailshaft of the transfer case.

Mine does the same thing, I have switched drive shafts and added a tranny drop etc and it still does it. I have been ignoring it but if someone has a fix please post it up.

Maybe it is the tailshaft or babbit bearing/bushing. Now that the driveshaft is at a different angle it is putting a different stress on it. Here is the process of how to remove and replace it:

You pull the driveshaft slipyoke out, remove the 3 or 4 bolts holding the tailcone assembly, depending on if it is an NP231 or NP242. Tap the assembly with a deadblow hammer to get it to come off. Once it is off you should be able to see the bearing. Find a socket or bushing driver the right size, and use a hammer to tap the babbit bearing out. The new one can be pressed in using much the same techinique. If you don't want to mess with pressing the old one out and such, just show up at your local automotive machine shop with the replacement bushing and I bet you can get it done for $10 while you wait

My buddies 2000 does the same thing, and he is running 3.5" rubicon express springs in the rear with no drop kit on the TCase. Back to mine though...the driveshaft is pretty much lined up with the tcase and rear end. Is it ok to continue to drive it around like this for awhile?

I encountered the same grinding noise after my lift. Decelaration caused it to sound like a giant blender. Once i installed the Slip yoke eliminator, it was gone. The angle of the driveshaft will cause the slip yoke to vibrate around the output shaft.

Well, if it were me I would take the rear driveshaft completely out and then put it in four wheel drive and drive it using only the front driveline. Obviously, you want to only do this for a limited time in the pavement but if you hear the noise still you know it is internal.....atleast it takes the driveline out of the equation. Or you know it is due to the driveline being installed.....then you can try and narrow it down to putting stress on bearings (pinion or babbit) or u-joints.

BTW, I drove around with the same noise for about 3 weeks before getting my SYE. Its really hard on the u-joints. The sooner you get a SYE, the better

I have been driving with this noise sense october of last year. It still goes and the t-case does not make noise. Am I killing my t-case? I have noticed that the rear seal is leaking some. Is there any way to make this better without doing a sye? I plan on doing the sye but money is tight right now. My jeep has 3.5 rear lift with 31's and a 231 t-case