Noise after 3 inch lift accelerating and decelerating
 

Hello everyone, I just had a 3 inch RC lift with new springs on my 1999 Jeep Cherokee XJ Sport (4x2)....yeah i know....
The main problem is a grinding noise comming from underneath while driving over 30 mph. At constant speeds, everything is fine until I let off the accelerator, then i hear a grinding noise that will last for several seconds then stop. When I push on the accelerator i hear the grinding noise again but for a quick short time. I also noticed the slip yoke shaft that slides into the transmission tail housing is sticking out approximately 1.25 inches more than before and the seal it is now leaking. I found a very slight play in it side to side but it didnt seem to be alot at this point. The shop that put on the lift is saying they contacted RC and confirmed it was installed correctly but when I asked what the solution and cause of the noise, they were not completely sure, advising RC stated it might work itself out once the lift has been on for awhile. Thay advised the u joints looked good. At this point, I found a shop that primarily works on Jeeps and i will be taking it to them when I can. I was wondering:
1) What could be causing that grinding noise when pushing and letting off the accelerator.
2) What is the fix.
3) I it normal to have that much of the slip yoke shaft exposed after a lift.
Sorry that this post was so long and Id appreciate your feedback.

Search....there are plenty of posts about this and similar problems that may help you.....knowing the model year/trans/t-case is a good thing too

here's one https://www.cherokeeforum.com/f67/xj...r-lift-247316/


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One more reason avoid RC....since when has just leaving things alone ever worked out? That gets the Darwin advice award of the year. Terrible.

First thing I'd check is the u joints. You may need a SYE.

Most likely trashed shaft u joints from changing the angles with the lift.

Sorry it took so long to reply and thank you for the replies....Im thinking the drivelines are not correct but not sure. The transmission looks vertical and the pinion is pointing slightly up. Just eyeballing, the driveshaft looks like around 15 degrees. I would like to put a sye on it but its a 4x2 and not possible. Didnt think that small of a lift would mess with anything major.....so im trying to see how to correct it. Any advise to correct on a 4x2? Thanks.

Thank you for responding....you are correct. I wont be doing any major off roading. So if I drop the transmission down would it also shift the engine angle and mess with anything in the engine compartment for example ac lines and other. Just checking. And is that a safe common practice. Thank you again.

Dropping the cross member will put stress on the motor mounts and cause potentially faster wear. I found using thick washers and new bolts worked well to adjust the drop just as much as it takes to get rid of driveline vibes. A single washer can make a difference in vibes. I am not saying one washer is all you will need just that adjustments are that small. Most produced tcase drop brackets are made of square stock and offer no way to adjust. You may need to shim the axle to get things dialed in. The only other real concern besides motor mounts IMO is to verify your mechanical fans clearance after the drop. Too much drop has the potential to put the fan very close to the radiator.

FWIW I ran a drop using washers for over 50k miles. I did replace original motor mounts during that time.

I appreciate the information!!!!Thank you and have a good one.

Cool. I appreciate yall.....my stress level is winding down now. Thank you.

Noise front and rear after MFC 3 inch lift with Dobinson springs, Fox shocks, RCV axl
 

I just had MFC+ 3 inch lift with Dobinson springs, Fox shocks, the RCV axles all installed last Wednesday. Been driving for passed 3 days. I have the same thing going on that you mention here. The ratcheting or diesel idle type sound is coming from the front end and also rear when accelerating and decelerating, letting of gas and coasting.. checking out this post.. hopefully it's been founded out why or what is going on.

I have the exact same issue on mine after putting a 3inch BDS on mine 2 weeks ago. Have you figured out the problem yet?

Still clicking noise when accelerating with MFC 2" lift
 

Not yet. So far since that post. I had taken back to dealer and they said same thing.. drive it. Christian from RCV Perfomance said to go jump it and that RCVs have a 5000 mile break-in time. I put maybe 300 at most on Jeep since the lift. May 9th the right RCV popped out. I'll post a pic of it. I had had HD Dobinson springs on front and back. It was shared with me by MFC Jesse Lambros and a rep from Dobinson USA on Instagram that the HD springs over lifted or extended the axles. So May 11th I had Jeep towed 70 miles to dealer. The dealer took off the HD Dobinson springs and of course the Performance axles putting my factory springs and RCVs back in. May 17th pick up my Jeep now only having a 2" lift. Found noise to still be there. Except now it is only when accelerating.. letting off gas so far it is making no noise. The clicking and ratcheting sound is not as bad or loud but it is still happening. May 18 took it back to dealer where it is getting diagnosed.
https://cimg0.ibsrv.net/gimg/www.che...934f640bf3.jpg
RCV that popped out May 9th while driving 30 mph on way to my work in the mine, road was smooth not rough at all