ninewon

Let me first say thanks helping me out.
To start.... I have a 99 xj that has 76k miles on it. It came stock with Dana 30HP in front and a 35 in back with a np 242 and an aw4. The gears are 3.55
I saved my pennies for some time to build a solid adventure rig to get away when I can.
I found a Dana 44 for the rear from an 87 xj.
Since I have no shop and my skills are fair, yet not expert I chose to have a 4x4 shop I felt was reputable to do the work so I can be sure it’s right.
It was suggested, and I accepted, new nitro 4.11 ring and pinion front and rear. I also got new nitro rear axles. And Tera flex disc brakes.
No I’m not made of money... I just wanted a clean new build to start from.
The rig was lifted with rubicon express 3.5 super flex and an advance adapters SYE.
New front ball joints, and any other suspension/steering parts that it needed.

Now here is the rub.... they had the rig for 2 weeks (14 solid days) and I couldn’t afford the rental car anymore. They said it was safe to drive yet needed some adjustments.
Got going down the road about 10 miles and as I slowed to a stop I have a whirring noise on deceleration. I called them and was told it might need the 4 degree axle shims changed to 6 degree shim. Also the new disc brakes are setting in. As the truck got warmer the noise got louder on deceleration. I took it back and they added new longer leaf pins and 6 degree shims.
I head out again and now it sounds and feels like I’m driving on super swampers on acceleration and cruising and the whirring is even louder on deceleration to a stop.
As I drove it that day the whirring is all the time now. Acceleration and deceleration.
Cold or warm.
I called them and was told that there might be something wrong in my transfer case...yet there was nothing wrong before I handed it off to them.
Also told the shims are at their max and the next step is to re weld the spring pirches to get better angle.
I’m at a loss. Is it SYE, transfer case, spring shims & pirches, or did the ring and pinion get set up wrong. Still can’t get an answer from them.
I Need to take it back to get sorted out or it’s all a waste.
I’d like to get some feedback from everyone on possibly what the problem is.
I’d like to trust this shop to do right.... and I’d like to learn more
Any help would be appreciated.

Thernlund

Driving it with a bad drive shaft shaft angle might have fried a bearing. In my limited experience, whirring sounds like you describe are typically bearings.

Did they change the pinion bearings when they did the ring and pinion? Are the universal joints new? (EDIT: If you did an SYE and new shaft, yeah, the U-joints are probably new. Might want to check them anyway.)

Try taking out the rear shaft and drive around in 4H (basically front wheel drive) and see if you still hear the sound. With the rear shaft still out, put it back in 2H and go through the gears sitting still and check for sounds.


-T.

4.3L XJ

It would help to know where the noise is coming from ie front middle or rear. You had a lot of work done on it and they have been into the transfer case and rear end. However that being said, first place I would look for that noise is the rear end gear install

ninewon

My hunch is poor ring and pinion build. The angle was wrong to start and they did some hot runs. My guess is about 90 miles of them. I hear the noise from the rear end. They are saying it’s migrating the driveline from the transfer case. I had no problems with it before they did the work. I did not mention in first post it got a HD Adams CV driveshaft.

ninewon

I plan on borrowing a infrared heat gun from a friend tomorrow and see what is cooking after 10 miles. That’s about as far as I can drive it before it gets so loud I fear I might seize something.

4.3L XJ

When you do that bear in mind that tcases and diffs get really warm. Warm enough you cannot hold your hand on them as a normal course of operation. No coolers to compensate

Transpoquick

That would be my suggestion.

You could drain your t-case and inspect the fluid, it should be clean. Gear fluid is probably dirty being a new gear set the r&p are wearing in.

The shop you brought it to was suppose to drive it for 15 to 20 miles then park it and let the differentials cool. Fluid in the diff should be changed after 500mi.

Also, there should not be any hard acceleration for the first 100 miles. So if they were doing "hot runs" in your jeep after the gears we're installed that could be a problem.

Post a picture of the rear driveshaft angle(I'm curious to see). As mentioned removing driveshafts is another way to isolate the issue.

From what your saying sounds like a r&p problem, but the sye install is easy to mess up when it's installed with the t-case in the vehicle.

That's a lot of work to do all at once though, hope ya' get it figured out soon.

Daniel_jeep

i've got a 99 myself i will be dropping off at a shop next week to install a 3.5" rubicon express lift, hopefully i don't run into any issues and the install goes smooth. hopefully they will make it right for you. shop around here quoted $1300 OTD for lift & install. may be easier tracking down the noise if you set it on jack stands and spin the tires, least from my previous experience.

Transpoquick

That's probably debateable.

I would think op will not get enough heat into anything in a ten mile drive to make a good judgement call.

That's probably debateable too though.

Transpoquick

Putting it on Jack's an excellent suggestion to!

If it's that loud, maybe op can hear something crunching.

ninewon

I’m guessing this is the correct angle of the pinion with double cardan driveline.
Not the standard 4 degree shim they first installed.
http://www.upload.ee/image/4499278/05.gif

ninewon

I’ll go take a photo and see if I’m allowed to upload it.

ninewon

Transpoquick

Somebody will have to chime in on that, I just figured out how to do that myself.

Pictures are always a huge help.

Transpoquick

That was quick!

Doesn't look to bad, maybe a little low.

Tom Woods driveshaft suggests straight to 1.5 degree down with a sye and double cardan.

That looks "ok" though.

Imo.