Carrier Slop?

Hoo Boy... Lift Kits can bring all kinds of suprises, can't they?

I finished my RE 4.5" lift a month ago, and I'm still working on some driveline issues (1991 Sport, 4.0, 231J and Dana 35C rear). I have a "grumble" coming from the yoke, between power/coast phases, and I'm trying to milk out major changes until Santa brings me my SYE and new driveshaft.

Things were boring at work tonight due to the holiday coming up, so I brought the Jeep into the back garage door, and changed out my rear diff fluid, since I had no idea how many times it's been changed- two colors of RTV tell me it's seen attention twice, but the "other" discoveries scared the daylights out of me.

I've ALWAYS had a "clunk" when shifting between R thru D, and I've had 2 other XJ's that had 35's, and did the same thing- but I'm paying more attention to noises now, since I'm trying to iron out some minor vibes due to a low pinion angle out back. My 6 degreee shims should be here today, so I'm just biding my time with the vibes. That will all be behind me once Santa makes the trip from WAAAY up north...

Anyway, when I pulled the diff cover I decided to put the shifter in "N", and check on where I might be seeing some sloppy meshing. What I found was that I could turn the driveshaft about 1/2". Yes, the U-Joints are NEW, due to the lift/vibe thing... Damn, it AIN't the U-Joints!

So I'm watching the ring, pinion and carrier, and they're all moving about 1/4" as I rotate the DS. It looks like the backspacing was pretty tight at some point, because both gears have VERY "horizontal block" wear patterns- the heels and heads of the gears are unworn, and the worn spaces are really clean and centered on the matching face- but the entire carrier rotates 1/4" before anything grabs ahold of the axles and idlers-

Reading up on all the ring/pinion websites and the Dana site shows me I'm in the game for ring and pinion mesh wear, but it's the idlers and the driveshaft gears that scare me- they have the ENTIRE faces worn. I searched HERE, and swept the Dana site, with no success. There weren't ANY things in the troubleshooting section that came close to what I have going on. Any new noises? Sorry, it's hard to tell until I get the driveshaft to shut up so I can listen. I have a new set of 31 M/T's, and they've been keeping the cabin in a mild rumble/drone since they went on. I can say the "clunking" isn't any WORSE that it used to be- but I haven't had time to investigsate deper.

My Primary Question:
Does anyone know how much "slop" there should/can be in a rear 35 carrier?
IS there such a spec? Does it sound wierd that the ring/pinion are good, and the driveshaft/idler gears get chummed? What "adjustment" got missed in previous services?
It's not really a HUGE issue, since I'm re-gearing both ends to 4.56's as soon as the income tax thingie clears, but it's winter in New England, and I'm hopeful I can nurse this issue gently until Uncle Sam caughs up what I over-gave him this year.

ANYBODY with rear end issues, past or present who can educate me?
Any COLONOSCOPY's don't count, but I'll admit it involves your rear end...
I'm pretty sure my own rear end gets checked more often than my Jeep has had! NOT ANYMORE!

Thanks in advance, for whatever skooling a gear-guy can provide!

I have a "grumble" when I get off the gas an start to coast. I have a 27 spline 8.25 though. I think I might check mine because I haven't been able to pin it down yet. Oh well, just another excuse for some gears and a locker!!

Sorry I am no expert. I have issues with my 8.25 as well, but i know before i started messing with the axle gears and such. my front 30 had almost 3/4" of turn before anything moved on the carrier. rear had about the same. I put new gears in myself and boliched it up or somthing because it got worse. and now my rear end gets hot enough to steam when you spit on it... :repair:

My frist guess would be. If you are stock leave it and don't sweat it untill you start messing with them...
its probebly ok.

My 93 has the "grumble" and so doesn't my girlfreinds 94. I have also replaced the u-joints in both and it made it better but its still there. I am just carefull but i am interested in what is causing this. Oh both of ours have the 8.25 and 3 inches of lift (about mines a little more.) The noise was not present untill i lifted them. Oh and with those shims they might make the vibes worse. You want your transfercase and rear end so that they are parallel. I had shims and a t-case drop and had bad vibes. I took out the shims and its got very very small vibes. But its alot better. With you planning on replaceing these parts i would just drive it with the noise. Just my 2 cents.