Front D30 Detroit Locker Noise Help

[Cburb88XJ]

So i did axle swaps and the front seems noisy. History on axle i bought it from somebody who said the axles fullcase detroit locker, 4.56 spicer gears and everything had i think 12k miles on it. He ran it daily and wheeled some.

Just to include everything i know,96 D30HP, its detroit fullcase, 4.56 spicers, stock shafts with brand new 760s, like new wj swap parts,1 ton otk brand new, trussed, outer c gussets, lower c gussets, LCA skids, timken unit bearings, brand new spicer upper balljoints, brand new moog lowers, brand new control arm bushings everywhere, 1 inch centric wheel spacers and im running 35 MTR kevlars.

Ok so when driving as soon as i get to maybe 20 mph i start hearing a rolling clunking clicking sound, and it honestly seems like the sound doesnt go away, i cant really tell if its still making noise at higher speeds because of tire noise and whatnot but i think it is still making the noise. doesnt really seem that loud in turns either just going straight, the axle does lock fine going offroad. Axle has new synthetic 95 140 oil i believe and after driving a few miles i stopped to feel the tubes and the diff, the tubes werent warm and the diff itself was only slightly warm nothing bad at all, so ima kinda clueless sorry for the novel just looking for help thanks.

 

[Cburb88XJ]

Bump, anything? Long story short: d30 Detroit front locker making rolling metal noise going down road. Lol

 

[RoyalXJ]

Pull the cover and check the bolts that hold the diff together. For some reason the bolts on the detroits have a tendency to back themselves out.

 

[Cburb88XJ]

 

[Cburb88XJ]

So I jacked jeep up all wheels off ground. Spun front wheels by hand and no noise at all and spun freely. Then put in 4wd 3rd gear idle about 20mph and I could hear the noise just not as loud as on road obviously. I used a piece of wood to hold up to my ear trying to pinpoint noise and it definitely sounds like its from the diff.

Pulled the diff cover and oil didn't have any big chunks or particles just a very fine metal flake in it here and there probably normal specially with axle going in service for first in a lil while. Spun everything over and didn't see damage or anything. Then checked all the 5/8 and 11/16 bolts inside and none was loose I had a wrench on them all. So now I'm clueless. Is this somehow normal? No idea.

 

[RoyalXJ]

How's ur pinion bearing

 

[blondejoncherokee]

pretty sure thats a true trac and not a full detroit. maybe one of the little helical gears inside the thing is fubar if it is?

 

[jonoabq]

If you are using a Truetrac do NOT use synthetic oil. Switch it to old fashioned dinosaur oil. Castrol, Mobile, Shell not Valvoline (per Eaton tech service). Running summer weight / extreme use 95/140 weight will help as well.

 

[Cburb88XJ]

Haven't really checked pinion bearing I will though. I was told it was Detroit fullcase. I know it locks both wheels in real well. And great.....I did use synthetic oil. I hope it's not a true trac.

 

[jeeperjohn]

Looks like a truetrac from the pics.

 

[Cburb88XJ]

Guess that explains why it doesnt ratchet, weird thing is it locks in really well doesnt act like a limited slip. What should i do next with this thing? Check pinion out? if it had excessive play would it cause the noise? strange it doesnt make any noise turning by hand. only when up to speed.

 

[blondejoncherokee]

Are you 100% it is actually the front diff, and not the tcase, rear diff, DS, wheel bearings, bushings, etc?

 

[RAPTORAZ]

If you are using a Truetrac do NOT use synthetic oil. Switch it to old fashioned dinosaur oil. Castrol, Mobile, Shell not Valvoline (per Eaton tech service). Running summer weight / extreme use 95/140 weight will help as well.

I have a TrueTrac in the rear 8.25" in mine. Been running full synthetic 75w90 for several years now.

 

[Cburb88XJ]

Are you 100% it is actually the front diff, and not the tcase, rear diff, DS, wheel bearings, bushings, etc?

I used a wooden piece to hold up to my ear and put it up to multiple parts and it's loudest when it's right on the front diff.

 

[jeeperjohn]

Check your pinion for up and down and in and out play. If there is any then that is likely your issue. I would also remove the carrier bearing caps and check that the truetrac is firmly preloaded into the case. If you can pull it out by hand then there is not enough preload on the carrier bearings.

 

[Cburb88XJ]

I believe my gears were setup wrong or something, either carrier or the pinion i guess. there isnt much play but the tracking on my ring gear is very deep...so i guess im going to get some shims and see if it can be setup right with my dads help, not sure what else to do.

 

[jeeperjohn]

I believe my gears were setup wrong or something, either carrier or the pinion i guess. there isnt much play but the tracking on my ring gear is very deep...so i guess im going to get some shims and see if it can be setup right with my dads help, not sure what else to do.

It is not likely the gears being a little deep is causing much noise if there are no signs of overheating on the ring gear or pinion. Did you run a pattern with gear marking compound? If so please post a pic.

 

[Cburb88XJ]

I havent ran a pattern yet but from the look of the ring it seems like its too deep, ill try to run a pattern, is there any place i could get the compound local or would something else work? graphite paint maybe? with the pinion bearing being fine and if the pinion being too deep wouldnt cause the noise then what else would? If the true trac was shot id figure it would cause alot more problems i believe once they are bad there isnt much you can do because of the worm gears inside them.

 

[Cburb88XJ]

Tried running a pattern, turning yoke in both directions.

 

[jeeperjohn]

Sorry for the late reply. Those gears are way too deep. I suggest taking out .008" from the pinion and see where that puts you. Hopefully there was no severe overheating of the ring and pinion. That first pic looks like the gears might have gotten too hot.