front diff whine with tru trac?!

[drsus]

I did a search on this and could not find and answer on it.

My front Diff, which has a Tru-Trac, is making a whining noise that starts as a low pitch at about 15mph and gets higher pitch and a bit louder as speeds increase. B ythe time im doing 70mph (it happens...downhill and tail wind) it at a pitch that's just crazy... and my stereo is not loud enough yet.



I took it to a shop because just cant take that apart myself since i park my disco on the street. The shop tells me "you need new diff" i don't see how a whining noise would add up to me needing a whole new diff.... or does it?

I thought whining noises front diffs were either bearings or the R&P gears, im i off?

 

[DOHC Holliday]

If you grab the pinion flange can you move it up and down or in and out?

Could just be a bad bearing/loose pinion preload causing a weird contact pattern. Don't drive it for now.

 

[drsus]

nothing loose when i try moving things around... the truck is at the shop but the whinning noise had been hidden for... thousends of miles because it had these gigantor mud pit bull tires the truck had when i bought it that made tons of road noise. Only when i changed tires did i realize the whining was there. Its never gotten worse, its just there.

 

[DOHC Holliday]

Was the TT installed with the loud tires on there?

It really sucks you can't take it apart and look at the damage yourself. Another thing could be carrier bearing issues, but you'd need to have it apart.

 

[drsus]

the TT was on the truck when i bought it..with the tires.

I wish i could take apart myself... but besides the fact that my garage is full of other toys, the disco would never fit in there anyway.

 

[vanhorn2dallas]

this exact thing happened to me, a really annoying high pinch whinning noise, but only when I pressed the gas. I took my range to will tillery and had to get a front diff installed.

 

[p m]

are you sure it's not the LT230 whine?

 

[ajh]

Well, if they were over 33" tires Eaton tells you not to use them with a TT, at least if you're running stock ratio.

 

[marc olivares]

Nick,

yank that front diff, put it in a 5 gallon home depot bucket and send it to me. but before you do that, make sure that it's not coming from your transfer case like Peter is suggesting. lt230 are notorious for being whiny.
oh, i'm working on a solution for your shock issue.
i might have some lower mounts that will work with the 12's

 

[DOHC Holliday]

the TT was on the truck when i bought it..with the tires.

Damn, so this thing could have been like this forever. Are the gears the factory ones? If not, it's possible the diff was set up improperly.

Chances are the R+P have worn such an awkward contact pattern that they may never be quiet again, even if it's a bearing issue.

Try putting it on 4 jack stands and check it with the front shaft in and out. Harmonics love to travel from component to component.

 

[drsus]

I checked rear, tranny and transfer case.. just the rear u-joint needed replacement but everything else was ok. The front was the culprit for sure i just wasnt buying the "you need a whole new diff" comment from the shop...but now the tru trac is out and he looked at it closer, it does needs works, not sure that the whine was coming from it, but it was not in good shape at all. The whine most likely came from the bearing?! they are shot as well, so it was a combo of stuff. Im stuffing a stock unit in there for now.

the killer is that im not able to be there to look at the stuff with him since im out of town...nice huh?

The tires where 33", and running 4.11s so i think it was just set up wrong from the start because it the whine was there, just covered up by loud tire noise and the whine never got worse... i was just ready to stab my ears with pencils to make it stop so i took in to the shop.

and yeah the whine was most evident when on the gas.. off the gas it was kinda there, but gasing it really got it going good.

Marc, ill do that, ill stick in in a bucket and send it your way, see what you think. The shock issue has me stuck... the lower shock mount is all i could think of myself. I Didn't account for how much longer remote res shock bodies are compared to emulsion... or at least crapchos compared to Foxies

 

[ajh]

if the R&P are shot you'll have problems even with the stock diff, you'll want to do a dye check on impact shape to make sure it's lined up right.

 

[drsus]

Ive made it clear to him that i wanted him to go over all the component before re assembling.... hopefully he knows that means to check the R&P..

 

[rovercanus]

I don't see how a TT is going to cause a whine.
What was it that needed work on the TT?

 

[drsus]

well, thats my whole thing, when the shop told me the whine was due to the fact that i needed a new front diff i just couldnt see how that was. But supposedly the diff AND bearings were bad, that would cause a whine. But some here are telling me that a bad TTT also cause a whine so.....?!

he also threw in that he called around to see what rebuilding the TT would cost and was quoted $600+... that really didnt make any sense either, that why i told him to stick my spare stock front diff in til i get back and have a look at this TT.....well, have Marc take a look at it, i dont know a thing about TTs, hence this thread.

 

[nosivad_bor]

Id say its a combination of bearings and poorly installed R & P. I'd guess that the TT is still good. Marc will let you know fo shizzle.

 

[drsus]

That makes the most sense to me since the whine has been there for so long... you'd think if the TT went "bad" it would be a bit more serious that just a whine and it would def get worse every...minute!?

 

[Cadaver]

I would be careful stuffing a stock R&P diff into the front while running the 4.11s in the rear. I guess it would be ok for a while, but I would be worried about putting excessive strain on the transfer case. I suppose you could run without the front driveshaft. I had a similar whine with my truck and it was shot Ujoints in the front shaft.

 

[ajh]

A brand new TT is about that so that's nuts. Though I'll probably drop my TT eventually and go full locker in the front too. Depending on TC to be working with the amigos always waiting in the wings is a bit nerve wracking on hard trails.

 

[marc olivares]

just send me the 3rd nick, and we'll go from there