4.11 gears

[DiscoveryXD]

I put in 4.11's, ARB air lockers, and axles from GBR. I had a whining noise in the rear that got worse as the months went by and the whole time I was replacing things trying to figure it out. I've replaced the hub bearings, rear output bearing on the t-case, new Tom woods driveline, and then I sent the new diff back to GBR to be rebuilt. It checked out ok, so I put it back in and it still sounded horrible. (loud whining noise with a clanking sound when you float the drivetrain at neutral throttle) So now I have a whole NEW diff in and it's not nearly as loud, but there's still a clanking noise when i'm at neutral throttle. It sounds like something is loose.

I'm going crazy trying to figure this out.... I've tightend EVERYTHING, I replaced the back body mounts, taken off my rear bumper, sat under the truck banging on it with a rubber mallet trying to produce any loose or vibration noises. It has to be something with the drivetrain since it only appears at neutral throttle.

What else can I do? I'm running 75 W90 mobil 1. Should I put in a different weight oil or go away from synthetic?

I have never hated my truck more than I do right now. I have missed every 4 wheeling or fishing trip I wanted to go on this whole summer because of it, and school starts next week.

 

[msggunny]

Who set up the gears? Sounds like the R&P werent set up properly.

 

[robertf]

are you sure its the axle? Transfercases make that noise too


clunking is from too much backlash when setting up gears. Whining is from incorrect pinion depth. I think all of the specs are in the rave manual. Checking backlash is pretty easy once you get a dial indicator and base. If the backlash is out of range it is possible that correcting that will also correct the pinion depth. Unlikely, but possible.

 

[DiscoveryXD]

Who set up the gears? Sounds like the R&P werent set up properly.

GBR. I sent the first diff back to Bill and he said it checked out OK. I put it back in and still had the loud whining noise with the clank at neutral throttle. He then sent me a whole new diff, which sounds a lot better, but still has the clank at neutral throttle. He's been very helpful trying to figure this out with me and I'm thankful, but I just don't know what to do anymore....

 

[DiscoveryXD]

are you sure its the axle? Transfercases make that noise too


clunking is from too much backlash when setting up gears. Whining is from incorrect pinion depth. I think all of the specs are in the rave manual. Checking backlash is pretty easy once you get a dial indicator and base. If the backlash is out of range it is possible that correcting that will also correct the pinion depth. Unlikely, but possible.

I've actually had someone drive the truck while I sat in the back with my ear to the floor. It's definitly coming from the passenger side rear around the diff.

I'm actually thinking about taking a large section of garden hose and securing it under the truck pointing at the diff, then having some drive the truck while i sit in the back with the end of the hose near my ear. That's helped me find exhaust leaks before since the noise travels well through the hose. It's worht a shot since I've done everything I can think of....

 

[OFFROVER]

Dont want to start the debate on syn vs dino oil but for the price of some 90w oil I'd try swapping back to nonsynthetic in diffs and t-case.

~Corey

 

[GregH]

Re: Clank

Have you checked your DS U-joints? What is your pinion angle?

Have you checked your trailing arm bushings?

 

[DiscoveryXD]

I have a new driveshaft so that can't be it. The bushings are new too... I need to check the pinion, but haven't since nothing has changed as far as that goes.

 

[MUSKYMAN]

the pinion bearings are the likely culprit it the gears look ok.

if they were whining they would show some gauling from a incorrect pattern

 

[bmn1965]

X2 on the dino oil.

 

[flyfisher11]

Dont want to start the debate on syn vs dino oil but for the price of some 90w oil I'd try swapping back to nonsynthetic in diffs and t-case.

~Corey

Right on Corey. If you read the info from Eaton themselves they say to use Dino. That is the only place I use Dino, the diffs.

Cheers,

Mike

 

[marc olivares]

sorry folks...the oil wont make it whine.
bearings will

 

[flyfisher11]

sorry folks...the oil wont make it whine.
bearings will

Then why does Eaton say use Dino? Oil will have an affect on bearings.

 

[marc olivares]

cause some eaton locking carriers dont like synthetic oil
has nothing to do with the gear set or bearings
sounds like a bad pinion bearing to me
could be carrier, hard to tell on the webbernet
pinion bearing noise increase/decrease with speed, carriers are typically all the time
just because the third is "fresh" from GBR, does not mean that at some point shit got into the pinion bearing.
just it throwing out there...

 

[flyfisher11]

cause some eaton locking carriers dont like synthetic oil
has nothing to do with the gear set or bearings

I'll just have to agree to disagree with you on this one. I am basing my experience with Eaton products and Matt does have ARB's which I don't know shit about. It wouldn't hurt for Matt to call ARB and see if they have any technical insight.

Cheers,

Mike

 

[marc olivares]

I'll just have to agree to disagree with you on this one.Mike

Huh, mike, you never struck me as the type that like to be wrong...lol

 

[flyfisher11]

Huh, mike, you never struck me as the type that like to be wrong...lol

Who me????
:smilelol:

 

[D Chapman]

Is this a "pegged diff" from GBR? Could the peg be dragging the ring gear?

If not x2 on the pinion bearing.

 

[DiscoveryXD]

Well I'm gonna call Bill tomorrow...

what's "pegged" mean?

I found it kinda weird that this diff actually looked a lot different than the first one. The bearing caps look different. They just have little pins instead of the "fingers" like the 1st diff and the copper air line for the locker goes around the ring gear (which was a bitch to get in the axle without pushing it down on the gear)

I don't know if any of this matters, I just thought it was weird for them to look so different....

 

[GregH]

I have a new driveshaft so that can't be it. The bushings are new too... I need to check the pinion, but haven't since nothing has changed as far as that goes.

Check your pinion angle. I don't know what lift you are running but if your pinion angle is too high you may be running your pinion bearings without lube.

Double check your trailing arm nuts/bolts for tightness (since bushings are new).

Type of lube (dino/syn) is not the problem. Lack of lube may be.