Rear Diff/Pinion Squeal

Cmpugh7 · 2017-01-03T14:51:53+00:00

13 4runner Limited - rest in signature Installed ECGS front and rear diffs several months back. 4.56 gears and ARB Lockers - a few weeks after the install I noticed a metallic sound coming from the rear end, but only occurred after I had been running at highway speeds for 10-15 minutes. The metallic "brushing" sound turns to a high pitched squeal at less than 15 MPH First thought was brakes, but sound did not go away jamming on the brakes, or applying the parking brake. Checked dust shields etc, and had clearance. Next thought was U-Joints... at slow speed (<5mph) the squeal pulsed a bit. Jacked up the rear end, and put in drive, and the sound was definitely coming from that area... easy enough... replaced U-Joints. Sound was still there. Repeated jacking up the rear end, putting in drive... Thinking I'm an idiot, it's the pinion dust shield... bent it out a bit, and made sure there was sufficient clearance... Sound was still there. Jacked up rear yet again, and sprayed WD-40 behind the dust shield... sound quieted, and then went away. This was with a continuous spray of WD-40. It would stay away for 2-3 minutes, and then return. I spoke to ECGS. They said growling yes, squealing no... It can not be replicated on a bench, because it has to be hot... Gear oil level is good. With as many miles as I've put on it, if it was a "dry" bearing... it would have blown up by now, and there is no movement in the driveshaft or pinion. So... here is my question - I have rebuilt Land Rover thirds, but never had the pinion out of a Toyota... what's behind the dust shield? Is it possible dirt/debris is wedged between the pinion and the housing behind the shield? My U joint working angles are about as high as I feel comfortable with, 2 degrees. Is it possible the angles are causing the pinion to move a bit within the housing after it gets warm and is making contact? There is some very slight wobble in the drive shaft, but nothing I haven't seen before or what I would consider out of the ordinary. Any other thoughts? Sorry for the book.

Thread starter Cmpugh7
Start date Jan 3, 2017

Uni1brow

New member

Jun 25, 2019

mrfobbyaccent said:
I wouldn't blame the shop, since I've heard of this issue from multiple people after their re-gear and all these people went to different shops.

Although, it's not the shop's fault and more of a design flaw,I would still bring it back to the shop and let them try to resolve the squeak since they did touch it last. They should try to resolve the issue since you obviously brought it to them without the squeak.

Well I fixed the problem
I ripped that sucker out
Thanks again for the help guys