Rear Diff/Pinion Squeal

[Cmpugh7]

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.

 

[BigredTEX]

I have never rebuilt a Toyota dif, but I would definitely want to do an internal inspection. The rear pumpkin comes out relatively easily which will allow a close inspection on the bench. I agree that a gear or bearing problem usually shows up as a growl rather than a squeal, but you can spin the pinion by hand on the bench to check for any rough movement.

 

[Cmpugh7]

I have never rebuilt a Toyota dif, but I would definitely want to do an internal inspection. The rear pumpkin comes out relatively easily which will allow a close inspection on the bench. I agree that a gear or bearing problem usually shows up as a growl rather than a squeal, but you can spin the pinion by hand on the bench to check for any rough movement.

I had thought about pulling it, but everything is silky smooth underneath when cool. And the WD-40 quieting it down when spraying behind the dust shield really throws me off.

 

[1engineer]

The only time I have ever heard a gear set or pinion (or even a sun gear) squeal is when there is slippage. Gears grind, bearings growl usually. I would remove it for a visual inspection and measurement.

 

[Engineer]

I agree with the above assuming you have called ECGS directly and discussed with them. If its something related to their work* you may shoot yourself in the foot with follow up warranty etc.


*Unlikely but its possible, I have heard nothing but good things about them and when/if I go with 4.56s I plan to order with them.

Related note, aside from the noise how do like the new ratio?

 

[(none)]

Related note, aside from the noise how do like the new ratio?

THIS is the important question.

Also, don't tacomas come wth 4.11s? Are their diffs compatible with ours?

 

[Cmpugh7]

I agree with the above assuming you have called ECGS directly and discussed with them. If its something related to their work* you may shoot yourself in the foot with follow up warranty etc.


*Unlikely but its possible, I have heard nothing but good things about them and when/if I go with 4.56s I plan to order with them.

Related note, aside from the noise how do like the new ratio?

I did talk to them, and they don't want me tearing in to it for obvious reasons... so it would require sending it back to them, and if they find a problem, they will fix it and ship back free of charge... otherwise I pay the freight.

The gears have been the best mod by far... I was gear searching like crazy on the interstate prior to getting them. Well worth the money IMO.

Their service is great, and all of the techs are knowledgeable.

I am still struggling with pulling the diff for this metallic noise... it just doesn't make sense given my WD-40 test. If it was internal, the WD-40 would have had no effect. I'm going to try a few other things this week. I'll pull it last resort...

 

[BigredTEX]

I did talk to them, and they don't want me tearing in to it for obvious reasons... so it would require sending it back to them, and if they find a problem, they will fix it and ship back free of charge... otherwise I pay the freight.

The gears have been the best mod by far... I was gear searching like crazy on the interstate prior to getting them. Well worth the money IMO.

Their service is great, and all of the techs are knowledgeable.

I am still struggling with pulling the diff for this metallic noise... it just doesn't make sense given my WD-40 test. If it was internal, the WD-40 would have had no effect. I'm going to try a few other things this week. I'll pull it last resort...

Not suggesting that you tear into the dif, but just remove the 3rd member, which is completely self contained, to inspect. You would not be altering any of their work.

Who installed their 3rd member into your axle housing?

 

[Vinsil]

I've re geared Toyota thirds a few time. I'm no expert at all but a few questions.


Did they use a solid pinion spacer or a factory "crush sleeve?" The sound your describing doesn't make sense, and behind the dust cover is a seal. My theory is if they used a crush sleeve which honestly, they should not, and it didn't get torqued properly to crush the sleeve (this produces the proper amount of tension on the pinion bearing and the seal isn't quite seated fully, it could be rubbing that dust shield making a odd noise. You might not be able to see this until you pull things apart...and I wouldn't as you void your warranty.

You mentioned ARB's. The next thing might be the tubing route could be making an odd harmonic sound but that doesn't explain the lubing you did to make it go away. Improper routing of the copper line could produce odd noises. I'd look for copper color in the diff fluid.

If you have rover thirds before, Toyota thirds will be as simple as can be. The crush sleeve is the only "oddity" in them and should be replaced with solid spacers when gearing and upgrading them anyway.

Good luck!

 

[Cmpugh7]

I've re geared Toyota thirds a few time. I'm no expert at all but a few questions.


Did they use a solid pinion spacer or a factory "crush sleeve?" The sound your describing doesn't make sense, and behind the dust cover is a seal. My theory is if they used a crush sleeve which honestly, they should not, and it didn't get torqued properly to crush the sleeve (this produces the proper amount of tension on the pinion bearing and the seal isn't quite seated fully, it could be rubbing that dust shield making a odd noise. You might not be able to see this until you pull things apart...and I wouldn't as you void your warranty.

You mentioned ARB's. The next thing might be the tubing route could be making an odd harmonic sound but that doesn't explain the lubing you did to make it go away. Improper routing of the copper line could produce odd noises. I'd look for copper color in the diff fluid.

If you have rover thirds before, Toyota thirds will be as simple as can be. The crush sleeve is the only "oddity" in them and should be replaced with solid spacers when gearing and upgrading them anyway.

Good luck!

Didn't give me the option for solid spacer in the rear... just the front, and since it's a limited w/ all time 4wd it's moot... At least what I gathered from talking to them.

Oil was changed less than 1000 miles ago and no odd coloring.

Not suggesting that you tear into the dif, but just remove the 3rd member, which is completely self contained, to inspect. You would not be altering any of their work.

Who installed their 3rd member into your axle housing?

I installed it... Pulling it this weekend (hopefully) for inspection.

 

[Cmpugh7]

Posting a conclusion... it ended up being the seal rubbing on the pinion dust shield. Apparently they all make minimal contact with the dust shield because they have large lips. I pulled the shield back as far as it would go, and sprayed the seal with some cleaner and white lithium grease. Been 2k miles now with no return of the squeal.


Sent from my iPad using Tapatalk

 

[(none)]

Posting a conclusion... it ended up being the seal rubbing on the pinion dust shield. Apparently they all make minimal contact with the dust shield because they have large lips. I pulled the shield back as far as it would go, and sprayed the seal with some cleaner and white lithium grease. Been 2k miles now with no return of the squeal.


Sent from my iPad using Tapatalk

Glad to hear that's all it was.

 

[Uni1brow]

Same issue I'm having on 5th gen

Did you have to remove the whole housing or just the driveshaft

 

[Uni1brow]

Same issue I'm having on 5th gen

Did you have to remove the whole housing or just the driveshaft

 

[Jetboy]

Did you have to remove the whole housing or just the driveshaft

In order to spray the grease inside the dust shield you do not have to remove either the housing or the drive shaft. The description I believe he was saying was to spray inside the dust shield by prying it just a little bit. To remove the dust shield requires removing the pinion nut. If you do that you will have to remove the entire differential because once you loosen the pinion nut the preload on the crush sleeve is ruined. So you will have to disassemble the differential and install a new crush sleeve as well as a new seal.

 

[Uni1brow]

Thanks for the info

I just had everything installed by a shop but I didnt purchase the parts from them they did everything by the book according to them,
They said exactly what was said here
The cover hitting the seal or diff cover
It didnt make noise for 1st 75 miles after install
But once it hit 100 started making what I think is the noise you're having

Are they to blame for this

 

[mrfobbyaccent]

Thanks for the info

I just had everything installed by a shop but I didnt purchase the parts from them they did everything by the book according to them,
They said exactly what was said here
The cover hitting the seal or diff cover
It didnt make noise for 1st 75 miles after install
But once it hit 100 started making what I think is the noise you're having

Are they to blame for this

I wouldn't say the shop is to blame for this. I had the same issue as you after my re-gear. The first 75 miles were good but then I started to hear the squeak. At first I was scared it was something internal, but the shop re-assured me it was not during my 500 mile maintenance.

I know one of the ways on fixing it is by replacing the pinion seal, but they simply bent the shield out of the way on my truck and now the noise is gone, but I do hear a click once in a while when I turn, and I'm sure it's that shield. All in all, i just live with it since I've put 3K miles on it with no leaks or issues. I rather live with a small clicking noise then tear it open again and run into issues.

 

[nb rob]

I'm having this exact squeal, unaffected by braking, and it occurs after 10-15 mins on the highway. I recently had a leak at the third member and had a new gasket applied by toyota. I had them go ahead and replace the rear brake pads at the same time, so I've been going nuts trying to chase down this squeal. It took about 150km to show up, in the conditions exactly as described by the OP

the thread is 2 years old, but thank you [MENTION=136823]Cmpugh7[/MENTION] for the excellent description, and follow up.

 

[Uni1brow]

I wouldn't say the shop is to blame for this. I had the same issue as you after my re-gear. The first 75 miles were good but then I started to hear the squeak. At first I was scared it was something internal, but the shop re-assured me it was not during my 500 mile maintenance.

I know one of the ways on fixing it is by replacing the pinion seal, but they simply bent the shield out of the way on my truck and now the noise is gone, but I do hear a click once in a while when I turn, and I'm sure it's that shield. All in all, i just live with it since I've put 3K miles on it with no leaks or issues. I rather live with a small clicking noise then tear it open again and run into issues.

Thanks for the reply guess I'll get under there and bend that shield

 

[mrfobbyaccent]

Thanks for the reply guess I'll get under there and bend that shield

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.