Diff rebuild by "pro" not going well

Piratetip

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Just scratching the surface man.

The fun is when 1 change or adjustment affects 3 others.
Have to really understand the relationship between everything to hit your targets correctly.

Landing a perfect gear mesh is my peak elation on a diff build.
Once that lands into place the rest becomes lock step.
 
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alcyon

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Remember when I said I was gonna leave pinion preload as it was? I lied. I figured since I need to wait for the shims to arrive and thats about 8 to 10 days away, I might as well work on the pinion preload again. I removed the carrier, and pinion, and resanded the spacer the 4th time, and got a reading of 0.7Nm (6 in.lb)(yellow arrow). Previously it was under 0.5Nm (4in.lb)(red arrow)
1662080410100.png
I am wondering if I should at least try to shoot for 1Nm or 8 in.lb or just under that since its semi used bearings.
 

Piratetip

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I would keep it where it is on used bearings.
You could edge it up a little with a breaker bar on the pinion nut if you like at the very last assembly.
Or leave it as is.

Edit: meant extension pipe on breaker bar.
 
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alcyon

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While waiting for the shims, i decide to inspect the spider gears:
1662342087797.png

There is a little up to down slop on the side gears, and I can slide the side shims . However, I do not detect any backlash on the side gears, even a tiny movement on one side gear moves the opposite side gear, even with one side gear lifted. Should I shim it a little tighter. Could this cause the clunking when shifting from N to D ?
Also, i had avery close look at the ring gear and noticed that two tooth are chipped right at the edge where the pinion does in to the housing. I think it is still usable , because with the weir eliminator set up properly, the pinion should not move anymore, which I think caused this chip.
1662423892418.png
 
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Piratetip

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Did you disassemble and do anything with the center carrier LSD unit?
Assembled you can't check spider gear backlash, only can do that when it's apart.
I would say no, that won't be any cause of the clunk noise.

You are correct the sloppy pinion / loss of crush sleeve preload probably was the cause of the chipped teeth.
The coast side of the pinion impacted way out at the Toe end of the ring gear teeth.

You should inspect the pinion for any dents / marks on the gear faces.
 
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alcyon

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Did you disassemble and do anything with the center carrier LSD unit?
Assembled you can't check spider gear backlash, only can do that when it's apart.
I would say no, that won't be any cause of the clunk noise.

You are correct the sloppy pinion / loss of crush sleeve preload probably was the cause of the chipped teeth.
The coast side of the pinion impacted way out at the Toe end of the ring gear teeth.

You should inspect the pinion for any dents / marks on the gear faces.
I have not disassemble the center part, but plan to have a look. So far it looks ok, the most I would tighten up is 0.1mm on each side. It is an open diff 4 pinion setup with 2 side gears. The spider gears look really good.
I just got news the carrier shims I ordered arrived at my home. I can start testing preload , backlash and pattern tomorrow.
Edit, I just opened the diff center. Everything looks good. decided to leave it alone.
1662598595385.png

Parts arrived :
1662599622247.png
 
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alcyon

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I just tried to get the best preload and backlash. Results :, I need to buy more shims.
1662706332605.png
It seems a total shim thickness of 5.73 , 5.76 and 5.79 is simply not enough preload.
5.82 is just ok, I wager that 5,85mm is the sweet spot, but at 5.82, the shim is very hard to knock in already. With a total of 5.82 I am just touching 1Nm, which means my bearing preload is 0.3Nm only, A bit under spec of 0.4Nm. Depending on the situation I might just stick with this preload instead of going for 5.85mm. Anyway, the backlash in 2 places are now 0.2 and 0.19mm. Just shy of the spec maximum of 0.18mm. Left Shim 2.73, right shim 3.09 total 5.82
So I need to buy a 2.76 and 2.79 . The 2.76 will put me in spec for sure, but better to also have the 2.79 just in case.
After I get my shims, time to try 2.76 L and 3.06 R, and 2.76 L and 3.09 R.

Then its off to check gear pattern. Hopefully I dont need to change the pinion head shim.
 
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alcyon

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Received my shims. I proceed to put the thickest shim of 2.79mm on the left, and 3mm on the right, which gives me a reasonable preload, that is tighter by 0.09mm than the original shim stack.
I measured backlash on 18 tooth randomly.
The tightest is 0.124mm and loosest is 0.175mm
The average is 0.1585mm
1663309947276.png

Then i marked the gear and with loading I got this gear pattern :
1663310017357.png
1663310062330.png
1663310138294.png
1663310214920.png
Not perfect, but the pinion tooth isnt touching the flank and the face, and also clear of the heel and the toe. The pinion seems a tad deep, but since the drive and coast are more or less close, can I wrap this up and install ? Test spin is also smooth, even and silent.
 
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Piratetip

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Looks like you are in good shape, backlash at the low end of the spec.
Good pattern on the gears.
Run it.

Slightly deep on the drive side ring is preferred anyway.
Nice work.
 
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alcyon

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Looks like you are in good shape, backlash at the low end of the spec.
Good pattern on the gears.
Run it.

Slightly deep on the drive side ring is preferred anyway.
Nice work.
Thanks piratetip. I brought the diff home already and preparing to install tomorrow, its like 5 weeks already. I have not changed the side gear flange clips. I tried using a normal circlip plier but it seems its not opening large enough to open up the clip. Is there another tool to remove this clip ? Also I installed the front oil seal a tad deeper than 1.5mm from edge as per TSRM. I got mine roughly 2mm, is this ok?
 

Piratetip

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For those you would need large circlip pliers. They are very stiff.
99% of the diffs never need them replaced.
I think I've only ever encountered one or 2 with problems, otherwise fine to just re-use them.

A slightly deeper pinion seal is no problem, better this way to ride the lip seal on a new clean area of the pinion flange.
 
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alcyon

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After struggling the whole day installing the diff, i took it for a test drive. Looks like all my work is for nothing. The knocking sound (kluk kluk kluk) on decel is still there. The sound is loudest at lower speeds at 45 to 15kmh, worse when engine braking is in effect. I was thinking of putting it in N and roll it down a hill to hear if the coast sound is better or not.
There is still a slight hum on accel around 60kmh but otherwise it feels solid on acceleration. I am really stumped. I am gonna look around for a new ring and pinion , was thinking of getting SVL brand. I was thinking of buying this 4.56
I heard that the V6 pinion is the same as the mk3, long pinion head ?

For now I am not going to do anything, I am tired and fed up. My plan is to drive this car around a bit more at least 4 weekends, and then check the diff oil condition, if it is loaded with gunk again, and also check the pinion preload. If the preload has come loose, I will just replace the nut and tighen it a tad tighter and re test.
I was wondering what else could cause this kluk kluk kluk sound on decel.
Update. I just tested the car in N while coasting to a stop. The intensity of the knock remains the same. In conclusion its nothing to do with engine braking.any ideas ?
 
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Piratetip

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Don't think the diff is causing the noise you are referring to.
A worn diff transitioning from accel to decel will clunk once, as well as the other way.

Only thing that may cause a noise like this would be a physical damage to the ring/pinion.
One of your photos showed a chipped ring tooth on the coast side, but way our on the toe end.
Later you state after setup that the diff spins freely and smoothly.
You would have felt by hand an issue with the gear mesh.

You are hearing a constant klunk noise?

Have a recording?

I think it's something else in the driveline.

You should run it while the vehicle is up in the air on a lift.
Would be easy to pinpoint then.
 

alcyon

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Don't think the diff is causing the noise you are referring to.
A worn diff transitioning from accel to decel will clunk once, as well as the other way.

Only thing that may cause a noise like this would be a physical damage to the ring/pinion.
One of your photos showed a chipped ring tooth on the coast side, but way our on the toe end.
Later you state after setup that the diff spins freely and smoothly.
You would have felt by hand an issue with the gear mesh.

You are hearing a constant klunk noise?

Have a recording?

I think it's something else in the driveline.

You should run it while the vehicle is up in the air on a lift.
Would be easy to pinpoint then.
The clunk is not constant, its only on lower speed decel. Nothing on accel at all. I did not really test the diff much in opposite direction. I am stumped as to why it only happens on decel. I mean afaik if its u joint , cv axle or wheel bearings its supposed to make noise all the time it moves. I have a tiny camera that records sound too. I will try to find an attachement point. Then again there might small edge damage on the pinion that i simply missed. Will that truck pinion be a direct fit on the mk3 diff ?
 
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Piratetip

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It's is the same fitment yes. G series Toyota diff. Yes.

You checked the coast side gear mesh, should have felt an inconsistency there.
A bit strange, but there might be a mark on the pinion or ring somewhere.
 

alcyon

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It's is the same fitment yes. G series Toyota diff. Yes.

You checked the coast side gear mesh, should have felt an inconsistency there.
A bit strange, but there might be a mark on the pinion or ring somewhere.
On this coming weekend, I will detach the prop shaft and lift one wheel up, and spin that lifted wheel as fast as i can. this would forcefully turn the ring and pinion, like decelerating, lets see if that same sound is there, i will get it recorded. Also gonna try with the prop shaft attached but trans in N.
 

andrew_mx83

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Steer clear of SVL gears. "Dana aftermarket" = "Dana rejects"
Mine had machining errors, and burrs on the corners of the teeth causing inconsistent backlash from one to the next. Would not recommend.
 
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alcyon

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Steer clear of SVL gears. "Dana aftermarket" = "Dana rejects"
Mine had machining errors, and burrs on the corners of the teeth causing inconsistent backlash from one to the next. Would not recommend.
Thanks for the heads up. There is one more in Rock Auto. Is this ok ? or maybe I need to buy from somewhere else.
1663552046646.png

Edit, if I find that it is R & P, i might as well just buy OEM. I dont want waste my time again. Planning to find a way to put a drill to turn the side flange to mimic the coasting conditions.
 
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