Hey guys,

Just wanted to get some clarification to see if these 4.77 gears are still good to be used. The gears originally came from a Kia and were not correctly installed on the s2000 differential. Pulled it apart and took some photos. Wanted to get some input on these, thanks.


This washer was installed in the wrong location so there was some play with the pinion gear when torqued with the companion flange nut. You can see where the bearing cage was just destroyed because it was rubbing on that washer. I know what parts to replace, I just want to make sure these gears are runnable. There is a VERY LITTLE amount of burr on the gears. The heel and toe look correct, the wear pattern is on point and the backlash was set correctly.

Let me know what you guys think, thanks for your input in advance!!

 

How do the pinion teeth look?
Post a picture.
The burr on the ring was caused by the main bearing.. right?
The contact on the ring looks ok - in the middle and all - but kinda at an angle - not paralel with the tooth.
I guess the pinion moving axial destroyed the seal too.
Lots of shavings on the magnetic drain plug?
Wash out the Torsen with petroleum/diesel!

 

Thanks Spitfire.

I don't have a picture of the pinion gear, but in all reality, the wear pattern looks similar to the OEM. Even the OEM pinion has a little burr on it and it's never been cracked open. I measured the backlash prior to uninstalling it and it was correct to what is recommended for the specs, but there was still a little play where the companion flange is (moving in and out).

The heel and toe look fine on the 4.77 gear (pics above).

There was actually not a lot of shavings on the magnetic plug. No more than my OEM and I never launched my car or anything so I know it couldn't have been abused. I'm not going to re-use this diff as I don't feel comfortable, so I'm just going to remove the gears from the diff and install the 4.77's on my own diff since I know it's all up to spec and has never been touched.

 

Are you saying the companion flange moved axial - on the splines - but the pinion itself didn't?
It is not clear to me.

The main spec is the shim under the main bearing, to set the pinion depth.
Backlash can be set, thats relatively easy.

Compare the thickness of the shim under the main bearing between the 2 diffs / housings.
It may give you an idea of the difference between housings.
Diff Master PuddyDad can tell you what the most used OEM shim is.
But you still need to check the pinion depth with your pinion & ring and be prepaired to switch shims if it is not right.

IMO this is one of the main problems with any gear install: the OEM shim may not be right for the new gear set.
But its "all there is" so in it goes.

 

With the companion flange installed and the locknut tightened, you could pull the companion flange in and out. It wasn't a large amount, but there was a space. Reason for that being, in the first picture, the bearings weren't pressed to where the crush sleeve is so when tightening the locknut, it wasn't locking into place because the pinion shaft (with the splines exposed) didn't have the bearings underneath pressed down. There was too much thread exposed and the nut hit the end of the thread with no room for tightening the nut hence the slack.

Also, in the image below, thrust washer (A) was installed UNDER the tapered roller bearing instead of on top (right after the companion flange oil seal. That's why in the first photo, the cage is trashed.



Hope that clarifies things a bit better.

 

[quote name='SpitfireS' timestamp='1317059955' post=


Compare the thickness of the shim under the main bearing between the 2 diffs / housings.
It may give you an idea of the difference between housings.
Diff Master PuddyDad can tell you what the most used OEM shim is.
But you still need to check the pinion depth with your pinion & ring and be prepaired to switch shims if it is not right.

IMO this is one of the main problems with any gear install: the OEM shim may not be right for the new gear set.
But its "all there is" so in it goes.


[/quote]


The reason the flange has play and the thread on the pinion has bottomed out is because of the miss-placement of the washer. Put the washer in it's proper location along with a replacement bearing and you should fix the issue of the play you have with the flange. As for the LSD/diff clean it out and check to see if you can turn it, if it turns free it is still good to use.
Good luck

 

Driving forwards, on the throttle, the pinion drives the ring and pushes it away, IOW pushes itself into the main bearing.
The load is on the main (big) pinion bearing.
A little play in the pinion bearings doesn't hurt.
But you have to keep driving forwards on the throttle.

Driving forwards, engine braking, the ring drives the pinion and pulls the ring towards itself.
The load is on the rear (small) pinion bearing.
It is pretty bad if the pinion can actually move towards the ring.
That is why you want 0 pinion play.

Installing this set in the old housing or another housing will make it noisy.
It will take more time to wear-in again.

 

Yeah I saw that, that's why the cage is toasted. Just wanted to make sure that these gears are still good to go. The LSD and such spins, but I did notice there is a slight scrape noise, either from the cage that's toasted or from the diff not having fluid. Going to use my stock diff to be safe

If it's good to re-use, it's going to be re-used haha.

 

Gears are being installed tomorrow. Just took apart my stock differential. Going to keep the other as a pumpkin or something. The LSD spins, but I feel more comfortable using mine since I know how it's been running. Looks like I'll have a stock LSD for sale haha.

 

Gear is installed, backlash is in spec after loading the bearings. After tightening the pinion nut, backlash remains corrected! Going to install the differential today.