Quaife LSD Installation in R180 - With Questions About Installation Also

[inline6]

I have a magnetized base and dial gauge.  I attach the magnet and arms and gauge on the back of the differential to the surface that the  rear cover bolts to.  I get the arms situated so that the dial gauge pin is vertical with and sitting on a ring gear tooth.  Moving the carrier one way, then the other by hand, you can measure the amount of free play, which is the backlash.

[Patcon]

So you checking sounds correct. Just make sure your indicator is set at the very outside and tangential to the ring.

So, from the sound of post #70 you changed two things at once and you are currently focusing on the shims at the front of the case?

I had a thought, so I did some research to see if I was on the right track. I have never done a differential, so I wasn't confident in my thought process.

I thought you need to set the depth of the pinion in the case and then adjust for backlash. I forgot about preload. That would be second. So it's my understanding that the shims at the front will mainly change patterning. While this will affect backlash, that's not the main purpose.

The side shims are used to adjust backlash. Move the ring closer for less backlash further away for more.

Here are some things I found. Take all of these with a grain of salt because alot of these are solid axles but most of the info aught to transpose.

https://www.randysworldwide.com/blogs/gear-backlash

https://www.yukongear.com/blogs/12-tech-tips-for-differential-assembly-setup_1

One of the main things I took away from this thread, was if you move the wear pattern, it can "sing".

https://www.garagejournal.com/forum/threads/adjusting-an-old-ring-and-pinion.447201/

So I would try to keep the wear pattern as close to the original as possible. I believe as the lash goes down the heel/toe drive/coast patches will move towards the center of the tooth.

Did that make sense?

 

Edited January 21 by Patcon

[inline6]

Thanks for the links.  I will check them out tomorrow, as I continue to think through everything, especially after my experimentation today. 

From my efforts today, I realized that moving the side shims changes back lash a lot.  My issue is, I can't get the backlash in spec just by moving the side shim(s) as the manual instructs.  

As assembled at the factory, this differential has one left side shim and two right side shims.  To reduce backlash, you move shims from the left to the right side.  Per the manual, you are not to change the overall thickness of the side shims.  Mine are: left = .3mm (0.0118") and right = one .4mm (0.0157") and one .5mm (0.0197"). 

With everything assembled with factory shims in all locations (including the .126" pinion shim), and pre-load on the pinion bearings set to specification, I had about .020" of back lash.  Moving my one left side shim to the right reduced back lash to about .014-.015".  With no other shims to shift to the right side, I first became aware of my problem - replacing the pinion bearings changed the pinion to crown relationship from the factory setup.  I went ahead with getting some pics of the wipe pattern on the coast and drive sides of the crown gear:

  

Contact appears to me to show heavy on toe (inboard edge of tooth) on coast (first pic), and heavy on heel (outboard edge of tooth) on drive (second pic).

Today, I put three shims (supposedly .001" each) in with the .126" pinion adjusting shim.  In theory, that moved the pinion .003" closer to the crown gear.  I moved the shim that was originally on the left side, back to the left side.  I measured backlash at about .018" to .019.  I went ahead with getting another set of pics of the wipe pattern on the coast and drive sides of the crown gear:

  

It looks to me like the contact on the coast side is close to the "correct" position.  However, on the drive side, it looks like the contact is still too much on the "heel".  After posting those pics earlier today, I went back out to the garage, and moved the left side shim to the right, and measured backlash.  It was about .010" to .011".  That was very interesting - it seemed like I had improved things overall by bringing the pinion gear about .003" closer to the crown gear. 

As a last iteration today, I cut some more shims.  I took the pinion out again, and stacked a total of eight .001" shims together with the .126" factory shim.  My thought was that perhaps moving the pinion .008" closer instead of .003", I'd be able to keep the one shim on the left. 

This time, when I got everything back together, when I torqued the pinion nut to the same 124-ish ft lbs, the amount of effort required to rotate the pinion was much higher than the times before.  I backed the nut off again and retorqued.  Same thing.  Somehow, the pinion turning torque has become excessive - it is difficult to turn by hand.  I am not sure what happened but I was using the same torque wrench that I had issues with on the front strut nut.  Anyway, I will attempt to sort that out tomorrow.  I see the torque spec in the differential manual that was uploaded to the resource section today is 101-123 ft lbs., while my factory service manual shows 122.9-144.6 ft lbs.  Dang it. 

Anyway, I measured backlash, again with the side shims back in their factory locations.  This time, I got about .014"-.015".  So, with the side shims in their factory locations, I appear to have progressed from about .20" with the .126" pinion shim, to .018"-.019" with the three .001" shims added, to .014-.015" with the eight .001" shims added.  And when moving the left shim to the right in combination also, I measured backlash at about .014-.015" with the .126" pinion shim, to about 010"-.011" with the three .001" shims added, and about .007"-.008" with the eight .001" shims added.

It took most of the day for me to work on this.  In conclusion, stacking a bunch of home made .001" shims in addition the existing factory shim which is between the rear pinion gear and the rear pinion gear bearing, does not change backlash a lot.  But it does change it.  By comparison, moving side flange shims has a larger effect on backlash.

Either tomorrow, or some day next week, I'll pick back up on this again.  It helped to write up all my observations, to get what I found out today on paper... so to speak.  I need to correct the bearing preload.  I hope I didn't damage a bearing.  I wouldn't think that is likely though.  I will back the torque setting down to about 100 and see if that puts the preload back in spec as tested by checking turning torque with the Quaife unit out of the case.  

If I can get that in spec again, I'll check the tooth contact pattern and see how it looks.  I am somewhat excited that I was able to get backlash within spec.  I think this is decent progress.

Edited January 22 by inline6

[Yarb]

True Determination, I personally thank you for passing this on to the forum. The effort you’re showing is impressive.

[Patcon]

So the shims your are changing on the pinion are #4 on this diagram?

The side shims are #9 & #18?

If so adding shims is going to reduce lash because the pinion gear is conical and as it moves further back in the case lash is going to go down, but that's going to move the contact pattern on the ring. I'm not sure that I would hold to this instruction about overall thickness. You've got a new center section and new bearings. It's possible that a minor manufacturing tolerance has changed the overall thickness needed. I would be passionate about keeping the original contact patch in the same place though.

11 hours ago, inline6 said:

Thanks for the links.  I will check them out tomorrow, as I continue to think through everything, especially after my experimentation today. 

From my efforts today, I realized that moving the side shims changes back lash a lot.  My issue is, I can't get the backlash in spec just by moving the side shim(s) as the manual instructs.  

As assembled at the factory, this differential has one left side shim and two right side shims.  To reduce backlash, you move shims from the left to the right side.  Per the manual, you are not to change the overall thickness of the side shims.  Mine are: left = .3mm (0.0118") and right = one .4mm (0.0157") and one .5mm (0.0197"). 

 

 

 

Edited January 21 by Patcon

[inline6]

Yes to the question about the pinion shims and washer (4 and 5) - this differential only had one pinion washer and no shims at that location.  I am stacking the .001" shims at item 4 location.  Oddly, the side retainer shims do not appear to be in that picture.  The side retainer shims can be seen in this picture.  

9 and 18 are probably in the stock carrier, which I am not using - I have replaced with the Quaife unit:

Note that I have not and will not be touching #30 in your picture.  Therefore, the "stack" of parts between the front and rear pinion bearings is staying the same.  I was able to achieve correct pinion bearing pre-load with about 124 ft lbs of torque on the pinion nut (a couple of times).  So, I am hopeful that none of those parts needs to be changed.

From your comments about getting the mating of the gears as close to what it was as possible or they may sing/make noise, I will make all the effort I can to make the wipe pattern ideal.  Too much back lash impacts the wipe pattern a lot.  So, getting the backlash back to .004" or .005" (what I measured before taking it apart from stock) is going to be a goal here.  

Another thought I had today: just as the pinion spacer has to change because of the new bearings, so it is possible that my side retainer shim "stack" may have to change.  The side retainer bearings also were replaced with new.  And, as such, they may have slightly different thicknesses from the ones that came out.  If so, that changes the preload on the side bearings.  

I don't have the factory tools, so I can't follow the procedures in the differential manual, but it has been quite helpful.  The next time I take the carrier and pinion gear out, I will assemble just the carrier portion to make some kind of assessment on the preload for the retainer bearings.

 

 

[inline6]

11 hours ago, Yarb said:

True Determination, I personally thank you for passing this on to the forum. The effort you’re showing is impressive.

Thank you for the compliment.  Even with all the Subaru diffs that interchange, the supply these R180 diffs seems to be more scarce as of late, and they seem to be much more expensive.  

Since I can't find info like this, I am attempting to capture as much as possible to help both myself and others if they find themselves in the same situation.  We shouldn't have to accept that pinion bearings can never be replaced. 

 

[inline6]

22 hours ago, Patcon said:

https://www.randysworldwide.com/blogs/gear-backlash
https://www.yukongear.com/blogs/12-tech-tips-for-differential-assembly-setup_1
https://www.garagejournal.com/forum/threads/adjusting-an-old-ring-and-pinion.447201/

So I would try to keep the wear pattern as close to the original as possible. I believe as the lash goes down the heel/toe drive/coast patches will move towards the center of the tooth.

Did that make sense?

 

I read these this morning and got some good info and reinforcement from them.  Thanks for sharing them.

I tried backing of the pinion nut and pressing the pinion shaft down a touch to unload the bearing before retorquing to 101... but the turning torque was still far too much.  Long story short, I discovered that I had damaged the "pilot bearing".  I had to remove the front seal (destroy in the process) and the pilot bearing.  When I ordered all of the diff parts, I ordered two sets of everything because I planned on rebuilding the stock differential as well.  I don't know if I will do that, but at least I had spares on hand.  

How I damaged the bearing is a bit hard to explain.  Basically, when you press the pinion shaft in place, if the pilot bearing is already installed, it tends to move a bit from its correct position.  Normally, the pilot bearing is installed after the pinion and pinion bearings.  It is a lighter press fit the than the pinion bearings.  But, since I was working a bit differently with the pilot bearing and pinion seal already installed, when I would press the pinion gear in place the pilot bearing would shift out of place a little.  The mistake was putting on the pinion nut and using the action of tightening the pinion nut to squeeze everything together... including shifting the pilot bearing back into place.  Once, or perhaps after a couple of times doing that, the pilot bearing got damaged.

Along the lines of getting the pinion to mesh with the crown gear has before, have a look at these pics - when I removed the pinion gear today, I noticed the yellow paint vs. the previous wear on the pinion gear:

  

Do you see how the yellow gear marking compound does not quite start at the same place as the old wear line in the above pictures?  And, in the below pictures, the yellow extends a bit past the wear marks (I rubbed it off partially so I could see the wear line).  

  

 

I find that to be very interesting. This seems to indicate that the pinion gear is still not extended out as far as it used to be to match the assembled location from the factory!

While the pinion gear was out, I installed the carrier and side flanges to check the pre-load on those bearings.  It has some... and it feels very similar to the pre-load on the pinion, before I damage the bearing.  I think the side shims are sized correctly, so I will not be messing with changes there.

My next step is to make 8 more shims and stack them with the first 8 and see how things look.  I put together this set of changes based on my experiments thus far.  I don't know if it is actually accurate, but it is based on what I have seen with my various changes.

shim thickness     backlash         movement
0.126                     .020-.021    
0.130                     .017-.018        3 to 4 thou
0.134                     .014-.015        3 to 4 thou
0.138                     .011-.012        3 to 4 thou
0.142                     .008-.009       3 to 4 thou
0.146                     .005-.006       3 to 4 thou

8 more shims should give me something close to the .142 thickness.  We'll see where that puts me. 

I will be shooting for .005" backlash as that is what it was before I took it apart.  
 

Edited January 22 by inline6

[inline6]

I happened across this 10 pack of .005" International FAK8492 Front King Pin Shim Set on eBay tonight.  And these in a .010" thickness on another site:

https://www.fleetrite.com/parts/front-axle/king-pin/fltkp8493-king-pin-shim-kit

Do these look promising?

The stock spacer/shim is nearly the same ID and has about a 2.13" OD  These are 1.39 ID and 2.24 OD:

Edited January 22 by inline6

[AK260]

So here is a question I’m wondering about. How do you centre the crown wheel onto the Quaife? I’m pretty certain the Quaife is machined to tighter tolerances, so while the 10 bolts centre the crown wheel, I can’t imagine tightening bolts alone does a perfect job.

And the other questions are: will it have material effect on the leashing with the pinion gear? If so, is it possible to measure / adjust any run-out when mounted into the case?

[inline6]

13 minutes ago, AK260 said:

So here is a question I’m wondering about. How do you centre the crown wheel onto the Quaife? I’m pretty certain the Quaife is machined to tighter tolerances, so while the 10 bolts centre the crown wheel, I can’t imagine tightening bolts alone does a perfect job.

And the other questions are: will it have material effect on the leashing with the pinion gear? If so, is it possible to measure / adjust any run-out when mounted into the case?

There is a spec for runout on the crown gear in the factory work shop manual.  Pretty easy for me to check.  Regarding the securing of the crown wheel, the bolts were very tight, meaning no slop when securing the crown wheel.  And the gear was a tight fit on the carrier as well.  I actually had it clocked a touch and couldn't spin it while on the carrier - I had to slide it back off and re-align and slide it back on to get the crown gear bolts to align.   

I will measure runout before long and post it here.

[AK260]

Excellent!  That’s great news and makes it easy.

A very capable buddy of mine is building mine and this is how far it’s got last night! Although we’re not touching the pinion.
 



I was thinking of building a jig for my R200, to hold the carrier assembly at the bearings in order to spin / test / adjust run-out. But it doesn’t sound like I need to. I’ll check with him to see if mine is as tight as yours.

Been stalking your progress with great interest - especially as someday I will likely buy the Kameari gear set and build into one of my spare diffs.

What is disappointing is that we need to shim 0.3mm and 0.26mm and in the UK you can find really thin 0.01mm up to 0.05mm shims, then 0.5mm and increments of 1mm but nothing in 0.05mm increments past 1mm. So we have to shop from the US. [emoji20] Or get some laser cut as the postage/import duty costs are silly!

Edited January 24 by AK260