Differential carrier bearing end play - SMD

DanMD

Member
I am in the process of replacing all bearings in my SMD rear end. The way I read the manual, it says to remove all end play without binding for the carrier bearings. I used an indicator and have a side to side endplay reading of .001 and no drag. Next I installed the pinion gear shaft with the original shim pack and proceeded to set the backlash to .008 to .012 by moving the carrier bearing shims to one side or the other and ended up with .010 to .012 measured across 4 spots on the ring gear.

My question/concern is, why does the drag on the ring gear increase when I finish tightening up the pinion housing if I have endplay of .001 and backlash between the pinion and ring gear of .010 to .012?

I've never done this before, so it is all new to me, but seems straight forward.

Thanks,
Dan
 
what is your original backlash before removal?you say you are replacing only the brgs. so ? all shims had to kept in order . the backlash should have been checked and recorded so it can be set back to original reading. you want the same gear pattern as it was running before removal. changing pattern causes a gear howl .you might be causing a preload on pinion brg when tightening the cage. ball brg. does not need a preload just zero end play.
 
One side is set for the backlash and the other side set to get .010 to .020 side to side play. As the other poster said if installing the same parts back and nothing was damaged it's a good idea to check backlash before removing and set back the same unless way off.
 
(quoted from post at 22:45:49 02/18/19) One side is set for the backlash and the other side set to get .010 to .020 side to side play. As the other poster said if installing the same parts back and nothing was damaged it's a good idea to check backlash before removing and set back the same unless way off.
Where did you get the.010 to .020:spec? Both manuals I looked at said remove end play with no binding.
 
I think the .010 to .020 is in later books, not matter, just don't want side pressure. I will add, if your old bearings are quite loose, even with same shims on pinion you will be getting a deeper tooth pattern and it will be noisy.

Even if the old ones have a lot of back lash, I go for setting them back to close to same, unless bearing is busted up, then it is anybody's guess.
 
M service manual and service manual for a SM says .008 to .012. For some reason .010 to .020 started being given later on.
 
(quoted from post at 02:33:36 02/19/19) M service manual and service manual for a SM says .008 to .012. For some reason .010 to .020 started being given later on.
My manual says .008 to .012 for ring to pinion backlash. It says zero end play for the differential carrier side to side. Are you saying .010 to .020 for the diff carrier side to side end play?
 
Yes mixed numbers. Manual printed in the sixties gives .010 to .020 for side to side differential movement with ball bearings. Right side is shimmed for backlash and left for side play. 0 to .001 would be kind of tight if heat affected settings.
 
Thanks for all of the good information guys. I am new to this kind of work and unfortunately did not measure backlash when I took this apart. But I do know all of the shims were on the right side and there was so much carrier slop that I could move it side to side at least 1/16". It was extremely loose looking. I currently have the side to side play at .007 and still have an extra .010 and .015 shim I didn't use.
 
I was in your situation about a year ago I replaced all my
bearings in a M transmission. I took everyone?s advice and put
my shims back in the same location as before I measured my
backlash it was on the loose end of things at like .018 I did a
wear pattern test with some grease and it seemed to be very
close to how to the pattern was before. It worked for me and
have very little howl in the transmission.
 
you need to find out what the shims are that you have installed already. then remove shim or shims to get to 0 end play. then once that is done you go ahead and adjust the backlash. this is where you transfer the shims from side to side , and do not remove any.
 
(quoted from post at 01:31:44 02/19/19) I think the .010 to .020 is in later books, not matter, just don't want side pressure. I will add, if your old bearings are quite loose, even with same shims on pinion you will be getting a deeper tooth pattern and it will be noisy.

Even if the old ones have a lot of back lash, I go for setting them back to close to same, unless bearing is busted up, then it is anybody's guess.

How loose is acceptable without hurting anything for the backlash? It appears mine was worked on at one point as all the shims were on the right side and there was a lot of backlash.
 
https://www.yesterdaystractors.com/cgi-bin/viewit.cgi?
bd=farmall&th=904691
Try this post it was helpful to me when I re did mine
 
(quoted from post at 20:48:47 02/20/19) https://www.yesterdaystractors.com/cgi-bin/viewit.cgi?
bd=farmall&th=904691
Try this post it was helpful to me when I re did mine

Not to be a dummy, but how do i view the thread?
 
(quoted from post at 19:06:11 02/20/19)
(quoted from post at 20:48:47 02/20/19) https://www.yesterdaystractors.com/cgi-bin/viewit.cgi?
bd=farmall&th=904691
Try this post it was helpful to me when I re did mine

Not to be a dummy, but how do i view the thread?

Highlight it (hold down left mouse button, then drag across). Then right click on what you highlighted. select open in new tab.
 
(quoted from post at 04:01:05 02/21/19)
(quoted from post at 19:06:11 02/20/19)
(quoted from post at 20:48:47 02/20/19) https://www.yesterdaystractors.com/cgi-bin/viewit.cgi?
bd=farmall&th=904691
Try this post it was helpful to me when I re did mine

Not to be a dummy, but how do i view the thread?

Highlight it (hold down left mouse button, then drag across). Then right click on what you highlighted. select open in new tab.

I tried that and get this:
Ooops! We cannot find the page you are looking for.
Click Here to return to the forums.
 
Ok guys, I am looking for advice for a novice. I unfortunately did not pay attention to shim placement when I took everything apart because I didn't know any better. I saw how much side to side play I had and figured I'd just set everything up to the specs in the book. Now I realize I made a big mistake since I am reusing used gears.

Going forward, I am reusing the same pinion and bevel gears with new bearings. I am going to make sure I reinstall all of the pinion shims. I removed one .010 shim for the side to side end play to end up with a .015 end play value. Sadly, I have no idea what the backlash was originally, so I need to figure this out. I currently have .028 backlash and am going to check my gear pattern tomorrow for a starting point.
 
(quoted from post at 02:10:23 02/24/19) Ok guys, I am looking for advice for a novice. I unfortunately did not pay attention to shim placement when I took everything apart because I didn't know any better. I saw how much side to side play I had and figured I'd just set everything up to the specs in the book. Now I realize I made a big mistake since I am reusing used gears.

Going forward, I am reusing the same pinion and bevel gears with new bearings. I am going to make sure I reinstall all of the pinion shims. I removed one .010 shim for the side to side end play to end up with a .015 end play value. Sadly, I have no idea what the backlash was originally, so I need to figure this out. I currently have .028 backlash and am going to check my gear pattern tomorrow for a starting point.

Correct me if I am wrong. I am thinking worst case scenario, if it howls after I get it all back together. I can start moving shims as needed to start increasing backlash without having to split the tractor and remove the top cover. I am thinking I could do it just by removing one diff carrier at a time and add the smallest increment of backlash as shims allow until the noise subsides.
 
How does this look? Currently at .028 backlash. I think it looks good but think I should try it tighter.
mvphoto31945.jpg


mvphoto31946.jpg


mvphoto31947.jpg


mvphoto31948.jpg
 

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