8 3/4 ring and pinion setup opinions

[747mopar]

I just bought all the stuff to build my 489 pig and have been reading up to make it go as smooth as possible and wanted to pick your brains for pointers. I purchased a set of Richmond 4:30s, a Richmond rebuild kit and the crush sleeve eliminater. I remember I think it was Cranky mentioning honing a used set of pinion bearing to slide on and off the pinion shaft to aid in the setup so I will do that (good idea) but was hoping for some more tips. My manual is pretty useless seeing how it constantly refers to all of these special gauges and jigs but having done other rears I know it's not rocket science. The way I see it you get the pinion preload correct using the crush sleeve eliminater, start with original pinion spacer, set up the backlash and check contact pattern. From there it's just fudging the pinion shim around, resetting everything and checking the pattern until you got it?

 

[benno440]

no idea buddy, what locker or/ did you go with? a true trac??

 

[D575]

Crush sleeve eliminator is the only way to go.

 

[HYRDGOON]

Wait a minute..... You mean you didn't make your own gears!! Slacker!!

 

[benno440]

Yeh comeon I would of thoug you had hand carved them out of unobtanium

 

[HYRDGOON]

Yeh comeon I would of thoug you had hand carved them out of unobtanium

Or adamuntium!!

 

[747mopar]

no idea buddy, what locker or/ did you go with? a true trac??

I've got the old factory disc type posi hehehehe (I know that's a Chevy term). I already opened it up and looked it over, looks new inside so I'll just run it plus that's what I'm running right now and it works great.

- - - Updated - - -

Crush sleeve eliminator is the only way to go.

I just put one together last year that had the crush sleeve and said that was the last one. That was no fun at all, put a huge wrench on the yoke, sit it on the floor while you bounce off of a 4' cheater bar on the nut just to get it to crush............. yeah I'm over that! I don't like the idea of not being able to go the other way either (get it a little tight and your done, go buy another sleeve). Thanks

- - - Updated - - -

Wait a minute..... You mean you didn't make your own gears!! Slacker!!

C'mon guys, even I won't go that far!

 

[mopar 3 B]

I just bought all the stuff to build my 489 pig and have been reading up to make it go as smooth as possible and wanted to pick your brains for pointers. I purchased a set of Richmond 4:30s, a Richmond rebuild kit and the crush sleeve eliminater. I remember I think it was Cranky mentioning honing a used set of pinion bearing to slide on and off the pinion shaft to aid in the setup so I will do that (good idea) but was hoping for some more tips. My manual is pretty useless seeing how it constantly refers to all of these special gauges and jigs but having done other rears I know it's not rocket science. The way I see it you get the pinion preload correct using the crush sleeve eliminater, start with original pinion spacer, set up the backlash and check contact pattern. From there it's just fudging the pinion shim around, resetting everything and checking the pattern until you got it?

Need inlightnment on the idea of using used bearings for setup other than being easier to get off the pinion after being honed. Pinion depths will change using different new bearings so why start with something other than the one intended?

 

[747mopar]

Need inlightnment on the idea of using used bearings for setup other than being easier to get off the pinion after being honed. Pinion depths will change using different new bearings so why start with something other than the one intended?

I'm not sure but I would think maybe he's referring to the outer race for the large end and the small inner bearing for the pinion although the inner bearing for the small end came apart easily so this may not be a problem? I'll know more once I tear into it but if I'm not mistaken you have to remove that large outer pinion race to adjust the shim thickness for the pinion depth, having to take multiple stabs at it would concern me because that race drove out pretty hard so by using a looser fitting race you could easily hone in on it but it would obviously need double checked with the new parts in place. A plus is the old and new bearings are all the same make so they should be close.

 

[383man]

Most guys use a new bearing like I do on the pinion when setting up the rear. I take a new inner pinion bearing and hone the inside of the race until it slides on the pinion shaft and dont have to be pressed on. The reason for this is because without the right pinion depth tool to determine the pinion depth shim you can use the shim you think is right and put it on the pinion and then slide the inner pinion bearing on that you honed and put the rear together. Then check the gear pattern and if its off and the shim on the pinion under the inner bearing needs to be changed and that bearing is normally pressed on so you would have to have a tool to pull the inner pinion bearing off to change the shim. Now this way you just slide the bearing off and change the shim so you dont have to worry about damaging the bearing when puuling/pressing it off. You simply slide the bearing off to change the pinion depth shim. Once you have the right shim and a good pattern you then take it back apart and press the other new pinion inner bearing on since you have the right pinion depth shim on it now you dont have to worry about pulling/pressing the bearing off and ruining it. So thats the reason some get a second inner pinion bearing and hone it so it will slide on. Once the rear is done and set up right then I take it back apart and press a new inner pinion bearing on and save the honed inner bearing for the next rear you do. Ron

 

[mopar 3 B]

Have you noticed and differences in pinion depth between the new inner bearings?

 

[747mopar]

Getting confused, I have it all apart and the install kit (RMG-8310311) has different shims than what came out of it? My 489 had the shim that I highlighted in the pic and nothing else but the kit only includes shims that seam to fit either the small end of the pinion on the outer race or behind the large end inner bearing but definitely not where the one that was in it was. Driving the larger outer race out banged up the original shim so now I suppose I'll have to hunt that down. My manual shows only cone style diffs and mines the disc so does anybody have a break down of a 489 with the disc setup?

 

[66Satellite47]

There is no difference in the setup between disc type & cone type diff's. The issue seems to be you're eliminating the crush sleeve, so you need to assemble it like a step pinion, Fig 21. But that's a real quick look.

OBTW the honing the bearing thing really helps & we mic'd used vs new bearings to check for the difference.

 

[Cranky]

My 'used' dummy bearings are pretty low mileage bearings that came out of a unit that someone honed the pinion gear making it a slip fit to make his rear end easy to set up. I don't like a slip fit bearing for being the final in service piece and honing the pinion shaft for that isn't my cup of tea. Using a new honed bearing is good but having a low mileage honed bearing is ok too and much cheaper . And I've been using this set up bearing for a lot of years now....

Have you noticed and differences in pinion depth between the new inner bearings?

I've noticed a very slight difference but have noticed the same thing between new bearings of different brands. It's usually only a few thousands of an inch tho. Tapered roller bearings are pretty tough and the wear is very slight even over a long period of time IF they haven't been abused in some shape or fashion.

Getting confused, I have it all apart and the install kit (RMG-8310311) has different shims than what came out of it? My 489 had the shim that I highlighted in the pic and nothing else but the kit only includes shims that seam to fit either the small end of the pinion on the outer race or behind the large end inner bearing but definitely not where the one that was in it was. Driving the larger outer race out banged up the original shim so now I suppose I'll have to hunt that down. My manual shows only cone style diffs and mines the disc so does anybody have a break down of a 489 with the disc setup?

View attachment 252694

I'm setting up a 42 case right now and the shims I got in the kit for setting pinion preload didn't even fit the pinion shaft. They wouldn't even fit over the splines let alone the bearing fit and have no idea what they fit. I'm just glad I have a nice stash of shims here. I also like to place my pinion depth shim between the gear head and the bearing instead of placing it behind the bearing race in the case but I also have a honed race for doing it that way too. It just depends on what shims I have on hand to assemble it with. Btw, only cone type SG's came in the 89 cases.....but they they don't care what number the case is so long as you have the right carrier bearings. The clutch place units have a smaller bearing fit for the cone. The cases all use the same size cup OD's tho.

 

[747mopar]

Thanks Cranky, so if I'm understanding you correctly it doesn't matter if the shim goes between the race or the bearing on the big side of the pinion? The shims in the kit will fit behind the bearing just not the race as it was. The fact that I have a 489 case with the old disc setup suggest somebody has tinkered with this before which explains the setup not matching the books too. I'll get some pics uploaded soon but I think I got it now.

- - - Updated - - -

Also, I did order the kit for a 489 but the bearings fit the disc style carrier?

- - - Updated - - -

O.K. I beleive the kit just said "larger tapered pinions".

 

[747mopar]

Anybody, know the torque spec for the bolts that bolt the carrier halves together?

- - - Updated - - -

Either 5/16 or 3/8, I'll have to look next time I'm in the garage.

 

[Cranky]

Thanks Cranky, so if I'm understanding you correctly it doesn't matter if the shim goes between the race or the bearing on the big side of the pinion? The shims in the kit will fit behind the bearing just not the race as it was. The fact that I have a 489 case with the old disc setup suggest somebody has tinkered with this before which explains the setup not matching the books too. I'll get some pics uploaded soon but I think I got it now.

- - - Updated - - -

Also, I did order the kit for a 489 but the bearings fit the disc style carrier?

- - - Updated - - -

O.K. I beleive the kit just said "larger tapered pinions".

Really doesn't matter if you shim the bearing cone on the pinion shaft or the bearing race in the case. Both will do the same thing but if you have the factory thick shim, stick it back on where it was and see what the pinion depth measures. I have been able to do that and the pinion ended up exactly where it needed to be. And if you ordered bearings for the 89 unit and asked for carrier bearings too, you will most likely get the larger bore carrier bearings. The numbers for the plate clutch unit is 25590 for the cup and 25520 for the cone. You probably got the 104949 and the 104912....

Anybody, know the torque spec for the bolts that bolt the carrier halves together?

- - - Updated - - -

Either 5/16 or 3/8, I'll have to look next time I'm in the garage.

I know the cone unit uses a 3/8ths bolt and that is 43 lbs dry. I use a very small line of Loctite 620 across a couple of threads or so. Man, I just put together a plate unit but can't remember if they are 3/8ths or not. I'm thinking they are.....

 

[747mopar]

Thanks guys, between your answers and some phone calls I've got what I need to take a stab at it now. I see why it doesn't matter where the shim goes (either place pushes the whole pinion into the ring just the same). The bolts are 45 lbs

 

[Meep-Meep]

On the power lock unit (disc type) the bolts are 3/8-24 LH thread. 45 ft lbs is correct. Many of those bolts get stretched badly but I made my own out of some long grade 8's and the appropriate threading die. I also found out (after the fact) that ARP makes replacements but are listed under diff case bolts or something like that.

 

[747mopar]

On the power lock unit (disc type) the bolts are 3/8-24 LH thread. 45 ft lbs is correct. Many of those bolts get stretched badly but I made my own out of some long grade 8's and the appropriate threading die. I also found out (after the fact) that ARP makes replacements but are listed under diff case bolts or something like that.

Thanks Meep I was wondering about replacing those bolts just for insurance so I'll check with Summit.