Sonix

iTrader: (1)

So i've got my nice shiny pile of parts ready to go together with my 10 bolt, a few Q's now:

(installing a new Detroit true-trac posi, used 3.73 gears to replace my 3.23's, and a solid pinion spacer, along with a rebuild kit).

-How do I know if i've got the right pinion depth shim? Will backlash or contact pattern tell me if i'm out?

-Crush sleeve, or in this case, solid pinion spacer, ONLY effects the preload on the pinion bearings right? It should not effect the gear contact pattern right? Just shoot for 15in/lbs or something to turn the pinion and only the pinion?

-Carrier shims -> I want to adjust for .008-.012" backlash lets say, but how much do I need to preload the side bearings? Should I measure the amount of torque to turn the pinion and carrier? Any spec for that?

-Then i'll turn the pinion by hand while a buddy puts some drag on the ring gear, and check the paint marks eh? I have a decent idea about what to look for on contact pattern, but if someone has the link to that elusive webpage that shows an example of all different contact patterns and what to change, i'd appreciate it

Thanks
-J

sofakingdom

iTrader: (1)

Pinion depth - if they're practically any gears besides Richmonds, then a .035" shim has about 100-to-1 odds of doing the trick. To check, put the pinion into the housing, put in the carrier and ring, and set the backlash; and look at the pattern. You can't get a pattern that tells anything meaningful until the backlash is right. You can get an extra set of pinion bearings, and take a brake cyl hone to the cone, until they slip freely over the pinion; that way you can take them back off if you need to. Then once you get it like you want it, take it all back apart, put in your chosen shim, and press on the un-hones bearings.

Right; the tightness of the "crush" affects pinion bearing preload ONLY. With new bearings I'd suggest aiming a bit higher on the preload; something in the 20-25 in-lb range, WITHOUT the seal installed.

Carrier bearing preload - as much as you can possibly get. I put the thing together just hand-tight and get the backlash right, then I take it back apart and add equal amounts of shim to both sides until I can't squeeze the outer races together enough any more with a BF C-clamp to get it in.

z28man355

The crush or solid pinion spacer does only affect the preload on the pinion bearings.
Contact pattern will show if pinion depth is correct. If you have the pinion shim that came out of the rear end and contact pattern was good use it first. 9 times out of ten that will put you where you need to be any way .
As far as carrier preload I don't know the actual spec but it should require some persuasion to install the final side shim pack and you should not be able to slide the carrier back out by hand only with a prying tool of some sort.

Sonix

iTrader: (1)

I owe you a keg by now chesterfield man.

I know the head bearing is a ^&%*( to get on and off, (I tore the outer half off using a 2 jawed puller, then dulled a chisel trying to split the inner part of the bearing shell. I'm going to just use a grinder until it splits now...)
but the tail bearing seemed to easily come on and off. Can I just hone out a new head bearing?

Ok, excellent re: pinion spacer. I'm reusing the one I had with my 3.23 gears, and I threw out all unneeded shims. Here's hoping i'm right as is, otherwise i'll have to call up Ratech and try to get a few more shims.

I couldn't figure out how a C-clamp could be used to hold the assembly together, and force it into the housing. That boggled my mind. I bought the tool from Kent Moore that allows me to hammer in the carrier shims.

I was just worried if I shimmed it too tight it would tear up the carrier bearings and/or cause excessive drag. Or maybe even worse, too loose and it fails. Maybe 10-20ftlbs to turn the entire carrier assembly? Last time I set this rear end up using my stock gears and a JY open carrier I re-used the stock carrier shims and it was HARD to turn by hand. But the gears didn't shred themselves in the following 1000 miles until now...

sofakingdom

iTrader: (1)

For the C-clamp thing, I use 2 of them; about 8" ones. Put the outer races on the carrier bearings, and crank down the C-clamps on them. That mashes the bearings together same as preload. Then put it in as far as it can go before the C-clamps hit anything, which might be all the way, depending on your C-clamps.

As you probably already know, you can measure the ones that came out, and assemble new ones that are the same thickness, for starting out. Use the thick ones on the outside of each "pack" and put the thin ones in between. Put them in the case first, then the carrier w/bearings.

I wish I had a case spreader, but I don't. Oh well.

Sonix

iTrader: (1)

Yea... I'm not sure what kind of C-clamps you've got, but I can't imagine how that works. If i've got an 8" c-clamp, mostly open, i've got another 7" of threaded rod sticking out the end. So once I try to set the carrier in the rear end, the threaded rod will be hanging up on the back face of the rear end.

I think I only have one big C-clamp anyway, but i'll try it and see what happens. I did buy this $40 side shim installer for this very purpose, so i'm aching to get my moneys worth... And hopefully not destroy a set of shims...

jtrescot

Don't hone the new bearing that is going to be used for final assembly. Hone out another one to use while you are test fitting everything. The small price of that extra bearing is well worth it. Later on down the road you can use it again for the same purpose. I've never read or heard of a spec for carrier bearing preload - pretty much by feel. Like others have said it needs SOME persuasion to get the carrier in and out.

Pat Hall

iTrader: (31)

Here's a link for ya with some contact patterns. Also has advice on break-in procedure, etc. http://www.precisiongear.com/pgtechpatterns.htm A tip for you on getting the carrier back in with a really tight shim pack is to put the carrier in the freezer for about an hour before you install it. I never bought the fancy Kent Moore shim installation tool, but using the freezer trick, and using a hammer and a small brass drift to tap the shims in works great. I've had carriers that absolutely refused to go in, even with a BFH, and they drop right in after sitting in the freezer for a bit. This works good for the pinion bearings or carrier bearings too if they're really hard to press on.