8 3/4 - 742 Sure Grip Recondition

[Charlie Brown]

Vintage 1962. I have disassembled carrier to put in new clutch plates and a pinion seal. Before taking apart I measured backlash ( 7 thou). I also marked caps etc. to re-assemble unit as it was. My question is - upon reassembly will my gear tooth pattern be the same as before disassembly if I maintain the 7 thou backlash? I'm not changing any other internals except the pinion seal. All bearings / races check out OK.

 

[Nate S]

Yes. If you keep the backlash the same, with the other parts unchanged you’ll have the same pattern. Probably sensible to check in case you make some sort of mistake.

 

[Potts]

If it's open already, why not take out the guesswork and check with gear marking compound.
Found this decent video on pinion depth and backlash:

 

[Runcharger]

Yes it will: Follow the factory procedure for setting backlash/side bearing preload.

 

[Cranky]

And it's always a good idea to check backlash in at least 3 places. I like to use 4. Gear machining like most machine operations have a tolerance and then over time, things can move around a bit. The diff carrier also has a tolerance and can also end up with some run out and run out can increase especially if there's ever been a gear failure. When you go back to together, make sure you don't have an area where the back lash is too tight.

 

[R413]

Make sure you put both axles in the differential to line up the splines before tightening the bolts.

The service manual shows how the plates should be stacked, follow that so it’s working right. There are large and small, flat and dished, thin and thick plates in there.

yes you have the same bearings so go back to .007 with proper side bearing preload and things should be nice.

do you have a service manual for insstructions?

 

[Fran Blacker]

I'd buy your pinion seal from drdiff. Parts store may not give you the right one.

 

[Cranky]

Make sure you put both axles in the differential to line up the splines before tightening the bolts.

The service manual shows how the plates should be stacked, follow that so it’s working right. There are large and small, flat and dished, thin and thick plates in there.

yes you have the same bearings so go back to .007 with proper side bearing preload and things should be nice.

do you have a service manual for insstructions?

View attachment 1216931

Lots of people get messed up on that including me lots of years ago. Ended up with a locked Power Lok lol

 

[Fran Blacker]

Lots of people get messed up on that including me lots of years ago. Ended up with a locked Power Lok lol

My first FBBO post was about axle not going in all the way.

 

[RemCharger]

I see it doesn't say it in the manual ,, but also you should soak the clutches in a 80-90/ modifier concoction .

 

[Charlie Brown]

Thanks to all for your feed back. I am currently awaiting a package from Dr. Diff. which includes clutch discs, double lip pinion seal and some misc. items. This is really my first time taking apart a diff. and with the info. from the group, I'm hoping it will go back together as it's supposed to. If I run into issues, I'll know where to ask. Happy New Year to all.

 

[Fran Blacker]

Clean oil off gears and put gear compound to get a pattern before you take it apart. Take pictures of both sides of teeth you'll drive and coast pattern.

 

[Charlie Brown]

Clean oil off gears and put gear compound to get a pattern before you take it apart. Take pictures of both sides of teeth you'll drive and coast pattern.

To late for that - dummy me - it's the rookie in me I guess. Already apart - but I'm pretty sure I can see the original tooth pattern on the gear set via the "shinny" areas.