How To Recondition a Sure Grip Cone

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Great thread! That SG looks the same as the one I'm getting ready to install in an 8.25 rear end.
 
Much needed how to and good demostration of how simple it really is and I salute you for doing this,gives new life to the battered 'cone style' which I always felt was more aggressive..You did a DAMN GOOD JOB ROB...KEN
 
Great thread, thank you so much. I have 2 of the cone units that could potentially need servicing in the future.

Where do we get these shims now? Just tell the machine shop that machines the cone, they're going to know what it is and what to do?

Thanks again.
 
Great thread, thank you so much. I have 2 of the cone units that could potentially need servicing in the future.

Where do we get these shims now? Just tell the machine shop that machines the cone, they're going to know what it is and what to do?

Thanks again.

I believe Dr Diff sells the shims. If I recall correctly, he uses pieces from a D60 application.

You may wanna check mcmaster-carr to. They may have one that'll work.
 
Nice thread with pics.
The shim thickness would be the amount you machine off the cones.
My guess those are about .030"
 
very cool.
I've heard of similar "fixes", none as good as this.
I've also heard the "locker" method with a little weld :D

$100 for you to do the unit?
Can't beat that with a stick
 
The preload on the springs helps keep the shims in place, but it is not critical that the shims have a larger hole. They cannot go anywhere. There is not movement there on a full time basis at all. Only when cornering. Other than that, the unit acts as a spool.

I am aggressive with material removal and shim thickness. I want the job to last. I remove .100" from the small face of the cones and add a .100" shim. This way, you remove enough that the case to assure the cones will contact tie sides of the case for a long time and not bottom in the ends.

I used a friend's lathe and cut it down myself. Normally, he does not charge me anything, but this time he had to because business as been bad. :(

The danged shim kit was also a bit more expensive this time. I guess everything is goin up.
 
Mike (73Swingerbuild) asked me a very good question. He was concerned about the thrust block since he will be using green bearings. The thrust button on the clutch type is what has to be removed. The thrust block on the cone type also holds the preload spring pack in place. It cannot be removed. The axles will fit and work fine with the green bearings with the thrust block in place. In the cone style, it is a necessary piece.
 
Thanks Rob, I always wondered how exactly those worked.
I had a good idea, but knowing the exact design is cool.
Nice job.
 
Mike (73Swingerbuild) asked me a very good question. He was concerned about the thrust block since he will be using green bearings. The thrust button on the clutch type is what has to be removed. The thrust block on the cone type also holds the preload spring pack in place. It cannot be removed. The axles will fit and work fine with the green bearings with the thrust block in place. In the cone style, it is a necessary piece.


I rebuilt one of these with my friend. Got 25-30 runs when a loud bang and had the axles splines stripped right off. Wondering what went wrong. Looks like we did it the same way as you Rob.
 
Rest assured it was not because of the recondition. The axles go through the splined cones and the splined side gears. Even the .100" I milled off would not compromise that engagement. The cone style is really not made for competition, anyway. Although a lot of people have raced them successfully. They do have only one cross pin and two spider gears. For a street car they are great. Start racin um and or stickin slicks on um and they can break.
 
Just got say good thread, never really understood the differences in the rear ends. now that I have seen one torn apart makes much more sense.
 
Ok. My unit was so worn that the car wouldn't move. Both sides were bottomed out. Took it apart Monday and found a general machine shop local to cut .100 off both cones. Found a shim kit at advance in stock. Gear motive Part# 1105. 8 shims in the box. 4 were .100 thick so enough for 2 units and the price...just $5.99. The machinist here had the job done before I could drive home and eat lunch. He charged me his minimum of only $30. I thought was a deal. Finished assembly today and installed. Giving the rtv over night to dry before adding fluid tomorrow. I do recommend 2 bolts that are 5/16 by 18 and 3" long to put the unit together. 1 on each side like a set of jack screws to get the other bolts started. I also assembled on the bench and used 1 axle to line up splines on both sides before tightening everything up. You can see the splines and tell if they are aligned. Had no problem during install putting the axles in. Big difference putting it together than taking it apart. That's why I used the 2 longer bolts to get it started. Lots of spring tension now. Saw this years ago in one of the mopar mags. Thanks RustyRatRod for your help.
 
Just want to clarify a couple of things. Yes, .100" is probably the absolute max you would ever want to remove. Reason I did that was because both cones were worn sufficiently that they bottomed in the case halves really badly. Once the cones contact the case ends, all bets are off, the limited slip function is gone.

The cones grip the case on the outsides, where they are threaded. Once they wear to the point they contact the case ends, they can no longer engage the sides. That is also why I added the shims to this one. Sometimes the shims are not needed, or a very small amount.

The shims are usually only to restore spring preload, but this one was worn so badly that the shim function also had to include moving the side gears back into the spider gears.

As I said from the beginning, this is not a boni fide recommended repair. You are taking a chance because you are milling away a small portion of the splines on the cones. They could possibly strip. But, if they do strip, it is likely the unit was being asked to do something that it shouldn't anyway.

I am glad those of you who enjoyed this did. Thank you C for cleaning up the bickering. It serves no purpose other than to dilute the thread. The whole purpose of this was to show that you can restore the sure grip function and use it again in a mild street application. It sure beats buying a new 400 buck plus unit.

Lastly, if yall want to discuss why this isn't a good idea, or your own ideas or any disagreements, please create a thread for that. This was meant as a how to thread to add to the tech section, not an argument and discussion thread. C worked real hard cleanin all this up to look presentable in the how to section. Lets not make more work, ok? Thanks.

Thanks again, C.
 
I'm going to try this on mine that's worn out. Good thread.
 
Thx x#? Rusty,exactly how I planned on resurrecting mine when the time comes,nice to
see someone has already done this w/success.Nice tip to those using greens,they're not for
me,but an essential for those they are.Another "not serviceable","non-rebuildable","discard
when functional performance ceases" part serviced,rebuilt,&function restored by those who
are willing to try. :burnout:
 
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