8 3/4 489 case cone style sure grip

[1970challenger]

So the trans shop has told me they need about 1/4” of shims on my yolk to touch the crush sleeve.
It’s a 8 3/4 489 case with a cone style sure grip. It had 355 gears that were damaged, I purchased 373 gears to replace those. The original yoke was a coarse spline, and the new gears required a fine spline. I purchased it with new bearings and crush sleeve from Mancini Raving.
So my question is it possible that the parts I bought were for a different style of sure grip and that’s why they there is this big gap? Or does this just happen? Anyone have any knowledge let me know, this cheap center section is now costing me as much as if I had just bought a new one!!

 

[Ronbo73]

If you could, pull the new items out of the carrier and lay them next to the old parts and compare. I would think the difference would be able to be seen. If not I would contact Mancini Racing with your question. They should be able to answer you.

 

[john-9]

how did they come to the conclusion that your yoke is 1/4 inch out from the crush sleeve ,, your NEW crush sleeve should be 3inches long +/- 0.010 thou before installation , the yoke DOES NOT contact the crush sleeve at all it sits against the front bearing which sits on the crush sleeve which is between your front and rear bearing ,, i would pull your parts from this shop and find a shop that knows what they are doing. the type of sure grip has nothing to do with with the pinion set up on any case.

 

[1970challenger]

how did they come to the conclusion that your yoke is 1/4 inch out from the crush sleeve ,, your NEW crush sleeve should be 3inches long +/- 0.010 thou before installation , the yoke DOES NOT contact the crush sleeve at all it sits against the front bearing which sits on the crush sleeve which is between your front and rear bearing ,, i would pull your parts from this shop and find a shop that knows what they are doing. the type of sure grip has nothing to do with with the pinion set up on any case.

Thank you, I will go and measure the crush sleeve to check its length. That had me take the pinion and crush sleeve. I was a little concerned because they had the old yoke, but couldn’t find the new one I bought. Ugh

 

[540HemiCuda]

Almost sounds like they are trying to reuse a crush sleeve. But why are you using a crush sleeve rather than the far superior spacer and shims? The crush sleeve is quicker and easier to set up, but can be 'beat out' of spec. Do you plan on beating on it much? If not, then the crush sleeve will be fine. But if you have sticky tires and plan to shock the rear with hole shots, the spacer and shims will save you grief and money in the long run.

 

[Chryco Psycho]

Toss the crush sleeve & use a spacer

 

[Daves69]

..........

Mopar 8 3/4" (8.75) 489 Case Crush Sleeve Eliminator

Mopar 8 3/4" 489 Case Crush Sleeve Eliminator

www.doctordiff.com

 

[1970challenger]

Thank you, I will go ahead and order the spacer and shim kit. Thank you.

 

[Challenger RTA]

Almost sounds like they are trying to reuse a crush sleeve.

I'm not a third member expert, but that came right to mind.