I bought an LT1 rear out of a 95 Firebird Formula. I am in the midst of completely rebuilding it. I tore everything down to the bare housing, with the exception of the pinion races because they were absolutely gorgeous so I didn't bother. That might be my problem but let me explain more. I bought a set of Motive Gears 4.10 on a guy from ebay claiming that they were for 98+F-bodies and I was under the impression and the internals were the same gear wise for 93-02. To double check I called Motive's customer service and they gave me the OK. I mic'ed the original pinion and the new to make sure they were the same over all height with the same steps on it. Perfect, just like the original. I took the original pinion spacer shim and had it pressed on under the inner pinion bearing like its supposed to be. The I threw in the outer bearing followed by the seal on the yoke side. Slid the new pinion in with the crush sleeve and it wobbled around a bit (the outer pinion bearing is loose inside the seal which might also be the problem). When I started to tighten the nut down it wobbled still. I have the nut all the way down and it wobbles probably a good 1/4". Is there a spacer that goes on the outer bearing that I may have missed?? Should I have installed the new races that came with the bearings? Could they be sized accordingly to the bearing instead of stock specs??

Any help would be greatly appreciated. I have pictures of the swap on my cardomain site in the sig.

Please help me!

 

Hey you didn`t miss the crush sleeve did you?

 

sounds like you left the crush sleeve out, or haven't tightened it enough. You need to crank on it pretty hard to crush that sleeve until you can feel no slop and a little drag when you try to spin the pinion. It should take about 30 in/lb to break it loose without the diff in the housing.

 

I just got off the phone with my dad, Ford tech back in the 70s. He thinks that I didn't crush the sleeve. He told me that it takes a lot of pressure to get that sleeve to crush. Supposedly one it crushes it pulls the pinion in some more. The sleeve is in there and I got the old nut on as tight as I could and cant get it to move, almost like the yoke has gone as far as it can. He told me that I need a big azz breaker bar. Thought I could do it with a 3/4 ratchet and my special tool to hold the yoke but apparently not. May have to take it to a shop to have it crushed right.

 

What you're doing is pressing the outer bearing onto the shaft and crushing the sleeve at the same time, so yes, it's very difficult. Easiest way is with a 1/2" impact gun because it's hard to hold the pinion from spinning. Too loose and it will make noise, too tight it will make noise and wear out the bearings faster.

 

Gotcha. That makes sense now. I noticed that that outer bearing was a little loose so pressing it on while tightening would make sense. Would it be better for me to use a solid sleeve instead of the crush or will I be fine with the one that I have?

 

it takes over 150lbs to crush the sleeve. A solid spacer is fine if you measure rotational drag on the bearings with an inch-lbs torque wrench.

-- Joe

 

pinion nuts aren't reusable, neither are crush sleeves

 

I know that. I was just using the old nut to sinch down the yoke.