Pinion nut too tight?

K-rover

Well-known member
Jan 15, 2010
2,125
45
Raleigh, NC
I had a leaky pinion. Changed the seal and flange. But when I try and tighten the nut down past 40ft lbs and the flange wont spin by hand. What am I missing here??? Its the rear diff on my D2. Was built by Lucky8 almost 6yrs ago with 4:11s and air lockers. Hasnt. Been touched since.
 

K-rover

Well-known member
Jan 15, 2010
2,125
45
Raleigh, NC
your going to need to use the flange that was in it and any spacer they had in it. The pinion is not a stock part and the flange needs to match it.
No spacers were on it. New flange and old flange are identical. The old flange is doing the same thing.
 

discostew

Well-known member
Sep 14, 2010
7,007
748
Northern Illinois
No spacers were on it. New flange and old flange are identical. The old flange is doing the same thing.
That’s kinda weird. Do you think it was torqued to spec to begin with? I’ve seen them not torqued because of this stuff. Are you sure that each flange is really identical? I would stand them next to each other and measure up all the distances that would effect this.
I doubt the pinion nut is too tight. I used to just hammer them home. Trigger tourque with a 3/8th impact.
 

K-rover

Well-known member
Jan 15, 2010
2,125
45
Raleigh, NC
That’s kinda weird. Do you think it was torqued to spec to begin with? I’ve seen them not torqued because of this stuff. Are you sure that each flange is really identical? I would stand them next to each other and measure up all the distances that would effect this.
I doubt the pinion nut is too tight. I used to just hammer them home. Trigger tourque with a 3/8th impact.
I put the two flanges side by side. They are identical in depth and design. Not sure about how tight it was before as I used my 1/2" impact to remove the nut.
Would a bad bearing cause this? Like I said both the original and new flange get tight to the point where I cant spin the flange by hand.
 

discostew

Well-known member
Sep 14, 2010
7,007
748
Northern Illinois
I put the two flanges side by side. They are identical in depth and design. Not sure about how tight it was before as I used my 1/2" impact to remove the nut.
Would a bad bearing cause this? Like I said both the original and new flange get tight to the point where I cant spin the flange by hand.
We’ll the way to set up the pinion bearing preload on these is way different than setting up what I would call a normal axle. We usually use a crush sleeve on the pinion shaft. These use a shim under the big pinion bearing. If my preload on the pinion feels good on these I usually don’t mess with it. The proper way to correct that is a thinner shim under that bearing. Pounding that race out of the housing to try 5 different shims is a pain in the ass.
What your experiencing now is why I’m always afraid to run anything but stock factory gear sets. Cause if that pinion is somehow very different it’s going to be very difficult to get it right.