12 bolt pinion shim

Dirk Olson · 05-30-2023, 01:17 PM

.026 to .028 will get you close. Remember when setting a used gear set that it is highly possible that you will not see a good pattern. you can get close adjust backlash a little on the loose side monitor noise on coast adjust if necessary.

Alan Nyhus · 05-30-2023, 05:54 PM

Doing a new set, .030-.032 is my default. On a used set, I'll hedge thinner by a couple thou. and pay more attention to the coast side. A bit of red Loctite on the pinion shaft where the front bearing registers and eliminate the crush sleeve.

3 window · 05-31-2023, 09:04 PM

Thanks everyone. We’re on the right track for sure. I set it up with a .030 and based on the master housing depth of 4.670, it’s dead nuts on (pinion depth of 2.755 plus the thickness of the pinion head 1.915 equals 4.670).

Glenn Briglio · 06-01-2023, 06:46 AM

Quote:

Originally Posted by 3 window

Thanks everyone. We’re on the right track for sure. I set it up with a .030 and based on the master housing depth of 4.670, it’s dead nuts on (pinion depth of 2.755 plus the thickness of the pinion head 1.915 equals 4.670).

That's fine but pattern and backlash are what matter.

3 window · 06-02-2023, 08:15 PM

So here we are at .030 shim and .0075 backlash. This gear is used and from ‘66 so it’s got some miles on it.

Mark Yacavone · 06-04-2023, 11:03 PM

Don't know what you're doing with this car but it's probably a hair deep.
I'd try a .027-.028 if you're not in a big hurry. ;-)

3 window · 06-06-2023, 08:29 PM

Just drove it. Quiet as a church mouse. Thanks everyone.

05-30-2023, 01:17 PM	#1
Dirk Olson Member Join Date: Mar 2003 Posts: 199 Likes: 52 Liked 172 Times in 46 Posts	Re: 12 bolt pinion shim .026 to .028 will get you close. Remember when setting a used gear set that it is highly possible that you will not see a good pattern. you can get close adjust backlash a little on the loose side monitor noise on coast adjust if necessary. __________________ Dirk Olson 5036 STK

05-30-2023, 05:54 PM	#2
Alan Nyhus VIP Member Join Date: Dec 2002 Location: Lower Dakota territory Posts: 1,180 Likes: 1,074 Liked 799 Times in 236 Posts	Re: 12 bolt pinion shim Doing a new set, .030-.032 is my default. On a used set, I'll hedge thinner by a couple thou. and pay more attention to the coast side. A bit of red Loctite on the pinion shaft where the front bearing registers and eliminate the crush sleeve. __________________ "That'll never work....." Last edited by Alan Nyhus; 06-02-2023 at 04:38 PM.

05-31-2023, 09:04 PM	#3
3 window Junior Member Join Date: Jul 2016 Posts: 15 Likes: 0 Liked 3 Times in 2 Posts	Re: 12 bolt pinion shim Thanks everyone. We’re on the right track for sure. I set it up with a .030 and based on the master housing depth of 4.670, it’s dead nuts on (pinion depth of 2.755 plus the thickness of the pinion head 1.915 equals 4.670).

06-02-2023, 08:15 PM	#5
3 window Junior Member Join Date: Jul 2016 Posts: 15 Likes: 0 Liked 3 Times in 2 Posts	Re: 12 bolt pinion shim So here we are at .030 shim and .0075 backlash. This gear is used and from ‘66 so it’s got some miles on it. Attached Thumbnails

06-04-2023, 11:03 PM	#6
Mark Yacavone Veteran Member Join Date: Mar 2002 Location: Miles From Nowhere Posts: 7,832 Likes: 2,926 Liked 5,139 Times in 1,962 Posts	Re: 12 bolt pinion shim Don't know what you're doing with this car but it's probably a hair deep. I'd try a .027-.028 if you're not in a big hurry. ;-) __________________ "We are lucky we don't get as much Government as we pay for." Will Rogers

06-06-2023, 08:29 PM	#7
3 window Junior Member Join Date: Jul 2016 Posts: 15 Likes: 0 Liked 3 Times in 2 Posts	Re: 12 bolt pinion shim Just drove it. Quiet as a church mouse. Thanks everyone.