LilJayV10

iTrader: (39)

At work we use the Rotunda tools to rebuild 8.8's and 9.75. It's pretty straight forward. You install a tool where to pinon goes to simulate it, use a a large tube that simulates the carrier. Using your pinon shims, you use whatever combination to achieve the right amount of drag as you slide them between the tube and the pinon simulator.

Is there something similar for the 7.5? I'm going to put a set of gears in my Firehawk this winter and wonder how everyone is doing it.

Thanks.

J

guppymech

iTrader: (7)

I think most people just reuse the pinion shim that was installed in the rear and check the pattern with the grease paint. When I did mine found that a factory shim gave the best pattern.

LilJayV10

iTrader: (39)

I was hoping for something a little more scientific but I do appreciate the reply none the less.

therabidweasel

iTrader: (5)

I have a tool from ratech. The little plastic nub goes in the divot on the head of the pinion and a tab reaches over to the axle tube. You use your calipers as a depth gauge to the carrier bearing journal and a number printed on the tool to get a checking distance. Id say it gets you within 10 thou...which is about as close as reusing your old shim...lol. what can you expect from a $15 tool?

LilJayV10

iTrader: (39)

Thanks for the info on the tool. I'm having a hard time picturing how it works though.

FirstYrLS1Z

iTrader: (4)

the white nylon button sit on/in pinion center,the other end sits over bore in housing where the carrier bearing sits. the hole in that end is for a depth mic/vernier caliper to measure down to that bore. found dimension with dimension stamped on tool equals pinion depth.

Jr.Samples

I bought one of those things. It is pretty worthless. I had to start from scratch because the former owner put in gears and it did not have a pinion shim at all.

I took the old pinion bearing and hogged it out until it would just slip in the pinion . I then started with an .024 shim putting it all together and looked at my pattern. I did this a few times. When I was happy with my pattern I had a shop press on my bearing with my .028 shims and it was just like my pattern of my old bearing.

If you have a cheap Harbor Freight press you could do this yourself but run the risk of ******* up your new bearing. I have run this for over a year with just a little whine on coast. It has taken a beating with no problems. Oh yea I used a Summit gear set.

guppymech

iTrader: (7)

I too used a old bearing opened up for a slip fit on the pinion. After I had a pattern I liked I did the final linstall with the new bearing and solid pinion spacer, the settings changed slightly because I used a worn old bearing as a setup bearing. Next time I set up a rear I'll be using new bearings for setup bearings.

Jr.Samples

You are spot on Brother the only thing that matters in the end is the pattern.

shepss217

iTrader: (5)

i'm not, i'm throwing mine in the trash, lol

LilJayV10

iTrader: (39)

If this site had a like button, I would be using it now.

LilJayV10

iTrader: (39)

I'm going to wonder down to our Chevy dealership this week, they should have the tools to set the rear up correctly.