Mugbie

Howdy guys.

I'm attempting to get my pattern set right myself. I can't say I'm enjoying it but hell, it can save me some money and it is a good learning experience.

I already know this pattern sucks, but I just wanted some opinion about where I should adjust to get the proper pattern.

It's motive 4.10 gears in a 8.5" 10 bolt.

I'm using a .020 pinion shim now, and backlash looked to be in the recommended .007 - .009 range but I may need to triple check and make adjustments.

Coast Side


Drive Side

guppymech

iTrader: (7)

Google: Yukon Gear Install manual, it's a PDF file and full of very useful info. Also this link has lots of good info, pay particular attention to the pic's and info about the pinion shim sitting on the pinion shaft fillet. I ran into this problem and it caused me alot of setup grief.

http://houstonperformancetrucks.com/...redmariner-%29

By your pattern it looks like the pinion is too deep, which I would not expect to be the case with a .020 shim. Maybe you are having the shim problem I mentioned above and your pinion bearing is not seated all the way?

dgcustomz

iTrader: (127)

Pinion is too deep. Put a bigger pinion shim in it to pull it further back. Also, adjust the backlash again if needed. I would put around a 32-36, then adjsut from there as needed.

dgcustomz

iTrader: (127)

You want it to be more in the middle...

Mugbie

Thanks for the input guys. It turns out my pinion shim wasn't sitting flush and after I read that article where the fillet problem is mentioned I learned that was a problem I was having. I ended up boring out the .020 shim to clear the fillet and I'm still running my previous backlash and this is what I came up with.

Coast Side


Drive Side


It still doesn't look right but it looks a lot better than the first pattern.

Mugbie

But wouldn't that push the pinion closer to the ring gear? Like how it previously was when the shim/bearing wasn't flush? I thought from the new pattern I got that I might need to put a different pinion shim that's a hair smaller and perhaps nudge the backlash.

dgcustomz

iTrader: (127)

You are correct, it will move it toward the ring. After looking at your new pattern it looks way better than the first. Every 8.5 I have built has been a 30 shim or above. We use gm gears and sometimes motives if that's what the customer can afford.

Mugbie

Hmmmm, well if the information helps, I'm going from a 2.41 gear to a 4.10 and there is definitely a difference in the pinion head thickness of the two. The original 2.41 pinion had a .040 shim. It would make since that you could use a larger shim around the 30 range, but I would have to completely re adjust my backlash. I don't know, just trying to think outside the box.

dgcustomz

iTrader: (127)

Did you replace the inner and outter pinion bearings? What about the races? When knocking out the races it burrs up the flat mating surface where the race should go. If it is not cleaned up the race will not seat properly. Just a thought......