Gear Pattern Opinions
Gear Pattern Opinions I set up some Motive 4.10 gears in my stock 10 bolt last weekend. This was my first time ever trying this from scratch, so I'm open to opinions on how this looks. I have a 0.0325" pinion shim installed and about 0.0065"-0.0075" backlash depending on where you measure it. The pinion preload was about 25 in-lbs and they were new bearings in the rear end.
I'm just curious if this looks good enough. I really hope this thing doesn't whine too bad...
I'm just curious if this looks good enough. I really hope this thing doesn't whine too bad...
I played around with 5 or 6 other pinion shims of both thicker and thinner, just to see what the results would be. I ended up at a 0.034" pinion shim and 0.007" backlash. The gears are in the car and are 100% quiet from 0-100 mph, but I did get a bit of a driveshaft vibration. They are not technically to 500 miles yet, but they have probably 15 heat cycles on them.
Here are some pics of the final pattern. It was as deep and wide as I could get them to be.
Here are some pics of the final pattern. It was as deep and wide as I could get them to be.
I also see an improvement in the amount of 'marking compound' applied. You used less the 2nd set of pics,the pic in the original post had too much and smearing causes the true pattern to become less visible.
I learned a lot about gears doing this myself. Not just how to set up gears, but what the different adjustments actually do. It cost me $119 for a Harbor Freight 12 ton press and $30 for a Bearing Splitter Kit to do it. Everyone around me wouldn't touch it because it was a 10 bolt, or they wanted $350-$500 to do it. I figured I could trash a set of gears and still be about the same in cost, plus learn something, so why not. The grease amount was something I read after doing the 1st setup, so I actually cleaned the gears and tried them again, and the pattern was in fact a little shallow. With the 2nd attempt, I feel I got everything a lot more right.
Best news of all though is going 3.42 to 4.11 only cost me 1 MPG and I gained a whole lot of driveability with the cam. I averaged 24 before (50/50 city/hwy) going to work and back, and I just filled up and still got right at 23 with the same driving. I do not drive it easy, either!
Best news of all though is going 3.42 to 4.11 only cost me 1 MPG and I gained a whole lot of driveability with the cam. I averaged 24 before (50/50 city/hwy) going to work and back, and I just filled up and still got right at 23 with the same driving. I do not drive it easy, either!
gears aren't complicated,fear stops most. I started working on gears in the late 60s' (yes,I'm old). Worked on 7.5/7.625/8.2/8.5 10 bolts and 12 bolts. Never worked on a 9" but am familiar with them. Re-using used gear sets don't bother me as I picked up a set of used Richmond 4.56s' for $25 at a swap meet and used them for 4 years in the Z. Took them(the entire rear) out and put the OEM 3.23 rearend back in,but that 4.56 rear is just sitting there waiting to be put back in. Probably won't as I'm building a 4.10 rearend.
