Wanting an opinion on if this looks like an acceptable pattern? I think it is based on the illustrations online. The drive side pattern is centered, but the coast side pattern is towards the toe. If I try to re-shim the pinion to center the coast side I'm afraid it will negatively effect the drive side. This is a motive ring and pinion gear set for a Ford 9" rear differential. Truck is a 1968 F100 4X4.
Top pic is drive side. Bottom pic is coast side.
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Last edited by aelmo on Sat Dec 27, 2014 8:48 pm, edited 3 times in total.
Backlash is 0.010" or ten thousandth. Spec shows non oem 7 - 10, oem 10 - 16. I guess since it is a Motive gear set that would be considered non oem. I had the backlash at 0.005" but I felt that was too tight. Moved the adjusters over 1 hole and it changed to 0.010" I was thinking I may need to increase pinion depth or move pinion closer to ring gear some. I have a 0.021" shim between pinion housing and main housing now. I will try changing it to a thinner shim which will move it closer and see how it effects the pattern. I have the pinion housing bolts pretty snug but, haven't torqued them to spec. yet. Torquing it possibly could move it a tiny bit closer as well. The pinion bearing pre-load is 24 in.lbs.
Thank you!
Last edited by aelmo on Sat Dec 27, 2014 2:08 pm, edited 1 time in total.
I took the 0.021" shim out and added a 0.016" shim. Backlash changed from 0.010" to 0.009" Took pictures and set the pics up side by side for comparison.
What's your thoughts on the pattern change?
It appears the coast side shifted to the center slightly more towards the out or heel side, and the drive side shifted to the toe or inner side slightly.
Also appears it moved down slightly more towards the flank away from the face.
I think that was a positive change. Not sure if I should shim the pinion even closer.
Nice, looks better! When I set up gears I get to where I think its correct then make one additional adjustment to see if it gets better or worse. So I would go another .005" deeper to see what you get.
I took out the 0.016" shim. Added a 0.010" shim. Backlash changed from 0.009" to 0.006"
The 0.016" shim is definitely about right. The 0.010" shim pushed the drive side pattern too far towards the toe inside. Although the coast side looks centered.
I could try adjusting the backlash now but, I think I would wind up with about 0.011"
I want to thank you for your advice and opinions. It was a great help to me.
This is the final setup I decided on using a 0.015" shim. Backlash was at 0.007" to 0.0075"
You do not have the required permissions to view the files attached to this post.
Wanting an opinion on if this looks like an acceptable pattern? I think it is based on the illustrations online. The drive side pattern is centered, but the coast side pattern is towards the toe. If I try to re-shim the pinion to center the coast side I'm afraid it will negatively effect the drive side. This is a motive ring and pinion gear set for a Ford 9" rear differential. Truck is a 1968 F100 4X4.
I want to thank you for your advice and opinions. It was a great help to me.