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Full Version: TECH - How to set up the Ford 9 inch rear end
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Very good information to have here at hand. I have set of a 9" once in my life and it was still on the road last I knew. Good to have the needed information right here for my next time. No doubt it will be a 9" from a Mach 1!
Years ago there was an article in Hot Rod called a poor mans posi. It was in regards to a standard 9" Ford diff, and simply added shims on the side of the axle drive gears thus increasing the preload when assembled to the point that they could actually lock the rear end solid. They recommended not going that far, but said it worked better then a limited slip and they had not had any failures. As the case and everything was more then strong ehough to handle the extra pressure. They said it was the quietest and best working posi they had tested and it only cost the extra shims and gaskets to build. They also claimed no real accelerated wear from the modification. I will try to find and post the article. I have several stacks of old magazines to go thru. SCo_hmmthink JTS 71 Mach1
When finding your pinion depth you don't have to keep removing the pinion housing and starting over when you are trying to find the right shim. I always "sneak" 3 feeler gauges around the edge where the shim sits and lightly tighten 3 of the bolts down. This way you can just loosen up the bolts and add or remove feeler gauges till you get the right depth. Makes it a lot easier and faster when setting one up.
I'm sure there are many different ways to do things.
Keep in mind this article as stated is from 1990.