pinion depth

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moparraceman

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does any one know what the pinion depth is for a 391,in a #742 case ,83/4 housing ? or can someone post a chart ? thanks
 
It varies... You need to measure your case.... These parts were made a long time ago, they weren't CNC machined...

Do you have the original pinion gear from the housing? Starting with the original shim & a set of honed set-up bearings is probably the easiest cheap way to get an axle set up...
 
I would think that if the case you are going to use has a "current" set of properly "were working" set up gears, you could "work backwards" to figure the depth?

I believe? there is a figure supposed to be stamped on each pinion to indicate depth variation. As said above "cases vary" which is the whole reason you need the factory fixture/ tool
 
I'm having flashbacks to when I set up my Dana 60 that I bought bare. I think I had the center section in and out a dozen times. Its just trial and error in the end. At least the 8 3/4 is easier.
 
I would start with original shim under the pinion bearing. If not a .030 shim under the pinion bearing. I have done about five this year and it is a good starting point.
I do not think any of factory gears are marked like the aftermarket gears.
 
Kendog 170 said:
:popcorn: I'm no expert but probably been lucky setting up three units so far mainly because I used the pinion shim it came with. Maybe this will help.
8 3/4 pinion depth
Click to expand...
I used to set up Ford 8.8s that way. There is also a tool I believe that you install to take a measurement to get the right size shim. But I am referring to 8.8 Ford I have the most experience with them. Basically set pinion depth then ajust backlash...

Here is a link to some Mopar tools at Summit. Pinion Depth Gauges - Natural Pinion Depth Gauge Finish - Chrysler 8.75 in. Axle Model - Free Shipping on Orders Over $99 at Summit Racing
 
Opps Same thing lol
Dartswinger70 said:
I used to set up Ford 8.8s that way. There is also a tool I believe that you install to take a measurement to get the right size shim. But I am referring to 8.8 Ford I have the most experience with them. Basically set pinion depth then ajust backlash...

Here is a link to some Mopar tools at Summit. Pinion Depth Gauges - Natural Pinion Depth Gauge Finish - Chrysler 8.75 in. Axle Model - Free Shipping on Orders Over $99 at Summit Racing
Click to expand...
 
all i have is the case no shims that were in the case, i bought a new ring and pinion from doctor diff, have one pinion depth on end of pinion it was scratch out, then they put another number on there, and its no good either
 
You're going to have to end up going strictly by the gear pattern. Some of these posted specs might get you close, but in the end, the gear pattern will tell the story.
 
RustyRatRod said:
You're going to have to end up going strictly by the gear pattern. Some of these posted specs might get you close, but in the end, the gear pattern will tell the story.
Click to expand...
Agree. The spec gets you in the ballpark. I would start with a .090 spacer on a 742 case.
 
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