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S197 @4o6racing Build Thread Profile - S197 Mustangs

570
722
Exp. Type
Time Attack
Exp. Level
Under 3 Years
SoCal
What I'm seeing in that particular chart is a different procedure, which may be different entirely in what corrections may need to happen. It very clearly puts setting backlash ahead of setting pinion depth.
Pinion depth has to be set first by default of assembly order. Backlash can be adjusted without removing the pinion, but pinion depth can’t be adjusted without removing the diff carrier. Adjusting pinion depth also adjusts backlash without adjusting the diff carrier shims. Not sure if that makes sense.


If you’re going from Ford OE gears to other Ford gears (recommended), I would use the exact same pinion shim thickness that was installed from the factory. I tried measuring mine with a tool, and ultimately ended up very close to the OE thickness.

'm pretty sure that differential shims will fit behind the inner pinion bearing race as an alternate method of setting pinion depth deeper toward the differential carrier, mimicking the use of a thicker pinion bearing shim. Can anybody confirm this? Without a press and if needed this might be an easier alternative.

Personally I have not tried this, but conceptually it should work. One challenge will be accurately measuring the thickness of the OE pinion shim without pressing the original bearing off.
 

Norm Peterson

Corner Barstool Sitter
930
702
Exp. Type
HPDE
Exp. Level
5-10 Years
a few miles east of Philly
Thanks for the prompt response.

Pinion depth has to be set first by default of assembly order. Backlash can be adjusted without removing the pinion, but pinion depth can’t be adjusted without removing the diff carrier. Adjusting pinion depth also adjusts backlash without adjusting the diff carrier shims. Not sure if that makes sense.
Makes perfect sense. What I was seeing (as a now-retired professional nit-picker of technical writings) just jumped out at me as being "different".

If you’re going from Ford OE gears to other Ford gears (recommended), I would use the exact same pinion shim thickness that was installed from the factory. I tried measuring mine with a tool, and ultimately ended up very close to the OE thickness.
Yes, Ford gears (3.73). Wasn't going to gamble with Motives, which I've heard tend to be noisier. And I did install the big bearing with the same shim thicknesses - within a thousandth or so - of what was with the OE 3.55. Without re-measuring or chasing my notes down, I think that was 0.032". Those numbers seem to at least be in the ballpark with your smaller ones and not too far away from blacksheep's numbers.

Personally I have not tried this, but conceptually it should work. One challenge will be accurately measuring the thickness of the OE pinion shim without pressing the original bearing off.
I actually saw this approach on some website dealing with ring & pinion setup. It'd just be on me to ensure there were no burrs and that I got everything fully bottomed. My feeler gauge set goes down to 0.002", but like you I was going by sound when first installing the race. 0.002" didn't even feel close to fitting anywhere.

This would be something I'd only be doing after going through the checking distance thing with the Ratech tool and getting an indication of at least 0.010" more shim thickness required. If that happens, I'll probably be on the hook for getting just a shim kit (shouldn't need bearings) so I won't run out when I set the backlash.


One other item . . . I'm considering the idea of heating the pinion flange up by 50°F or so just to ease installation a bit. Should be enough to take a few ten-thousandths out of what appears to be an interference fit at the splines.


Norm
 
3,594
3,396
find or buy a used set of pinion bearings and go at them with a die grinder and sandpaper roll so you can slide them on and off, set the pinion depth this way, and once it is set, them you can press the "real" bearings on. Guys that are real good at this, and do ti all the time, don't need that kind of crutch, but the rest of us do.
 

Norm Peterson

Corner Barstool Sitter
930
702
Exp. Type
HPDE
Exp. Level
5-10 Years
a few miles east of Philly
find or buy a used set of pinion bearings and go at them with a die grinder and sandpaper roll so you can slide them on and off, set the pinion depth this way, and once it is set, them you can press the "real" bearings on. Guys that are real good at this, and do ti all the time, don't need that kind of crutch, but the rest of us do.
That's what I should have done, and would have done if I'd been looking far enough ahead at the tyme.

But maybe with a little luck this'll turn out to be a non-issue. One can hope.


Norm
 

Norm Peterson

Corner Barstool Sitter
930
702
Exp. Type
HPDE
Exp. Level
5-10 Years
a few miles east of Philly
Sorry for dragging your thread a bit off of its nominal topic.

I'm going to continue my adventures/mis-adventures in my own build thread now that I've been able to at least make some real measurements.



Norm
 

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