Hi Gene,
The answer to your question is somewhat convoluted.
I’ve been exploring the Jeep T176 and Ford iron case toploader transmissions as a possible solution to the scarcity of the Ford T170 RTS/TOD.
The conversion using a Jeep T176 is certainly doable as it shares many of the attributes of the T170, they are the same family of transmission. The issues with the Jeep trans are:
1) The input shaft is much longer than the T170 and with different spline size
2) The output shaft is splined for direct coupling to a transfer case. This may or may not be an advantage, I’m still investigating.
3) The rear of the T176 case has a bolt pattern that is different from the T170. Therefore, an adapter plate that is different from the commonly available T170 adapter plate would have to be fabricated. Alternatively, the rear of the T176 case could be drilled/tapped for the T170 adapter. Either way some fabrication is required.
4) The Jeep T176 uses a smaller front bearing. Therefore, the front bearing retainer is smaller and may require an adapter or bushing to make it fit the bellhousing.
Another option, as mentioned by 51504bat, is using a Toploader with a Jeep T176 top (shifter). As I mentioned in our PM discussions this would produce a 4 speed with the same dimensions as the T170. This same configuration can be used on an Iron case O.D. Toploader with 3rd and 4th being reversed in the shift pattern. The problem with this configuration is:
1) If using a closed driveline (torque tube) the area of the output shaft, just behind the rear bearing, has to be re-splined to use with the Model A u-joint. The iron case, car version O.D. is necked down too small, in this area, to be re-splined. Meaning the output shaft would have to be replaced with a trucks output shaft, cut, and re-splined.
2) I’m not sure about the V-8 car (non-O.D.) output shaft diameter but I believe they are bigger and could be re-splined.
All the conversions I’ve seen, using a Jeep T176 shifter on a Toploader transmission are using an open driveline but there’s no reason, I can see, that a closed driveshaft couldn’t be adapted, same as the T170.
The reason I said the T176 output shaft may or may not be an advantage is:
1) Compare pic of T176 shaft to T170 shaft cut & re-splined.
a. It may be possible to use the T176 shaft with a modern 1310 series u-joint. I’m still investigating this. The problem is the T176 has an odd 23 spline shaft and it may (or may not) be difficult to adapt this to a yoke that can be used inside the clam shell but it certainly looks promising.
Article on toploader with Jeep T176 shifter:
https://www.jalopyjournal.com/forum/...rsion.1035578/
Tom
Also, I just splined that shaft pictured a few days ago. While I have my lathe and mill setup I'm going re-spline the remaining 4 shafts I have. As soon as I find some T170's I'll be building them. Still working on the house though. Gotta keep the wife happy.
