toploader topshift with overdrive

[Burkulater]

does anyone have pics of this transmission? I want to see where the shifter come out of the top and if anyone has pics of it in a EB

some people say it works other people say it doesnt..... I think it does.

I also have questions when I find someone running the set-up like if the 4x4 ones from the trucks will bolt right up to the D-20?

 

[Burkulater]

found it its the T170ft and the shifter is comming out of the top farther back then some of the other tranys being used which is a good thing

 

[73stallion]

think you're talking about a ford RUG-T170 with a jeep RTS-T170 shift tower. i looked into this a long time ago.

 

[Burkulater]

yeah from what I read you could piece one together by doing that but the T170FT they put in 80's F series came with the tower shifter

 

[Viperwolf1]

I came across one of these, sort of. Really looks like a '60's version toploader converted to Bronco output shaft and with a T170 shift tower. HEH-P is '64 mustang toploader and it has a C5AR casting. I would expect the OD models to have a much later casting number. What do you guys think?

 

[broncodriver99]

I came across one of these, sort of. Really looks like a '60's version toploader converted to Bronco output shaft and with a T170 shift tower. HEH-P is '64 mustang toploader and it has a C5AR casting. I would expect the OD models to have a much later casting number. What do you guys think?

Definitely looks like an earlier 4 speed. I have a late '70's 3+1 OD that I am getting ready to swap in. On the pass side it has a large "bump" that was added to the housing to clear the OD gear.

 

[Broncobowsher]

The OD model has an easy to identify buldge on the side of the case near the front, where the 3rd gear would be on a normal toploader. This is needed to fit the overdrive 3rd gear.

If you didn't realize it this is how they got the overdrive into a top loader. In a normal 4-speed 1, 2, and 3rd gears are a series of step down gear ratios. 4th bypassing all the speed gears and is a direct drive. By buldging the case and fitting a larger gear into 3rd it is now a step UP (overdrive) ratio. They also went in and altered the 1st and 2nd gear ratios to better split the difference. So now the shift pattern is 1-2-4-3. Flip the linkage over on the 3-4 gate and they are all in the right places.

The car versions ran the overdrive on bushings. The trucks ate bushings so they got bearings to ride on. The truck version is much happier pulling a load in OD then the car version.

 

[broncnaz]

Usually the late 80's ODs have aluminum cases as well I just saw one at the pick and pull last week was tempted to grab it but didnt. Didnt realy pay attention to where the shift tower was located but I would imagine its like the one in vipers pics.

 

[bad 68]

yes it works. Ends up being about 1/2 inch longer than the stock setup. Same adapter as a toploader non OD.

The shifter for the 4sp OD comes out of the floor exactly where the coffee cup is sitting, (it's covering the hole in the carpet where the shifter came through).

In this photo is a nv3550 coming out of the floor.

No the OD out of the F150 and Big bronco do not bolt up to the D20 without replacing the outplut shaft and machining a stock EB v-8 adapter housing to accept a larger transmission output bearing.