Ford 4sp Tranny Swap in '74 CJ5

My neighbor is having problems swapping the stock transmission in a 6 cyl. CJ5 with a Ford 4sp unit. He's doing it for the overdrive. Has anyone done the same?

 

Questions about this ... which 4-speed? The only 4-speed with an overdrive is the SROD top-loader, a passenger car transmission that also came in some Broncos. That's an unusual transmission, and he'd need the specific adapter. If it's a heavy-duty Ford truck transmission, it's not overdrive.

 

:iagree: And I don't think it is a very common swap. If he is only doing it for an extra gear, he would be better off trying to find a 4spd Jeep trans. Just my .0213

 

The Tremac T-176 that Jeep used in the 80's was also used by Ford (does that make it a Ford tranny?). Maybe that's what he's doing? The T-18 was also used by Ford. Neither of these have an overdrive gear. Fourth gear on both is 1:1 ratio.

 

I believe I have a Ford T18 with overdrive in my 1963 Jeep. I was told it was from a 1-ton Ford truck. It is mated through an Advance Adapter to a 4.3L GM out of a 1984 Astro Van. I inherited the setup from the previous owner. The tree on the shifter indicates Low, 1st, 2nd and 3rd. Would you call this 4 speed? or 3 speed with a low gear?

Anyway, the 1st low really makes a mess of the gravel driveway.

 

Are you sure you don't mean 'underdrive' or 'granny gear'?

 

First, knowing specifically which tranny he's trying to install would be helpful. Also, what kind of problems he is having also would be helpful. If it is an SROD car style overdrive then using the '76 up AMC bellhousing will allow the tranny to bolt right up to the motor. Will have to change Pilot bushing and clutch disc. Nickmil

 

That's what they call a 4 speed truck tranny or 4 speed granny tranny due to the low first gear. Normally driven like a 3 speed starting out in second and only using first for heavy pulling or going slow. Still a 4 speed however you look at it. The T-18 4th gear is still 1:1 ratio just like any other non-overdrive transmission so if you have a T-18, then no, you don't have overdrive. Nickmil

 

Well, I do have the overdrive (would account for the 4th shifter on the floor). and I do have the low "granny" gear as well. Will have to take another look to see if it is a T-18. Hints on where to look?

 

I think maybe a correction to my previous reply, possibly the overdrive is connected thru the transfer case not thru the T18? So though I have the overdrive and the T18, maybe not the T18 overdrive. Does that make more sense?

 

Doug, your overdrive is mounted on the transfercase and replaces the transmission drive(bull) gear. It isn't a part of the transmission at all, but an aftermarket unit, probably built by Warn. If you crawl under the rig and look at the back of the transfercase, you will see the unit up and to the left of the parking brake drum.

 

Ahhh, Sooooo. That makes more sense as the U.S. used T-18's didn't have overdrive in them. On the side of the transmission case should be cast in T-18 and some numbers or 13- and some other numbers IIRC. Don't go by the shift top as early T-18 and T-98 shift tops interchange. There may also be a tag bolted to the top with some stamped in #'s. Nickmil

 

This smells funny. '74s have a dana 20 tcase. As far as I know nobody ever made an overdirve for these. Thus I suspect that the whole setup may not be stock. Been wrong lots before, this might be another occasion.

Karl

 

Don't get mixed up...there are two threads in one here -- sorta got hijacked. Original poster has a neighbor with a 74. Doug has a 63, probably with an 18 xfer and warn box.

 

Sorry my fault!

 

Thanks.

Karl