Transmission gears interchange

[t35]

I have a 35 ford transmission case. will the later model gears (39,40,41)fit in this box?
if so do i need i 39 top gear selector?

[V8COOPMAN]

Yes, and yes! DD

[t35]

is this also true for a 32 case?

[Seth Swoboda]

Originally Posted by V8COOPMAN

Yes, and yes! DD

Coopman, will there be any fitment issues with the later cluster in the earlier case? I'm not sure that's why I'm asking. I was told once that there was a slight fitment issue. Not that it was impossible though.

[cas3]

they go in a 32 also, but its a tight fit. some times some grinding is needed, and you have to put the front bearing on while the shaft is in the case if i remember correctly.

[Seth Swoboda]

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Originally Posted by cas3

they go in a 32 also, but its a tight fit. some times some grinding is needed, and you have to put the front bearing on while the shaft is in the case if i remember correctly.

Yes, this is what I was thinking about. Does this hold true for a '35 case too?

[cas3]

35, being a 48 case, has i believe a deeper well in front for the cluster gear, so they fit better

[V12Bill]

There can be a problem with a clutch over 9" fitting the case.

[flatheadmurre]

Originally Posted by V12Bill

There can be a problem with a clutch over 9" fitting the case.

That is not based on if it´s a 18 or 48 case from what i found out...you have to look if there´s notches in the casting down at the clutch shaft and if the reinforcement of the inspection lid casting goes inwards or outwards.
They must have used different style of molds...for both 48 and 18.

[Seth Swoboda]

Is it not amazing how much knowledge there is and knowledge that is exchanged here on 85 plus year old technology? We at times have differing opinions but are all in it for the same objective. It's really great that we have this ability. Just an observation from my end.

[cas3]

i thought all the 9" fit, but the 10 or larger dont. correct?

[Mart]

In the back of my mind I think (not sure) it is the later 15/29 gear sets that may or may not fit. Earlier gearsets are generally 16/28 and ought to fit regardless of the year.

Agree on the clutch. A 10" will foul the earlier cases. My 33 had a 34 case with a 10" clutch. You could see where it had been clattering around. It must have made one hell of a racket.

[Step-down]

I just finished building a 48 case out of parts. Installed a later style Cluster big tooth in and i had to polish the inside the case ever so lightly to make everything work.

[Hoop]

Edit: Deleted

[rotorwrench]

The later 91A design transmission with a 78 case requires the correct shift fork for the later type synchroniser. The ones prior to 1939 with the 48 case or the 78 case had the earlier narrow type synchro fork. The older tower from 36 through 37 or 38 can be made to work by installing the 91A fork in the tower but most of them are just a single detent type. The old slant back tower is kind of a different story. I've heard folks tell that they made a fork work for them by welding some up some stuff to get a successful alteration but I don't know the particulars on that. The 39 car and later 3-speed light duty pickups through around 1950 or 51 had the double detent shift tower that works as is.

[t35]

i'm told that my case is a 32. i thought it was a 35. will 35 rear mount fit on my 32 case?

[V8COOPMAN]

Originally Posted by t35

i'm told that my case is a 32. i thought it was a 35. will 35 rear mount fit on my 32 case?

Yup! DD

[rotorwrench]

The numbers above the inspection port (18-XXXX or B-XXXX for 4-banger) will tell you what year it is if it hasn't had a case change along the way. It seems like the 32s had a fitting for throw out bearing service or something like that on the case too. VanPelt Sales web site has a rundown on US manufactured numbers.

[svm99]

Originally Posted by t35

i'm told that my case is a 32. i thought it was a 35. will 35 rear mount fit on my 32 case?

A picture of the case will help. To put the late gears in you need a case with the 2 1/2" dia rear thrust surface. The '32-'35 case ("18" & early "48")had a small rear thrust surface while the later "48" cases had a large rear thrust surface.

Good luck Paul