Sherman transmission "pops out"

I have a 1952 TO-30 that hasn't been used for a while. Tractor starts and runs ok but the selector lever for the transmission won't stay engaged. I don't recall hi/low vs up/down on the selector but in order to keep the transmission engaged I have to keep my foot on the lever to hold it down and it won't engage "up" at all. Any ideas?

It depends on which sherman trans you have. On the combo if you have the first generation style the detent shifter
rods are exposed at the ends as in the one on the left in the photo. Later generation models were enclosed like the
one on the right.
Some rust could have developed if the tractor sat or hadn't been shifted for a while on the exposed rails. Pop your
steering box off and you might be able to spray some PB Blaster on it and get it going again. If it's the second or
third generation you will have to put the top cover off the sherman to have a look see. You might be able to work it
out thru the steering box hole. I have done this many times on the fords and it's not easy but I have only taken them
out by splitting the tractor on a ferguson. I Never try to pull the top cover off the sherman on a ferguson. Don't
know if your starter rod will be in the way.
BTW, the ones in the photo are both ford cases. The one on the left has be altered so it will fit a ferguson so that
the starter rod stayed intact. This came out of one of my TO30's. With so many more ford sherman's available guy's
adapted them to fit the ferguson. There were ferguson models build to fit the fergusons available back in the day but
you don't see many around any more.
If you need more photos of any of the sherman parts I have several on the bench part for rebuild.

Kirk

Here's a photo of accessing thru the steering box. Although this is a ford you get the drift.

Kirk

As for what model transmission I have, turns out that is a "HUPP" rather than a Sherman. I never really looked before but the lever on the outside right of the gear case does indeed have hupp embossed on the end. My son-in-law ordered a Ferguson manual yesterday so we wait to get that and see if we can dig up any information on the hupp tranny before tearing into it. JP.

Here's some sales literature. The dual drive had a round ball at the end of the shifter where the overdrive model had a
tab at the end of the shifter. I don't think they made one with a top cover that could be removed so you are probably
going to have to split the tractor to gain access.
literature link

Given the ball rather than a tab on the end, it would be the "dual drive" version. The cover I mentioned is for the tractor transmission itself which does not allow access to the Hupp mechanism so yes I will need split the tractor. I did it about 20 years ago to replace the clutch plate so if my memory is not too atrophied I can likely get it done in a timely mannner. Also I can make my son in law do much of the work as he will end up using the tractor this winter.

A HUPP. Just curious as to the top speed of your tractor. Was it 15 MPH or 25 MPH?
Popping out of gear could very well be worn gears or shift forks. Might get lucky with a bent shift fork. Either way sounds like you
have a split in the future. Just don't forget to pre-fill the Hupp prior to installation. In fact, over filling also works as it
will drain down to the proper level through the rear gear. Failure to pre-fill will damage it as it will not fully fill during
initial operation.

Although I have never paced the tractor with a vehicle, I would guess the top speed is well over 20mph.

Hmmmm! On every Hupp overdrive I have ever seen the lever comes out the right side, not the left. I think you have a Sherman combination. I don't get that lever deal with Hupp on it. If the picture shown is your Ford, the lever looks like one for a Sherman combo. The lever for a Sherman overdrive is a 3/8" rod with a plastic ball. The combo is cast steel so it can be pulled in and out to go between hi and low without bending.
Look up "Sherman Transmissions-Smiths Old Ford Tractors". That will help you more than me.

Irv

Guessing ain't knowing.
Once you split that tractor and remove the Hupp front cover you will find out.
If the Allen headed bolts in the rear are covered by the rear gear you have a low range Hupp. If you have no problem getting to the bolts, you have a high range Hupp. In the first case, rotate the rear gear to the notches that line up in the gear to allow access to the bolt heads.