Bushing and pin in 1939 shift fork

K

ktgarcia

Senior Member
Are there any tricks to changing out the two brass bushings in a 1939 Ford 4-speed transmission? I have removed the one side (the easy one) and have tried to tap the new bushing into place with not much success. Is it ok to heat the bushing hole with a torch to expand the opening to allow for the new bushing?
I have tried to tap out the pin on the other side where the shift rod fits but no movement has occurred. Again, should I heat this and try to knock the pin out so I can then change out the other bushing. Any ideas would be appreciated. Thanks.
 
Curious.....where are these brass bushings you are trying to replace? Are you by any chance talking about the two bushings that control the clutch release shaft & fork?
 
Yes. The two brass bushings are where the clutch release shaft and fork rod rides when shifting. The pin I am referring to is the one where the clutch release shaft arm (part #7511)is connected to the clutch release shaft. It appears I need to take out the pin to replace the bushing on that side. The other bushing can be taken out by just sliding the clutch release shaft to the other side which leaves enough room to drive it out. If I heat the cast iron transmission housing, will that hurt anything. The pin seems like it is going to be more difficult and if I heat that, it would seem the heat would be transferred to the pin and make it
just as tight. Thanks.
 
I haven't had the honor yet to replace these bushings, but I'm assuming it's best done on an empty transmission case ON THE WORK BENCH, with the cross shaft out. Most likely, after the bushings are in, they might need to be reamed or honed to get the shaft back in. Also, if the bushings are that shot, the shaft would probably need to be replaced too (or maybe just rotated 180 degrees.)
By the way, I think that getting the two pins out (for the fork on the inside and the lever on the outside) rank high on the list of nasty things to do on these old cars!
 
If you have a dremel tool, get the 1/8" dia bit (tungsten? or something....looks like a drill bit but made for grinding steel). If you are patient, you can grind off the head of the retaining pin. Then use a long (12" minimum) 1/4" drift punch to drive the pin out from above....place the drift thru the inspection cover hole and use a big heavy hammer. THen you can knock the clutch release shaft out the side, which will slide thru and out of the fork in the process.

Use a pointed tool (or old beater screwdriver) to catch the lip of the bronze bushing. Tap the driver down thru the opening to collapse the bushing, then knock it out. Tap the new bushing in with a bushing driver if you have one. Be sure to line up the grease hole in the bushing with the same in the case.

The shaft can be rotated 180 degrees to bring the good side of the shaft toward the front on each side. Or replace the shaft with a new one. Chances are you will have to ream or hone the inside of the new bushings to get the right fit on the shaft. It should not be hard to rotate with your hand.

Replace the pin in the fork & shaft with a new one. I drill and cotter the bottom end of the pin. Some guys use a new grade 5 bolt and lock washer instead.
 
You must log in or register to reply here.
Back
Top