1929 transmision

P

pinball73

Senior Member
Ok guys! I need some info! this past winter I rebuilt the transmission in my restored 1929 two door model a! it went good, at least I thought it did. after getting it back in the cat I still have a little noise in second gear that I just don't think sounds right! maybe a little noise in first, but not bad, but the other gears seem to be alright ! after reading on this I am wondering if I could have a 28 gear box instead of a 29? if I am correct the 28 uses brass shims on the front & back of the cluster gear! there were none it it when I tore it down! but I am probably not the first one to be in there! is there a way to for shore identify a 28 case from a 29, other than the boss where the cluster fits. I had a little front to back slack in the cluster, but I didn't think it was that excessive . Maybe I an just too concerned & just forget it & drive on, heck it is only 89 years young!
 
A little front to back slack does not give an accurate description of end play. You do not want an excess and the end play should be very little as in "only a few thousandths clearance between the two bosses in the case" as stated in the service bulletins page 311. The case changed in January 1929 btw. If it is the old design case there will be more than 1/8" clearance and be necessary to use the thrust washers.
 
when you rebuilt the gearbox did you knock the ridge off from the gears? over the years of people clashing gears they get "upset" at the mating ends so the teeth arent flat( square) and can cause some noise.
 
denniskliesen said:
A little front to back slack does not give an accurate description of end play. You do not want an excess and the end play should be very little as in "only a few thousandths clearance between the two bosses in the case" as stated in the service bulletins page 311. The case changed in January 1929 btw. If it is the old design case there will be more than 1/8" clearance and be necessary to use the thrust washers.
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where could I find a copy of the service manual that you mentioned? if I decide to go back in to it again this coming winter ii would want to have the specks! almost Shure I have more slack than you are talking about.
 
At this point and after going back and reading the original post, you could first remove your floor covering and or what you have and the floor board. Remove the shifter tower. Drain the fluid. Jack up the rear axle and release the park brake. Have a good light and slowly turn the shafts looking at all of the teeth on every gear with the sliding gears in neutral. If there is flaking from the teeth then your transmission will have a grinding sound. You will need to turn your engine to get a look at the teeth on the input shaft gear. With the top cover off you will also be able to stick a screw driver down in between the case and the cluster gear rocking it forward and back to determine how much end play you have. It's normal for a Model A transmission to have some noise in reverse, first, and second gears because all of the gears have square cut teeth. Later style transmissions made after the Model A have bevel cut teeth and therefore will not make as much noise.
 
When you take the trans cover off try to move the cluster ahead and astern.There should be very little play .If you have a 28 case with no shims in place there will be a lot of play,you could not miss it .Do not start the engine with the trans top off or engage the starter but I bet you most likely know that .


John in sunny Suffolk County England .
 
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