3 Speed Trans Open Drive to Close Drive?
- Thread starter 2935ford
- Start date
rotorwrench
Well-known member
You will need the main shaft as well as the rear bearing retainer & clam shells from any of the different 3-speed Ford transmissions depending on what rear engine mount you choose to utilize. Stuff like this can still be found on flea-pay or from used parts sources. The 39 thru 48 car transmissions all use the same or similar gears & shafts depending on the drive gear ratio preferred,
My jalopy has a 39 ish rear with 3.78’s, about the same year truck trans. I also had leftover 46 parts and put the later gears in the early case, good shape. Wish I didn’t, 1st seems tall and with aluminum flywheel prone to stall. I guess a 29 tooth cluster is the way to go
2935ford
Well-known member
The cluster gear is 28-24-18-14. Haven't seen the part number yet.
The 18 gear is a bit chewed up (of course.....being the expensive set).
As is the low/reverse sliding gear.
Will also need synchros and roller bearings etc for a nice rebuild.
I will clean up the case and check for cracks.
The 18 gear is a bit chewed up (of course.....being the expensive set).
As is the low/reverse sliding gear.
Will also need synchros and roller bearings etc for a nice rebuild.
I will clean up the case and check for cracks.
V8COOPMAN
Well-known member
That should be the most common gear set with a 2.82 1st gear. That give you a 10.65 OVERALL 1st gear ratio which is just fine for a street-driven car. DD
Bored&Stroked
Well-known member
The conversion is easy, but the harder part is finding a really nice main shaft. I've found a few NOS ones in recent years - but they are hard to find as of late. Make sure you mic the nose of the input shaft - it should not have any rust pits and should not be worn in the least. Do not buy the repop caged roller bearings for the cluster and main shaft - every one that I've seen has the wrong material and heat treatment of the cages on the ends - causing rapid wear and potential failure of the bearings. Try to find NOS originals or used ones in really good shape.
Do not buy the repop cluster gear shafts (the .750 ones that go from end-to-end in the case) - they are of the wrong material, wrong hardening and are .001 undersize. This causes lots of issues over time - starting with a nasty tendency to leak gear lube on your garage floor, rapid wear, etc. I make my own shafts from linear shafting materials. You can surely use original shafts - just try to find one that is not worn (and many are).
The fitment of the main shaft to the input shaft is critical - so using the best parts possible is key. The goal is to reduce the amount of play/deflection in the fitment - which takes really good bearings and unworn main shafts. Make sure you pay close attention to the amount of end-play on the main shaft (with the gears stacked on). I try to achieve the low-end of the scale (which is .004) - in some cases going to .003 if I can.
Also, I have Charlie NY re-bush the 2nd gear for a tight fitment on the actual main shaft I'm using. He recently did 4 of them for me - he does really nice work! Having tight tolerances seems to help prevent the all to common "popping out of 2nd" problem that many of these transmissions experience.
Lastly, Mac VanPelt's rebuilding book is a good resource for all the specifics and various parts combinations (as there are multiple synchro hub/mainshaft combinations - just one example). He is a good source for rebuild parts as is ThirdGen Auto and others . . .
Do not buy the repop cluster gear shafts (the .750 ones that go from end-to-end in the case) - they are of the wrong material, wrong hardening and are .001 undersize. This causes lots of issues over time - starting with a nasty tendency to leak gear lube on your garage floor, rapid wear, etc. I make my own shafts from linear shafting materials. You can surely use original shafts - just try to find one that is not worn (and many are).
The fitment of the main shaft to the input shaft is critical - so using the best parts possible is key. The goal is to reduce the amount of play/deflection in the fitment - which takes really good bearings and unworn main shafts. Make sure you pay close attention to the amount of end-play on the main shaft (with the gears stacked on). I try to achieve the low-end of the scale (which is .004) - in some cases going to .003 if I can.
Also, I have Charlie NY re-bush the 2nd gear for a tight fitment on the actual main shaft I'm using. He recently did 4 of them for me - he does really nice work! Having tight tolerances seems to help prevent the all to common "popping out of 2nd" problem that many of these transmissions experience.
Lastly, Mac VanPelt's rebuilding book is a good resource for all the specifics and various parts combinations (as there are multiple synchro hub/mainshaft combinations - just one example). He is a good source for rebuild parts as is ThirdGen Auto and others . . .