What transmission parts do I need?

sjhark

Member
Hi all,
I'm restoring my 1931 Deluxe Roadster, using money from what my wife refers to as "the Family Food Budget". I will be working on the transmission, as I know that at least the throw out bearing is bad. The car has about 5000 original miles on it, mostly town miles, driven by a little old lady.
My question is: what parts of the transmission usually need to be replaced during a typical overhaul? I already have a couple bearings, but what about the shafts and gears? The Family Food Budget won't allow me to spend upwards of $900 for a complete kit, so what parts should I absolutely get as I can afford them? I understand that I will only know for sure when I get it apart, but I'm on a self-imposed timeline to get this done and need parts available when I get to it.
Thanks for any and all your help! I've been lurking in the forum background for years and only recently joined and started posting. The wealth of knowledge here is incredible!
 
gears are typically good but check for acid pitting and or chipped teeth. Any high spots where the gears clash need to be removed. I chucked my main gear up in a lathe and turned the tops of the teeth true ever so slightly (maybe .001) just until one pass would barely touch across the entire tooth. Same with the sliding gears. Check the piolit bearing nose on the input shaft - high wear area.

I would replace all bearings - its not that much and then you know they are good. Trust me - removing the trans twice isnt fun all for a $6 bearing...

I would buy the new main shafts (main cluster and reverse idler) machined for an O ring to seal oil leaks for sure.

Then you just need a gasket set and some 600W oil.

Check the ball on the end of the shift rod and the forks in this area - 9/10 times its worn to a square - supposed to be a 1/2" round ball. If its got slight flat spots its probably still useable but the more out of round it is the more shifter slop you have and eventually it wont fully engage gears and may pop out of gear.

Check the forks for wear - will probably be shiny but shouldn't have any groove worn into them.
 
Well, I would think a true 5000 mile car should not need anything. Certainly spending any money on parts before you take it apart would be foolish.

First take the cover off and look at what you have. The gears should not be polished smooth. From the factory they would have parallel lines across the faces from the manufacturing process. The part of the gear where the sliding gears engage the other gears should have a slightly pointy and even face. The sliding shaft should not have a step on it that can catch your finger.

Look at the shifter forks for wear. Do the detents catch well when you move the shifter?

Look at the oil in the sun, does it have shiny spots from metal flakes?

If it does not look so bad and it shifts ok then put a new throw out bearing on and make sure you have the real correct oil in it. Do not try to make more work or spend more money then you really need to spend.

Les will have you put some oil on the spline shaft and see how fast the gears slide down. I measured the shaft and the gear mating surface and found I had about .001" wear and that failed his test, but is purfectly fine. If the spline shaft has a noticable bump then it may be a bit too worn.

Some will have you add O rings and seal bearings. The ****** will not leak more than it was designed to leak with the right oil. The shielded bearings will limit the amount of oil getting back to lubricate the U joint. As for the roller bearings. I measured a pile of used ones and they were the same size and just a nice a surface as the new ones. I like to use original era Ford parts cause they seem to just work better.
 
Well, I would think a true 5000 mile car should not need anything. Certainly spending any money on parts before you take it apart would be foolish.

True that a NEW 5000 car shouldnt need anything but add 60-70-80 years onto that and you have acid pitting, rust, debris, etc that can chew up bearings or completely lock up and fail.

At mimimum you need to completely dissassemble and remove all traces of the old oil/sludge and im guessing you will find some not so nice shafts/bearings but ive seen some miracles.

Be VERY observent when dissassembiling as there were slight internal modifications to the trans' over the years.

To me miles dont mean anything anymore - Ive seen new cars with 70,000 city miles that are completely shot (slipping trans, completely shot steering system, etc) yet have seen (and driven) a few with over 200K highway miles that feel new with only basic maintenance under thier belt.. The "little old lady" that previously had this model A could have clashed every gear and only drove it 2 miles a week where all sorts of nasty acids and rust form - OR someones rebuilt it long ago and reset the odometer:p
 
It sounds like you have a driver! If it doesn't jump out of gear, doesn't make weird noises,gear shifter snaps in and out gears. Replace the to bearing, flush the box, refill with good oil and enjoy! Wait later in life when you have money for a frame off restoration ! Yes I have been there and done that, trying to restore with little money, you will be redoing later.
 
If it really only has 5000 miles. I would rather have those parts than any new ones. Most of the time, original parts are better than reproduction parts.
 
Agree with he seaslugs and Kevin. Don't worry about self imposed timeline.
Tear it down and inspect all parts. Any gears that are pitted will make noise so replace them if you don't want noise. Get whatever parts you need following inspection. New repro gears are decent if they are the MARK gears from Brattons or Snyders or Berts.

I've done over 75 A trans and none of them needed just bearings and gaskets. They all needed something .
Larry Shepard
 
Also check the forks on the transmission tower for wear. You will find that the reverse idler gear bushing is wore thin. Mine had 84,000 miles on it, I replaced ever thing but the gears. The reverse idler gear is good the bushing is bad. I'm replacing the bushing not the gear. I'm not paying 70.00 dollars when all I need is a bushing.
 
Given your situation it makes no sense to take it apart. just change the oil and go. Don't take it apart unless it's broke and then only if you know what your fixing. Save your money to fix only what keeps it from moving and general maintenance
 
When I restored my transmission, the only part I replaced was the bearing between the input and output shafts. The ****** sounded like a broken threshing machine due to some crushed rollers on that one bearing, but all the rest of the parts looked like NOS parts. I never replace good original parts.
 

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Thanks for all the advice! I plan on taking it apart for cleaning and new bearings, but wanted to know if there were any inherent problems that I would need parts for.
I also updated my profile and added photos of the car. I have others that I took to get a general idea of what I had to work with, however, I haven't jacked it up to crawl around underneath yet. I'll post more photos as I get good ones.
 
I would drain the oil, flush with kerosene, look for any apparent defects on the running surfaces, refill with the correct oil and test drive. Ideally, you have a person experienced with Model A's along with you on the test drive.

On my first "A" I pulled the ****** and replaced all the gears and shafts when I had the engine out for an overhaul. It was actually relatively smooth and quiet in the beginning but I was unfamiliar with straight cut gears and thought it should sound like helical gear ******. After changing out the shafts and bearings it still ran about the same. Sometimes it is OK to leave well enough alone.
 
Today must be transmission day. I just got back from the shop and taking the transmission out of my 29 Roadster. I had a cracked axle I needed to replace so while I had the rear end and drive train out thought I would check the transmission. Haven't done much investigation yet - tomorrows job - but when I took the bell housing and throw out bearing off the bearing was not good. I agree with not replacing the old stuff if it is good so looking forward to tomorrow! Lot of good advice here.
 
I just put a nos transmission in my 30 pickup. My old transmission was leaking that's all.
Shifts better that's all. The old tower was shot,so I'll replace the gaskets in the trans and save it.
When you have a good thing leave it alone.
 
sjhark,
You're doing it ALL BACKWARDS!
That's like having internal surgery, BEFORE you know the symptoms, or WHAT organ, or a diagnosis on what that organ even needs or if the parts are on BACK ORDER or are no longer supplied or the parts are inferior re-pros & require a "little" fine tuning, BUT, the price is RIGHT! (non-returnable!)
"Dr." Bill W.
 
You're doing it ALL BACKWARDS!
That's like having internal surgery, BEFORE you know the symptoms

X2.

If it is truly a 5,000 mile car, I would change all fluids, inspect and adjust the brakes, lube it, check for any obvious mechanical fault and fix if any...then take if for a drive for evaluation. A 5,000 mile car is VERY special. I would hesitate changing ANYTHING if not necessary. My guess would be the transmission needs nothing (other than a drain, flush, and refill)

BTW, I just looked at your pictures. That was a rough 5,000 miles! :eek:
 
my 2 cents...If it ain't broke..don't fix it. I can't tell you how many times I have bought parts and didn't need them..that's one of the many reasons you have to walk sideways in my shop (ha,ha). Seems like you got a good project on your hands. Good Luck, Benny
 
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