Noisy Transmission

Colorado Greg

Colorado Greg

Senior Member
I finally have my '29 Coupe running and stopping. This car was restored in the early 70's and was not driven very much, (2000 miles or so) It had been sitting for 7-8 years without being run before I got it. I went through the fuel system, cooling system and brakes.

Now that I'm able to drive this car, the transmission is awfully noisy in 1st and 2nd gear. It does quiet down in high gear and sounds ok. When I drained out the old fluid, it was awfully thin and ran out easily. I changed the fluid to the 600w stuff the Model A stores are selling and it seemed to help the noise and ease of shifting, but I still have the noise.

Any ideas or comments will be greatly appreciated.
Greg
 
More than likely the two slider gears and the cluster gear have worn and pitted teeth. It is also possible that the three small roller bearings (two in the cluster gear, one in the input shaft) are shot.

When you are in high gear the drive is straight through the transmission from the input shaft to the output. There is no gearing going on. If there is noise in high gear it is usually caused by eiher of the two ball bearings, front and rear, being shot.

If you can live with a noisy transmission I would leave it alone until the times comes when you need a new clutch, then you can rebuild the transmission while it is out. A noisy transmission usually won't completely fail and leave you stranded.

Tom Endy
 
all model a trans make noise because of the straight cut gears, watch an old movie that shows an a taking off, you can hear the whine in first and second gear, as tom said if it has set for a long tine either some of the gears and pocket bearings have rusted from moister in the trans caused by condensation, seeing it is a major operation to remove the trans and if the noise is not unbearable just drive it, your not in first and second that much anyway, if you dont live in real cold country and dont drive in the winter put a half can or so of stp in the trans, real thick oil makes it hard to shift in very cold weather till the oil warms up and thins out, as long as the noise is sort of a whining noise and not grinding and rumble in the trans just drive it
 
It's more than likely there is condensation and rust in the ******. I got the car out of CA and everything was starting to rust, chrome is pitted etc...

It is a whining noise, no grinding or rumbleing. Its just louder then it should be in my opinion.
 
run it awhile it might quit down some more. You might want to rechange the fluid again later.
 
RonC said:
run it awhile it might quit down some more. You might want to rechange the fluid again later.
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I agree;

I do not think you can hurt it by running it. If it starts to get a lot worse, it may be time to remove the transmission and get into it.

Just my opinion,

Chris
 
i had a transmission sitting for a couple of months, i filled it with diesel then pulled every thing apart and held all the parts against the wire wheel before reassembling, removing all the rust made quite a difference. it still wines but low noise. i put most everything through this process.
 
I agree with the others, drive it.. Some of the model A vendors sell a concoction of 140 wgt oil with STP as their 600W.. It you are only going to use this monster in warm weather then maybe changing to 250 wgt would help.. I've had the tower off my transmitter several times and everything looks pretty good for its age, but, its a howler.. Its all part of owning an old-timer and it gets peoples attention..
 
one other thing to check is if the brass horseshoe shims are in the flywheel housing. They should be between the block and the "ears" on the fly housing where the throttle bracket attaches. If they are missing, the transmission drive gear is misaligned between the clutch pilot bearing and the cluster gear and will wear the cluster teeth until they are pointed if allowed to run that long. The stress on the inner needle bearing between the main shaft and main drive gear wears the bearing and inside pilot too. It also makes more noise when it does that. The shims are not difficult to install if there are none. It is probably not the only cause of noise, but could be one. I suspect rusty or pitted gears are involved as well.
 
pat in Santa Cruz said:
one other thing to check is if the brass horseshoe shims are in the flywheel housing...
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Good advice, but a word of caution--many of us are using RTV instead of a gasket between the flywheel housing and the block. In that case, the shims must be deleted as they would cause equal but opposite misalignment. A thin layer of RTV takes up essentially zero space.

It may be difficult to tell, but if the shims are missing you should make an effort to determine whether the gasket is also missing.

Joe
 
JoeWay said:
It may be difficult to tell, but if the shims are missing you should make an effort to determine whether the gasket is also missing.

Joe
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GOOD POINT;

Suggestion;

Loosen the top two flywheel housing bolts and see if you can slip a feeler gauge between the ears of the housing and the block. If so, install a shim of equal thickness to the thickest feeler gauge you can slip in. If there is no gap, re-tighten the bolts.

Usually, what I find if these shims are missing is that one or both of the ears are broken off.

Something you may want to try.

Chris
 
Your second sentence kind of explained it to me.Early 70's restoration.Restoration expectations(with exceptions of course)were a lot different.Model A's were mostly fixed up by old timers that planned to go 45 MPH,tops.Info was not as easily available.Parts were not available as they are now.If you turned in Model A circles you had access to good used and NOS.Those guys knew transmissions would howl,but they also knew actual breakage was pretty rare.They made the cars shiny but never went far with them.I always feel that if you buy a 70's restoration figure on doing the chassis over.I have seen probably a dozen cars that I would not drive anywhere.Mostly poor steering and brakes.I got a 29 phaeton running a couple of years ago,it was an old restoration that had been in the owners family since new.Nice looking and kept under cover.I got it to run,then took it up the driveway.I didn't even want to drive it the 600 feet back.1/2 turn play in the steering,front spring flattened to the point of the eyes jammed against the perches,in-out clutch,no middle ground,the transmission actually screeched at me.Grandpa had redone this car in the early 70's,and it was beautiful,just not driveable.I constantly hear,All restored,All restored,All restored.Then they buy it and find they can't even drive it.I usually tell them,look,you have a nice body,paint and upholstery,we can attack one piece of the underpinnings at a time.
 
The ****** in my '28 Special Coupe is very noisy in 1st & 2nd too - nasty growly-grunchy. Third is silent.

I had a '50 Chevy car years ago that made similar noises; that turned-out to be worn counter-shaft bushings.

Some gear whine in reverse, 1st, 2nd is normal; I actually like it... direct drive ( 3rd) should be all but silent, as there are no gears transmitting power.

I don't know how much whine is acceptable for an A; mine sounds like a rock-crusher.

SC Frank
 
When you change the oil follow with a flush of kerosene, then the new oil heavier than 90wt.. Sounds like you are the judge of how noisey you want the transmission to be. Just keep in mind either way you remove the transmission to rebuild it you are looking at a big job for a first time project. Team up with someone to make it go easier. May as well redo the clutch and brake pedal, and the shift tower at the same time.
 
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