****** or rear end

Peter J

Peter J

Well-known member
Hey Guys,
I've checked the old threads but I couldn't find this question addressed. My 29's older resto. was cosmetic only so I keep finding these things. The drive train is really loud whine in all gears (I know some is acceptable). How would I isolate the gear noise? Trans or rear end. Both have fresh fluid and no metal flakes when I changed them.
Thanks for your thoughts
Pete
 
Do to lack of knowledge some people, when doing a restoration, fail to take the rear end apart and check the preload on the pinion gear; if loose can make some very strange noises and can eventually fail; also the axel nuts need to be checked for at least 80 lbs of torque. Loose axel nuts will sound like the rear end is goind out.

Ron
 
The trans will make little or no noise in high gear as the power is merely going straight through the trans and not utilizing any of the gears. 90 wt. oil is not too thin, that is what I have used for the last 40 years, with no problems.
 
Gear noise in trans will be different in each gear, with no gear noise in 3rd.
Front trans bearing will make noise in neutral, but not in gear with clutch depressed.
The ring and pinion gears if noisy will make different noise under power than when coasting, pinion bearings can also make different noise between driving and coasting, Differential side bearings make a slower grumbling because they are only turning wheel speed.

With my car there is no perceptable gear noise in 3rd, and only slight whine in the other gears, but I started with a car that probably had less than 50,000 miles.

In 3rd gear does noise change when going on and off throttle? --if so then probably is in rear.

Does noise change in neutral when pushing on clutch and putting in 1st ? --then look in trans/clutch.

If you have jack stands put rear of car on stands, run in different gears and listen ---don't run fast , some brakes can be used to simulate driving load (only for short time, then let cool) ---sometimes I just turn wheels in neutral with my hands and listen when the car is jacked up or on a lift --

A lot of times a gear noise will need more speed to be evident, a bearing noise can be evident with any movement.

It is possible that everything is making noise making it hard to find a single problem.

What are you using for gear oil?
 
I know I'll get some reaction, but I put 600W+some STP in the rear end (about 1/2 inch below the hole) and STP in the trans.
 
I wouldn't recommend STP as a lubricant. Studebaker Technical Products only recommended it as an engine oil additive to modify viscosity. You will have a hard time even getting it out of your trans. Lubriplate makes gear lubricants from SAE 90 to SAE 250 viscosity that you can buy from a distributor. I would say at least mix some SAE 90 with your STP.

The rear axle can make a lot of noise and it travels up the torque tube giving an effect like it is coming from the trans area. Gear whine in all gears is most likely the rear axle due to not enough preload on bearings or too much/to little ring gear to pinion backlash. Higher viscosity lubricant won't make this problem go away.

Kerby
 
Thanks guys. I took it for another spin around the block and it's noticeably quieter coasting and in high gear. Could it also be due to a number of years just parked with little or no lube circulating? I keep reminding myself that my 1st A in highschool was over 40 years ago which would make it almost new!
 
Peter,

I also use STP, straight in the transmission, mix in the rear differental.

My son was a mechanic on a drag racing team and he said to not use STP in the engine as it would all end up in the bottom of the pan; he suggested using it in the transmission and differental as it was captave and the gears would continually be picking it up and moving it to the top; he said the only reason the drag team used it was because the engines were set up loose and after a couple of runs the engine would been torn down.

It sure makes the transmission shift easier and I have had no problems; been doing this for about 20 years and its worked fine for me.

Ron
 
Thanks Ron,
I think I'll keep running it. If the trans. is going south anyway, it shouldn't hurt. I guess I can pull the shift tower and take a look at the gears to see how bad they are. If they look OK, I guess it's probably the bearings.
Pete
 
My experience with drive train noise is that it is almost impossible to tell where it is coming from. Whatever is causing it telegraphs itself up and down the drive train. Quite often a customer will describe a noise coming from the drive train and ask where it is coming from. I don't have a clue. The only way I could ever build a data base of faults is if I drove the car a considerable amount, then tore it down to find the cause. Most cases when I rebuild a rear end and find all sorts of things shot, I never drove the car so I don't know what it sounded like.

If your car sat for many years I would try to correctly lubricate everything possible. The Model A is very forgiving and if it runs and the drive train noise is not too bad and you can live with it, leave it. If not tear the transmission and rear end down and rebuild them. It is not that difficult.

Tom Endy
 
Thanks Tom,
I didn't mention that I was running it without the floorboards in which could contribute a lot to my preception. Trans. and rear end work has always seemed daunting to me anyway. Too many gizmos I've never truely understood but then again, I rebuilt the steering and learned a lot in the process. I guess learning new stuff is the secret of the hobby.
Pete
 
Peter J said:
Thanks Tom,
I didn't mention that I was running it without the floorboards in which could contribute a lot to my preception. Trans. and rear end work has always seemed daunting to me anyway. Too many gizmos I've never truely understood but then again, I rebuilt the steering and learned a lot in the process. I guess learning new stuff is the secret of the hobby.
Pete
Click to expand...

No wonder it is loud, I ran mine with floor boards of course and carpeting and I found the noise unacceptable. I insolated the floor and what a difference! I now have all the car insolated except the kick panels and will do them this winter.

dusty
 
Tom Endy said:
My experience with drive train noise is that it is almost impossible to tell where it is coming from. Whatever is causing it telegraphs itself up and down the drive train. Quite often a customer will describe a noise coming from the drive train and ask where it is coming from. I don't have a clue. The only way I could ever build a data base of faults is if I drove the car a considerable amount, then tore it down to find the cause. Most cases when I rebuild a rear end and find all sorts of things shot, I never drove the car so I don't know what it sounded like.

If your car sat for many years I would try to correctly lubricate everything possible. The Model A is very forgiving and if it runs and the drive train noise is not too bad and you can live with it, leave it. If not tear the transmission and rear end down and rebuild them. It is not that difficult.

Tom Endy
Click to expand...
I am not sure how this thread post works. Tom---
Do you rebuild rearends for model a;s professionally?? ronengen@cox.net
 
I had noise only in 3rd gear also and took it to a Model A expert and he said it's the bearings in the transmisson..... When I pushed the clutch in the noise went away in third and came back when the clutch was let out. This spring I have to drop the rear end and take the transmission to him to have a look at it. All this after putting a new engine in last summer. Learned this lesson the hard way!
 
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