Transmission Rattle

[51_Meadowbrook]

I had been enjoying my ‘51 Meadowbrook and took off from a red light. First gear was fine, second gear started making some rattling, then third gear was rattling so bad I thought I was going to lose my driveshaft. I got it home and checked and the driveshaft is fine. The u-joints seem solid. There is some play in the rear end. I topped off the differential and left the house and it started rattling bad in second too. After about a month of not driving it I took it out tonight around the block. Second gear sounded quieter but still rattling and third gear was rattling. I can’t seem to figure out what it is. It’s only when I accelerate. If I am coasting it doesn’t make the noise. If I push the clutch when coasting it doesn’t make the noise. But as soon as I press the accelerator it starts rattling again. There is no rattling in reverse. I see no signs of anything scraping. I checked the transmission mounts and they are tight. The transmission is a 3 speed manual fluid drive, not the gyro-magic electronic shift. Any suggestions?

[Doug&Deb]

This is a stretch but have you checked the engine mounts? Excessive wear could cause things to move strangely. Also are you sure the noise is from the trans?

[knuckleharley]

I would start with dropping the driveshaft,draining the oil from the rear and looking through it VERY closely before dumping it.

 

I can't remember if that rear has a cover plate or not,but if it does,pull the cover plate,put the rear wheels up on blocks,and then have a friend turn a tire back and forth while you look for slack and clashing. IF the teeth all look to be in pretty good shape,you might be able to get away with adding some shims to take up the slack.

 

Frankly,if there is a lot of wear you would probably be better off just bolting a more modern rear in it with better brakes. Probably be cheaper and quicker than tracking down NOS rear gear parts,buying them,and installing them,too. Especially if you don't have a dial indicator or know how to use one to set backlash.

 

I am sure some of the guys here can pipe right in and tell you which modern rears are an exact fit and what to look for,but I ain't one of them.

 

Hell,go ahead and keep your old rear instead of scrapping it. You might see new replacement parts to fix it for cheap on ebay or somewhere else,and then want to fix it and sell it to a restorer. Or even put it back in your car.

 

   BTW,I obviously got mixed up,but the same basic things apply to your transmission. There really ain't no easy fix. You are going to have to take it out to find out what is wrong and to repair it. Don't have the first clue as to parts abailibity,but I am sure someone here does.

 

Chances are someone here might even have a good trans to sell you cheaper than you can fix yours.

Edited September 15, 2021 by knuckleharley

[kencombs]

25 minutes ago, 51_Meadowbrook said:

I had been enjoying my ‘51 Meadowbrook and took off from a red light. First gear was fine, second gear started making some rattling, then third gear was rattling so bad I thought I was going to lose my driveshaft. I got it home and checked and the driveshaft is fine. The u-joints seem solid. There is some play in the rear end. I topped off the differential and left the house and it started rattling bad in second too. After about a month of not driving it I took it out tonight around the block. Second gear sounded quieter but still rattling and third gear was rattling. I can’t seem to figure out what it is. It’s only when I accelerate. If I am coasting it doesn’t make the noise. If I push the clutch when coasting it doesn’t make the noise. But as soon as I press the accelerator it starts rattling again. There is no rattling in reverse. I see no signs of anything scraping. I checked the transmission mounts and they are tight. The transmission is a 3 speed manual fluid drive, not the gyro-magic electronic shift. Any suggestions?

Well, the only I can think of is cluster gear bearings.   When In low or rev,it is under pressure. And would tend to move away from the pressure and stay there.  In second andhigh it is not loaded so loose needle bearings or thrust washers would show up