Transmission / Overdrive: loud gears

[raoul5788]

The other day I finally got around to replacing the clutch release bearing in my '61 6 cylinder 3 sp od Lark wagon. The funny thing is that the bearing seemed fine! My brother has a lift, so I "let" him do most of the work. Besides, he's a lot younger than I am! Anyway, we didn't replace the bearing because the old one seemed okay and besides, the replacement I got wasn't the right one. We did replace the pilot bushing and put in a rebuilt pressure plate and disc. Now the gears are noticeably loud when driving. The starter also is a lot louder. It sounds like the bell housing wasn't installed correctly, but we used the same alignment bolts that were there. Also, the driveshaft was a bear to get out. We had to loosen the axle to do it, and use a come a long to get it far enough forward to get the axle back in! I did check the motor and tranny mounts, and they don't seem out of place. Maybe the driveshaft has been too long all along? Anyone have any ideas?

[Skybolt]

That's not right. The drive shaft should easily slid forward and drop out of the u-bolts. It could be the wrong shaft which is putting undue stress on the transmission. If you check the length and post it someone will confirm it for you or it can be referenced against the manual. When I get home I can check with what I've got. I did a 3 speed to an OD swap and can Check lengths but your best bet is to check what the manual recommends.

[Skybolt]

I was just looking at the parts manual and questions pop up? Is it the original differential? Depending on that there can be an inch or more difference.

[studegary]

Either the driveshaft is too long or something (engine/trans. or rear axle) is out of place or something is in the way. If the rear end was hanging down when the work was done, there should have been a lot of room to move the driveshaft into the transmission. If you did it with a wheel lift, there still should not have been a problem removing or replacing the driveshaft. Have you checked the simpe things like something in the end of the driveshaft yoke or something interfering in the transmission where the driveshaft goes?

[raoul5788]

I don't know if the differential or driveshaft is original. The overall length including the saddle for the universals is 53 5/16". Gary, I think you may have hit on the problem. I don't think the slip yoke is all the way in. Here is a picture of it. There is about 5/8" of the yoke exposed. Would the driveshaft being like it is have anything to do with the noisy gears and starter motor?

[studegary]

I don't know if the differential or driveshaft is original. The overall length including the saddle for the universals is 53 5/16". Gary, I think you may have hit on the problem. I don't think the slip yoke is all the way in. Here is a picture of it. There is about 5/8" of the yoke exposed. Would the driveshaft being like it is have anything to do with the noisy gears and starter motor?

Some yoke should be exposed when installed. The driveshaft needs to be able to slip in and out a bit when the rear axle goes up and down as the car goes down the road.
You may have something obstructing the yoke and preventing normal installation.
At this point, I think that the most likely possibility is that someone changed a 27 rear for a 44. The 44 requires a slightly shorter driveshaft. If the driveshaft wasn't shortened or exchanged for a correct one, you would have the problem described. What rear axle style is now in the car?

[sweetolbob]

I don't know if the differential or driveshaft is original. The overall length including the saddle for the universals is 53 5/16". Gary, I think you may have hit on the problem. I don't think the slip yoke is all the way in. Here is a picture of it. There is about 5/8" of the yoke exposed. Would the driveshaft being like it is have anything to do with the noisy gears and starter motor?

Chip

I don't know Stude yokes but a lot of GM yokes are only broached about as deep as you show yours mounted. I'd make sure you 1/2" or more for the yoke to move forward on the trans output shaft.

Bob

[raoul5788]

Some yoke should be exposed when installed. The driveshaft needs to be able to slip in and out a bit when the rear axle goes up and down as the car goes down the road.
You may have something obstructing the yoke and preventing normal installation.
At this point, I think that the most likely possibility is that someone changed a 27 rear for a 44. The 44 requires a slightly shorter driveshaft. If the driveshaft wasn't shortened or exchanged for a correct one, you would have the problem described. What rear axle style is now in the car?

It's got a 44 in it. Anyone know what the correct length should be? Just how do you measure it? I have heard you are supposed to measure from weld to weld. Is that true?

[raoul5788]

Some yoke should be exposed when installed. The driveshaft needs to be able to slip in and out a bit when the rear axle goes up and down as the car goes down the road.
You may have something obstructing the yoke and preventing normal installation.
At this point, I think that the most likely possibility is that someone changed a 27 rear for a 44. The 44 requires a slightly shorter driveshaft. If the driveshaft wasn't shortened or exchanged for a correct one, you would have the problem described. What rear axle style is now in the car?

According to the parts book, the driveshaft for a 61s with a 27 rear is 2 5/8" shorter than one for a 44 rear, not longer.

[studegary]

According to the parts book, the driveshaft for a 61s with a 27 rear is 2 5/8" shorter than one for a 44 rear, not longer.

I don't have a parts book here, but the only 61S with a 44 may be a police/taxi application.

[Bob Andrews]

Just how do you measure it? I have heard you are supposed to measure from weld to weld. Is that true?

I assume Studes are like every other car in this respect; and that is, you measure driveshaft length from centerline of universal cap to centeline of universal cap. That's how I've always measured driveshaft length.

Some cars have different length slip yokes, so be sure of that as well.

[raoul5788]

I assume Studes are like every other car in this respect; and that is, you measure driveshaft length from centerline of universal cap to centeline of universal cap. That's how I've always measured driveshaft length.

Some cars have different length slip yokes, so be sure of that as well.

After looking at the websites of some driveshaft companies, it apparently varies from shop to shop. Most say to measure from the end of the transmission to the center of the back universal. Not all are the same, though.

[sweetolbob]

After looking at the websites of some driveshaft companies, it apparently varies from shop to shop. Most say to measure from the end of the transmission to the center of the back universal. Not all are the same, though.

If you put the yoke in the trans output shaft and run it forward until it stops and back if off about 3/4" to allow play and measure centerline to centerline, you have established a length and description than any drive shaft fabricator or shop can understand. It will also give you the dimension you need to answer your question.

Bob

[Skybolt]

Looking at the manual for the year and model helps but measuring the diameter of the tube helps even more in determining what length you have but it does change for different years as well. If just the differential was changed your drive shaft would be 2 1/4" longer than needed. Does any one know if there is a part number cast into the yoke?

[studegary]

Looking at the manual for the year and model helps but measuring the diameter of the tube helps even more in determining what length you have but it does change for different years as well. If just the differential was changed your drive shaft would be 2 1/4" longer than needed. Does any one know if there is a part number cast into the yoke?

I thought that the driveshaft for a 44 would be shorter than one for a 27 (not necessarily 2 1/4"). Gary A's research indicates otherwise. Has anyone else double checked this?