Restoration-Mini

Technical Forums => Maintenance and Modifications => Topic started by: Rosebud on August 01, 2017, 07:08:49 PM

Title: Driveshaft Help Needed
Post by: Rosebud on August 01, 2017, 07:08:49 PM
While replacing my ball joints, the right hand driveshaft slipped out of place on the transmission side, bringing with it a ball bearing cage. I've managed to collect all of the ball bearings from the garage floor and get them back into the cage, but I'm having a heck of a time refitting the whole thing back into the differential. I've got the rubber gaiter turned inside out so I can see what I'm doing.

I expected to see some sort of spline on the inboard side of the driveshaft. I see nothing but a blunt end extending a bit past the bearing cage. I think Haynes is calling this whole thing an "offset sphere joint" Yes?

Among my many questions, let's start with these...

Does the driveshaft need to somehow be indexed to the differential? Without any visible splines, what the heck joins the two together?

Any help would be greatly appreciated. Thanks.

Car: Non-S, Type IV w/ disk brakes.
Title: Re: Driveshaft Help Needed
Post by: MiniDave on August 01, 2017, 07:21:48 PM
It's a very simple joint, the balls fit into the cage and the cage slides into the pot......what holds it in is the outer hub once it's in it's proper place.

Here's a video that shows the different parts....

Title: Re: Driveshaft Help Needed
Post by: John Gervais on August 01, 2017, 07:27:48 PM
I hate when that happens...

There are ball-sized grooves in the pots, so you might need to rotate the drive shaft to line up the ball & cage assembly so that it can slide in.
Title: Re: Driveshaft Help Needed
Post by: MiniDave on August 01, 2017, 07:36:45 PM
Right, but since you didn't mark which ball went where, it really doesn't matter at this point, just line it up and slide it in.

John, good to hear from you again, we've missed you around here!
Title: Re: Driveshaft Help Needed
Post by: John Gervais on August 01, 2017, 08:05:58 PM
Hi Dave -
Title: Re: Driveshaft Help Needed
Post by: Rosebud on August 01, 2017, 08:09:18 PM
Quote from: John Gervais on August 01, 2017, 07:27:48 PM

There are ball-sized grooves in the pots, so you might need to rotate the drive shaft to line up the ball & cage assembly so that it can slide in.

Ah... ball-sized grooves. So that's how the torque gets transferred from the diff to the driveshaft. I just couldn't see it happening w/o splines of some kind, so I thought I was missing something important. So I can just slip the cage back into the diff housing, wiggling it a bit as I go until the ball bearing find the ball-sized grooves?

So, what do you think about the entire bearing cage coming out of the diff without any real effort. I just disconnected the ball joints, let the hubs droop and out popped the inboard side of the driveshaft, cage and all. Excess wear? Or is that normal?
Title: Re: Driveshaft Help Needed
Post by: John Gervais on August 01, 2017, 08:16:01 PM
Normal enough, it's designed to slide in and out such that as the drive shaft angle changes on droop or lift, there'll be less stress on the joint compared to if it were a 'U'-joint. 

I usually cut the cuff off of an old rubber glove to hold the balls in place as I slip them into the pot.  Now's also a good time to clean and re-grease them.
Title: Re: Driveshaft Help Needed
Post by: MiniDave on August 01, 2017, 08:18:41 PM
I find the stickiness of the grease holds the balls in place no problem, but John's way would work too.....
Title: Re: Driveshaft Help Needed
Post by: Rosebud on August 01, 2017, 08:59:45 PM
Quote from: MiniDave on August 01, 2017, 07:21:48 PM
It's a very simple joint, the balls fit into the cage and the cage slides into the pot......what holds it in is the outer hub once it's in it's proper place.

Here's a video that shows the different parts....

I did not see this one. Thanks! Slightly smaller cage and bigger ball bearings, but same operation. Also, I understand now the cage (offset sphere joint) would naturally pull free from the diff as the driveshaft itself is fastened to the cage with a C-clip. I think I'm good guys. Thanks so much!
Title: Re: Driveshaft Help Needed
Post by: Rosebud on August 01, 2017, 09:02:37 PM
Quote from: MiniDave on August 01, 2017, 08:18:41 PM
I find the stickiness of the grease holds the balls in place no problem, but John's way would work too.....

So what you and John are saying is that the ball bearings don't fit tight in their seats and tend to fall out. So, not necessarily excessive wear. Nice.
Title: Re: Driveshaft Help Needed
Post by: Rosebud on August 01, 2017, 09:04:04 PM
Quote from: John Gervais on August 01, 2017, 07:27:48 PM
I hate when that happens...

There are ball-sized grooves in the pots, so you might need to rotate the drive shaft to line up the ball & cage assembly so that it can slide in.

A little wiggle & jiggle and the cage slipped into the diff nicely. Thanks.
Title: Re: Driveshaft Help Needed
Post by: Rosebud on August 01, 2017, 09:06:42 PM
Quote from: John Gervais on August 01, 2017, 08:16:01 PM
Normal enough, it's designed to slide in and out such that as the drive shaft angle changes on droop or lift, there'll be less stress on the joint compared to if it were a 'U'-joint. 

I usually cut the cuff off of an old rubber glove to hold the balls in place as I slip them into the pot.  Now's also a good time to clean and re-grease them.

Cleaned up and re-greased. Thanks.
Title: Re: Driveshaft Help Needed
Post by: LarryLebel on August 01, 2017, 09:28:25 PM
To help your terminology, the part you refer to as the diff is not the diff. Its the outer cage of the CV joint itself. This part has a splined shaft that goes into the diff and is held in by a wire spring C-clip. To separate this cage from the diff requires prying it off which is not easy. To clarify what JEG said CV joint allows the input and output shafts to rotate at the same speed regardless of the angle between the shafts, hence the term constant velocity joint. This is in contrast with the U-joint where after a certain angle the shafts do not rotate at the same speed and the joint binds up.
Title: Re: Driveshaft Help Needed
Post by: Rosebud on August 01, 2017, 09:50:04 PM
Quote from: LarryLebel on August 01, 2017, 09:28:25 PM
To help your terminology, the part you refer to as the diff is not the diff. Its the outer cage of the CV joint itself. This part has a splined shaft that goes into the diff and is held in by a wire spring C-clip. To separate this cage from the diff requires prying it off which is not easy. To clarify what JEG said CV joint allows the input and output shafts to rotate at the same speed regardless of the angle between the shafts, hence the term constant velocity joint. This is in contrast with the U-joint where after a certain angle the shafts do not rotate at the same speed and the joint binds up.

Thanks for the clarification. Yep, it was the CV cage I was referring to, not the actual diff. As far as CV joints  vs. U-joints go, I never did understand the difference—thought the terms were interchangeable. Great explanation.