1966 230sl differential - new questions

[Ed Riefstahl]

Greetings folks,
I've been recovering better than expected from my rotator cuff surgery. In 2nd week of rehab and in a sling for another 1-1/2 weeks. Wife Clover is also doing far better than expected with chemo - tough gal.

I'm getting ready to have the rear axle from my 1970 280SE parts car pulled and bring it to my house garage.
I've been reading plenty of posted info. and was fascinated with the rear bearing topic from a while back. It is my impression that I should be able (if lucky) to pack rear bearings, replace axle seals. Also I plan to replace pinion shaft seal and the boot.

I do understand that I will have some additional work to do converting to disk brakes, but doesn't sound too complicated.

I'm pretty sure the gears from the 280 are a little higher than the 408's in the SL.
I'm hoping they will allow me to be there when the axle is removed. I want to make sure that they don't remove the shocks without support under the axle halves. Thanks Dan (Benz Dr) for that valuable pc. of info.

I'm still trying to get someone to help me with the swap and do most of the work due to my shoulder issue.

I do have one comment that really bugs me about the SL. It's on my small lift with wheels hanging at the moment. The left rear wheel spins as freely as a front wheel. So, I'm sure something broke, but sure doesn't feel at all like I'm spinning the axle.  Completely free wheeling like spinning a bike wheel.

Before I get everything together for a axle swap, is it possible something broke that wouldn't be that hard to fix on the car? Just asking - never had one apart.

Once again, thanks for the thoughts and prayers sent our way during a challenging
time and thanks for any and all comments and advice.

Ed Riefstahl
Erie, PA

1966 230SL (Ms Magoo)
1970 280S (Miss Daisy)
1989 300SE (Majestic)
1999 BMW Z3 5 speed
1991 BMW 318I 5 Speed
1997 Toyota Paseo Convertible - Red 5 speed (have you ever seen one?)
1997 Ford Ranger (Step Side 54K)
2012 Toyota Rav4

[cfm65@me.com]

Hi Ed,
I trust you and your wife are recuperating and that the chemo will be successful.   
Re your differential, that is exactly how a diff is supposed to work. When going around a corner the outside wheel has further to go than the inside wheel and the diff will ensure that the one wheel speeds up slightly and the other will slow down.
I suspect that the brake on the one side is slightly dragging. If you hold and stop the ‘loose’ wheel turning, the other will be able to turn. The answer is in “differential”
The diff ratios are stamped somewhere on the housing.
Regards
Chris

[Ed Riefstahl]

Hello folks,

It's been almost 3 months since my shoulder surgery and I'm finally able to do some mechanical things as long as I don't do anything stupid. My wife (and assistant mechanic) is doing much better than expected and will be in Chemo until mid March. We're both really looking forward to spring and summer.

I was finally able to drop the drivers half of the rear axle and the remove the boot yesterday so I could get a look inside the differential. It wasn't a difficult job and took about 2 hours using mostly air tools. I was working by myself and being very careful not to strain my left arm.

As it turns out, the male splined end of the internal u-joint yoke that faces the drivers side axle, broke completely off where it is connected to the yoke. After removing the boot to have a look from the other side, I don't think it's repairable without a complete rebuild and I don't think I'm up to that task.

So, I think swapping the rear axle using my 1970 280SE parts car is the way to go. I'll deal with the disk brake issue when the time comes and I'll also replace some seals before I put it in. I'm also thinking that having the slightly taller gearing might not be a bad thing.

The rear axle from my parts car is being pulled as we speak. I had a discussion with the young man that is pulling the axle and he's already examined the axle and is familiar with the split design and assured me he won't allow it to drop free and damage the axle. (thanks Dan for that tip).

I'll keep you posted and any suggestions are always welcome. Thanks for all the well-wishes from many of you folks. "Getting old ain't for sissies" my grandma would say.

Kind regards,
Ed Riefstahl
Erie, PA

1966 230SL (Ms Magoo)
1970 280S (Miss Daisy)
1989 300SE (Majestic)
1999 BMW Z3 5 speed
1991 BMW 318I 5 Speed
1997 Toyota Paseo Convertible - Red, 5 speed (have you ever seen one?)
1997 Ford Ranger (Step Side 55K)
2023 Mazda CX5


 

[Benz Dr.]

Hello folks,

It's been almost 3 months since my shoulder surgery and I'm finally able to do some mechanical things as long as I don't do anything stupid. My wife (and assistant mechanic) is doing much better than expected and will be in Chemo until mid March. We're both really looking forward to spring and summer.

I was finally able to drop the drivers half of the rear axle and the remove the boot yesterday so I could get a look inside the differential. It wasn't a difficult job and took about 2 hours using mostly air tools. I was working by myself and being very careful not to strain my left arm.

As it turns out, the male splined end of the internal u-joint yoke that faces the drivers side axle, broke completely off where it is connected to the yoke. After removing the boot to have a look from the other side, I don't think it's repairable without a complete rebuild and I don't think I'm up to that task.

So, I think swapping the rear axle using my 1970 280SE parts car is the way to go. I'll deal with the disk brake issue when the time comes and I'll also replace some seals before I put it in. I'm also thinking that having the slightly taller gearing might not be a bad thing.

The rear axle from my parts car is being pulled as we speak. I had a discussion with the young man that is pulling the axle and he's already examined the axle and is familiar with the split design and assured me he won't allow it to drop free and damage the axle. (thanks Dan for that tip).

I'll keep you posted and any suggestions are always welcome. Thanks for all the well-wishes from many of you folks. "Getting old ain't for sissies" my grandma would say.

Kind regards,
Ed Riefstahl
Erie, PA

1966 230SL (Ms Magoo)
1970 280S (Miss Daisy)
1989 300SE (Majestic)
1999 BMW Z3 5 speed
1991 BMW 318I 5 Speed
1997 Toyota Paseo Convertible - Red, 5 speed (have you ever seen one?)
1997 Ford Ranger (Step Side 55K)
2023 Mazda CX5

That's what I expected as far as damage. Most break in that exact spot.

[roberhofer]

I had my 230SL rear as well replaced - one of the upshots is a lower gearing. From 4.08 to 3.68 (I think from memory). This was for the US 230 model.
The upshot was that it is a bit more comfortable at highway speeds without loosing too much ooomph from a stop.

[Benz Dr.]

I had my 230SL rear as well replaced - one of the upshots is a lower gearing. From 4.08 to 3.68 (I think from memory). This was for the US 230 model.
The upshot was that it is a bit more comfortable at highway speeds without loosing too much ooomph from a stop.

That's actually higher gearing being 3.69 from 4.08. I did the same thing but it was also a LSD and disc brakes.