1966 230sl differential questions

[Ed Riefstahl]

Greetings,
I am new to this group. I'm retired, living near Erie, PA and married to the same gal (also a car gal) for over 46 years.
I have owned/repaired/restored Mercedes Benz cars for 45 years as a hobby and have had 3 W113 MB's.
We currently own a 1966 230SL (Ms Magoo). We have owned it for 21 years and have driven it over 60,000 miles coast to coast and from Main to Florida, since our body on restoration by my wife and I in 2001 and 2002. We are the only people who have worked on this car during our ownership. I started out as a mechanic in the mid 70's.
Recently starting off at a red light, the car make a pretty significant bang in the drive train. We lost power to the rear wheels and coasted off the road. We had the car flat bedded home. After lifting the car in my garage, I have determined the drive shaft turns but rear axles don't. I have never had a MB swing axle differential problem or had one apart.
I am looking for advice, possible cause and most common failure with the 113 differential. We also own a nice W108 sedan and have a complete 1970 280SE parts car for possible differential swap, but not sure of compatibility or gearing.
Thanks in advance,
Ed Riefstahl

   

[BobH]

Hello Ed, nice to meet you

I'm sure some of the more knowledgeable members on here will reply soon, but in the meantime, if you're not familiar with this site, use the search function above left under your log in button

Search "Differential" and you'll find volumes written about various problems and replacements

You might also look at the W11X chassis cars, on the main index page, which may tell you about what other cars parts are compatible

Quite a lot discussed in this thread

https://www.sl113.org/forums/index.php?topic=1642.0

Good luck

[stickandrudderman]

Since 230 axles have drum brakes, it's not straight forward to swap out a disc brake axle.
These diffs are pretty reliable so my recommendation would be to find a second hand 230 axle, fit a new pivot push and single piece boot and install.
I have such an axle but I'm in the UK so shipping would likely be prohibitive.

[Berggreen]

Hi Ed

Sorry to hear about your problems with your 230SL.

Have you checked that it is not one of the joints, rubber connection plate etc. in either end of the drive-shaft which have given up?

Normally, the differential does not give up like this, but will start making noises much before any mechanical failure. But have you identified, if you still have oil in the differential?

Is it a manual or automatic 230SL you have?

Cheers,

Christian

[Ed Riefstahl]

Thanks for the replies everyone.
The drive shaft turns at the differential, but axles don't. These differentials don't have a removable cover like most do. So I have no way to look inside the differential to see what has broken.
I was hoping someone could shine a little light on what likely failed. I was also thinking that I could possibly use parts from the 280se parts car without removing the differential from the car, which appears to be pretty difficult.
I am not opposed to swapping the entire differential and switching to disk brakes in the rear, but would rather replace what has broken. It looks like I can split the differential in half on the car with some difficulty by removing the drivers side axle section, drivers side spring, center spring and drivers side swing arm. This would allow me to access the inside and gears.
I'm not sure if anyone has tried this, but I have some time to figure out how to go about this. I'm having rotator cuff repair this coming Friday, so I won't be able to work on it anytime soon. We do have very long winters here in northern Pennsylvania snow belt on Lake Erie, so maybe after the new year with some help I'll be able to look inside to see what failed.
Thanks in advance for any help.
Ed Riefstahl

1966 230SL (Ms Magoo)
1970 280S (Miss Daisy)
1989 300SE (Majestic)
1987 Toyota Paseo convertible (5 speed)
1999 BMW Z3
1991 BMW 318i (5 speed)

[johnk]

I don’t know a damn thing about the make
Up of our differentials but I do know that I am very jealous that your wife works on the cars with you! My wife won’t even sit in my 280.

[Berggreen]

Hi Ed

I guess it cannot harm to take a look what caused the failure of the rear diff.

However, be prepared that if you take crown and pinion wheel sets out, or change anything that compromise the position of those in the diff, you will have to re-align these again, which is a complicated and problematic task, which may end up being a trial and error process of adjusting, assembling, mounting, testing, disassembling, adjusting, assembling, mounting, testing etc. etc. process going around in the wheel over and over again. Also it requires special alignment and adjustment tools, and getting it wrong will result in a loud singing noise from the rear diff.

Therefore, to by-pass this, many will just find another similar complete rear axle and replace with the failed one. Also, many will change to a rear diff. ratio which was used in the European spec cars to bring down rpms on the highway.

I just changed the rear axle on my automatic 280SL from the US spec 1:3.92 to the European 1:3.69, and it has made the car feel much more in balance.

Good luck! 

Christian

[Benz Dr.]

Most 230SL's are 3.75  gearing which is about right for the engine used; I wouldn't go any higher ratio on a stock platform.

My guess is the universal joint broke. Not inside the actual joint but right beside it where inserts into differential gears. This quite rare but I have seen it once. Best to pull the whole axle to repair one. I would think it would be less work than trying to split one still installed.

[Berggreen]

Most 230SL's are 3.75  gearing which is about right for the engine used; I wouldn't go any higher ratio on a stock platform.

Just as add-on information, please find a table with the rear diff gearing for the 230SL.

Yes, 1:3.75 stock, but only for European delivered cars. US delivered cars had 1:4.08, which will give you almost 300 rpms more at 100 kmh (63 mph).

So Ed, assuming your car is a US delivered 4-speed manual or automatic, and you end up replacing the rear axle, a European spec 1:3.75 will make a noticeable impact on rpm level at highway speeds. However, it will come at the price of slightly less acceleration from stand-still. For the 280SL the impact is so small that you will not notice, due to the higher torque on the 280 engine. But I don’t know with the 230SL.

Maybe some who have made the change from US to European rear diff spec in a 230SL can comment on acceleration at low RPMs.

Cheers,

Christian

[rwmastel]

... but in the meantime, if you're not familiar with this site, use the search function above left under your log in button

Search "Differential" and you'll find volumes written about various problems and replacements.

Ed,
Welcome to the Group!!  Bob is right, the search feature is going to provide you with lots of reading material.  Perfect way to spend your time recovering.

Christian,
I own a Euro 230SL with the 3.75:1 ratio and it is no rocket ship off the line.  But, once the tired old engine gets rebuilt (along with fuel system and more), that may not be the case.  When this group was new, I wondered why everyone wanted to switch their rear axles to sedan axles with 3.27:1 (I think?) because I felt mine was fine.  Then, I learned about and rode in a car with 4.08:1 and understood.

[Benz Dr.]

Just as add-on information, please find a table with the rear diff gearing for the 230SL.

Yes, 1:3.75 stock, but only for European delivered cars. US delivered cars had 1:4.08, which will give you almost 300 rpms more at 100 kmh (63 mph).

So Ed, assuming your car is a US delivered 4-speed manual or automatic, and you end up replacing the rear axle, a European spec 1:3.75 will make a noticeable impact on rpm level at highway speeds. However, it will come at the price of slightly less acceleration from stand-still. For the 280SL the impact is so small that you will not notice, due to the higher torque on the 280 engine. But I don’t know with the 230SL.

Maybe some who have made the change from US to European rear diff spec in a 230SL can comment on acceleration at low RPMs.

Cheers,

Christian

I've worked quite a few 230SL's and almost all of them were 3.75 gearing. Most of them were USA version cars and NOT euro so I don't believe where the car was sent had any bearing on axle designation.

[Berggreen]

I've worked quite a few 230SL's and almost all of them were 3.75 gearing. Most of them were USA version cars and NOT euro so I don't believe where the car was sent had any bearing on axle designation.

Ok, I just copy-pasted from the table, they show at the SLS homepage:

https://www.sls-hh-shop.de/main/de/mercedes-230-280sl-w113/35-hinterachse/35-b-info-achsuebersetzung

But also, the same information can found in the Pagoda literature.

I think a lot 230SL were originally sold to US military personnel stationed in Germany, and many took these cars with them to the US , when their service in Europe ended. These cars were then sold with European configuration, and then later converted with miles speedo etc., but I guess not the rear diff..

Also, Mercedes actually at that time also had a service that you as a US costumer could pick up your car in Stuttgart, then use it for a vacation in Europe, and then Mercedes would ship it to the states afterwards. Maybe these cars were also with European specs (?).

Well just guesses from my side why there is a lot of 230SL with European 1:3.75 rear diffs in the US. But maybe there is some truth in it? 😀

Cheers,

Christian

[neelyrc]

…………Also, Mercedes actually at that time also had a service that you as a US costumer could pick up your car in Stuttgart, then use it for a vacation in Europe, and then Mercedes would ship it to the states afterwards. Maybe these cars were also with European specs (?)……..

Christian,
These cars, of which mine is an example, were all U.S. specification cars.

[Ed Riefstahl]

Hi Folks,
Thanks for all the replies and great info.
Been very busy these days. When it rains it pours I guess.
My wife has been going through breast cancer and started chemo last week.
I will be having rotator cuff surgery tomorrow morning, so I'll be out of commission for a while, so the SL will have to wait.
I thought I'd get as much info. as possible so when I'm able to work on it, I'll have an idea where to start and what parts will be needed.
I do have a 1970 280S sedan parts car, but it has rear disk and not sure what gear ratio. I also know of a rear end from a 65 220SE convertible 111 with drum brakes. I'm told the ratio is D 3/9. Not sure what that is.
I have a feeling finding a differential for an early 113 could be difficult and expensive.
Thanks again for any and all help.
Ed Riefstahl
Erie, PA

[Benz Dr.]

It shouldn't be that difficult at all. Any 230 sedan axle should work. Find out what your rear axle ratio is first before looking for a different one.

[Leester]

Hello Ed,

Good luck to you with your surgery and prayers go out for your wife. Lee   

[Ed Riefstahl]

Hi folks,
Thanks for all your replies, comments and suggestions. I also really appreciate the concern and well-wishes for my wife and i at this rather difficult time.

My rotator cuff surgery went well and I'm now in recovery. I'll be in a sling for 5 more weeks, but I can finally use my left hand enough to reply to you folks.

My wife of 46 years and my assistant mechanic is doing better than expected with the whole mastectomy / chemo / loss of hair etc, I think even better that me. Life sure can be unfair at times. I was told the other day, "when it rains, it pours". I said yep, it's pouring at the Riefstahl's at the moment.

I think Dan suggested that I find out what ratio my differential is. How do I know thi?. The car is a US version. I know of a rear axle available from a 1965 230SE, W111. They are saying the ratio is D 3/9 and I'm not sure what that is.
Also as mentioned, I own a W108 (1970 280SE) parts car, but it has disk in rear. It would be a real challenge to move that car once I removed the rear axle, but it would be free.

How difficult would it be to switch to disk? I think I wouldn't mind the slightly higher gears, especially at my age. My SL is currently on my small (Quick Jack) lift at the moment, so I could probably have my son get under look for numbers. I'm currently looking for a mechanically inclined person in my area who would be willing to help swap the rear axle during the winter in my garage. It will be months before I'm able to do this myself or even with help, but trying to do the leg work while we are laid up. it sure would be nice to have Ms Magoo back on the road by next summer.
Thanks again for any and all suggestions and comments.
Kind regards,
Ed Riefstahl
Erie, PA

[zak]

Check the for sale section.
Cabrioletturbo has a 230 sl read diff and axel for sale . He is located in Montreal I believe.

jz

[rwmastel]

Ed,
I hope everyone recovers and heals well.  Getting old ain't for wimps.  Hang in there.

I think Dan suggested that I find out what ratio my differential is. How do I know this?

Unless it is on the data card, one must crawl under the car and look at the differential.  There is a flat (machined?) verticle surface near the bottom, I think on the USA driver's side, with the ratio stamped in.  (Random pic from internet attached.)

Also as mentioned, I own a W108 (1970 280SE) parts car, but it has disk in rear. It would be a real challenge to move that car once I removed the rear axle, but it would be free. How difficult would it be to switch to disk?

I know many people have swapped out axles on W113's that already have rear disk brakes. You should be able to find several threads on it, and maybe information in the technical manual.  I'm not sure how much has been documented here for drum axle swap out since it is less common.

Again, the forum search is your friend!!  Educate yourself as much as possible, it's fun reading! Then you can ask pertinent questions that save yourself and others time, because you're not going down the wrong rabbit hole.

[Benz Dr.]

That's where you find the gear ratio on early drum brake axles. ( above picture ) Later disc brake axles have the ratio stamped into the housing on the bottom left side.

The one shown above is a 3.75 probably from a 230SL. 

[Ed Riefstahl]

Hi folks,
Well, I was able to get under my Ms Magoo (66 230SL) and have another look at the stamping on the real diff. Not an easy task with one arm still in a sling.
It looks just like the photo Rodd posted except the stamping clearly is as follows: SL 4 / 08. which I'm interpreting as 4.08 gears.
After a nice conversation with Dan (Dr Benz) I am feeling pretty comfortable with using the rear axle from my 1970 280SE parts car which was a running driving car when parked and not even messing with the existing diff.
I have no idea what gears are in the 280SE, but would guess 3.27 which I hope would be an improvement. I also think converting to rear disk brakes is pretty straight forward and I feel would also be an improvement.
I have folks willing to remove the axle from my parts car and place it in the back of my truck for $100.00. I sure appreciate the advice from Dan regarding the danger of letting the axle halves drop and damage them. I'm hoping I can be there for the removal, but not sure they will allow it.
I like the idea of having the ability of looking the new axle over before installing it.
Looks like I'll be busy this winter and hopefully will have some help as I'm going to need it.
Thanks again for all your advise and suggestions, as well as well-wishes for my wife and me during our recovery.
Kind regards,
Ed Riefstahl

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

[ctaylor738]

Ed,

There is a cap screw that holds part of the sliding joint to the drive assembly. If this fails or falls out you will experience the symptoms you are describing.  You can pull the RH axle out and see if it's in place and tight.  If it is, you have other problems over my pay grade.  If it is isn't you can remove the axle tube, find the screw and reconnect the joint.  Sometimes it stays loose but in place.  In either case, loctite is a good idea.

Parts diagram attached, screw is #112.

[Benz Dr.]

Hi folks,
Well, I was able to get under my Ms Magoo (66 230SL) and have another look at the stamping on the real diff. Not an easy task with one arm still in a sling.
It looks just like the photo Rodd posted except the stamping clearly is as follows: SL 4 / 08. which I'm interpreting as 4.08 gears.
After a nice conversation with Dan (Dr Benz) I am feeling pretty comfortable with using the rear axle from my 1970 280SE parts car which was a running driving car when parked and not even messing with the existing diff.
I have no idea what gears are in the 280SE, but would guess 3.27 which I hope would be an improvement. I also think converting to rear disk brakes is pretty straight forward and I feel would also be an improvement.
I have folks willing to remove the axle from my parts car and place it in the back of my truck for $100.00. I sure appreciate the advice from Dan regarding the danger of letting the axle halves drop and damage them. I'm hoping I can be there for the removal, but not sure they will allow it.
I like the idea of having the ability of looking the new axle over before installing it.
Looks like I'll be busy this winter and hopefully will have some help as I'm going to need it.
Thanks again for all your advise and suggestions, as well as well-wishes for my wife and me during our recovery.
Kind regards,
Ed Riefstahl

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

From our conversation, I would say that the 280SE you have is likely a 3.92, unless you have the 4.5 engine, in which case it would be 3.27

[Ed Riefstahl]

Greetings folks,

Thanks Chuck for your advice and the great expanded view of the rear axle. It's the best I've seen so far. I've studied the diagram and even expanded it 300%. I'm still a little unsure of what exactly the cap screw does or what it holds in place or what could have let go to cause the real axle no to turn. I guess I won't know until I disassemble things.

From your instructions, it sounds like pulling the passenger side axle will allow me to see the the cap screw. I assume I will need to remove the boot also.

At this point I can't do anything remotely resembling the above after having rotator cuff repair 2 weeks ago. I'm not permitted to use my left arm at all for another month and even then, very limited for 6 months. I've been looking for someone (hopefully mechanical) to hire to help me in my own garage with my car during the winter months. I do have a young guy (late 30's) in mind that I think will do just fine. He works for a local farmer, so maybe after grape season is finished. He's a little autistic, but but strong and pretty mechanical. I think he'll do just fine and be happy to have the work during the winter.

I'd sure like to check a few things to see what exactly failed before I go the next step and remove/replace the rear axle. I'll have to be patient, (which is killing me) and not do anything stupid.
Thanks again for your knowledgeable input and suggestion / diagram.

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