Modern auto box

[cfm65@me.com]

Hi Gents,
I have tried my best to search info wrt a modern auto box in a Pagoda. Most posts are about retro fitting 5 or 6 speed manuals.
Trust me, I would love to have a modern manual tranny, however the crank/clutch balancing issues could prove finacially challenging.
I have a 250 SL Auto with a crappy 2 to 4 speed(rebuilt)auto box( they only use 1st gear on spesial occasions, birthdays, Mondays, Christmas, paydays, unless manually selected)
Has anyone come up with a viable auto 5 speed/overdrive conversion for a 113, without going over the top?
Regards
Chris
Cape Town

[cfm65@me.com]

Nix

[ja17]

The sedans of the era switched to a more modern style four speed automatic in 1969. The old style automatic was left in the W113 till end of production. It might be an easy switch since this later style automatic was already used with the M130 engines in sedans (1969, 1970, 1971).

[hkollan]

The sedans of the era switched to a more modern style four speed automatic in 1969. The old style automatic was left in the W113 till end of production. It might be an easy switch since this later style automatic was already used with the M130 engines in sedans (1969, 1970, 1971).

I suspect that the switch might not be that easy. I seem to recall that the transmission tunnel was widened on the later w108s to accomodate the new auto trans.


Hans

[Benz Dr.]

I give the same advice to everyone:

 Buy a new car if you want modern amenities.

[cfm65@me.com]

Still nix

[Tyler S]

The issue would be finding an automatic overdrive with the correct bell housing. The bell housing on automatics is part of the transmission and not removable like manuals. You would likely run into balancing issues as well. Overdrive transmissions weren't available on MB untill the very late 70's/ early 80's. Up untill then they were direct drive 4 speed units with 1:1 final ratio.
A simpler option may be a mechanical overdrive unit mounted in place of the front drive shaft. This has been done before on 4 speed manuals. There would still be modifications needed to the drive shaft, mount and trans output shaft.

something similar to this pic.

[georgem]

Well, I`m with Dan on this one.  The cars are 50 years old. We own them because they are iconic, classic, period etc etc etc. They will never be as comfortable/reliable/fast/easy to drive as a Mazda Mx5/Miata or whatever they are called in your country.

Sure, you can upgrade the brakes, put a more modern engine in, 12 speed tranny, better seats, digital instruments, sound system that will shatter your glasses, electric windows - the list is endless. In some ways I am happy for you to do it - it means there is one less Pagoda out there of value - meaning my poor old car that is original gets more valuable.

I give the same response to guys that own VW Kombis (I own a 73 Kombi pick up) - the lowering, ratting, repower with a Subaru motor brigade - fill your boots - just makes mine more valuable and your worthless.

If you pick up a bit of frustration in my post - yup!

[TheEngineer]

I have had my 1969 280SL now for more than 12 years and it took me many years to get the automatic to shift smooth to my satisfaction. Sure, many owners who rode with me, or drove my car said "it shifts so smooth" but I knew better. The up-shift from 2nd to 3rd was rough. I took the transmission apart (I have the workshop manual) and checked for wear. I found that some PO had things misadjusted. After properly adjusting things my transmission shifts really well. Yes, it starts in 2nd gear and that is normal. i can select to start in 1st gear and I sometimes do. As Dr. Benz points out: If you want it to work like a modern car, buy one. Please keep in mind that one newer Mercedes transmissions the reverse gear clutch will wear out at about 150,000 miles. On the transmission used in our cars the brake bands do not seem to wear because there is little sliding. And for those of you who do not believe me you are welcome to drive my car. You must buy a full tank of gas (20 gal.)

[Benz Dr.]

Hi Gents,
I have tried my best to search info wrt a modern auto box in a Pagoda. Most posts are about retro fitting 5 or 6 speed manuals.
Trust me, I would love to have a modern manual tranny, however the crank/clutch balancing issues could prove finacially challenging.
I have a 250 SL Auto with a crappy 2 to 4 speed(rebuilt)auto box( they only use 1st gear on spesial occasions, birthdays, Mondays, Christmas, paydays, unless manually selected)
Has anyone come up with a viable auto 5 speed/overdrive conversion for a 113, without going over the top?
Regards
Chris
Cape Town

Who told you that you would have balancing issues going to a 5 speed? You wouldn't. Aside from all of the parts you would need, there is no crank balancing needed on a 250SL when changing from auto to standard or standard to auto ( not an idea I'd recommend, BTW ). If you have a 230SL? Yes, you would have some work to do.

[cfm65@me.com]

Benz Dr,
I have seen other posts on this forum which implies that the crank and flywheel are balanced as a unit in the factory and that changing from auto to manual would require the crank and new flywheel to be balanced as a unit before fitting the manual box.

Are you saying it is not so on the 250 SL?  That a manaul setup could be fitted without splitting the motor to be balanced?

The work involved in fitting a clutch etc does not scare me, BUT if it requires opening the motor to balance the crank, I'll happily stick to what Ive got.

Regards
Chris

[Benz Dr.]

This only applies to a 230SL. Your 250SL is good to go.

[cfm65@me.com]

TKS Doc,
You made my day.
Regards
Chris

[Jimbo1907]

I am with Doc on this one. I think trying to put a modern automatic into a 113 chassis would be a very long and difficult run for a very short jump, as we say. Putting a manual into a car which already had a manual is difficult enough. Substituting another automatic for an original automatic seems really difficult.

However.............. there is someone who knows about this. If you contact Karl Middelhauve at mbGrand600.com, I think it is, he has put modern GM automatics (TurboHydraMatics) into MB 600s. He may have an idea how you could put a GM automatic into a 113 car.

I think if I was contemplating this, I'd find it cheaper and easier to rebuild what is already in there and make sure it was working correctly. You might be pleasantly surprised.

[Benz Dr.]

I find it odd that Karl, who is considered a 600 guru, which isn't too far out of the realm, also managed to street rod a lot of the cars that left his place. Modern ignition, modern fuel injection, and, he even managed to put a super charger in one with water injection for Jay Leno!
 
While these are all wonderful upgrades, it also raises the value of the originals that are not messed with. When 600's left the factory, they were beyond sate of the art and there was nothing out there that even came close. Serious collectors of high end rare cars, look for things that are correct, hard to find, or hard to sort out. To them, and to me, it shows that someone did their homework and went that extra mile to get it right. Because doing this is a real PITA, those who know generally reward that effort with the best price at time of sale. Those who street rod or custom modify, may end up with as much or even more work to get to the end but not always higher price. The only real measure of value of a highly modified car then becomes quality of materials and quality of build; not how right it is. 

[Shvegel]

I think the biggest hurdle would be that the tunnel of the body is just too small.  the Automatic gearboxes in our cars are really tiny compared to anything else I have seen. Our transmissions are 18" end to end and most common modern automatics are 30" or so.   The second hurdle would be finding an automatic that is not electronically controlled or deal with a ton of issues trying to get the signals to the control module that would be needed.  Modern transmissions are really integrated into the car electronically and do things like adjust throttle during the shift etc.  Probably the best starting point would be a GM 700R4  which is a standalone unit or 4L60 which although an electronic has a ton of aftermarket support from the street rod community. 

[perry113]

I have a 1965 230SL with an automatic transmission.
If everything is in adjustment which includes your throttle linkage then the gearbox will upshift and downshift very nicely. As far as the 2nd gear startup there are times I will manually shift the car to 1 on a standstill when needed. I will say that in a perfect world I would prefer the car to be a manual but in terms of originality and being fully numbers matching I am happy with what I have. I find the gearbox to work as designed. It shifts smoothly strongly and tight. Its a bulletproof setup and does what it was designed to do.
Someone else pointed out that if you want a car to shift like a modern car then go buy a modern car. The only kind of conversion from an automatic that sounds realistic is going to an original 4 speed or ZF 5 speed manual transmission and that being said is a lot of parts and work.
These cars are becoming too valuable to make them into something they not by design.
Just my perception.