'91 300SL 5-Speed? - PeachParts Mercedes-Benz Forum

STORMINORMAN · #1 03-29-2012, 02:43 PM

Will the 5-Speed manual from a COMPLETE and running '91 300SL "easily" swap into a W126 Series Sedan, i.e. one of my 420SEL's?

I can understand it would require some custom fabrication, but is this even a reasonable project? I would imagine (hope?) the transmission could handle the increased hp/torque and there certainly should be enough room...

Anyone familiar with this modification?

Am I even on the correct ShopForum board?

Thanks!

duxthe1 · #2 03-29-2012, 07:29 PM

Never seen a 5 speed manual in a 129 chassis but I know for sure that the 104 and the 117 do not share the same bellhousing.

Hit Man X · #3 03-30-2012, 10:31 AM

I have wanted to slap a five speed behind my 300SEL for a while and even perhaps my W116 280S. I made a post about this a while back.

I have seen many M110 cars with a manual (four and five speed) and some M103s with a five speed too (mainly in W201s).... this includes the ECE R109 280SE/L with a manual.

So, I know the pedal box exists for the swap for the W126... which to me is the biggest part of the mystery. Apparently there were some 3.5L V8 cars with a manual too back in the SLC days. The US 4.2L M116 does not make that much power... when new it was 201hp/221tq.

I say go for it, it would be an interesting project.

rayhennig · #4 03-30-2012, 01:05 PM

Quote:

Originally Posted by STORMINORMAN

Will the 5-Speed manual from a COMPLETE and running '91 300SL "easily" swap into a W126 Series Sedan, i.e. one of my 420SEL's?

I can understand it would require some custom fabrication, but is this even a reasonable project? I would imagine (hope?) the transmission could handle the increased hp/torque and there certainly should be enough room...

Anyone familiar with this modification?

Am I even on the correct ShopForum board?

Thanks!

No.

The 5-speed (722.5) box went with the 300-24 M104.980 engine. It has some rudimentary electronic control operated by the engine controller (MAS box) and was never partnered with a V8.

Doubtless, nothing is impossible but I feel it would be much cheaper and easier to stick with the original box, even if it has to be rebuilt.

Also, for me at least, it would be immensely more interesting to get the SL up and running for the summer with its drop top and 5-speed.

My 2c worth.

RayH

STORMINORMAN · #5 03-31-2012, 09:57 AM

I appreciate the responses. I saw an ad for a '91 300SL, "new clutch, etc." and just wondered if perhaps the 3.0 l's with 5-speed manual in the SL & W126 cars were close enough to swap tranny's...

Wow! Was I surprized at how many different versions of 103 vs. 104 vs. 116 & automatic tranny's there were in just a few model years.

Again, I appreciate the responses: it looks like a 116 motor and a manual transmission is possible but rather expen$ive and complicated. Maybe an entire swap with a later V8 and a 5-speed automatic out of a wrecked S-Class (or even an SL?) might be more practical and not a whole lot more co$tly?

I have seen the swap from a later model SL into a W126 Coupe and it looked as if it was a very comprehensive and professional job. I have to admit I still prefer the W126 Sedans over later S-Class cars because of their simple, basic engineering excellence.

Cheers!

cth350 · #6 03-31-2012, 06:41 PM

In the performance area, we've been talking about the engineering work required to get a getrag 265 transmission mated to the back of an M117 or M119 motor. It can be done for less than the cost of that black car.

-CTH

deanyel · #7 03-31-2012, 09:02 PM

Quote:

Originally Posted by rayhennig

No.

The 5-speed (722.5) box went with the 300-24 M104.980 engine. It has some rudimentary electronic control operated by the engine controller (MAS box) and was never partnered with a V8.

He's asking about a stick, not an automatic. There were quite a few 116 motor stick shifts over the years, 107s, 108s, 109s and 111s, always 3.5 liter, not 4.2. And they were always pretty rare, Euro only, so very rare in the U.S. In fact all Mercedes V8 sticks were 116 motors, never was a 117 stick.

The 129 SL manual transmission was also used in the Porsche 928 so handling the torque shouldn't be the problem. They were also all dogleg shift pattern which to me is no fun. I think if you drove a 129 stick you'd lose interest in it. The car was a big disappointment.

POS · #8 04-01-2012, 12:00 AM

The Getrag 265 5-sp transmission works well with the M117, but you'll need to find a bell housing for it. AMG did this swap on w126s but no one has yet to figure out what bell housing they used.