300SD transmission options?

[Alexporter8.3]

Hello all, brand new to this forum. Recently I’ve been wanting to do performance upgrades to my 1981 300SD and I’m concerned about the factory transmission. Really don’t want to try to hunt down a manual, has anyone ever done a successful transmission swap to another type? (Such as chevrolet automatic of some sort). My apologies if this has been talked about before, I couldn’t seem to find anything when I searched for it. Thanks in advance!

[sixto]

Chevy / GM Adapters

Sixto
98 E320s sedan and wagon
02 C320 wagon

[Sugar Bear]

The factory transmission is rather durable if maintained and not overheated. Delayed reverse engagement is an early sign of failure.

I've heard that 85' trans performed aittle better due to a different stall speed converter and differential ratio. I had two 85's that ran really well.

Good luck!!!

[luketmarx]

There are adapter kits for 5 speed toyota transmissions, i saw $1,000 for the adapter kit...easy to find the trans if in fact you actually want a manual...

[awsrock]

I am not sure if a 722.6 would bolt to a 617 but if you were willing to deal with the electronics you could put one of those in for 1000-1500

[Frank Reiner]

Originally Posted by Alexporter8.3

performance upgrades > 1981 300SD

Oxymoron

[Maximan1]

Originally Posted by Frank Reiner

Oxymoron

With a few thousand in upgrades you can get decent power out of these.

There are a few running close to 400 whp.

If you're not going to contribute useful information, why bother responding to the thread?

[resto108]

I'm not knowledgeable about gasser Benzes, but the 560SL, SEL, SEC, etc, used the same trans, no? I don't think AMG put Toyota transmissions in their upgrades...

[Clemson88]

It seems like I remember reading that the bell housing are different on the gas engines. Seems like someone said they could be changed and suitable but I've not really investigated this enough to say it's possible.

[dude99]

There are very few good trans options for a 617. If you swap in a 603 you have a lot more options in terms of manuals and the 722.6.

[rwd4evr]

Early six cylinder gas single cam and m110 dohc and 4 and 5 cyl diesel have the same bolt pattern and infact the same intemidiate plate. The manuals are out there, I have a couple. There is no 722.6 to early motor option I'm aware of. There is a jeep ax15 5 speed adapter I also have that I'm. Using in my wagon I just won abd haven't picked up yet. A Dodge Dakota v6 or 2wd jeep Cherokee ax15 will bolt up then. I think its Novak but maybe advanced adapters. There may be a Chevy setup too. Look. At the 4x4 places, they like to put im617 in the trucks. Jeep used Pontiac iron dukes which is the same bolt pattern as a SBC so that's a possibility. W126 clutch pedals are tricky to come by but you can mod the auto braket with a clutch pedal. I could possibly have some Lazer cut if interest is there for them. The stock autos SUCK and suck power but they work..... Until they don't. Filter and fluid change seems to keep the kicking for awhile when they begin acting up.