Hi I am hoping someone out there will know this:

I am installing a 4 speed manual trans into a w123 chassi but one day I would like to replace that with a 5 speed manual (God willing).

My question is:

Could I simply switch out the 4 speed manual trans with a 5 speed manual trans? Are they both the same length? Would this effect anything with the drive shaft or rear differential? (ie drive shaft length or gearing in the dif). Also what about clutch petal placement etc - those would remain the same, correct? Are there other considerations I am over looking?

Any help would be really appriciated (since I have grown restless looking for the elusive 5 speed manual trans for these car but would still dream of owning one eventually)

Cheers!
-L

 

my intrest what year and kind of car now you won't have to change the differential the other things i'm not sure on yet but in one of my repair manuals the for my 240d 115 1974 said a bit about 5-speeds went into Japan models. i'm also intrested in finding one too so let me know if you have any luck sorry thats all i know for now

 

as far as shortening driveshaft it is relativly inexpensive.take it to machine shop and they can do it just measure it good.however if you need to extend it it will cost you more because you have to replace whole tube.dont let that scare you from going thru with your idea.it sounds good.also you can check out and find other transmissions that are manual and make adapter plates to fit your engine.everything is posible.good luck