Date registered: Oct 2012
Vehicle: Mercedes Benz W108 - 280 SE (1970) / Mercedes-Benz W123 200T (1983)
Mentioned: 0 Post(s)
Quoted: 12 Post(s)
Will a 5 speed (W108 / W113) manual transmission fit in a 4 speed W108?
We own this lovely, lovely 280 SE W108 from 1970. It's a blast to drive and looks great. The engine sounds amazing but I've always been pondering if the RPM's were a bit too high for the engine to be comfortable at speeds. I've talked a bit with the previous owner, he agreed with "It does sound like it's doing quite some RPM every now and then" (and if you read this, I love the car man). It has no tachometer, but a rough estimate would be 3-4000 RPM at 50-60 mp/h in fourth gear (fourth gear change happens at about 25 mp/h). This is obviously quite an amount of RPM for such speed, so I've been thinking about giving it a 5 speed W108 transmission. They are very hard to get by, so it's just when time and money are there for it.
Anyways onto the question, will a W108 5 speed manual fit in what is currently a 4 speed manual? I'm not sure if there are big size differences compared to the 4 speed, which is why I'm asking. I have also heard that it's possible to use a W113 5 speed transmission as they are identical(?). Another option would be to order a 5 speed W108 transmission from Mercedes, however I really don't want to even think about what that would cost in the end.
Anyways it's not a racing car and I'm totally fine with doing 50-60 mp/h tops (or maybe the engine just sounds like it's up in the RPM's and it still has way more left), as you really just need to cruise in it, I'd just like to do those speeds without thinking that the engine is really pushing it.
(another suggestion I've heard is adding a 4.5's rear diff, however I'm not sure how doable that is here, as 4.5's are very expensive just in parts and I'd still love to have that low speed torque and power).
Last edited by Jackpody; 06-12-2013 at 08:16 AM.