bboesser

Hello everyone,

Really need some help here. Have a 1990 M103 260E Sportline stock 4 speed manual that I'm looking at swapping with a 5 speed manual box from a 190e M102 5 speed.

The torque converter in the auto box has busted & i was already having problems with the transmission so I figured i'd try manual swap for the benefit of everything.

I'm just in dire help of WHAT EXACTLY DO I NEED?

I understand the bellhousing is the same, but what else? I know i need pedals shifter etc.

What about driveshaft? clutch & flywheel is getting me confused? and anything else??

Please assist me if you can,

Any help is much appreciated, thanks for taking the time to read my post.

Plutoe

Have you checked the rear end ratios???

FYI: I think your nutz repeat nutz----I'd be looking for another four speed or buy a rusty SH with a five speed!!

bboesser

Well thanks for being a dick about it.

QVHK

You will definitely need the pedal box and shifter, flywheel from the manual version, and possibly the drive shaft if the size of the 4-speed and 5-speed gearboxes are different (imagine when the 5-speed gearbox is bigger than the 4-speed your original drive shaft would be too long to get back in place. You may have to replace the clutch, pressure plate and bearing (collectively called the clutch kit), clutch master cylinder and slave cylinder if they are nearing end of their lifespan, replacing them later once the gearbox is inside the car would be more hectic. These should be available on eBay and many online stores. You will need to make a clutch fluid hose to connect to the brake fluid bottle. The flywheel sensor may also be different. Anyway, this is a doable project (many have done it before) but there would be some difficulty doing DIY.

GB300E

He's not being a dick man, seriously.

He's trying to save you from having to parts hunt by suggesting you find a full trans w/ pedals, clutch, rear drive, etc and then it's a straight swap - as opposed to having to double and triple check your parts # to ensure they all mate up.

No offense at all buddy, we're all brothers and sisters here!

QVHK

The rear differential ratio for 260E is, according to various sources, is 3.27:1, but the differential is unlikely relevant to gear box swap project (but read on). I have a M103 3.0 and replaced my stock 3.07 differential with a taller one, initially 3.67 and then 3.46 and both perform much better in terms of low end acceleration than the stock differential. The set back are the car runs at higher rev on highways, reaches lower top speed, and the speedo gives you a reading based on the stock differential. The latter can be fixed by finding a speedometer that matches the differential. GB300E is right - if you can find all the right bits from a donor car it would be a much easier project. The 190E 5-speed manual will fit, but ideally the rest would have to be found from another manual W124. My 300CE (Right Hand Drive) originally had 4-speed auto transmission. I managed to find a 5-speed manual gearbox together with the flywheel, drive shaft, pedal box, differential, etc. from another W124 (Left Hand Drive), and took the opportunity to fit new clutch, master and slave cylinders, and it turned out to be a success, but the differential from the donor car was problematic - found out later that its ratio was 2.87 so acceleration was worse than when car was fitted with the auto transmission. After replacing the differential the car was reborn and now drives like a dream. Wish you good luck.