Found '86 300E 5-speed being parted out... Ease of tranny swap?
 

I finally managed to find a guy parting out a 1986 300E 5-speed that he had picked up to restore, but ended up giving up on it and is looking to sell it... Or pieces of it. I'm torn between buying the whole car and having at it and an eBay field day, or just requesting the transmission and pedal assembly... Anyway, my question boils down to this: how easy is it to install the 5-speed in my 1988 300E? Do the wiring harnesses hook up with no problems, or will modifications be necessary? I know I'll be looking at a bit of firewall modification to run the necessary clutch hydraulics, but aside from that, what should I expect? Please let me know your thoughts, because I'm hell-bent on having a 5-speed in this car. The suspension needs a rebuild, so I'm going to be going the Sportline way at that point, along with 17" AMG 5-spokes (depending on finances), and I think this car is finally getting to the point where I won't ever be able to sell it :) . Any input would be appreciated.

I can say that it's a straight forward conversion from what I've heard. I'd say go for it. There are other members on this board that have first hand experience with this and should be able to offer you some detailed information to help make your project a reality with ease. You might want to also post in the Performance Paddock section.

Good Luck!

I have said this in many threads before. I would not do such a swap unless I could do it right and the only way that I know that I can do it right is to have the entire donor car setting next to the recipient or at least nearby.

To do it right will require MANY more parts than just the pedal assembly and transmission. I can list the main things that are different on these cars and I'm positive that the list would forget something. There are lots of parts that you won't think of unless you are in the middle of the project.

Things that will be required from the donor car are the driveshaft(different length), flexplate(different), pilot bearing, flywheel, clutch, pressure plate, throw out arm, throw out bearing, slave cylinder, master cylinder, brake master cylinder reservoir, speedometer cable, possibly the speedometer, shifter, shifter wood trim plate, shifter rubber boot.

That was a partial list of REQUIRED parts. Parts that are different and should probably be changed, motor mounts and some other pieces that I can't remember.

I am NOT discouraging you from doing this swap. I think it is the best thing that can be done for a 124 car, what I AM doing is encouraging you to get the whole car so that you can do it right and not have a cobbled up jerry rig.

Good luck,

Thanks for the input guys.

I just spoke to the person selling the 300E, and an offer is on the table for $1,000. The body has some rust, and the transmission is currently in need of a new 2nd-gear synchro, but aside from that the car is wholly in-tact. I think it's worth the $1,000 (plus $600 or so in shipping from what he told me from New York to Texas) for the transmission and such, and the ability to part out the rest of the car (I'm sure I could find lots of little bits I could use myself). I'm also tempted to pick this vehicle up so I can use its engine as an experimental rebuild before I do mine... Or, if this one proves to be in good shape, simply use it as a future replacement (or build it up for the planned turbo project I have in mind). Think $1,000 for an '86 5-speed is a good deal? The only reason he's letting it go so cheap is because he wants to make sure it goes to an enthusiast who appreciates the 300E's... It's also currently somewhat in pieces since he bought it as a project but ran out of time for it, which helps keep the price down.

So bottom line... Think I should do it? Even if the rest of the car ends up being complete junk, I think it'd be worth it just due to the parts resource (everything aside from the synchro is mechanically sound).

So for a total cost of $1,600.....it sounds like a fair deal to me.

I recently bought a Getrag 5 speed with 'everything' needed for the converson from a seller on ebay. Total cost was about $900. Upon receiving the parts, I realize I will need a new pressure plate, disc and few other odd/ends.

If you can sell pieces off the donor car, I could see recouping your investment.

Tinker

Good luck with it, it becomes a different car. From my statistical sample of one, you also need the trans. crossmember and the exhaust pipe bracket that bolts to the trans. I didn't need the speedo cable (both old and new carried the same p/n). Brake fluid resv. only needed the closing cap clipped off to allow attachment of the clutch fluid line. All lines and fittings are bolt in, no modifications required. As Larry said, even the wood around the shifter is different. You also need to do minor wiring (use existing loom) for the backup light switch. Enjoy, 4th gear ratio is the same on both manual and auto, but put it in 5th and its got legs.

Excellent.

I'm going to see if I can talk to this guy about letting me make a few installments on it (I just hope to god he's trustworthy). I just started a new job, and now that I'm getting about 30% bonuses (after calculating my living off the base salary), I can pull this off by the middle of next month without making a sacrifice to savings or my food budget. I can't wait to start this.

Oh yeah, another concern... How much time and space would you say I'd need to do this conversion? I have an attached garage in my apartment, but would I need to take it elsewhere? My uncle owns a shop in Austin (Ben's Workshop), so if need be, I could do it there. Also, how much time (with a donor car, and supposing all parts I have are in perfect shape, no need for hunting) would it take to make the swap with an extra pair of hands? I might end up saving the tranny swap for the same weekend I do the suspension work. I just don't know how I should go about doing this. Thanks in advance.

You'll need enough space for 2 disabled cars, plus laying out some of the extra parts for inspecting/cleaning (especially the manual trans and driveshafts).

Removal of both trannies can be done in the same day if you're comfortable w/ tools and have 1 or 2 people helping you. Also helps to read up and survey the parts to see where everything bolts/unbolts.

The manual trans install can be done in one day, but don't expect to be road-worthy right away. That's mostly to get everything bolted up and fluids topped off/bled. It'll probably take a bit more time to get it looking and driving right.

I'd definitely getting at least one helper, and a 2nd one to help remove the auto and install the tranny (just helps to have 2 people up near the bellhousing and one person to push from the back when it's ready.)