Ok, Some Very Serious W124 Manual Conversion Questions - PeachParts Mercedes-Benz Forum

350SL4spd · #1 07-08-2004, 09:51 PM

I have gotten a line on a pristine 88 300E 5spd tranny. The car is currently intact, but wrecked w/ increadibly low milage (60k). The bone yard that it is in is going to crush it after pulling the tranny and a few other things they can sell and is willing to send me "everything neccisary (sic) for a conversion". I need a little info from all involved on this site to see if this will work;

First: My car is a 1991 300E (I love her!). Is this even possible? I know they made some changes after 1990, but would it would still bolt up, right?

Second: What was the rear end ratio difference from an 88 stick to a 91 auto? Would it be better to get the diff too?

Third: Do I need the center console? Or will I be able able to get the stick to work in my console w/ a few small linkage mods or the like?

Fourth: What about hydraulics? Do I need the brake booster or what other hydraulic components?

Fifth: Has anyone actually done this here? I have seen much talk on the subject, but no one ever seems to go through with it. The only consensous ever seems to be that you need the donor car... So....anyone have a parts list?

I know I need gear box, linkage, pedals, flywheel, clutch/throw-out bearing, drive shaft (right?),

Will I need: starter set-up? Hydraulics/master cylinder?, console?, rear trans mount?, what else???

I would love to get the whole chassis w/ tranny set-up shipped, but that might not be poss and I do not want to trust the guy to just send me "everything".

Any opinions, parts lists, condemnations, cheering-on's, suggestions, and, most especially, answers will be accepted w/ open arms!!!

-Matt-

Chamorro · #2 07-09-2004, 12:41 AM

Tranny and flywheel should bolt up; they're the same engine. I'd recommend getting new clutch parts, i.e. clutch disc/pressure plate/throw-out bearing/master cylinder/slave cylinder.

Not sure about the center console or brake booster and brake fluid resevoir, but I'd recommend getting them anyway if you have the money...that way you won't have to go searching for them if you do need them.

Ask for the drive shaft/tail shaft; get new flex discs. You'll need the reverse light switch, neutral safety switch, possibly the speedo cable and AC and cruise control relays.

I don't think the rear end ratio is much different, but don't take my word for it. All I'm aware of is that the '87 and older autos had a numerically higher ratio than later models.

Where are you located? Do you know the owner of the wrecker? I've been trying to track down a whole 5-speed 190e 2.6, but I may end up having to use a 2.3 instead and just getting the flywheel from a wrecker.

#3 07-09-2004, 07:56 AM

In '88, the rear ratio is the same between manual and auto. I don't know if the ratio changed between '88 and '91.

The clutch hydraulics have nothing to do with the booster. You will, however, need the reservoir since it has a nipple for the clutch. You will need all the shifter components, console panel and boot. Make sure they get the clutch switch and wiring harness so that your cruise works correctly. Also the ENTIRE pedal assembly, clutch m/c and lines, driveshaft, speedo cable, front flex disk, motor mounts (yes they are different on the manual)

I am sure there are other parts that are more subtle. This is why I have always said that I personally would not do such a conversion unless I had both cars sitting side by side.

Also, your crankshaft may very well not have provision for a pilot bearing. Some measurement, good engineering and a trip to a general machine shop should take care of that part.

Best of luck. A manual transmission in these cars does a total transformation.

Enjoy,

hanno · #4 07-09-2004, 08:53 AM

WDBA, been there, done that. I'll try to answer some of your questions that have not already been addressed. Crankshaft pilot hole for the input shaft should be there (based upon my statistical sample of 2 previously automatic transmission engines), get new bearing, spacer, and cover. Check your existing brake resevoir for molded in clutch outlet. If its there, just snip off the end seal and you are done (no other changes to hyrdaulics/booster is needed). Drive shaft is required. Trans. cross member is required. Complete shifter with 3 linkage rods and 6 clips, wood surround, and boot is required. Some minor rewiring for the backup light switch is required. Starter is fine. I kept the original motor mounts, will replace when required. There is no neutral safety switch (on an 1987). Speedo cable was the same p/n. No relays needed to be changed. This is all from my swap of an 86 5 spd into a 1987 automatic. There can/will be changes in 1991 model. Its not difficult to do, just intelligent grunt workand time if all parts are there. No fabrication, welding, etc. is required. Beg or borrow a trans. jack. I purchased ALL parts from "European Connection", Bernard Schuetz, 800-395-8636. He was most helpful and I would deal with him again in a heartbeat. PM me if you need additional information.