4 Speed 300SD in the works - PeachParts Mercedes-Benz Forum

DrewGerhan · #1 12-31-2008, 05:20 PM

Today I looked at a parts 240D with a manual transmission. The tranny would be going into my 81 SD. I have read about all the auto to manual conversion stories and am very confident with the whole swap. My question is, when I looked at the car I moved through the gears all engaged except for reverse. It seemed like it wouldn't even go into the pattern. I read that reverse has its own linkage and this could be the problem. My buddy also said it could be a bad synchro. Do either of these sound like a common problem? I know my way around the entire car, but having not had a manny tranny before I feel like a child walking into the middle of a movie wanting to know whats going on. ANy help/advice would be greatly appreciated.

StaggerLee · #2 12-31-2008, 05:50 PM

You have to lift up on the shifter to get it to go over into reverse. Did you do that? Otherwise it's just as you describe. Hope that helps and good luck with the swap. I love the manual.

DrewGerhan · #3 12-31-2008, 06:02 PM

Like physically pull the shifter upwards? (in the same motion as those crane games?)

arcticathlon · #4 12-31-2008, 06:48 PM

Yes, lift. then move it to the left and forward.

bgkast · #5 12-31-2008, 07:21 PM

Well there's your problem.

Stevo · #6 01-01-2009, 12:41 PM

Quote:

Originally Posted by bgkast

Well there's your problem.

LOL, first time I drove a manual, I'm stuck in some guys driveway trying to figure out where the hell reverse is so I can finish turning around and get back to the seller

DrewGerhan · #7 12-31-2008, 09:12 PM

Hahaha. I feel like I have disgraced the Mercedes name. That makes a lot of sense though. I think I will buy the whole car then. It has 189k on it. Does anyone have any info about getting the mechanical and electrical speedos to work together? That and the drive shaft length are my only real questions. This also seems to be a bout a weekend project once you have all the parts. True or false?

DeliveryValve · #8 01-01-2009, 07:51 PM

Quote:

Originally Posted by bgkast

....Try a search for "SDS" here on this forum for info on another manual SD

Link to 300SDS

Quote:

Originally Posted by YoungBenz

Hahaha. ..... Does anyone have any info about getting the mechanical and electrical speedos to work together? ....

From that Thread:

Quote:

Originally Posted by Apotheoun
...... There is a lot of thought planning and measuring twice involved before cutting. You will need to invent or create a home made rotational electronic pulse signal generator to run the speedometer, odometer, and cruise control, or you will have nothing to read on the dash.

This is the case with my conversion, which was finally made right. It formerly utilized a poorly hooked up 240D speedometer that was horribly inaccurate, and now it has a correct 300SD speedometer. To make it work though, Kurt had to invent a new signal generator by welding four magnets onto the drive shaft and attaching a nearby sensor, completely hand wrought. It works great, but nearly self destructed in the first two miles due to faulty clearances. The magnets are still bent over from the initial snafu, but work just fine. What a noisy racket that made!

t walgamuth · #9 01-02-2009, 11:52 AM

Be sure to mark the flywheel from the engine you are planning to use and its position on the motor. Then have it and the fw you want to install for neutral balance. If they are both neutrally balanced you are good to go. If not you must match balance the new fw to the existing motor's fw.

Most 123s and 126s seem to have neutrally balanced fws but some do not. In about four cases I had one that was not neutral.

I would love to have a 126 300sd with a stick....especially a fiver.

JEBalles · #10 12-31-2008, 09:59 PM

I just wanted to offer my support for such a project. You are the only other person I've even heard of that wants a land yacht like an sd, but wants a manual too. I thought I was alone. I'm also curious how young you are. I'm currently removing my transmission for repair, which I thought was quite ambitious at 17. Also, my driveshaft could move back and forth a few inches, so it's length is variable. It seems like it should be able to accomodate another transmission quite nicely, but I couldn't swear to it, I've never been under a car with an automatic transmission. Also, are you sure the bell housing would bolt into the engine block the same way an automatic transmission would?

diesel don · #11 12-31-2008, 10:58 PM

I did the swap in an opposite application. 300D turbo engine into a 123, 240-D manual car (whose engine had blown)

Still have it out back. We enjoyed it for five years or so and it was very dependable. Still is, but my son has graduated to a TDI (or been demoted)

Fortunately, I had:

300 flywheel (from a euro manual)
Drive shaft from the same

The only mods I had to do were to shorten the linkage

I think you'll find plenty of advice on the forum as a number of guys have done it

If you have the right stuff on hand, a weekend is do-able. I've always figured about four hours to take an engine out and about the same to put the next one in. Then you can start dinking with the extras.

The guys recommended that I use a new pilot bearing.

I hope you enjoy the process as much as we did.

Diesel Don

DrewGerhan · #12 01-01-2009, 07:11 PM

Quote:

Originally Posted by JEBalles

I just wanted to offer my support for such a project. You are the only other person I've even heard of that wants a land yacht like an sd, but wants a manual too. I thought I was alone. I'm also curious how young you are. I'm currently removing my transmission for repair, which I thought was quite ambitious at 17. Also, my driveshaft could move back and forth a few inches, so it's length is variable. It seems like it should be able to accomodate another transmission quite nicely, but I couldn't swear to it, I've never been under a car with an automatic transmission. Also, are you sure the bell housing would bolt into the engine block the same way an automatic transmission would?

Well I am 18. My buddy and I have done many transmission and clutch jobs on various vehicles like Jeeps, Broncos, Subarus but this will be the first time with a Benz. As for the bell housing, it will bolt up just like the auto. Only thing I'm worried about will be the custom drive shaft, but I'll have a shop do that. Other than that I'm going to get a new clutch, pressure plate, resurface the flywheel, new pilot bearing and anything else I need too. My new job at Auto Zone is really going to help here. I plan on pulling the engine from my SD, removing the auto, attaching the manual and putting it back in as a unit. This is after I clean and paint them both of course. I'm hoping to start the day after midterms so I can afford to not have the car for a few days if need be.

With the engine out I am definitely going to "adjust" the torque control some more. I found today at a local yard, another hood. This is going to have a hole cut in it and have a 3in stack come up through the hood. This in no way will be permanent, but only because I lost a bet. Haha.

I will definitely take pictures of everything while I go. Anyone who has done this have anything they'd like to share?

StaggerLee · #13 01-02-2009, 12:09 PM

Unless you can get a measurement from another car that has the same conversion, I would drop the engine and trans into place and then take your measurements. The best way is to use a long stick as opposed to a tape measure so you eliminate any sag.

I had a custom one made in Portland for around $400 delivered to Seattle.

DrewGerhan · #14 01-02-2009, 03:57 PM

Quote:

Originally Posted by StaggerLee

Unless you can get a measurement from another car that has the same conversion, I would drop the engine and trans into place and then take your measurements. The best way is to use a long stick as opposed to a tape measure so you eliminate any sag.

I had a custom one made in Portland for around $400 delivered to Seattle.

Thats what I want to do. Do it once, do it right.

Is that $400 for real? Was that for a whole new shaft or just having the original lengthened? I was just going to lengthen mine, if possible.

I did get all the parts today. $87 all said and done. I got the transmission, flywheel, pressure plate, clutch disc, pedal assembly, shifter assembly and linkage, brake reservoir, slave cylinder, associated hose and line, and every nut and bolt that came out. Does it sound like I missed anything?

winmutt · #15 01-02-2009, 04:00 PM

Quote:

Originally Posted by StaggerLee

Unless you can get a measurement from another car that has the same conversion, I would drop the engine and trans into place and then take your measurements. The best way is to use a long stick as opposed to a tape measure so you eliminate any sag.

There is no need for this as the correct size is posted in several places on here and other forums.