300d 4-speed swap: are you happy with it? - Page 3 - PeachParts Mercedes-Benz Forum

Walkenvol · #31 02-11-2013, 01:50 PM

Looks like you trust those jack stands with your life - I never do. I always put something else substantial under the car (blocks of wood, steel wheels, etc) so if that one in a million happens and it comes off a jack stand it doesn't crush me.

Probably overkill to most, but you can't ever be too safe!

54dan · #32 02-11-2013, 02:24 PM

Charmalu, yes, I was happy. I spent considerable time staring at those starter and top trans bolts wondering just how I was actually going to get them out. Then I'd decide to do something easier like pull the speedo cable or the cooler lines. Eventually, I was left with only the "hard" stuff and it wasn't really that bad once I actually tried. My plan on bleeding based on what I've read here is to pressurize from the slave cylinder. What could go wrong?

Good point Walkenvol; you are right and that is a good plan.

Also I'm thinking, given the fun that was involved in removing the starter bolts (10mm allen head, dang they were tight!) that now might be a good time to take the (perfectly functional) starter to the local trusted starter/generator shop for an overhaul. Any thoughts on that?

-Dan

cooljjay · #33 02-11-2013, 02:34 PM

Quote:

Originally Posted by 54dan

Also I'm thinking, given the fun that was involved in removing the starter bolts (10mm allen head, dang they were tight!) that now might be a good time to take the (perfectly functional) starter to the local trusted starter/generator shop for an overhaul. Any thoughts on that?

-Dan

I would do it, you have no idea how long the starter has been in the car and how many starts it has done. If you ever have starting problems in the future you can rule that out. People don't like to hear me talk about starter problems.....but use common sense....are they really suppose to last 30 years? Carbon builds up in them when brushes ware, grease gets hard....starter starts to over heat....kills the battery.....call it preventive maintenance

54dan · #34 02-15-2013, 08:47 AM

So, finally have most everything, see attached picture ...

Planning to install new expendable parts (clutch, master, slave, hose, bearings, trans mount, etc). In shopping on peachparts, I see different numbers for different chassis numbers. Does anyone know what the real differences are between these parts? This stuff allegedly came out of a 1980 240d.

-Dan

charmalu · #35 02-15-2013, 11:06 AM

Great assembly of parts, but you will want to use the trans X mount from a 240d automatic. not the one the 240 uses with the manual trans.

Here is some good info.

Manual Transmission Conversion Vibration - A Solutions

Charlie

54dan · #36 02-15-2013, 01:53 PM

Ah, great info, Charlie -- I had missed that detail!

If anyone has a 240d auto crossmember to sell, let me know...

-Dan

54dan · #37 02-16-2013, 09:37 PM

Well, it's starting to look like a manual transmission car ... today I installed the manual shifter and the manual pedal cluster. The trick to the latter was to have and assistant pull back the brake master cylinder while I wrangled with the pedal cluster under the dash. Then get that weird hook thing engaged at the top of the cluster to get it to sit correctly.

Also lifted the manual trans up into the car and put a couple of bolts in the bellhousing in order to figure out the shift linkages and rear crossmember. I've managed to thoroughly confuse myself as to which rod goes where in what orientation, so will revisit tomorrow. Also rod-ends on the shifter end are stuck pretty solid; soaking in penetrant now.

Planning to install shift rods to trans, mark, cut, and thread to fit rod-ends on shifter end.

Ordered new master, slave, flex hose, pedal pads, pilot bearing, 240d auto trans mount from peachparts. Forgot to get flywheel bolts and shift linkage bushings.

So the todo's so far are:

- shorten shift linkages
- decide what to do with pilot bearing (machine from brass or try to hone small '85 crank hole to fit 240d bearing)
- get flywheel machined and balanced
- get starter overhauled while it's out
- find 240d auto crossmember

So, at least I can sit in it, press pedals, move shifter and make manual transmission noise now. I'll be happy when I can have the satisfying shift noises too.

-Dan

charmalu · #38 02-17-2013, 01:49 AM

Trans is out of a 80 240D, then it is the older one with the seperate bell Housing and iron box. All three levers should point up and are forged steel with a bolt squeezing the lever to the shaft.

the forward lever is the 3-4 shift.

the center lever is the reverse lever

the rear lever is the 1-2 shift.

the curved shift rod is for the 3-4 shift

the longest straight rod is the reverse

shortest rod 1-2 shift.

Looking at the shifter levers from the rear. the left one is the reverse.

center is 1-2 shift

Right lever is 3-4 shift. closest to the driveline.

Each one of the shift levers has a hole for a nail, drill bit etc... to be inserted to keep the levers centered. there is a upside down "V" plastic piece on either side to keep the drill bit etc... lined up. this way the shifter assy is centered so you can then adjust the shift rods to the Transmission.

When I cut my rods to fit my swap into our 85 300D. I unscrewed the Aluminum ends, and atached them to the shift assy levers. held it horizonally and laid the rod on top of it, then marked it to be cut. threaded the ends and screwed them on. notice how far they are screwed on first before removing them.

I had quite a time tweeking the rods to fit and clear each other and the tunnel.

Measure twice, cut once.

Iam not so sure you want to hone out the crank hole to make the pilot bearing fit.

Charlie

54dan · #39 03-24-2013, 09:34 PM

Finally had a weekend to devote to the conversion and am so close I can taste it!

Current issue is that I cannot get the new driveshaft in -- it won't clear front or rear centering pin by about 1/2". Driveshaft shop had me measure from the flexplate on the installed new transmission to the center of the center bearing holes, and this dimension looks perfect.

This is the (pretty much) last thing between me and a test drive ... it was the end of the day and I was getting tired so I figured I'd give it a rest before I try to force it and break something. Pretty sure the splines are all the way in, and I removed the parking break pivot thing to let the shaft bend a bit more at the u-joint.

Other random notes so far:

* I had a heck of a time bleeding that &^%$ clutch! Final apparently successful method was to put teflon tape on the bleeder threads, and suck from the bottom using a mityvac and a container inline. No luck with an assistant opening and closing the bleeder as we pumped the pedal, and no luck pressurizing from below.

* A machinist friend and I made a bronze bushing to serve as a pilot bearing. We think that MB just never did the final machining on the crank hole to make it a clean 35mm hole to fit the standard pilot bearing. I will get and post the exact dimensions of the bushing we made -- it was near 1.366", I think.

* I am an expert at tweaking those shift rods now. I thought I would be smart and cut them in straight sections and then weld together to avoid getting the bends out of whack and in order to not have to cut threads. This worked well except I cut the 3-4 rod in exactly the wrong place and got it all whompered up. I eventually got it back into shape.

* A cable come with the conversion parts that appears to plug into the weird 4-pin plug on the L side of the console that formerly went to the neutral safety switch. The new cable has that 4-pin plug on one end and a 2-pin one that looks like it goes the the backup light switch on the shifter. True? Will this cable connect what was the neutral safety circuit?

* Got the 240d auto crossmember from a forum member. fits perfectly.

So, that's where we stand so far. Hopefully a clear mind will show me what I'm missing tomorrow to get that shaft in.

Many thanks for all of the help.

-Dan

54dan · #40 03-26-2013, 08:54 AM

Took a fresh look at things last night and got the driveshaft installed with minimal drama. Amazing what a fresh look at things will do -- the driveshaft was simply not fully compressed.

Got everything done under the car ... stared at things for a while ... plugged in the mystery reverse-light wire where it looked like it would go, and ... shazam, it started and runs well, with no apparent vibration!

Unfortunately, I discovered that the clutch is not yet completely bled. Right now I'm ready to buy the baddest power bleeder I can find. Where does the air go in that system?

Hopefully this afternoon/tonight, we will get to go for a test drive!

-Dan

MNBenz · #41 03-26-2013, 10:02 PM

Congratulations on nearly finishing the job! I had done this to my 1983 300TD with a 4 speed I got out of a 240D. Once it was in turned out the trans had a bad bearing! But I picked up a 5 speed from a forum member and man it's fantastic! Trust me you will love your wagon even more when it starts driving!

Bleeding the clutch is a PITA! I tried several different methods with my mityvac and then finally with an oil can pushing the fluid up through the slave. There is a method of hooking a hose to the right front caliper and the back of the slave. It probably works well but be careful the hoses can pop off easily.

My conversion had parts from several cars and it turned out I had the wrong pushrod on my master cylinder. There is a white and black pushrod and one is longer than the other, I couldn't shift because the rod wasn't long enough...if you have a bunch of problems and you installed a new master maybe it's the wrong pushrod like what happened to me.

54dan · #42 03-26-2013, 10:43 PM

So, after work today the only thing between me and a test drive was getting the air out of that &^%$ clutch! I decided to try the hose from the right front caliper trick -- and after several mishaps with the host popping off in the midst of furious brake pedal pumping, lo and behold ... the clutch suddenly functioned like a clutch!

I took one last look at everything, put the carpet back in, halfheartedly tried to figure out where the cruise amp will go now that the slave cylinder is in the way, decided to do that another day, lowered the car down off the jackstands and fired the wagon up and took my first ride in a manual 300td.

Man, this was worth all of the work. The dang thing is exactly perfect, just like it was supposed to be like this. I drove it to the gas station and treated her to a new tank of diesel ... I peered nervously underneath, half expecting to see pools of oil or something, but everything was dry. RPMs seem to be much lower at 60 mph (2800, I think?) than I recall with the auto.

I have zero vibrations of any type at any rpm or load that I have noticed so far. After a lengthy discussion with a trusted machinist, we wound up neutral balancing the flywheel and the pressure plate, not match balancing to the old ring gear/flex plate. The flywheel was heavy on one spot (IIRC) by 14g. He had to weld significant metal onto the pressure plate (!) to get it balanced. Apparently, this plan worked in this case.

The car is a joy to drive. Many, many thanks for all of the help, ideas, kind words, and encouragement -- I could not have done this without you guys.

-Dan

JimSmith · #43 03-27-2013, 01:16 AM

Congratulations! Sounds like a hell of a lot of work with exceptional results! Makes one wonder why MB elected not to make the drivetrain available then, and today. Thanks for posting the adventure.

Jim

t walgamuth · #44 03-27-2013, 06:33 AM

Welcome to the turbodiesel stick club.

charmalu · #45 03-27-2013, 11:44 AM

Yes welcome to the club. I see you already joined the

"W123 300D/CD/TD Turbo Diesel Manual Transmission Club".
http://www.peachparts.com/shopforum/groups/w123-300d-cd-td-turbo-diesel-manual-transmission-club.html

We are an exclusive group. this give you access to the prestigious Country Club of Stick Shifter and Gear Grinders.

Congratulations on a successful surgery and the patient survived.

Enjoy many happy miles with your new baby.

Be sure to post the measurments of the Pilot Bushing you had made.

You will notice about a 3 mpg increase which is nice. you should see 30 on the Hwy with the 2:88 Diff.

How difficult was it to drop the auto trans out. they are a heavy %^&#, the 4-spd manual is around 50+ lbs. I can drop those at PNP w/o any problems, but an auto would take me out. did you use a trans jack?

The snout on the Torque Convertor is smaller to fit the small crank hole on the 85 crank, not sure why they did this, as it is the last yr for the 123 body and the 617 engine. the pan gasket on the Cali version is different also, one of those mysteries in life.

Now you need to start your quest for a 5-spd manual trans.

See.... it never ends with these cars.

Charlie