what year 4spd manual trans to install?
 

I'm in the process of freshening up a 617 w/some minor performance mods and have a 4spd manual trans to install. I'm not sure what year the trans is, but it seems to be in good condition (shifts fine, spins freely in all gears, bearings seem good) Is there a particular year that is best? does any one happen to know the length of the shift rods for this conversion? Would I be crazy to install this without tearing it down for inspection? I am trying to get everything ready so I can do the engine/trans swap at one time with minimal suprises/complications.
The swap is in an 82TDT with 2:88 rear end swaped in.:dizzy2::dizzy2:

All the iron body transmissions from the W115 and W123 cars are the same. The all-aluminum case transmission came in later 240D's and isn't as strong/reliable as the iron model.

I strongly suggest you get rid of that 2.88 or your clutch will be glazed in less than a year, especially with the additional 400lbs of being a wagon. The 3.46 is about as ideal as you can get since Mercedes never made a 3.2x-3.3x ratio.

Set the shift rods to where they place the shifter in a good location for each gear without anything binding.

Search for "auto manual conversion".

I think the 3.07 would probably be ok. 3.46 is no good for highway travelling imo. As far as the transmissions.... 83+ was aluminum body but had a really short first gear which would mate well with a 2.88 rear and a turbo. I had a 83 euro 300d and never had problems with the transmission. I would be interested to find some people who did.

I'm sure it would be better. I went from 23mpg to 26mpg just by changing from the 3.69 to a 3.46.

240D Sep83 and on had the aluminum tranny with 4.23:1 1st gear vs. 3.9x for the iron manuals used through the years.

4sp manual
A 3.90-2.30-1.41-1.00 R3.66
B 3.91-2.32-1.42-1.00 R3.78
C 4.23-2.36-1.49-1.00 R4.10
D 3.91-2.17-1.37-1.00 R3.78
E 3.98-2.29-1.45-1.00 R3.74

5sp manual
F 3.82-2.20-1.40-1.00-0.81 R3.71

FINAL DRIVES
3.92 3.69 3.58 3.54 3.46 3.07 2.88
------
200D 1976-Sep80, std 4sp manual A 3.92
200D Oct80-Aug83, std 4sp manual B 3.92
200D Sep83 on, std 4sp manual C 3.92
200D Feb82 on, opt 5sp manual F 3.92

220D std 4sp manual A 3.92

240D to Sep80, std 4sp manual A 3.69
240D Oct80-Aug83, std 4sp manual B 3.69
240D Sep83 on, std 4sp manual C 3.69

300D std 4sp manual A 3.46
300D opt 5sp manual F 3.46

280 to Apr77, std 4sp manual A 3.54
280 May77-Oct77, std 4sp manual E 3.54
280 Nov77 on, std 4sp manual E 3.58

280E to Apr77, std 4sp manual A 3.54
280E May77 to Oct77, std 4sp manual E 3.54
280E Nov77 on, std 4sp manual E 3.58
280E Oct81 on, opt 5sp manual F 3.58

240TD to Sep80, std 4sp manual as A 3.69
240TD Oct80-Aug83, std 4sp manual B 3.69
240TD Sep83 on, std 4sp manual C 3.69
240TD Feb82 on, opt 5sp manual F 3.69

300TD std 4sp manual A 3.46
300TD opt 5sp manual F 3.46

280TE std 4sp manual E 3.58
280TE Oct81 on, opt 5sp manual F 3.58

280C to Oct77, std 4sp manual E 3.54
280C Nov77 on, std 4sp manual E 3.58

280CE to Oct77, std 4sp manual E 3.54
280CE Nov77 on, std 4sp manual E 3.58
280CE Oct81 on, opt 5sp manual F 3.58

Having had both, I think the almuminum cased tranny (Getrag) shifts significantly better/smoother than the iron box. The issue of reliability is still in question as far as I'm concerned.

A 2.88 shouldn't be too much of a problem unless you live in San Fransisco or someplace with lots of stop-n-go driving on steep hills. FWIW, I have an '85 parts car (bought from sublettm on this forum) that had been a 300D until it ate an engine somewhere down the road. It then had a 616 installed in it and was a daily driver for several years with the 2.88 rearend when someone smacked Mike and he sold it to me. Slow off the line? Yes, but the clutch and flywheel are in another car I have. No glazing evident. But, if you're a clutch slipper, all bets are off.

Yes, driver technique is a BIG factor in clutch life. Foot - clutch pedal contact should be kept at a minimum. I'm usually in 4th gear by 30mph.

I like the 2:88 since I drive about 700 highway miles a week and now I can cruise at 80 with out it screaming at me, I still pull the long hills pretty well, does not down shift as long as I go into the hills fast. I know the first gear is pretty long in these manual 4spds, but I think with a fresh clutch and some careful driving I'll be fine for a long time.
I have the aluminum case trans, not as strong eh?

I have yet to hear anything good about Mercedes' 5-speed manuals on the European/UK MB forums.

From mercedesclub.org.uk:
"They weren't popular over here either - they're horrible boxes"
"I think the term used here is woolly and not much feel"
"I agree, a nice 5-speed is lovely...but MB don't make a nice 5-speed"
"I had a W123 230E with a 5 speed box and agree that it was horrible and made the car impossible to drive smoothly."

I would love a 5spd and a 3;46, but cant find one (or afford one).
Forced induction, that is one sweet car you have!

Oh, the 5spds are no good, I did not catch that, good to know.

Randy (R Leo) seems to like his.

I've only once driven a 190D 2.5 non-turbo with a 5-speed so I can't personally say much about it's long-term quality. That was a quick little car though. :)

Question of wide or narrower torque power bands no doubt. Like if 1-4 on 5spds in closer and tighter gear ratios than what you get on 4-spd trannies then makes sense would make the car less comfortable to drive.

IMHO, a 5-speed coupled to the 617 is the perfect combination. There's plenty of get up and go then, for economical cruising, there's 5th. The only drawback is that I have an annoying driveline vibration that's engine speed dependent. If I can ever sort out that issue, I'll be golden.

How straight is your drive shaft (does it bend at the u joint?)? I had to lower the engine just a tad to straighten it out. I used some thick washers between the body and cross member. What rear tran mount you use makes all the difference in the world.

Thanks for the tip, I was not aware the mounts were different heights. I don't know how straight the driveshaft will be yet, I still need to get it lengthened. I am measuring the difference of overall trans lengths and will make it out of two driveshafts I guess. Unless the drive shaft I need is available.