Need Guidance.. Transmission..

After a month and four thousand miles I've come to some conclusions and realizations on my first Mercedes.
I love the car. 1983 300D with 242K miles on it.
The motor is sound, oil preasur is very good, never seen below 2.5bar, ever, not after very long high mph interstate running. Uses little oil, leaks little. turbo has a little play in the shaft, but hey.
It has it's share of odd and end 242K mile car problems. It has not been perfectly maintained, but not abused either, and HAS had very regular oil changes.
Now, the only real problem and think I don't like, is the transmission. I dislike an auto to start with, especially with a diesel. And this one is original with this millege, which I read and am told is rare. I suspect it's lasted so long because the modulator was connected to a line the service manual labels as a "vent to passanger compartment", hence, neck snaping shifts with no slip. It would break traction and move the rear of the car sideways on wet pavement at medium throttle, and ocasionally chirp the tires on dry asphalt. Not that this isnt a little fun, but it's not right. So I hook the modulator up to it's correct line, and it shifts firm but smoother than it was, and the shift points are better, though I also adjusted the cable as per the manual. BUT, the 3-4 shift has some slip, not flare, but slip, and it takes about three seconds do drop into reverse(and always has since 120K says the previous owner). I'm not done tuneing and fixing the vacuum system, but I am about sure the trans needs to be rebuilt.
Here lies the problem and the point I need advice on. I can't afford to rebuild this thing. Period. I was laid off not long ago, there's christmass, bills, etc, etc, I wouldnt have got the car but I bought it some time ago when I was employed and just now picked it up. It's crutch this tranny along or sell the car. I figure why not put it back as it was?
1: Hard shifts are better than none at all, and theoreticaly less wear on the transmission, yes?
2: Is this best acomplished by either tunieing the vacuum system till the 3-4 shift is acceptable OR turning up the line preasure at the modulator?
3: A good parts source? I need the two switchover valves up top, there working but the plastic over the metal protrusion is worn away, and a few other things. I've seen them for $35 or so at a place or two, even for an MB, that seems a little much for a plastic valve?
I also plan to change to synthetic fluid and possibly update the B2 piston as I'm pretty sure this is the original and failure prone one. There is a newer modulator I've read, but if I end up diconnecting it I may not bother with it.
It really, really, really bugs me to have something not as it should be, but I don't have much of a choice at the moment. The timing chain I'm sure it's due and various suspension items are going to eat me up as it is. Is there anything else I should consider here? What little information I've come across says a manual trans swap is a pain with reguard to the flywheel swap and engine balance, so I gues that's out, though it would be absolutly preferable.
Thanks for any input.
Rex 83 300D 242K Missing his cheap, economical VW diesels..
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Rex,
A twenty year old car that starts in winter, doesn't use oil after 242K miles is a great car! You've restored the transmission's shift modulation to its original design and it works well BUT for the 3-4 shift AND the slow reverse engagement.
If this were my car I'd change the transmission fluid and filter and leave it alone. Hard shifts prove good internal transmission pressure but accomplish nothing so leave it as it is. It works, the objective being to keep it on the road at minimum cost. So don't look for things to do.
As to on-line sources:
http://www.peterschmid.com / http://www.germantransmissions.com / http://www.mercedesengines.net / http://www.atk-engines.com /
http://www.cvjreman.com/MercedesBenz.html http://germanstar.net / http://www.thebenzbin.com / http://www.epsparts.com / http://www.buymbparts.com / http://www.timevalve.com / http://www.euromeister.com /
http://www.tmcpubl.com//mercedes.html
Tom
'80 300SD, since new
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Rex, I'd suggest dropping the trans pan and inspecting the crud that has accumulated on the bottom. If you find metal shavings, you should probably be nervous. If you find some non-metallic (usually grey) 'mud', you're probably in good shape. The mud will be a mixture of additives in the AT fluid and clutch facing material.
Replace the filter and AT fluid.
Slow shifts into reverse are often an early indication of stiff or worn seals. There are AT fluid additives that will help restore the seals (makes them swell). I've been very pleased with the results of these additives.
Steve
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