1983 300CD Turbo, 199,400 miles.
I have been reading the threads on the flaring/shifting issues with the transmission here and elsewhere and started the check out of mine, this is where I am at.

1-adjusted linkage to VCV at IP to have the proper clearance at WOT
2 -Removed lines to 3-2 valve and tees, replaced tees with straight hose
3-at double tee from main line vacuum to brake booster = 20 in vacuum
4-at line to trans modulator = 10in vacuum
5-VCV vacuum starts at 10 in and drops to zero at WOT
6-Cleaned bajo bolt at intake manifold, found crud in the bolt, but little, if any, in the fitting. Cleaned out bolt.


I believe I have to adjust the VCV up to get to 15 at idle, does this sound right?

She is still flaring, much more at 2-3 than at 3-4, but not flaring anywher near as much.
I will also recheck the trans fluid level, this time in nuetral. She was about 1/2 pint low today, so checking in uetral rather than park might change the level reading.

After doing the above, I will adjust the modulator a turn CCW to see what happens.

__________________
1983 Mercedes 300CD Turbo- 199,370 miles - Lapis Blau
1974 Mercedes 240D - 186,445 miles - Aqua Blau
1982 Volvo 244GL Diesel wagon - 168,956 miles - to be sold
1994 Chevy G30 6.5 Diesel "short bus" converted for camping, painted red white & blue & white stars 78,956 miles
JD F935 diesel front mower

you need to harden the shifter. So turn the modulator clockwise.

__________________
1985 300TD Turbo Euro-wagon
1979 280CE 225,200 miles
1985 300D Turbo 264,000 miles
1976 240D 190,000 miles
1979 300TD 220,000

GONE but not forgotten
1976 300D 195,300 miles
1983 300D Turbo 175,000 miles

http://i42.photobucket.com/albums/e3...e485-1-2-1.jpg

Thanks for the pointer 79, that helps! Should I worry more about trying to get greater vacuum at the VCV, or just move on to the modulator?

__________________
1983 Mercedes 300CD Turbo- 199,370 miles - Lapis Blau
1974 Mercedes 240D - 186,445 miles - Aqua Blau
1982 Volvo 244GL Diesel wagon - 168,956 miles - to be sold
1994 Chevy G30 6.5 Diesel "short bus" converted for camping, painted red white & blue & white stars 78,956 miles
JD F935 diesel front mower

if you have no vacuum leaks then i'd adjust the modulator.

__________________
1985 300TD Turbo Euro-wagon
1979 280CE 225,200 miles
1985 300D Turbo 264,000 miles
1976 240D 190,000 miles
1979 300TD 220,000

GONE but not forgotten
1976 300D 195,300 miles
1983 300D Turbo 175,000 miles

http://i42.photobucket.com/albums/e3...e485-1-2-1.jpg

Everything noted above in points 1-6 is correct. You do not want to increase vacuum to 15 at idle........that will increase the flare.

The recommendation to increase the modulator pressure by turning the T handle one turn clockwise is correct.

Please report back with results.

Thanks Brian, I appreciate the direction. This forum is GREAT!! I'll report back later tonight after doing this and test driving.

__________________
1983 Mercedes 300CD Turbo- 199,370 miles - Lapis Blau
1974 Mercedes 240D - 186,445 miles - Aqua Blau
1982 Volvo 244GL Diesel wagon - 168,956 miles - to be sold
1994 Chevy G30 6.5 Diesel "short bus" converted for camping, painted red white & blue & white stars 78,956 miles
JD F935 diesel front mower

OK Brian, after 1/2 hour looking for the modulator, I found it on the drivers side. Green with black cap. Removed black cap, pulled key out enough to clear the notches, turned 1 full turn clockwise. (what a bear) Took for a test ride, still flairing, less than before, after warm up. Return her home, 1/2 more turn clockwise, retested, still a bit of flair.

Should I;

add 1 more turn at modulator and retest?
or
adjust VCV to 8 in vac at idle?

Please advise

Doug

__________________
1983 Mercedes 300CD Turbo- 199,370 miles - Lapis Blau
1974 Mercedes 240D - 186,445 miles - Aqua Blau
1982 Volvo 244GL Diesel wagon - 168,956 miles - to be sold
1994 Chevy G30 6.5 Diesel "short bus" converted for camping, painted red white & blue & white stars 78,956 miles
JD F935 diesel front mower

You could try to reduce VCV vacuum to 8 at idle.......but, it only works with a trans that's not too far on the way out.

If it doesn't work (and I suspect it won't), it's time for more modulator pressure.

If you cannot get it to stop flaring after three full turns at the modulator..........it's time is limited.

A buddy of mine has a 80 300CD and the tranny was flaring badly. He adjusted the modulator quite a bit and finally got it to shift good. I would just adjust the modulator clockwise another full turn or so. If you adjust the modulator alot more and it still flares then your tranny is on its way out. Good luck, let us know how it goes.

__________________
1985 300TD Turbo Euro-wagon
1979 280CE 225,200 miles
1985 300D Turbo 264,000 miles
1976 240D 190,000 miles
1979 300TD 220,000

GONE but not forgotten
1976 300D 195,300 miles
1983 300D Turbo 175,000 miles

http://i42.photobucket.com/albums/e3...e485-1-2-1.jpg

MB sells a replacement spring train (126 270 44 77) for the K-1 accumulator which is intended to address the 2-3 flare. It's easy to install, requiring only the removal of the transmission oil pan, plus four screws and a retainer plate.

You might also research the forum for "Superior Shift Kit."

Geez, on my '80 wagon with an orange modulator on the passenger side of tranny I was just moving the key in the modulator 1 notch at a time. Are yall talking about 1 entire revolution???
I guess since there was no VCV on the IP then maybe these modulators are quite different?

__________________
Jimmy L.
'05 Acura TL 6MT
2001 ML430 My Spare

Gone:
'95 E300 188K "Batmobile" Texas Unfriendly Black
'85 300TD 235K "The Wagon" Texas Friendly White
'80 240D 154K "China" Scar engine installed
'81 300TD 240K "Smash"
'80 240D 230K "The Squash"
'81 240D 293K"Scar" Rear ended harder than Elton John

Finally got some time to get back to this yesterday. I spent Saturday morning at the pick n pull in town. I could kick myself for not looking for another combination & Cruise control switch.

Anyway, I digress, I put another full turn on the modulator and she is shifting real crisp now. Only flares when the fluid is cold in the morning. I am thinking of backing off a 1/4 turn to see if the shifts will "smooth" a bit.

I may have to get the shift kit for K1 $ K2 springs. They should help from what I have read and it seems like a fairly inexpensive up-grade.

__________________
1983 Mercedes 300CD Turbo- 199,370 miles - Lapis Blau
1974 Mercedes 240D - 186,445 miles - Aqua Blau
1982 Volvo 244GL Diesel wagon - 168,956 miles - to be sold
1994 Chevy G30 6.5 Diesel "short bus" converted for camping, painted red white & blue & white stars 78,956 miles
JD F935 diesel front mower

Fine tuning the system can now be done with vacuum.........it's not worth the effort to try and tune it with modulator pressure.

The kit would be a benefit for you.

Brian, I took off the dome shaped cover to the VCV to adjust and I can not find the small screw. Do you have any pictures?

On another note, I believe I have ruled out the driver side axle shaft regarding the "clunk" I hear when the car slows enough for it to down shift into 1st. I did this by putting the shifter in L then hitting the throttle hard and stepping off throttle in quick succession 3 times, with no clunking. I did this in reverse as well and no clunking.

This leads me to think that the trans needs the Superior Trans spring kit for sure. I will investigate a local source tomorrow, they list a few places nearby that are stocking distributors. I'll get that and a trans filter & gasket and get this done this weekend, if work allows. Do you concur?

__________________
1983 Mercedes 300CD Turbo- 199,370 miles - Lapis Blau
1974 Mercedes 240D - 186,445 miles - Aqua Blau
1982 Volvo 244GL Diesel wagon - 168,956 miles - to be sold
1994 Chevy G30 6.5 Diesel "short bus" converted for camping, painted red white & blue & white stars 78,956 miles
JD F935 diesel front mower

Right beneath the dome is a locknut and a slotted screw.........you can't miss it unless it's a different VCV.

You don't need a Superior spring kit if the shifts are too harsh........you need more vacuum to the modulator.