Eureka! You may be onto something.

New oil in tranny but, this has me thinking....when I installed the tranny, I drained the old stuff ( nasty but no metal filings that I could see) and I replaced it with Mercon III ATF because the manual says to use ATF in the tranny.

Here's the rub: Mercon III didn't exist when that transmission was built (circa 1980). I wonder if I should drain that fluid and replace it with an earlier vintage ATF like Dextron?

Bummer, that looks like a dead-end. Apparently Mercon and Dextron III are basiacally the same.

From this thread:

Castrol Dextron-III/Mercon ATF F-30341
Castrol Transmax M-22257/22096
Chevron ATF Dextron III F-30108/30159
Exxon Superflo ATF Dextron III F-30111
Havoline ATF Dextron III/ Mercon F-30321
Texaco ATF Dextron III/Mercon F-30321
Pennzoil ATF D-22413/ F-30110
Quaker State Dextron III/Mercon F30161
Sunoco ATF Dextron-III/Mercon F-30176
Unocal Multi-Purpose ATF D-22413/22431
Valvoline ATF Type D

Randy, get some RedLine MTL. Hard to find, but worth it. Modern ATF will eat the syncros out of your transmission.

1977 300D with manny tranny (123.130/617.912) flywheel part number is A 615 030 12 05. Retail price $252.00 as of a couple years ago.

Randy, Austin VeeDub at the corner of 71 and Ed Bluestein has it... on the northeast side of that instersection...

Backwards Physics
 

"And, I do believe I now know why the 300's flywheel is heavier: they do it to maintain engine rpm between shifts. In the 1-2 and 2-3 shifts, the engine looses rpm so quickly it is difficult to make a smooth transition. OTOH, it also picks up rpm quite nicely= more fun to drive."

Ever seen a one lung engine ? They have huge flywheels... and as more cylinders are introduced less momentum from the flywheel is needed to keep things smooth...

Thus, the 240 flywheel should be heavier than the 300 .... not the other way around....

Will do on the RedLine MTL. Are you sure about modern ATF destroying synchros? I read in another thread that the high sulphur content of hypoid gear did them in too. Now I'm sooo confused.

Have to admit that I don't know that for sure. But I read it here from a reliable source. Somebody like gsxr or JimSmith. Not some wacko like Greg. :o

Rick, I'm really curious. Would you look up the number for the 240's (say maybe a 1978, 1980 and a 1982?) flywheel? Coz, the part number you show above is for a (old) 240 engine..

Lots of tranny fluid info here.

Hang on a sec while I look up that part.

Re: Backwards Physics
 

No Greg, I've never seen a one lung engine. However, I have seen a one cylinder engine. <grin>

Hey, thanks for the pointer on where to get some MTL.

Amen!

Same part number for all. Looks like you have the right one after all. :cool:

BTW, timing of engine revs dropping was adjustable on my 240D with the idle adjustment. When idle was turned up, revs dropped much slower and sometimes not at all. Once the engine was warmed up and the idle adjusted to the sweet spot, rev timing was also perfect. I'm assuming you are missing the adjustment for the linkage on your 617.

One more ancient myth dies by the sword. Touché! Thanks Rick!

Correct, no idle adjustment on my 617. I'll deal with it. I'm getting better at shifting all the time...the throttle response is so different on a diesel.

Correctamundo! I think the torque curve of the diesel combined with the somewhat laggy turbo on the 617 explains why they never offered it with a manual transmission in the first place. The way a typical person drives a manual, the shifts take so long that the engine will be off boost by the time they get to the next gear. Then you have to start all over again. The automatic shifts fast enough to alleviate that. My VW has a variable nozzle turbo, so it is always on the boost and you never have a problem.