I have just acquired an 80 W116 300SD with a non-functional transmission
From my read of the fault conditions (no forward or reverse at all, 2 quarts of extra fluid on the stick) and a diagnosis by a transmission shop that the PO had done, the front pump is a likely culprit. Apparently there have been reports of case bolts backing out, ruining the front pump. When I get the transmission out of the car I hope I can find something so obvious. But if it is a “hard part” failure, it would make an “over the counter” rebuild difficult as my core is not strictly rebuildable.
I am fortunate to have a 722.315 (6-bolt pan)transmission out of an’84 300D on my shelf and I was prepared to use it to fix this car. I realize that the 722.315 operates with a different vacuum modulator and system than the 722.120 that is in the car, and I have all of the related parts I need to make that part of the conversion work. However, my initial measurements (probably somewhat inaccurate) lead me to believe that the 722.315 is perhaps an inch longer than the 722.120 in the W116 300SD. Am I correct now in thinking that this will not fit without (expensive) driveshaft and rear mount modifications?
I have begun looking for a used replacement. I gather that the most suitable replacement is one out of a 78-80 300SD. That may be a little hard to find.
I know of two 722.1xx transmissions locally that can be had cheaply. One is out of an 80 300D with a very recent rebuild and one is out of a 78 280SE gasser. It would appear that the 300D would need a rear flange swap to carry the larger 300SD driveshaft but otherwise are either of these reasonably suitable for this car? Or would a 240D tranny work?
Any suggestions would be appreciated.
10-14-2004, 09:07 AM
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