300sd revival

[VaBob]

Bought a 83 300sd over the winter. Previous owner said it has sat for about 2 years because the inspection went dead and they didn't need it so they never got it inspected. I've fart3d around in the engine bay cleaning things up, finding vacuum leaks and repairing what I can find. And fixing some other common problems like the drivers door striker, back window plastic slider, and a couple others. I finally got it out on the road today and drove it for about a half hour. Dear God does it need shocks, but other than a oil leak onto the down pipe, and a very fast and hard shifting trans, I think it'll make a good daily driver.

So thanks for all the info I've learned already about this car, and I'm looking forward to learning even more.

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[tyl604]

Pics?

[VaBob]

No pics at the moment.

I have been driving it for a couple days now and i was wondering if someone could point me to a solution for a problem I'm having.

Transmission is shifting hard from 1st to 2nd. Then very quickly into 3rd, then when its time for 4th it flares it between 3 to 4. Down shifting while slowing down i get a hard shift going from 2 to 1.

Also, any suggestion on type of trans fluid? I think a filter and fluid swap is the first order of business.


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[tyl604]

Sounds like vac problems. Try to hook up all the lines under the hood and test VAC with Mityvac.

[VaBob]

I did replace the vac line coming off the side if the trans, and if i remember right it was pulling 10 on the gauge. I had read that was one of the first things to check. And indeed it was shot.

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[Diseasel300]

x2 on vacuum issues. You could also have problems with the vacuum modulator on the transmission itself.

Is this vehicle new enough to have the bowden cable? If so it and/or the throttle linkage may need adjustment.

Trans fluid is Dextron II which is no longer available. Most use Dextron III or Mobil 1 synthetic. I personally wouldn't waste money on the synthetic on a transmission that isn't perfect and low miles.

You might consider dumping a bottle of Trans-X in there and driving around a bit before you do the change. If the car sat and/or the fluid is old, you could have varnish or sludge issues in the valve body. My SDL sat for 10 years in a field and the Trans-X treatment and following fluid/filter change made a profound difference.

[VaBob]

I dont know what the bowden cable is. Let me google that real quick.

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[Diseasel300]

The bowden cable looks like a lawnmower throttle cable that comes off the accelerator linkage and runs down to the transmission. Not sure what year they phased them in.

[VaBob]

I do have one and it appears to be functioning fine by hand. Not boken or leaking

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[VaBob]

Originally Posted by VaBob

I do have one and it appears to be functioning fine by hand. Not boken or leaking

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Also, functioning doesnt mean adjusted properly. Ill read up on that and take a look when i get home.

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[Diseasel300]

Since you confirmed that you have the bowden cable, find the factory service manual page that deals with throttle linkage adjustment. It will give length measurements for the various rods. Once you have that dialed in, you can play with the bowden cable. If it is too slack your shifts will be very early. If too tight you'll have to rev the nuts off the engine before it shifts.