Wow, that's bad .

Expect to need to change the tranny oil again in no more than 500 miles .

Agreed, fully synthetics are the way to to, I've had numerous old trannies with black or gray fluid drain out that began shifting properly again with synthetic ATF .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

Well folks, I replaced the gear oil with ATF. The gear oil had been in there for about 100 miles and looked perfect with no bubbles. Flowed right out too.

Synthetic ATF went in, and no improvement in shifting. I think I have a worn or broken synchro. Oh well. I just have to shift slow from 2-3 to avoid embarassing myself.
thanks for the help, all.

Have you adjusted the shift linkage and replaced any worn bushings?

Check the gear oil for condition.

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer

I had an 82 manual. I think I tried gear oil once and it was too hard to shift especially on cold mornings. I went to ATF and it was too noisy. Whined a lot. I added some Lucas oil treatment and it quieted down.

Never thought to use Redline. I had some of their products for my dirtbikes.

Just a tip for the OP, my shift lever would jam up when shifting into 1st and 3rd when I first got the car. Turned out the hex bolts down the shift lever shafts on the tranny were loose on 1-2 lever so when I went into 3rd it was still in 2nd and all hell would break loose as the stick seemed to jam up. Stick a hex key down those tubes and check to see if they’re loose.

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79 300TD “Old Smokey” AKA “The Mistake” (SOLD)
82 240D stick shift 335k miles (SOLD)
82 300SD 300k miles
85 300D Turbodiesel 170k miles
97 C280 147k miles

I have spent a decent amount of time under the car adjusting and fussing with linkages, yes. The bushings in the rods look good, but the bushings in the shifter itself are pretty loose. It's my impression that these won't cause grinding, though right?

I got under the car, and asked my cute partner to shift all the gears slowly so I could see what was happing. Each lever moved as it should, so that's what made me think it's an internal issue.

Thanks! I think I found one of your old threads/replies about those hex bolts and I did indeed check them. Reverse is a little sloppy, and isn't getting better, but the other 2 arms are tight.

Any worn bushing can cause shifting issues. I'd suggest tightening up all of the bushings, putting a drill bit in the shifter alignment hole, adjust all of the linkage lengths, wash the shifter down with solvent and lube the shifter thoroughly with ATF.

If there are still shifting problems it would be either a worn clutch or internal transmission problem.

Good luck!!!

__________________
"Rudeness is a weak man's imitation of strength" - Eric Hoffer

Just wanted to post a follow up here, for posterity:

-Purchased the car, drained and filled w/ Pennzoil Syncromesh. Old fluid drained with odd sturdy air bubbles. No change, possibly worse.

-Drove 50-ish miles, drained and filled with cheap synthetic ATF. Fluid drained with no air bubbles. No change in driveability, but wasn't as noisy.

-Drone 100-ish miles, drained and filled with Redline MTL. No bubbles. This time, there is a slight improvement in the 3rd gear issue. Before, I had to wait a full 2 second in neutral and let the engine spool down completely before selectring 3rd. Now, with the redline, I still need to pause but only for about a second.

In addition to the above fluid changes I have done a bunch of other things like look at linkages, change engine and trans mounts, tighten the hex bolts etc. the conclusion is my synchro is worn, but Redline and careful driving make it liveable for now.

Side note: the general opinion out there seems to be that these 4-speeds are bullet proof. However, I've met 3 different people recently that said they have had the same issue as me. My 350k mile automatic transmisson on my 300D, however, still shifts fine. This is andectotal, of course.

(big thanks to Shern for the Redine recommendation. It made this car much better to drive)