Transmision troubles
 

Been a minute since I have been around here, but hey, these old MBs are just so dependable.
Stopped at a redlight Mon. and when I started off the trans would only shift from 1st to 2nd and seemed slow about that. If I shift it into neutral and then back into drive it will shift back to first and then to 3rd. No flare, no slipping, just missed shifts. Just wondering if this is something simple to fix in the vehicle or should I just change out the trans with one I have in reserve.
This problem is on my ol 53 F100 with the 617.951 and 722.303 out of a 82 300SD. I have driven it 85K miles pretty much trouble free.
Any and all help will be greatly appreciated, Jeff

.

start with simple things first,oil level and kick down switch (may be stuck)
/

Fluid level is correct and there is no kickdown switch installed.

Have you changed the ATF and filter in the last 15k miles? Did you use a cheapo filter from FLAPS, or make the effort to get a Mann / Hengst / Mahle filter? Filters can clog and collapse and cause all sorts of weird behavior.

Filter has about 15K on it and is a Hengst, ordered through our sponsors. I don't think this is a filter issue, it started all at once. There has never been an issue with this trans, no flare, no slip, just smooth shifts as it should be.

@mechmagcn
While I'm also doubtful that it would be your fluid and filter, it might however be a good (and cheap'ish) place to start.
On my '84 300D I lost 4th gear suddenly a few months ago. One minute it was there, and the next it wasn't. All the car would do is freewheel as if it was in neutral when it shifted into 4th, so 4th was totally gone.
I thought for sure my transmission was toast. Changed fluid and filter (and added 15 fl. oz of Trans-X fluid) and transmission has been working perfectly since.
http://www.peachparts.com/shopforum/diesel-discussion/369151-lost-4th-gear.html

Apparently fluid and tranny filters are insanely important on these transmissions, and the slightest impurity in the fluid or clogged filter will cause issues.

15k miles and it is time for new fluid and new filter, and don't forget to drain the torque converter. Start simple / cheap, work your way up to expensive / complex.

Any work done to the truck recently? Anything at all, like tinkering under the hood or under the truck? So many problems are caused when some work fixes one thing but breaks another, fortunately those are often cheap/free or simple to fix once you find them.

Nothing done recently. I think I have a filter kit already, I'll try a filter change this weekend.

Had a few minutes between jobs today to check farther into my transmission woes.
The rubber bellows on the Bowden cable has disintegrated and I thought that might be making the cable stick. Unhooked the cable and discovered that it wouldn't shift at all. The threaded part that adjusts was broken when I pulled the trans from the donor car. I checked the adjustment on two other trans I have in my possession and they measured 16 mm or so. Mine had worn down to about 11 mm, so I put a zip tie between to take up the difference. The trans is back to shifting all gears again, but it seems that I need to make some adjustment as they are higher than normal at wide open throttle.
Anyone have a link to the proper adjustment procedure for the cable?

My semi-hack fix on one 300D when the plastic Bowden adjuster broke was to cut a longitudinal slit in a steel tube (5/16"OD?) and slip it over the adjuster to hold that position. Of course, it is no longer adjustable, but works fine.

It's in the FSM (factory service manual) somewhere, but it really is quite simple. The end of the cable should be just slack with zero throttle. Set that, then adjust as needed to get desired shifting points. I don't remember for sure, but I think tightening the cable move the shift points higher into the RPM band (later shifts, aka holding the lower gear longer), and loosening will move them into the lower portion of the RPM band (earlier).

Tune it until you like how it shifts, then be happy.

That's pretty much how I've done it in the past. It just puzzles me that the cable being that far out of adjustment would cause it to delay shifts, I would have thought it would have shifted out like it was at light throttle. Guess there's a fine point where it shifts or not.

Well, I drove the truck about 100 miles yesterday and the transmission worked flawlessly. I guess when the problem started a piece of the threaded adjuster must have fallen out to throw it so far out.
How much trouble is it to change the Bowden cable? In looking at my spare trans it looks like it presses into the case and I assume there is a pin or clip attaching it to the valve body. Since it is time for a fluid change I might as well replace it while I'm in there.

Another question while on the subject of this transmission. I have driven this truck about 85K miles since the swap and have never been able to feel but two shifts. I had always heard that these were four speed transmissions. Is it possible that I am not getting first gear because of not having a kickdown switch installed?
I have pulled a 1600# teardrop camper from coast to coast and all the way to the Arctic Circle in AK. Never felt that I absolutely needed a lower gear, just wondering?

trans problem
 

I had a problem with my car a while back, though different symptoms. Mine suddenly wouldn't upshift, and another time it would shift but only if I did it manually with my automatic transmission.

The problem was a $12 plastic gear. My mobile mechanic got to the problem in under 20 minutes including jacking up the car, took out the (?) governor or a part prior to the governor and replaced the part. All worked well for a few months when it happened again. Turns out part 2 of the problem was that some of the parts from the broken plastic gear got into the rear pump, causing a repeat problem.

I did a write up on it including the part numbers (though my car is different than yours), you can search my posts on this forum.

jeff w124