300 U shifting problem

brmtdg · Jan 12, 2010

Currently starting work on a recently purchased 300U(no TA) that has a shifting problem.

Reverse and First shift quite smoothly and Fourth and Fifth are OK. But Second is stiff and Third is a real bear or almost impossible.

Searching the forum brings up some issues with shifter wear. But most of these are problems of engaging two gears at once or can shifter wear cause my problem. What problems does a worn shifter cause usually? There is some wear on it but it does not appear excessive for a 50+ year old tractor.

Other idea is the shifter rail/linkage is sticking from either wear or excessive crud. Would adding some kerosene or something help clean out the crud. If so what/how would you all recomend I go about it.
Would like to try all the obvious and simple fixes before removing the transmission case top.

Overall the tractor is solid and complete with most everything working with this exception and some minor issues(leaks,electrical,tach).The sheet metal straight just badly faded,tires like new.

As always any opinion,comments and advise is greatly welcomed.
Thanks
BRTMDG

nspec · Jan 12, 2010

I rebuilt the shifter on my super H. That and the brakes have been some of the most satisfying repairs. I"m assuming the shift pattern is the same on the 300 U:
R 2 4
1 3 5

From what I encountered, and keep in mind I had the basic shape but fine tuning was needed, the shift lever seemed the "longest" in the center position or gears 2 and 3. It is tilted ever so slightly when engaging the outer gears. Perhaps a quick cleanup of the very bottom with a grinder? Also, if you pull the lever, you can easily see inside and get at the shift rails or forks. Drop the lever back in without the cone on the bottom and then you can move the lever and watch what is happening in there. Mine also had a lot of crud. I cleaned it all out and it and lubed it and it made a world of difference.

Hope this helps.

504-2 · Jan 12, 2010

Take the shifter out,6 bolts, and you will see the shifter rails, they have a habit of rusting up. Clean them and oil them up, watch for the springs and detente balls under the shifter plate. you do not want to fish them out of the tranny. We bought one from an estate that was (locked up)the only thing wrong with it was the rails had rusted up from sitting outside.

BMD · Jan 12, 2010

I suspect the tractor was not used much prior to its sale and it probably has 50+ years of crud and buildup on the rails. Hopefully a good washing down of the rails with PB Blaster will do the trick.

If that fails we"ll drain a couple gallons of gear oil add some kerosene to the rear end and drive around the farm and then change the oil. As for the spring and balls , I plan to remove springs and place tape over the opening to keep the detent balls from escaping. Fishing for springs and balls in bottom of the transmission would be a really bad experience.

Thanks for the info.
BMD

BMD · Jan 12, 2010

Yes, it is the same shift pattern.
Thanks for the tip about removing the cone so you can see whats happening inside the shifter.

How did you go about cleaning the rails since the bulk of them are up under the transmission cover?

Thank you for your reply
BMD

300 U shifting problem

brmtdg

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nspec

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504-2

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BMD

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BMD

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