1975 JD 450C H-L-R trans problem

[reidejo]

Problems with shifting from forward to reverse. Starting out cold the trans shift into forward and reverse without problems as it warms up it gets slower in going into both forward and reverse gears. After about 30 to 45 minutes it gets real slow. Once it engages it will push and spin the tracks. Once it cools off it will go back to shifting ok,
Any help in where to start in diagnosing the problem would be appreciated.

Thanks,

J. Reider

[LeonardL]

The first thing I have to ask is this; Have you changed your Transmission filters and fluid? I would do the simple things first. It sounds like the filter in the transmission may be stopping up as you run the machine. Try this first and then go from there.

[reidejo]

Yes I have changed the trans fluid three times. I bought the old dozer and the trans fluid was very milky. The filters were horrible. I replaced the trans filter (screen) and have replaced the filter at the oil cooler three times. As dirty as it was it still might have trash getting in it. What else can I look at?

Thanks for the response any additional info will be appreciated.

J. Reider

[LeonardL]

There is a screen or an element in the bottom of the transmission as well. Have you changed or cleaned it? If not, then you will need to remove it and see what is in the bottom of the transmission case.

[LeonardL]

Sorry, I re-read your last post and see where you changed the screen. Do you have a tech manual for your machine? If not, then I highly recommend you get one. You may need to run your adjustments on the HLR and clutch pedal.

[reidejo]

Thanks, I do have a manual. I will run the adjustments on the H-L-R and clutch.

[tjdub]

I will run the adjustments on the H-L-R and clutch.

Even without adjusting the clutch, you can test out the difference that adjustment would make by depressing the foot clutch slightly when shifting.

I've got a bad habit of sometimes pushing the foot clutch when I'm stopping to shift. If that pedal isn't all the way back when I shift to reverse, it'll just about take me right off the seat.

If it still isn't shifting any faster when warm, I would guess it points to an internal leak (clutchpack?) or maybe a weak transmission pump. Either way, not a simple or cheap repair.

As long as it's shifting into gear, I would keep on using it, it might just start working better with use if it had been sitting for a while.