John Deere 450c Transmission issue

[Wayne P]

I have a John Deere 450c dozer that doesn't seem to have any power moving forward or backwards. It has enough power to move itself but that's about it but very slow. I read where there is a hydrolic valve that controls the oil flow to the transmission that could be bypassing or something. It said the valve may be stuck or needs replaced ?? Does anyone know where this is located ? I just got the dozer and can't figure out why it won't move very fast ? I pulled the transmission filters and tthey were clean ?? Looking for advice

 

[Don k]

When did it do this? Gradually or all of a sudden?

 

[lantraxco]

That machine has a mechanical clutch between the engine and transmission, as well as the clutch packs in the transmission and the steering clutches, could be slipping anywhere in there. Do you have it in low gear with the gear selector and does it behave the same in reverse, low and high on the powershift?

Make sure the clutch pedal is returning completely, or it may need adjustment, that's the first thing I would check.

 

[td25c]

To add to what lantraxco said there is also an inspection port on the upper left side of the bell housing . Inside the port is a mechanical linkage to the valve in the transmission . It works off the throw out bearing shaft & has some adjustment in it . Something could be fouled up with the linkage .

My understanding is with the clutch peddle partly depressed (couple inches ) this opens the valve & kills oil pressure to the clutch packs .

 

[Wayne P]

It happened after it set up a little while. The clutch seems to move about 5" before it feels like it is doing anything. I see the adjuster at the bell housing but I'm not sure how much to adjust ?

 

[lantraxco]

Actually sounds about right on the mechanical end, as td25c sez, check the valve linkage, I had forgotten that part. In my defense it has been over twenty years, lol!

 

[Don k]

Actually it is 3.75" of free clutch travel. There is a plug on top RH side of the transmission . Remove it and there is a 1\4 inch plug inside. Remove it and attach pressure gage. At 1800 rpm the pressure should be between 165 and 185. this is the pressure going to your H-L-R clutches.

 

[Wayne P]

That was it !!!! Thanks for all the input to my issue. I loosed up on the valve linkage and it works great.

 

[lantraxco]

Yay! I love it when it's something simple

 

[td25c]

Boy aint that the truth lantraxco :drinkup

Glad to hear you got the 450C going again Wayne P .

 

[Johnnie1987]

Actually it is 3.75" of free clutch travel. There is a plug on top RH side of the transmission . Remove it and there is a 1\4 inch plug inside. Remove it and attach pressure gage. At 1800 rpm the pressure should be between 165 and 185. this is the pressure going to your H-L-R clutches.

I'm new here but my dozer pull good for 30-45 minutes then stops pulling any help would be greatly appreciated