cat hydra stat transmission mechanic needed

[divedigger]

I have a 1989 943 seriel 19zo1128 that started slowing track speed after oil warm up about 30 mins but no loss of power just speed This machine has 10 k hrs and has had no problems winter or summer till all the sudden the travel speed slowed I have shop to put inside or may be willing to transport reasonable distance Location East Tn close to Bristol Motor Speedway

 

[Bob/Ont]

Sounds like a leak in the drive loops. Get a pair of hoses and 100 psi gauges, hook onto the drive motor cases and check the pressure that builds as you load them up with the brakes locked. You need to cut off the supply of brake release oil to lock the brakes. Be careful while testing.
Later Bob

 

[Mobiltech]

It sounds like a problem in the underspeed control system. Either loss of charge pump flow or internal leakage. Change the trans filter first .
It could be the seals on the lines to the underspeed valve. They have been known to leak. They are under the top trans cover.
You can test the underspeed system by unhooking the underspeed override lever from the throttle linkage.

 

[overworked]

If you move the throttle control out of the full speed detent, does yor track speed increase?

 

[divedigger]

Cat transmission

If you move the throttle control out of the full speed detent, does yor track speed increase?

I have 2 of the 943 a 1992 that I bought new and the 1989 that was a 1 owner and its the 1 that slows track speed as oil warms up. Both machines will increase travel speed if you move the travel lever over to the outside of the v pattern just a fraction of a inch, even the 1 that slows after oil warms will in erase travel speed slightly. It was noticeable when speed decreased as if there were a internal leak somewhere just affecting the speed not power. I am afreid to take to Cat house because of horror stories started just like this and ended up 20 k later with a rebuild because someone just kept changing parts till it was fixed And owner was broke

 

[Georgia Iron]

Hey dive.

I have a complete parts 943 with a blown motor and worn out under carraige if you need anything or want the whole tractor it is in marietta ga.

 

[Mobiltech]

The seals on the underspeed valve are just a rubber ferrule like on a low pressure fuel line. They are easy to check and change.

 

[overworked]

What i meant was when in forward or reverse and machine slows by it self when warm if you lower engine rpms with travel lever back will it speed up? If it does then its most likely leaking tube under cover, the seals are rubber and steel, and come with a new nut, but the lines get crushed and will still leak, make shure line is not worn.

 

[Bob/Ont]

Don't you mean when you throttle down?
Later Bob

 

[divedigger]

Hey Georgia Iron, PM me a # to call and I will talk about the 943 Thanks Divedigger

 

[overworked]

Don't you mean when you throttle down?
Later Bob

Yep. Thats what I was tring to say that at full travel to lower engine speed, sorry for any confusion.