2640 high low speed shift

Val Johnson

New User
I have a new model 2640 John Deere that was built in the 1980's. My father handed it down to me when he died. I had the engine rebuilt last summer and it runs perfectly. Recently the hi-low shift that is next to the steering wheel has quit working. If it is shifted from the turtle to the rabbit nothing happens and it jumps back to the turtle position all by itself. I has also started to act like the transmission is slipping. It almost seams like something is plugged. Could someone give me an idea of what the problem is? I wish Dad was still alive he always knew what to do.
 
If you dont have a factory repair manual you definatly need to get one to troubleshoot the hydraulic problems. You need to see what the transmission operating pressure is, not sure on the 2640 but a 2940 you remove a plug on the rightside of the top of the trans by the hydrualic pressure indicator. Should be 150 psi. Below 100 or 125 it will not let it shift to high range. You could have leaks at the hi-lo clutch packs or trans oil pump going. have you changed the hydraulic oil filter and cleaned the screen.
 
Always replace the trans filter first and examine the canister. If the oil has a sparkle like aluminum paint, this is a bad sign.

If there is any visible contamination, you will likely be removing the final drives to fix the brakes. The trans case will also need to be flushed out.
 
And by the way,

You can't expect to have the same gifts and talents your father had. There are things you excel at and things you are lacking, just like him. But they are usually in different fields. If you don't have a trusted friend to advise you in the areas you are still learning, you will have to educate yourself a little. Get an owner's manual, study it, and follow the directions. Oil and filters are cheap compared to broken pumps, bearings, disks, and major parts.

I too, miss having my Dad around for an instant answer. Too bad I didn't pay more attention to his words when I was younger.
 
When the engine was rebuilt, did somebody change all the tractor"s fluids and oil at the same time? If the hydraulic oil isn"t wet clutch compatable. The trans clutches will disolve and slip.
 
Yesterday's Tractor Forums

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top