IH 186 hydro reverse problems

[IH Ben]

I have an IH hydro 186 and we're having problems with the reverse on it. We've had the mechanic out and work on it, he put a new linkage in it that goes from hydro lever on the dash down to (I believe) the pump. This took care of the problem for a little while but now it is back. The problem only exists when we try to back up the only way it will move in reverse is to not use the clutch and put the lever in reverse, but if you stop by using the clutch it won't move again until you cycle it into neutral and back into reverse again without using the clutch. The mechanic seems to think its the cable linkage again, saying that sometimes the cable stretches. I don't think the cable is the problem though, thats why I'm here. Any information would be greatly appreciated.
Thanks

 

[Allan in NE]

Hey Ben,

They just can't be fixed. Maybe ya should just wash yer hands of it and sell it to me? :>)

I want one of those gizmos so bad I can taste it. Perfect darned loader tractor to my way of thinkin'. :>)

Allan

 

[Owen Aaland]

The two things I would look at would at would be a sticking high pressure relief valve or the snap ring off the end of the shuttle valve.

If you can get the tractor to move in reverse by putting it in neutral or forward and then going to to reverse the most likely cause is the shuttle valve.

The way to test it is to put isolation valves on the high pressure lines coming out of the center section. If the problem is still there, it is the shuttle valve spool snap ring or spring. If the problem can not be duplicated then the problem is a sticking reverse high pressure valve.

 

[IH Ben]

thats exactly what it is now a loader tractor, but its fustrating when the reverse is acting up like it is.

 

[Allan in NE]

When in forward range, it doesn't do any "lurching" does it?

Dunno, Owen may very well be right, but usually the thing will "jump" when that shuttle valve snap ring has come off or it's not centering right.

And again, when ya lose high pressure oil, you've lost it and it will affect both the forward and reverse directions; from either pressure regulator.

It is something that is directional. Either a pipe or a valve that only affects the one direction.

I'm still betting on the reverse check valve due to the fact that you've got problems in one direction only. Plus the fact, that this is the usual "high-wear" item on these things.

Good luck, hope ya get 'er straightened out.

Allan

 

[IH Ben]

I don't think it lurchs but I did notice last summer while I was cutting hay with it that it seems to want to slowly speed up on its own. Don't know if that has anything to do with it. Thanks for all the info so far though.

 

[Allan in NE]

"What I would do" is to "isolate" like Owen says.

Cap off those two pressure lines at the transmission, then give 'er a good road test.

This will make it a totally mechanical controlled outfit (you wanna have 'er out in the open when doing this as there is no more "clutch" and no more hydraulic buffering of the control; it's a bang-bang shifting, in/out deal).

If the problem is still there, you would then know the glitch is in the lower unit. If however, the problem disappears, you know the trouble lies upwards in the controls/hydraulics.

Be sure and let us know what you find, okay?

Allan