Hydro 186 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 streaches. 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]

Does everything pull right in "Forward"? Both Hi and Lo?

Allan

 

[Dave in Tx]

I would check the reverse cushioning valve. They may call it something else, such as a high pressure relief valve. If it works properly going foward, the pump and motor are likely ok.

 

[IH Ben]

yeah everything works great going forward hi and low

 

[Allan in NE]

Hi Ben,

First of all, make darned certain that the adjustment is right on the control lever.

Then, I'd sure check that foot-n-inch to make sure it is closing along with the operation of the two capsules up in the hydraulic control (reverse the two capsules temporarily) just to be on the safe side. However, these "usually" would affect both directions.

When only one direction is a problem, you've got a 90% chance that either the feed pipe to the reverse regulator is split/leaking or the reverse check valve is leaking by.

Sounds like this is kinda sporadic and you can temporally override it by hitting the "clutch" pedal. This action kinda rules out the "split pipe" thing, the upper capsules and would more fall right in line with either a bad/leaky foot-n-inch valve or what I'm saying about the reverse check valve.

Those pressure regulators and check valves really take a beating, but like I say, if the problem is only one direction, that narrows it down to just the check valve. A pressure regulator would make 'er limpy in both directions as both sides would loose drive oil.

The check valve will run somewhere around $170 from CaseIH and can be swapped out in about 20 to 30 minutes.

Also, these trannys are tougher than you would think. Really, really have to abuse ‘em to make the things fail and if you have good drive in one direction, your troubles are minor because all she needs is just a little tuning up.

I’m just betting that you have a bad reverse check valve. If you want to go to all the trouble of making sure, reverse the two check valves. The “problem” should change to the forward direction instead of reverse.

Allan

 

[IH Ben]

I will try that thanks a lot for the info

Ben