Ford 555 shuttle intermittent problem

I have a 555 that has been a reliable and trouble free companion (until yesterday). I was moving some rocks some distance. (lots of driving in 3rd gear at fairly heavy throttle)
Worked fine. I put it in 4th gear to go a little faster and it worked OK too, but didn't seem like a good idea to be trying to go uphill in 4th gear. Then it started to go slower like it wasn't pulling as good. Then it started to go really slow and finally wouldn't move more than a crawl in any gear. I crawled a little way and shut it off. After sitting for 10 minutes it would move normally again. I am worried that some screen is clogged or something is wrong with the tranny. New fluid at correct level. New spin on filter when I got the tractor a year ago and haven't used it enough to need a new filter I wouldn't think. Any suggestions on how to troubleshoot this and keep this from happening again?

Not into Fords very much but something on Ebay caught my eye. go to the link below if you don't have a manual.
AJ
Repair manual

Thanks. I have a manual. Probably going to try to troubleshoot if it happens again. Hopefully it just sucked up some garbage into a screen and draining the oil will take care of it. We will see.

Thanks,

Larry

I think the tranny sump screen is pretty inaccessible, if it's like my 755. Sounds more temperature related. When you say "intermittent", do you mean it's happened more than once? Your post indicates a one-time occurance from going uphill in 4th gear. If it was me, I'd just avoid going uphill in 4th again. Also, take a look at the tranny oil flow diagram in the manual. Is there a Trans pump bypass valve that could stick open, limiting oil flow to the Torque converter? I also think there's a port for checking pressure on the pump. Checking flow is a little more involved setup. Ford mechanic told me once those industrial shuttle trans's were pretty bullet-proof. (knock on wood) Be curious to learn what it is, if you do find something.

I have a 555 that had the same problem. I found a lot of silicone and rust flakes in the transmission that would suck into the inlet screen and clog it.

Draining will help, but not fix the problem for me. There is an access plate on the bottom of the transmission. Within that area is a 1/2" pipe plug that is the inlet cross-drilled passage from the screen to the pump. I put together a pipe and fittings that adapt the 1/2" to an air hose and blow air through the passage and backwards out through the suction screen while draining the transmission. I"ve drained the transmission several times using this method and filtered the oil through a shop cloth. I"ve gotten a lot of junk out of the transmission.

The best time is just after using the tractor while the junk is still suspended in the oil from all the gear action. I have the adaptor in place with the rear wheels off the ground, then run it for a while through the transmission and spinning it the rear wheels. Then quickly stop, shut off the engine and blow air backwards through that port for a minute or so then remove the drain plug and catch the oil. I have a ball valve in the temporary adaptor so that the air line can already be attached and I just open the ball valve to bubble the air backwards through the screen and into the oil. Be sure to have the fill plug/dip stick removed to allow the air to escape from the transmission cavity or you may blow a seal.

Also, within the inspection cover area at the bottom of the transmission is a small tube that has a 1/4" NPT plug in it. It is the pressure test port for the reverser"s oil pump. You can monitor the pump by connecting a hose and gauge to it, place it in a position to observe from the operator"s station, and watch it while operating. It should be a consitent 120 - 160 PSI. If it drops below 50 PSI, you will notice that the reverser clutches begin to slip and indicates that the screen is getting clogged. I used this method to determine what the problem was with my Ford 555 shuttle/reverser.

If it works well and then doesn"t, then is is most likely a clogged inlet screen. If I stopped the engine for a few seconds and restarted, the reverser would work excellent until it clogged again in a few minutes.

Good luck!

It only happened that one time, but I am concerned it will happen again. Just wanted a heads-up in case it recurs. I will let you know if it happens again. Battery is dead and I am getting a new one today. Hope to move some more rocks this weekend so I will let you know how it does. Thanks,

Larry

(reply to post at 07:17:34 09/27/07)

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AmeriKen - reading this and another post of yours on the same matter, I'm having trouble finding the bypass valve. Was yours a 555C? Can you describe how/where to get at it? Is the "inspect hole" under the cover plate?