HD4 Transmission Issues

Hi all,

My trusty but old HD4 crawler sort of bit the dust today. It has been a reliable performer mostly, except for the need to replace almost every hose on the machine. But today it started pumping transmission fluid on the ground and I shut it down immediately. I found the problem (I think). One the left side of the tractor was an open hole in the transmission casing about where the torque convertor would be. When running it was splashing trans fluid out the hole which is about 1-3/8 in diameter. I expect that AC had put a sheet metal plug in the hole and for some reason it blew out. Anyway, I bought a rubber expandable plug at the auto parts store and installed it. Seems to have done the job.

So then with the obvious leak sealed I added three quarts of trans fluid and the tractor worked okay for about a minute or so. So I added another three quarts and then later another 2 quarts. And now it moves around pretty well but lacks power in the drive train. It stalls pretty easily when pushing a pile of dirt which it had no problem with before.

So is my trans toast? Maybe a clogged filter or a stuck relief valve somewhere? I shut the machine down just as soon as I found the transmission oil leak so don't think it was damaged. But who knows?

Any and all opinions will be appreciated.

Randy

When you say it stalls easy when pushing a pile of dirt....do you mean the engine?? or that the transmission quits pulling?

The engine runs strong and does not stall, ever. It is the trans that seems to be lacking push power. This happened very suddenly with the loss of trans fluid. Now even when topped off with fluid it is weak. I am not suspecting drive clutches at all. Something has gone haywire with the fluid drive.

Randy

I'm not familiar with the trans in the HD4 but on my Allis backhoe I got a serious leak from the converter seal and it would run for a bit and then loose all pull. If I turned the engine off and restarted immediately the pressure was back right away. It's all fixed now, we put a brand new pump into the forward reverser and now it's all good. Your clutches may be all good but with loss of pressure they will slip. Well, the long and the short of it ..... it's sure fun when everything works again, sure hope you can find the problem.