Diagnosing Clutch Problems

[alskdjfhg]

Wrapping up the worlds slowest brake job on the F800 digger derrick truck. Once again showing my ignorance here, but got some questions about the clutch.

A few months ago, I was unloading a 3" horizontal boring mill from a rollback truck, weighed 20,000lbs. When you move a machine tool with a rollback, you need either an anchor point or something to pull, to help the load go from the truck bed to the ground.

Since the truck is easy to start and at the time had a working A/C, I figured it would be enough to help the machine make the aforementioned transition, considering the rollback bed was oiled and inclined. Attached picture shows what I was doing.

Chained the 800 to the load, it wouldn't pull the boring mill at all, all I got was that grey "worn-out clutch" smoke so I just figured that I needed a clutch.

Now doing a final test of the brakes with air, with the whole rear end still off the ground, I noticed the wheels would start turning with the truck in neutral. You can stop the rotation by hand, this seems kinda weird to me, is this normal? If not any ideas what could be going on?

As usual, thanks for my answer basic/dumb questions.

 

[Truck Shop]

Normal, especially when transmission is cold and oil is thick. The thick oil will cause enough drag to help free turn the out put shaft.
On the clutch issue- how much free play do you have? 1.5" to 2" is normal. Does transmission have 80 wt or 50wt oil? 80 wt stinks
50 wt does not.

Truck Shop

 

[Shimmy1]

Well played, Truck Shop. I took too long, now I have to edit.

Als, I don't recall what tranny you have, but if it's a synchro trans it will use gear lube. Does sound like you're going to need a clutch, unless you were slipping it excessively.

 

[alskdjfhg]

Thanks for the info guys. The truck is in the driveway, but I don't have the time to mess with it right now, school is keeping me busy.

Ill get back when I got some more info, but cold oil dragging sounds like a pretty plausible culprit.

And Shimmy, I wasnt slipping it unfortunately, so I'm pretty sure I'm going to need a clutch.

 

[cdm123]

I have had pickups that you would have to ease the clutch out in neutral while you held the brake @ -40, on 4x4's I would pt the transfer case in neutral to then go bac in for coffee