Cat wet clutch cold weather question

[ScottNC]

'67 D4D. It has been abnormally cold for two weeks, some nights zero or below. Most days in the mid 30's. Machine had been sitting for over a month since the last time it was started. One day last week it was 37° when a fellow interested in buying the dozer asked to look at it. After a (too short?) warm up I had to shut down the engine before I could put the thing in gear and even then the starter drug the machine on the restart. Once moving, disengaging the clutch and braking to stop lugged the engine almost to the point of stalling. After several minutes of operation normally clutch function returned but... I thought I felt just a hint of resistance in the last inch or so of forward lever movement before the clutch brake applied. Pulled the floor and looked at the linkage but could not get the "hitch" in the levers git-up to repeat, maybe heat soak while I spun out the floor bolts got things back to normal?

Should I be letting this thing run for a long period in cold weather before attempting to move it even if it is not to be worked any?

Is there a cold weather warm up protocol for a wet clutch?

 

[Bluox]

You can go to 10wt. oil in the clutch and warm up with the clutch engaged ,transmission in neutral .
Bob

 

[ol'stonebreaker]

If it's going to sit for awhile with engine running in any weather the clutch should be engaged with tranny in neutral to minimize pilot bearing wear.
Mike

 

[Old Magnet]

Clutch drag is a common event that gets worse the colder it gets. You can lighten up on the oil viscosity and longer warm up period is advised, also a good working transmission brake is a plus.

 

[Metalman 55]

On my D4D during an extremely cold spell about 4 years ago if I remember correctly even with the transmission in neutral it would move the whole machine forward, when I engaged the starter; brutal on the batteries. That made it very difficult to start with the drag being so bad.

I think it had 30 wt oil in it & we changed it out to #10 & got a lot better.

 

[ScottNC]

Thanks for the replies. Kinda what I figured. Changed it to the current CAT spec oil in March, I want to say it's TO-4 but that may be incorrect.

Usually warm it with the trans in neutral, the clutch engaged and the forward/reverse lever engaged. Since nothing is being worked in the clutch housing other than the oil running through the oil pump I guess warmth from the engine must work its way back to the clutch.

 

[John C.]

The 14A units I worked on a long time ago had the two speed transmission on the pony motor. When it got to around twenty degrees you had to shift them into low just to get the engine to turn over. Fifteen or twenty minutes in low you could shift to high and then get the engine started. When the pony motors died we push started them. Then it would take twenty minutes or more before you could get the clutch to stop turning enough to get the transmission in gear. That was with good clutch brakes.

 

[old-iron-habit]

On the old cable dozer machines or ones with cable pans attached we used to pull the winch handle on the CCU to get the clutch to stop so the transmission could get engaged. The oil clutches do take some time to warm up. The right oil is critical in cold weather.