Hey guys, I have this old CAT d6 dozer, I believe it's about a 56-58... Anyways, I've recently noticed that when I pull the johnson bar back to engage it and move, it has trouble climbing hills backwards. It wants to go but then just doesn't seem to have enough 'power' to get up a hill...even if I have the throttle all out. I can have the johnson bar fully engaged and it will just sit there and not move. I've never had this problem in the past and it just started happening. I can only make it up the hill going forwards if I get a little run at it and don't start directly on the slope...keep in mind this is all done in 1st gear. I also notice that as I'm skidding logs to my deck (in 2nd gear) it has some trouble making it up small inclines (these logs aren't very big, maybe 24'' dia and 40fters, skidding 2 at a time). Description of hills...I don't exactly know how to describe them BUT I will say they aren't very steep. They are steep enough you'd have to put your pickup in 1st gear to get up them but nothing like a 1:1 grade. I'd say it's probably close to a 4:1 slope that I can't make it up in 2nd gear and maybe a 2:1 in first gear backwards. I'm hoping it isn't the tranny and is just some sort of clutch adjustment as I know I need to adjust my clutch as well because it makes a little rattling sound when I engage the clutch but that should be a fairly simple fix from what I've heard...but wouldn't mind some input if you guys have any on how to do that as well. Hope that helps with things and hope someone can help me out. Thanks guys!!
Adjust the clutch until it snaps in over center. I think that will solve your problem. Later Bob
Thanks for the help Bob!... not many guys (including myself) are familiar with the older dozers, any advice on how to do the clutch adjustment?
Is it a 9U series. Your Johnson bar on your right hand side only shifts from forward to reverse. The clutch lever on the left side makes you go or stop. When you stop your machine and get off or when it is idling such as warmup, the procedure is to put the tranny in neutral and re-engage the clutch. Do not let it set with the clutch disengaged. I would recommend that if you are inexperienced with Caterpillars to go look on eBay and buy both a service manual and an operators manual that covers your serial number range. Clutches and other components while easy to adjust have changed over the different serial numbers. Your machine is going to get real expensive in a short while if you do not know how to maintain it. Is it a pony start or direct electric start? Start, care, and proper shutdown procedures for the pony motor is another topic.
Yes, it is a 9u series and I'm almost sure it's a 57. I do let it idle on warmups with it in neutral and the clutch bar engaged...had an older gentleman who ran one back in the day show me that shortly after I bought it. I have the parts book, service reference book and diesel engine service book for it (sn 9u6542) and have been looking through them but only able to find part numbers and descriptions of the various components of the clutch and entire machine so that is why I figured I'd post something here. Yes, it is also a pony start which we start with a rope around the flywheel rather than hook it up to a battery (starts easier this way). We always start the pony motor, let it warm up a little and until the main engine gets warm to the touch then fire up the main, once the main is started we turn the fuel off on the pony and let it run out. Thanks for the help and info, sounds like you have worked on one of these old guys before or have one?
9U6542 is a 1950 model with dry clutch. Here are the adjustment instructions.
Awesome! Thanks so much. I'll give this a shot when I get to the machine again and see how it goes. Really appreciate the help guys! Keep this old monster working. Gotta love the old machines!
So I tried what the information above stated and it didn't seem to work. I located the clamp bolt and loosened the nut. This will sound stupid but it's late and I've been up since 2 this morning...but in step 2, what are the transmission gears? Obviously the flywheel won't turn when the clutch control lever is engaged.
Puting the transmission in gear stops the clutch from spinning while making the adjustment with the clutch disengaged.
Thanks guys. Seems to be working fairly well...couldn't turn the adjusting collar much though, I wonder if it is 'tapped' out.
If the clutch is engaged you can't adjust it due to pressure on the clutch toggles. Mike