I need you guys to help me out again. The governor control lever on my D6C ser 76A suddenly started getting real rough. Normally pulled back is full throttle, you push it forward to a point where it has a stop in it, and then you push it all the way forward to shut off. Well it doesn't move back and forth very easily and its getting stuck at the idle stop. I can't get it to turn off unless I work it back and forth and force it all the way forward with some difficulty. Sprayed some lube on all the joints that I could see and it didn't seem to help any. Another strange thing is that it gets a little easier to pull back once the engine is running but it is still very hard to shut off. Decelerator pedal works fine. My question is this, does this mean the rods and levers and joints and such (i don't know all the names for whatever those parts are) must be repalced or is there a repair I can do myself? Looking at all the linkages I don't see anything broken but there is some wear. Anybody got a suggestion?
You sure a limb or stick didn't get wedged in there somewhere?
Yes i'm sure. Did some research today and found it's called a bellcrank. I'll probably have to replace it.
I could be wrong, but in my experience sounds like the problem is in the friction control mechanism that the lever attaches to, I've had to rebuild a number of them. Bearings for the shafts get dry, a little moisture gets in there, rust begins, bearings don't turn, pits on shafts. You basically just take the unit apart and clean or replace bearings depending on their condition. Same with shafts. If your de-cel is working properly, you don't have linkage problems, more than likely in the friction control. And yes, the same thing can happen to the bell cranks levers. Check out post #26 of this thread and you can see what a typical bell crank looks like and the bearings as well.
Thank you! Thats good news, I didn't know it could be rebuilt. And thanks for the link too.
Mind you, I haven't worked on a 6C, but most anything on older machines can be rebuilt. And the links on your machine aren't going to be much different than any other Cat dozer, very common stuff. Just start taking your control links loose working your way back to the throttle control lever, won't take you long to find one or more siezed links/bearings in need of service. Might as well check all the links/bellcranks of the throttle control while your down working on it, get her all in good order.
Yeah, that was my thought as well. Might find more needed repairs.
i am new to the forum and i know this is a old post and i hope i can find a answer to my question.i have just purchased a d6c 10k its in about average condition i guess and has done very little work over the past 8 yrs. i have alot of question about it but i am going to start with the first problem. my decerator is not working when i pull the hand throttle back then apply the decelerator it pushs the hand throttle back to idle i have been told that there are bearings and what not in there to replace but it would help if i could get more info and maybe part numbers to fix it. i have been spraying lube to every place i can and it has helped steering clutches and foot pedals start moving easier just has not made the decelerator and hand throttle work together you can hold the hand throttle back and use the decelerator but when you let go it goes back. any info would be a get help thanks for your time and effort
It's the bellcrank assembly. I think it'll show up in this picture.
this is the same thing that mustang gave me but i could not read the numbers on the sheets they printed for me so i should just order a new bell crank and be done with it?
jwest, your problem is in the round barrel bit in the linkage, its a bit fiddly to get to bits, there is woodruff keys and 4 little bolts to get past plus 2 rollers and 3 springs, the parts need to be clean with no oil or grease on them so dont be tempted to oil anything other than the shaft lightly in the bush contact area, there is also paper gaskets used, these keep out water etc so replace them if you can?? oh and dont strip this little chunk sat on a hay bail as bits fly easily, a cable tie might help get things back together, wet and dry sand paper (without the wet bit) is best used to clean up the inner component parts, if the rollers have flats on them ether repace them or put the flat towards the spring, it will work for some time like this, the important thing is clean DRY parts work best here, the complete cylinder new off CAT will cost in the U.K. around £600 so a few internal parts is the best line, these cylinders are fitted on plenty of the older CAT's even on D8K's they can be on the injector pumps or in the linkage, but this is what makes the throttel control ether fearfull stiff or slack, I hope you understand my script
well i took it all down tonight and there was grime and a bunch of other things along the shaft but anyways the barrel had never seeze in it and old grease in it that had harden. any ways how long are the springs suppose to be these are maybe 3/8" are they suppose to be longer? i order some parts today and it was right $270 but i may put it back together and see how it works. ALso which way are the rollers suppose to go parralel with the shaft or across the shaft. thanks for the info
This is a long shot and maybe a stupid question, but is your oil presure good? The reason being the govonor has a valve in it that wont let it throttle up in low presure situations. Or that valve in the govenor has failed or has some junk in it.
oh it will throttle up to any rpm and hold itself no problem but when you hit the decelerator it pushes the hand throttle back to idle, but if you hold the hand throttle and use the decelerator it will work but the second you let go of the hand throttle while using decelerator it pushes it idle. but to answer your question oil pressure is in the normal.
It's the bellcrank. Go to Mustang and you'll see a life size picture of the parts and they can gather them up so you can see how they work. It's hard to explain on paper. It's pricey, I used synthetic grease on the insides of it that I had left over from rebuilding some roto chambers on a 621 scraper. It works great so far and it's been 2 months now.
jwest, you cannot get things wrong inside the barrel, the 2 rollers are pushed out by the springs to form a lock effect and run straight with the shaft, I have already said about the grease thing, dont have any grease or oil inside the barrel these rollers need to grip not slide, the spring lenght is best judged by eye, 2 springs are the same lenght the 3rd is (I think) slightly wider that hooks the control plates together, by now you can understand its a bit of a fiddle to re-assemble, so take your time and clean everything well and get rid of any grease etc, when I see any trouble with throttle control not holding position its always the barrel bit.
Hi tc, The one item I didn't see commented on was to check for wear of the ramps inside the cover where the rollers live.....and to replace if worn. How often is that necessary?
well we are going to clean it up tonight and put it back together and ill let yall know how it goes thanks for all the help.
O.M., thats easy fixed as any marks inside the cylinder, all you do is rotate the cylinder 180 to put a bit of fresh iron in the quadrant area??
Thanks tc, Isn't every day that Cat lets ya get away that easy.
well i got it back together and i tell you i did put a little grease on the inside because this thing would not move when i got it all back together and had to take it all apart again ended up having to make a paper gasket other wise when i tightened it up it would compress everything on the inside and not move for anything. but it has worked well over the weekend. now if i could just get the fuel cleaned up i would doing better we drained the tank saturday and the diesel was like a black cherry color it was bad so i installled a inline to help keep from knocking out main fuel filters and they are not lasting but a hr at most. any ideas other than taking the tank off . i am using the clear plastic filters from the parts store this is the same thing i did to my D3 and it will last a good 100hrs now. anyways she seems to run well just learning the ropes with a 2 way blade makes me respect a 6 way more. is there a filter for the hydrualics because after i run for a while the hydrualics start moving slow or is this normal? is there anything i need to check?
jwest, there is 2 hydraulic filters in the tank, 1 below the other, oil level needs to be good to test correct working flow speed.
well i have made sure that i have the right amount of hydraulic fluid. when i first start using it it raises really fast but once it warms up the hydraulics start running really slow that if i don't give it some throttle it will not move barely. but it still lowers really fast. oh and anther thing is i think my fuel supply pump is going out because there is diesel coming out of the weep hole i just found this after i put my new inline fuel filter and hose on. i used a filter for a fuel tank with a sediment bowl on it and a 10 micro filter and i ran it all weekend no problems. i reduced the filter head from 1" to 3/8". but there is a lot of junk in the tank. thanks every body for the help.
oh and another thing is it bad to push dirt with this d6 in 2nd if i am not lugging the motor to much. what are yalls thoughts