The governor locking control on the side of the diesel engine won't  stay in position. When I  throttle up it just goes back to idol. Has anyone had this problem and fixed it. Some input would be appreciated.  Thank you. 

the pawls have worn that lock the throttle in position---either replace the pawls or a cheap way is to bend the throttle linkage so it develops more friction and doesn't move so easily

Is the parts something you can still purchase new old stock?

This dozer only has 4000 hours on it. It's hard to believe that the pawls would be wore out.

iv fixed many of these by just taking the pawls out cleaning the crud from them and the other mating surface and stretching the spring just a bit that forces them against the housing. just mark the orientation of the throttle handle and the governor shaft before you take it off. 30 minute job

get yourself a parts book for your model you would be surprised what is still available from the dealer. there is also aftermarket suppliers for track gear parts. pistons engine bearings etc are also available aftermarket and genuine.

you can have a machine with high hrs that was looked after or a machine with low hrs that was flogged. the throttle ratchet being worn could be a machine that was constantly varied on speed rather than select a lower gear and run at constant revs.

Bolt with a nyloc nut, so you can adjust the tension on the linkage,  to replace one of the clevis pins works pretty well.

Thanks guys. A lot of really good information. I will remove it and clean it first. Thanks again you've been really helpful in my venture.