1994 JD 650G - no 4th gear

[MrChuckles]

My dozer is a 1994 JD 650G. It quit working in 4th gear. I rarely use 4th and only noticed it the other day when it didn’t move the dozer. I plan to have the local JD service guys take it in to fix it when I can. Right now I need to work it using the lower gears.

My question is this; will I damage the other gears by using it while 4th gear is out? How urgent is it for me to fix this?

 

[dozr]

best thing that could happen , i would bend lever on d6c where they could not beat under carraige off, we forget we are on dozer, we have time to think about what we are doing and not do it twice. old school

 

[MrChuckles]

Sorry but I don’t understand your post. Should I continue to run it or not?

 

[mitch504]

What he's talking about is the practice of intentionally disabling high gear on dozers, because of the terrible track wear that comes with speed.

Nobody can tell whether you will damage your machine without knowing exactly what's wrong with it. Does it make noise in 4th? Does the engine strain?

 

[mg2361]

Your issue could simply be a linkage wear issue not allowing full spool travel, a 4th gear pressure tube failure (depends on your serial number which you should post), or a clutch failure. On a 650G you can have the rear cover off in about a 1/2 hour (so long as there is no winch or ripper) to peak inside to see if anything major is going on (after first checking the shift linkage).

 

[MrChuckles]

Thank you for the elaboration. The serial number of the dozer is T0650GH797180. It doesn’t make any unusual noises when shifted into 4th. In fact, it’s like it is in neutral. The dozer will try to freewheel on a slope.

I’m not a mechanic so will have to get the JD service company to do any diagnostics. It sounds like I need to get them to haul it to the shop to check it out. I hate to spend the bucks, but don’t want to mess it up further by running it when I perhaps shouldn’t.

 

[mg2361]

Based on your serial number your machine should already have the thicker walled transmission pressure tubes. So lets hope for a simple linkage adjustment.

 

[MrChuckles]

Thank you to all.

 

[Tinkerer]

Please post back how you resolve the problem so that others reading this thread will learn from it.

 

[MrChuckles]

Please post back how you resolve the problem so that others reading this thread will learn from it.

Yes I will. It may be a while. I have to wait for the rain to stop so the water well drillers can finish their thing and I can tow their rig up the hill. Then I’ll call for service.