850 b dozer

[Jon Odalen]

hi all- first post. I have access to a friends Deere 850b dozer that has over 8k hours on it. we have been using it for stump removal as we are creating some new pastures. recently we have had some issues with it that have led to me doing a bunch of PM stuff. New fuel filters, new Hydro filters and new air filters. It tends to use hydro fluid so that's always being topped up.
Big issue is that it has stopped moving. after the recent air filter change (engine was running ruff) the engine smoothed out and we got a good 1.5 hours of use before it started struggling to move again (it had kinda done the same thing on and off for a few days- but we put that down to chocked off air). the engine sounds great but no forward, no reverse at any rpm.

any insights would be much appreciated.

 

[alrman]

Welcome to HEF @Jon Odalen
You will need to specify if this is a CASE or Deere.

 

[Jon Odalen]

sorry- updated. Deere

 

[mg2361]

Welcome to HEF Jon!

Lift the floor board. Are the driveshafts turning?

 

[Jon Odalen]

They are

 

[mg2361]

What does the transmission pressure gauge read when the engine is running? When you put it in forward?

 

[Jon Odalen]

Which Guage is that? There are two red-orange warning lights. Oil press, engine temp. Etc. But All normal except one of the orange lights is lit. The one one the right

 

[mg2361]

Please post a picture of your instrument panel. There is supposed to be a transmission pressure gauge on the top right of the instrument panel.

 

[Jon Odalen]

Trans pressure is there but the Guage is broken

 

[Jon Odalen]

 

[mg2361]

Is the light below on when the engine is running? Are the filters you have the ones mounted on top of the hydrostatic reservoir, or the one mounted above the transmission?

If they are the filters mounted on top of the reservoir, then that might be an issue. One set are the suction filters for the left charge pump, and the other set are for the suction filters for the right charge pump.

Also, you need to get that gauge working so we can determine which direction to start heading.

 

[Jon Odalen]

I replaced 4 filters on the right side. Each set of two appears to wave its own warning light.

 

[Jon Odalen]

They were on top

 

[Jon Odalen]

And yes that light stays on

 

[Jeembawb]

Check out dirt perfect's youtube channel he has had an 850b for a long time and talks about how it is a common thing for 850b's to lose transmission drive. I remember a video from early this year I think where they pulled the 850b into the workshop for a full service and some repairs and he mentioned some of the transmission issues common to this model in the video somewhere... lemme see if I can find which video it was and put a link in here...

 

[Jon Odalen]

Thanks! Basically he said the Trans is toast given the hours

 

[Jeembawb]

Thanks! Basically he said the Trans is toast given the hours

Yeah Sorry Jon, if that's the case, it's not a pretty situation.

 

[Jon Odalen]

Anyone else have anything I can be checking? Is there a way to be certain of the issue?

 

[mg2361]

If you are going to want to work on this machine, then you will need to acquire the Operation and Test Manual TM1332.

The hydrostats on that unit are very complicated due to the system they use to control it, and the first thing you need to check is the charge pressure.

I PM'd you.

 

[Jon Odalen]

Thanks!!!