105 combine Hydrostat

[4020]

We are having problems with the hydrostat on our 105 combine. It has a tendency to want to free wheel at times. It does alright as long as you have a load on the combine but if you are just driving through the field or turning around at the ends is when it wants to free wheel. Then all of a sudden the hydrostat will kick back in and slam the combine back to the correct speed. It does it worse when the motor is wide open and the hyro lever is all the way forward. I was wondering if anyone had any ideas of what might be the problem. I was also wondering if anyone knew the book needed for servicing the hydrostat on a 105.

 

[bradk]

Dumb questions,but have you checked the fluid? Do you have the op.manual?

Also,start with the easy things and change the hydro fluid and filter.If you call any hydro repair facility,they will tell you to start there.

Can't remember off the top of my head,but the fluid is a pretty exclusive as is the filter to JD hydros.Make sure you get the right stuff. ~brad

 

[RayP(MI)]

I don"t have experience with that unit, but My first reaction is to check level on fluid and replenish as necessary.

 

[Leland]

go to www.redpowermagazine.com

post it there those guys will have a correct answer .

 

[Anonymous-0]

I agree with other posts. Fluid level. When driving through field or around ends it is more apt to happen, thats when you have used some fluid to raise header.

 

[IaGary]

Just happened to me on Thrusday with my 1660.

Guess what I added fuild and all was well.

Gary

 

[thurlow]

Once had the same problem with a L2 Gleaner; dealer had it apart for the third time before fixing it. Have forgotten details, but a snap ring (in the hydrostat) had worn a little.......or maybe it had worn the groove on the shaft a little wider.......and was no longer keeping the right pressure on disks...........You could be going downhill and it would just start free-wheeling. SCARY on the highway.

 

[4020]

This problem has been going on for several hundred hours. We change the oil and filter every season. We run over eight hundred acres a year through this machine. The hyrostat system and the hydraulic system are two completly seperate systems so it is not starving for oil. When we have the most problem is when we are combining in second gear,high rpm. It does it only when there is no pull on the machine such as going down hill or turning around. It will try to hold itself back then it puts forward pressure on the system again. This is not a big jerk it is just the slack between being under load and trying to hold itself back. It will do this 2-3 times before it "pops" free and it is free wheeling. The machine will coast to a complete stop and sit there for a short period of time then all of a sudden slam back to the speed that you was running or wherever the hydrostat lever is. We have always thought that it might be sucking air allowing itself to suck the oil out of the hydrostat pump and then when it reprimes itself which would give us the big jerk. We have never found any leaks though. We have been looking for a vaccum leak and havent found it and there is absolutly no oil leaks on it anywhere. We are wondering if there could be a high pressure valve that is messing up since it happens more at high rpm. We have all the books for this machine, operaters, service, and parts, except for the one that goes into detail about the hydrostat which we would like to have if anyone knows what number the book is.

 

[Anonymous-0]

SM2078 Technical Manual is what you need.

JD Part Details

Part Number: SM2078
Part Price: 48.15 USD
On Hand: 0 Check Other Stores
Description: TECH MAN,55,95,105 HYDR DR COMBINES

JD publications 800-522-7448

 

[HuskerMedic]

Sorry, can't help you with your problem, never been into the hydrostat on a combine, but...

I love this series of combines; I owned a 45 at one time. Any possibility of posting some pics, info about the machine? What heads do you use? How many hours?

Again, sorry I can't be of any technical help.

 

[fixerupper]

I can't help you either, but I still have my 105 gear drive in the machine shed ready to go though it hasn't been used for ten years. Been heavily involved with a couple of other brands for seven months a year, every year since then, but I still have a soft spot for the old 105. Used it for twenty years on 640 acres and it gave me lots of faithful service. Jim