Old 966 loader Hydraulic question

[donbj]

We have this old 966, I believe late 60's early 70's. A question for someone that knows more than me about the hydraulic steering. It has a nasty jerking motion, more when warmed up. All the other hydraulics work fine and is a very strong old machine. It's just when steering it jerks off and on as the steering is applied. With steady pressure on the steering wheel it has a jerking application to the steering. Quite annoying and am afraid something is going to get broken if not remedied. Have to operate at low throttle when turning so it's not so harsh.

Any suggestions or advice is greatly appreciated.

 

[Southside]

My first skidder was a 440 and it did the same thing, turns out the priority valve has a shuttle inside of it that had worn out of spec over the years and would get stuck, jump, etc and since it was plumbed to the brakes, steering, and blade the steering was the only component that had no resistance to it, so she would jump all over the place.  

I tried to find a replacement valve but there were no longer available so I gutted the old valve and just left the shell in place to act as a manifold and the issue vanished. 

[fluidpowerpro]

The purpose of a priority flow divider is self explanatory. It makes sure one circuit has priority and will always be supplied flow if the demand is greater than the pump can put out. Steering and brakes are examples of functions that should get priority. By gutting the valve and making it into a manifold, you may not notice any issues until you try to run multiple functions at the same time. When you do that the oil will take the path of least resistance and you will not have priority to the steering, etc.

[Southside]

Absolutely, but that was better than the steering wheel breaking my arm weekly. 

[donbj]

Thanks for the replies. That's kinda what this one feels like. It starts with some resistance against the steering wheel and feels normal starting out then it goes real loose and jerky. Will look into this. We have a book on it so should be able to find the valve. Maybe find a used one and try that.

[kiko]

All the 966s I have fooled with have a dedicated steering pump, but they are much newer so yours could have a priority valve, any chance I could get the serial number? 

[donbj]

I will see if I can find some numbers today. Thanks!

[barbender]

 I've spent many hours in those old 966's. The one I ran the most was really an old girl, it gad an open station with just a ROPS. Iirc, it didn't even have the power shift on the steering column, just a shuttle and then a high/low shifter next to the seat. It had the nickname "Flintstone" because it looked like it was off of that cartoon😊 It also had "Traxcavator" emblems and it had a label saying to check the oil with the engine running. It definitely came from another era!

 Sorry I can't help with he problem, I was just reminiscing.

[realzed]

We have this old 966, I believe late 60's early 70's. A question for someone that knows more than me about the hydraulic steering. It has a nasty jerking motion, more when warmed up. All the other hydraulics work fine and is a very strong old machine. It's just when steering it jerks off and on as the steering is applied. With steady pressure on the steering wheel it has a jerking application to the steering. Quite annoying and am afraid something is going to get broken if not remedied. Have to operate at low throttle when turning so it's not so harsh.

Any suggestions or advice is greatly appreciated.

Nice 'muffler'..  :-)

[donbj]

All the 966s I have fooled with have a dedicated steering pump, but they are much newer so yours could have a priority valve, any chance I could get the serial number?

Here's the tag on the machine.


 
This is the same as what Barbender says he ran. It has the Traxcavator label on the serial tag and the engine tag. Shuttle at steering wheel and hi/lo beside the seat. She's a beast.


 

[donbj]

Nice 'muffler'..  :-)

Haha, it's a 45 gallon drum. I fabricated the two stacks off of it to direct the smoke on start up upward. Looks cool with two plumes coming out:D

[realzed]

Sort of a redneck Dynomax or Flowmaster - :D - Love it!

 

[donbj]

The other issue with the steering is it turns all the way to the left but not all the way to the right. It started that last winter.

[kiko]

I tried to look it up but it must be too old to be on Cat SIS 2.0.

[donbj]

I tried to look it up but it must be too old to be on Cat SIS 2.0.

Thanks for trying, appreciate the effort. It is mid 60's as far as I can sort out. Did manage to get some direction from the antique Cat site so will dig into things when time permits.