I'm looking at buying a 966c caterpillar wheel loader. The steering wheel turns 1/2 turn between engaging one direction or the other. The pins all appear to be in fair shape, and as far as I can tell the linkage looks ok. The Colum has been oiled and the owner put a piece of hose over a steering rod { he said } to stop it from shaking or cavitating. Is there an easy way for me to diagnose the problem prior to purchasing the loader or should I plan on a new steering box. Any help or suggestions would be greatly appreciated. I am Fairly mechanical but definitely not a mechanic. Am I in over my head?
First up there are 6 different variations of 966C, a Serial Number would assist in identifying which one of those six you have. To complicate things even further there are breaks in the S/N ranges where differences exist in parts above and below the break. IMHO you should plan on some sort of investment in parts, maybe in the steering box, maybe elsewhere in the steering system, maybe both. Only some digging into the machine is going to reveal the root cause of the sloppy steering. Again a S/N would be essential in order to be able to identify the correct parts. I have to ask this. Why are you planning on buying a 966C..? What exactly are you planning on doing with it..?
Are you feeling the 1/2 turn while the engine is running of is this with engine off? Yes as always S/N S/N S/N!
Does this machine have the manual linkages that come from a box and hook to the rear frame or is it a rotary steering valve. If it has the manual linkages, walk away unless the machine is at a give away price. All those parts will cost a fortune and take someone with experience in setting them up properly.
John C speaks truth, we have 2 of those loaders which are awesome machines but the steering can be a chore to get right. The worst is when they get to jerking when turning, it is hard to tune that out of them when things are worn. If nothing moves when the wheel is making the 1/2 turn it probably needs work on the steering box but I haven't actually been into that part of them.
Maybe I should point out that it's been something like 20 years since I worked on a 966C, but I would say that 80% of the time problems like jerkiness in the steering can be narrowed down to a few basic things, at least with the manual linkages. One can be worn linkage to the steering valve, simple rod ends and such. Another is wear or binding in the steering column from lack of maintenance. Next is slop in the pins and bushings of the steering cylinders, again lack of basic maintenance. And Maybe to worst for ones pocket book is the center pins of the machine, do I have to say what the biggest problem there would be? Some others that come to mid would be the actual followup linkage and the mounting on the upper frame being loose. Then a loose cab mounting can do all kinds of strange things!
If indeed this is a machine with follow up linkage, I'm betting the spring in the follow up tube is weak. Saw that one on a 25K 992 a few years back. And if the valve actuation linkage has the smallest amount of wear in in the heim joints or the shaft in the steering box that runs the valve linkage has wear in the box bushings, that will make things jerky too. I'm leaning toward the spring though.
Wow are you right or what. Years ago I worked on a 966 with manual. What a job that was to get set up. Good reason I stayed with trucks.
If one piece of that linkage is worn, figure on replacing it all. You can't piece meal it cause you will be following up on it forever. Been there and done that more than once.
I went and looked closer today, I had my grandson turn the wheel from side to side while I looked around. The lever on the outside of the steering box connecting to the linkage rod has a bad bushing with a lot of movement, everything else looks to be in fair condition. Would it be possible to remove the lever and install a new bushing?
Its when the engine is off and on. Today I was able to see the lever on the steering box has a real bad bushing and moves back and forth. Any idea if the bushing can be replaced without removing the steering box?
Sorry I still don't have a #, We want it for ranch use. The problem appears to be a bushing or bearing on the steering gear box where the shaft comes out for the lever to attach that goes down to the linkage rod.
The linkage that operates the valve spool? Pretty sure you have to disassemble the box to do those bushings.
Unfortunately I believe that the shaft and bushings are about the last things to come out of the steering box. That said for someone with decent mechanical skills it's not a terrible job, heck I have done it a couple times! Not 100% sure of the serial number of you machine so this might not be what you have but take a look and see if it looks like what you are seeing, see attachment: Note the shaft two bushings and the seal all appear to be available from Cat for around $150.00. You might need some other things once into the steering box so price may vary. If you decide to go for it and need part numbers feel free to "Start a Conversation" with me.
And here is another attachment on the steering system that includes adjustments and trouble shooting for jerky steering.
Thank you everyone for all the help. I think I was in over my head with that loader so I changed directions and bought a 950 that seems a lot tighter. Thanks for all the help, your all great
While I'm a little biased toward the 966C's as I spent a good amount of time working on them if the 950 is a good fit size-wise you should be good to go with that. I believe many of the systems of the 950 are just scaled down from the 966C like the engine being a 3304 in place of the 3306. Good luck and order that manual!
Maybe there’s a problem with the nut behind the wheel?