The Classic Machinery Network

Hi all,
I have a 1983 JCB 3cx, which i have spend a lot of money rewiring and oil changes, servicing etc..
But I lent it to a friend who got it stuck in a very wet field, a more expericienced driver was call for and was able to lift the machine out using the back hoe.
However the back hoe no longer slews left/right,

Can anybody tell me what is wrong, or it this expensive to repair?

also another minor problem, the side shift lever is siezed, and it looks like the side shift hasn't moved in years, is this easy to fix?

No a positive note, I was able to get the machine road legal, and along with a letter from BC Plant, I now have number plates and the V5 documents!!

welcome john
does the arm slew left/right on its own or is it stuck in one position ,also does the slew lever sound like its doing something when operated
as for the side shift free it off on the spool block first and then use it to dig some holes with the sideshift in the unlocked position to see if the clamps free off ,if not you may have to strip them down

hi d4c24a,
when you move the slew lever, it sound like its moving, but it will slew slightly to the left but not to the right(viewed from the operators seat) and after that nothing happens.
If you are on the ground and physicially push against the hoe, it will move in the direction you are pushing, hope you can understand what i'm trying to explain

well the seals could be shot or the rack and pinion damaged ,i would say it would be the seals ,as it would /should have made some nasty noises if the rack and pinion had been damaged ,sounds like you need to get the spanners out

yes, i think you are right about the seals, as there was no crunching noise, or anything like that.
Can you give me a few pointer on removing the slew ram?
there is 4 bolts which i have managed to losen(on one side of the hoe and the same on the other), there is a steel hydraulic pipe on top of it connected to the black flex hydraulic hose, is this where the seals are located, is this what i should be taking off??

yes as far as i know you are heading in the right direction
not having taken on off myself ,but i think you slide the tubes off and you can then see the ends of the rack and the seals
someone else may be able to tell you better
cheers graham

Lets hope it is seals but would you be surprised if both side gave out at simultaneously? Worst case could be something that has sheared and will then make little noise. Might be talking out of the wrong end here.

might be an idea to check the steel pipes didnt get damaged when digger was stuck i have seen that stopping it slew only a suggestion

Sorry but I don't think it's as easy as your seals. I hope it is but I doubt if both sets would go at the same time.

I have had a machine that broke it's kingpin resulting in not being able to slew. If you had an experienced chap who knew how to lift and walk then that's putting quite a bit of pressure on what is an old machine. Place your bucket on the ground at 90 degrees from the rear and stretched halfway out and push down and lift up a couple of times and observe the movement between the kingpost and the kingpost carriage. When I took mine apart the kingpin was in two pieces and that allowed the splines to become disengaged from the rack.

If you lift the boom and can slew it by grabbing hold of the dipper and pushing it round by hand that is the classic sympton of kingpin trouble.

And if you decide that it's the kingpin and to replace it all yourself come back here for advice. You've got some heavy metal around there and it can get dangerous.

Good luck.

Hi John,

I have just had a similar problem with my 3cx. I was able to push the boom round. What had happened was the splines in the bottom of the king post carraige had broken up and worn away. This is a common problem, with 3c's. The only remedy is a replacement king post carraige, king post and bush kit.

Second hand units are like 'hens teeth' the cheapest way out is to use none genuine parts, it's quite a big job to do. I had an experienced JCB fitter who did the job in just over a day.

Hope this info is useful to you.....thumbs-up

johnyoung wrote:Hi all,
I have a 1983 JCB 3cx, which i have spend a lot of money rewiring and oil changes, servicing etc..
But I lent it to a friend who got it stuck in a very wet field, a more expericienced driver was call for and was able to lift the machine out using the back hoe.
However the back hoe no longer slews left/right, :dizzy:

Can anybody tell me what is wrong, or it this expensive to repair?

also another minor problem, the side shift lever is siezed, and it looks like the side shift hasn't moved in years, is this easy to fix?

No a positive note, I was able to get the machine road legal, and along with a letter from BC Plant, I now have number plates and the V5 documents!!