JCB 1CX chain case oil (and water)

[AussieChris]

I recently purchased a tidy late model series 2 JCB 1CX and I’ve been changing all the fluids and filters. It’s all going well except the chain case oils. Each side holds 10 litres of oil. I drained that amount of moderately dirty oil from the right side case. However, from the left side, I got about 25 litres of chocolate milkshake meaning there was 15 litres of water in there with the oil.

My task now is to find how the water is getting in so was wondering if anyone had any ideas. I have made up a replacement level plug which incorporates an air line fitting. My plan is to introduce low pressure air and then use soapy water to look for leaks. Does anyone know if these machines have a breather on the chain cases? I’m thinking it must be a serious leak to allow that much water in (like a missing bolt from a through hole) but there are no apparent oil leaks. The main openings would be the front and rear hubs, drive motor, and inside sprocket cover but I’ve not found anything amiss so far.

Any suggestions gratefully accepted.

Chris.

 

[AusDave]

Hi Chris.

When I purchased my first 1CX I found the same milky oil in one of the chain cases. I changed the oil and it's been fine for the years I've had the machine. I don't know if there is a breather for the chain cases or if the are sealed. If there is a breather then perhaps through the location of the machine in a number of rain events or deep water use water has found it's way in. If there is no breather and the machine has been working and been in water or bogged, then as the cases cooled a vacuum would occur in the chain cases which would suck water in the smallest of gaps.

I wouldn't worry too much as the event that caused the introduction of water in the past, such as being in deep water or bogged in a very wet situation, may never happen to you and if it did you could check afterwards. The oil in the chain cases is engine oil which is able to neutralise the effects of water to a large extent by emulsifying it, stopping most of the corrosion. The chain and bearings in the case are not running at high speed like in a motor or transmission and therefore have lower wear rates even in adverse conditions. I think abrasive dirt/sand or absence of oil would be be the real concern if it was found

Give the cases a flush with some clean diesel, fill them with the right oil and just check them occasionally as time goes by. I think if you treat your machine well and don't submerge it or leave it bogged deeply for a few days you won't have any more water in the cases. Keeping the 1CX under cover when not being used would also be a good idea as it stops rust and corrosion in other areas and wiring as well as stopping UV damage.

Let us know how you get on, regards AusDave

 

[jcb jeff]

I would say you problem was either a crack in chain case / chassis of the machine or the sealer that is around the o ring on the drive motor or the hub units them selves would be a good start.

 

[AussieChris]

Thanks Dave and Jeff for your suggestions. Today I hooked up my air hose adapter to the left side fill/level hole. I discovered air leaking from a couple of places.

Firstly, the where the drive motor bolts on there is a thick doubler plate. This plate includes the four mounting holes for the drive motor cover box. These holes are obviously drilled and tapped before the plate is welded to the side of the chain case which effectively makes them blind holes. However, while the plate is fully welded on the outside, it is clearly not welded on the inside of the hole where the motor passes through. So there is a leakage path between the doubler through to those tapped holes. Water can leak past the threads on the cover mounting bolts and into the chain case. So those bolts should have sealant applied whenever they are replaced.

Secondly, there are breathers on the chain cases. They are just a little cap thingy on top of the case at the rear (under the floor). The left side one is just in front of where the fuel lines emerge from the tank and the right side is in a matching position. With a large build up of oily dirt around those breathers, it is entirely possible for water to pool and enter the breather. As you can see in the photo, mine is now reasonably clean in that area! The breather is indicated by the blue arrow.

Anyway, I’m confident there should be no more water issues after I change the oil a couple more times.

Chris.