JCB 3CX Sitemaster - several questions

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topkit
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Re: JCB 3CX Sitemaster - several questions

Post #11 by topkit » Sun Feb 05, 2023 3:35 pm

If you have a search on Ebay you can quite often find the earlier 3cx handbooks there is a large A4 style one for the first version then a smaller version with a black front cover, You will find both very useful, Infact i have just found one on ebay item number
154316067345 This covers the models from 85 onwards but would be useful as it covers the earlier shuttle transmission as well as the later electric one it also gives you all of the oil specs too


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Re: JCB 3CX Sitemaster - several questions

Post #12 by Soulman » Tue Feb 07, 2023 3:24 pm

I went through the process of replacing the slew pot seals and details are here

Soulman @ 3CX Grey CAB Slew Cylinder Bolt Size


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Re: JCB 3CX Sitemaster - several questions

Post #13 by ady-uk » Fri Mar 03, 2023 10:43 pm

I’ve done the one side.
Now doing the other side.

I found out that the 4 bolt holes are just under 23mm diameter and screwfix sell a 23mm dia broom stale for £4 (cut in 3 sections) is perfect for a guide rails. (Screwfix code: 3396H - Bentley broom handle 47") The wood is just slightly bigger, but being wood screws in and is solid. Makes fitting really easy as all aligned on the wooden rods. A block of wood and few taps let it slip on easier than expected.

The other side, allowed it to slide off but not drop on the floor.
this side was leaking oil as i undone the bolts and pushed itself off whilst undoing the bolts, which was odd. Also this side the rubber seal ring was fitted inside out, the ribs on the inside.

Reason I didn’t finish the other side is because the pot has some internal pitting. I’ve bought it back home to decide whether to just live with it and possible (slight leak).


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Last edited by ady-uk on Sun Mar 05, 2023 5:03 pm, edited 3 times in total.


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Re: JCB 3CX Sitemaster - several questions

Post #14 by gecko.cx » Sat Mar 04, 2023 6:55 am

Good job.
I'd be interested to know why some pots go together easily and other don't.
I had a serious wrestle to get mine together with the yellow retainer popping out and getting damaged.


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Re: JCB 3CX Sitemaster - several questions

Post #15 by ady-uk » Sat Mar 04, 2023 3:34 pm

gecko.cx wrote:Good job.
I'd be interested to know why some pots go together easily and other don't.
I had a serious wrestle to get mine together with the yellow retainer popping out and getting damaged.


Couple of things, hope I'm not patronising.
The yellow ring has a 'V' on one side. The rubber seal also has a matching 'V' on one side. They fit together like tongue n groove.
I always put the yellow ring on first, then the seal slips in and, as it falls info the recess, naturally mates into the plastic 'V'
I can't see them coming apart when together properly as they become locked as one.

Putting in the plastic after requires a bit of force, it's not so easy.

I also applied grease on the seals and rings for two reasons, the grease is sticky, to hold the plastic rings inplace. It is also slippery, to help the pot slip over.

I also think the wood guide rods I used helped a great deal.
They let me slide it on square and not worry about having struggle with the weight. I could just concentrate of sliding it over the seals and gently pushing or tapping it home.


I'd like to know why my cylinder is so badly pitted, I mean it doesn't look like rust at all. It actually looks like the metal it really poor and defected. Part of me doesn't want to put it back on, but a second hand ones are over £200 and don't want to spend that either.


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Re: JCB 3CX Sitemaster - several questions

Post #16 by gecko.cx » Sat Mar 04, 2023 7:47 pm

Yep - I understand what you mean about the male and female "V" and how it locks together.
And no, you are not patronising - you got it to go together easily - I want to know how!
I oiled mine rather than grease - it looks like grease works much better.
My seals were very tight and I needed the tractor to nudge the pots into place.

The pitting down the bore looks exactly like the damage to an old brake cylinder.
An engine bore hone may clean it up, but you'd need sone fine stones or another way polish the surface.

Sure your broom handle isn't 27mm? (iirc the bolts are 1" UNF)


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Re: JCB 3CX Sitemaster - several questions

Post #17 by ady-uk » Sun Mar 05, 2023 2:46 am

The bolts are 1" thread and do measure 25.4mm o/a
To insert something in the threaded holes, the measurement inside the V of the threads was as near as 23mm. I was looking for threaded pipe or similar but was either too expensive or having to wait for delivery. Then I found the broom stale for £4 at screwfix and 23mm diameter. Perfect.
It should have just push into the holes tight fit, no threading but to my advantage it was just a really tight fit and I had to screw the wood in, letting the steel cut a very shallow thread in the wood. I'm literally talking about a slight indentation of thread on the wood. Managed to do it with my bare hands. It was perfect.

The filling of the gearbox is going to confuse me.
I've found the hex nut thingy in the kingpost.
It is a hex nut with a nipple on it. I can pull the nipple up and push it back down. It's loose and I can rotate it forever.
It won't actually come off or undo though.

I guess it's just a breather or vent and I have to undo the whole nut to fill it with oil. That's what I was going to do anyhow, so see if my assumption is right. Can inspect it when out.

I hadn't got another vehicle to push the pot back on, and reading your guide made me have to think how to overcome.
Why I came up with the idea of guide rods. Worse case scenario I planned to use the guide rods to hold it's weight and keep it aligned. I was then going to make a chain or strap loop around both pots. The put a bottle jack between the strap and the end of the pot I'm trying to push on. I was prepared for a battle but it went on easily. Maybe grease is the secret.


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Re: JCB 3CX Sitemaster - several questions

Post #18 by gecko.cx » Sun Mar 05, 2023 5:05 am

ady-uk wrote:It is a hex nut with a nipple on it. I can pull the nipple up and push it back down. It's loose and I can rotate it forever.
It won't actually come off or undo though.

I guess it's just a breather or vent and I have to undo the whole nut to fill it with oil. That's what I was going to do anyhow, so see if my assumption is right. Can inspect it when out.

Mine was missing the nipple bit, and I destroyed the rest getting it out. I replace it with a plumbing fitting to which I added a fuel filter and a length of hose to prevent water entering - not as elegant as the original, but more functional!


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Re: JCB 3CX Sitemaster - several questions

Post #19 by ady-uk » Sun Mar 05, 2023 4:37 pm

I'm going tomorrow to put it together.
I was deliberating wether to get some jenolite metal putty and fill in the putting. Jenolite is one of the market leaders in metal glue products. I wouldn't want it to come off and end up being hard debris in the hydraulic system. This is allegedly the product that'd do it.

Maybe just put it together as is, not scaffold bar tight, but still really tight, leave the drain plug out the box and slew it left and right a few times, see how much hydraulic oil drains out the gearbox, if any, and then have another think.

I reread my earlier post (37mm broom). I meant 23mm, honestly don't know were my brain was when I put that, it was late. Have corrected that post with the screwfix order item.

Be glad when this is done.
Need to get rid of a big muck heap

Picture of the gear oil filler attached.

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Re: JCB 3CX Sitemaster - several questions

Post #20 by essexpete » Sun Mar 05, 2023 5:12 pm

ady-uk wrote:I'm going tomorrow to put it together.
I was deliberating wether to get some jenolite metal putty and fill in the putting. Jenolite is one of the market leaders in metal glue products. I wouldn't want it to come off and end up being hard debris in the hydraulic system. This is allegedly the product that'd do it.

Maybe just put it together as is, not scaffold bar tight, but still really tight, leave the drain plug out the box and slew it left and right a few times, see how much hydraulic oil drains out the gearbox, if any, and then have another think.

I reread my earlier post (37mm broom). I meant 23mm, honestly don't know were my brain was when I put that, it was late. Have corrected that post with the screwfix order item.

Be glad when this is done.
Need to get rid of a big muck heap

Picture of the gear oil filler attached.

Image


Horse muck?


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