JCB 3CX Exhaust bodge

[RedLiner]

1993 JCB 3CX Sitemaster
The exhaust/expansion box started to fall apart some while ago and despite MIG welds etc. it finally went AWOL!

The new replacement part shipped from the UK was over £100, here in Spain the same plus another £30 odd quid

I bought a metre of 63 diameter flexible exhaust pipe from a local spares shop here in my part of Spain for 30 Euros.
I cut off the the three point flange from the old box and welded the flexible pipe to it and sealed the joint with "Stop Smoke" a high temperature mastic solution.
It was easy to route the flexible pipe through to the outlet in the bonnet, however it was much too floppy. The answer was to make up a bracket to hold the new flexible pipe in place. I did this with some 1mm galvanised sheet that I had knocking about.

My JCB is now up and running with a repair that cost in UK money around £35.

Perhaps my 3CX is the only one with a straight through exhaust, that said the noise level is no more than with a box fitted!!!!!Exhaust 2.jpgExhaust old.jpgExhaust 1.jpgExhaust 2.jpgExhaust old.jpgExhaust 1.jpg

[ianoz]

Turbo seems to quieten them down a fair bit .Non turbo motor would be a different story .

[Muz]

Got to be an 8/10 bodge factor on that one .. trouble will be keeping it there ... a temp fix you might say its the length of the stack vs vibration thats the killer on these fixes .. just did another one myself on an 8 tonne digger .. the exhaust I made was worthy of a WW2 tank but I then realised that it would vibrate off in an instant due to its weight and so came up with design #2 which was much lighter and more likely to go an extra couple of years before a re bodge required

Tip : the further away from the engine the bracket fixing to the exhaust is ... the harder the vibration/effect will be

And yes those boxes all failed at some point .. I remember a neighbour of mine welding one of his up after the machine was a couple of years old and I said "thats a bit shit " he said .. well just one of those things .. to which I replied ..." but that machine has been in development for 50 odd years ?"

[RedLiner]

Got to be an 8/10 bodge factor on that one .. trouble will be keeping it there ... a temp fix you might say its the length of the stack vs vibration thats the killer on these fixes .. just did another one myself on an 8 tonne digger .. the exhaust I made was worthy of a WW2 tank but I then realised that it would vibrate off in an instant due to its weight and so came up with design #2 which was much lighter and more likely to go an extra couple of years before a re bodge required

Tip : the further away from the engine the bracket fixing to the exhaust is ... the harder the vibration/effect will be

And yes those boxes all failed at some point .. I remember a neighbour of mine welding one of his up after the machine was a couple of years old and I said "thats a bit shit " he said .. well just one of those things .. to which I replied ..." but that machine has been in development for 50 odd years ?"

I'm hoping that with my exhaust bodge being flexible there won't be any metal fatigue. When I had finished and trimmed the flexible pipe to the top of the galvanised bracket and with the stainless steel stack in place, it was all a bit wobbly. To get over this two more sub-bodges were needed, one was to wrap a metal band around the galvanised bracket and the air intake, the second was to lengthen the slots in the SS stack pipe, stand on the bonnet and whack the stack pipe so more entered the flexible pipe. I realise in doing that it's going to be a bugger to get it off

[RedLiner]

Turbo seems to quieten them down a fair bit .Non turbo motor would be a different story .

That's a good point, I wondered why it was so quiet. And to what Muz mentioned about the years in development, why not a straight through system for turbo models?

[v8druid]

That's a good point, I wondered why it was so quiet. And to what Muz mentioned about the years in development, why not a straight through system for turbo models?

aye 50 years and been going backwards for the last 30 of 'em

love the new slogan mate ...... brilliant

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