# jcb 3cx movement problems



## eddieireland

hello everyone i have a problem with my jcb 3cx it has full moving power in reverse but when its shuttle is placed for it to move forward it just revs up and wont move what so ever.i have cleaned the filter for the torque converter and replaced its fluids and this hasnt worked i dont want to go stripping it apart unless i have some clue as to where i should start stripping.
the year of the machine is between 1986 and 1988 any help on this matter will go a long way thanks for reading my thread!


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## jhngardner367

Are you certain the shuttle is moving to the forward positin,fully? could it be disconnected,or out of adjustment?


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## horsepuller

I have a 1988 MY JCB 1400B, which I think is similar to your machine (US version, sort of?). I had a similar problem with intermittent forward operation. The problem with my machine was electrical. The forward/reverse lever operates microswitches that activate hydraulic solenoids on the body of the transmission. I had to replace the forward microswitch; that fixed my problem. 
You may be able to verify if the problem is electrical by verifying that the reverse solenoid is energized by touching it with a screwdriver blade - the blade should be attracted to the body of the solenoid. When you put the shuttle lever in the forward position, you should find that the screwdriver blade is not attracted to the adjacent (forward) solenoid. I don't know exactly where these solenoids are on your machine, but I'd guess they are on the transmission body under the cab. 
Good luck. 
A schematic diagram would help your trouble shooting. Sometimes CD-ROM versions of JCB manuals are offered on Ebay (check the serial # of your machine to make sure it is in the range of #'s covered)


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## eddieireland

jhngardner367 said:


> Are you certain the shuttle is moving to the forward positin,fully? could it be disconnected,or out of adjustment?


i have checked that and its all in adjustment and all in place.its just as if the forward gears are not biting as if a clutch is slipping when i took out the filter for the torque converter there wer metal filings caught in it but no rattles or humms from anywhere


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## eddieireland

horsepuller said:


> I have a 1988 MY JCB 1400B, which I think is similar to your machine (US version, sort of?). I had a similar problem with intermittent forward operation. The problem with my machine was electrical. The forward/reverse lever operates microswitches that activate hydraulic solenoids on the body of the transmission. I had to replace the forward microswitch; that fixed my problem.
> You may be able to verify if the problem is electrical by verifying that the reverse solenoid is energized by touching it with a screwdriver blade - the blade should be attracted to the body of the solenoid. When you put the shuttle lever in the forward position, you should find that the screwdriver blade is not attracted to the adjacent (forward) solenoid. I don't know exactly where these solenoids are on your machine, but I'd guess they are on the transmission body under the cab.
> Good luck.
> A schematic diagram would help your trouble shooting. Sometimes CD-ROM versions of JCB manuals are offered on Ebay (check the serial # of your machine to make sure it is in the range of #'s covered)


it does sound like something very sinister like what your talking about i will try your suggestion today and i will let you know how i get on later this evening!!thanks a million for your help!!!


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## eddieireland

wel man you wer correct about that inhibitor switch thanks again for your help a new one is just 25 euros plut VAT so happy days!!the switch had the two wires bridged for some strage reason and when i took the the bridging wire off the jcb wouldnt start so i presume its a switch so the machine wont start in gear but its also for selecting forward and reverse thanks again horse!


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## horsepuller

I'm glad to hear that you are making progress. You are right that the forward and reverse switches act to disable the starting system, so that you do not inadvertently start the machine in gear.


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## eddieireland

wel horse i put the new switch into the jcb and low and behold it didnt fix the problem!it still has full power in reverse but still nothing in when its time to move forward afraid to say we're back where we started unfortunitley


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## horsepuller

Sorry the switch did not fix your problem getting forward to engage. I think we have to go back a few steps.

First, we need to verify that your forward reverse actuator is really electrically operated. My 1400B has a lever on the left side of the steering wheel that is used to electrically select the direction of motion: pushed forward selects forward motion, middle position is neutral (for starting), and pulled backward selects reverse. Is this how your machine works? Your machine could have some sort of mechanical selection of direction: a rod or cable down to the transmission body. Please verify what you have.

If you do have an electrically controlled system, you will need to do some electrical trouble shooting to isolate the problem. Is this something you can do? Do you have any electrical trouble shooting experience?

I am (I hope) attaching a portion of the electrical diagram for my machine; yours may be similar. (Check the wiring color codes to see if they are correct; it woud make things easier if they are.) There are a number of component failures that could cause the symptom you are having. You will need to trace the power flow through your wiring to isolate which component is defective

Looking at the diagram, you can see that the power to operate the forward solenoid (on the transmission body) flows from starter switch (run position) through the white wire to the fuse block (5 amp) to one side of the dump relay, out the dump relay to the forward section of the forward/reverse switch, through the forward/reverse switch (when in the NO position), to the forward relay, to the forward solenoid on the transmission. 

The dump relay and switches are OK, or reverse would not work. The problem should be in the forward section of the forward/reverse switch, the forward relay, or the solenoid, or the wires connecting these together.

I'd suggest that you start at the fuse block and verify voltages as you go. You should, of course, have about 12 volts all the way through the system to the forward solenoid (above chassis ground). 

Note again, all this depends upon your machine being the same as mine. I'd suggest that you look on Ebay for a CD-ROM service manual for your machine. You need it.


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## AndrewEvan

Hi Folks, I apologize for jumping in with my own problem on this thread, I wasn't sure if where to post this and jumping in on someone else's issue without being able to offer you any help seems poor etiquette ... but, I'm having a similar problem with mine and it may be relatable. I just bought a 70's International 250a hoe/loader and the guy drove it about 2 miles to my home (he was just up the street). It has a hydraulic shuttle trans (I think), the guy I bought it from seems to know even less about it than I do, which REALLY doesn't say a lot. We parked it overnight on a slight upward incline, and when I went to move it the next afternoon, it doesn't appear to "engage". I tried both High and Low ranges forward and reverse, it just revs. All of the bucket and hoe seemed to be working fine? It has a couple of leaky cylinders and lost some fluid 1 pint or so which I collected in a bucket (not accounting for whatever fluid he lost on the way over). Could that coupled with the fact that it was parked uphill be the reason it seems to have no forward or backward power? I was hesitant to just start adding fluid because there isn't a gauge and I'll just be catching it in a bucket, lol. Any insight? Thanks


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## amine

i have the same problem with my JCB 3CX ECO 2013! and i have no idea what to do


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## joe90

I also have a 1983 jcb 3cx that has power foward and back but hesitates and jerks. it used to be very smooth on take up. any thoughts please.


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## Edgarloz

Hello!
Good afternoon, I have a JCB1550B 1987 backhoe.
My backhoe has a problem with reverse and forward, the problem Start gradually losing strength in the reverse and forward, the hydraulic system works perfectly, is very strong to excavate, can carry easily with the front loader.
Only I have the problem with reverse and forward.
Someone could help me with this problem?
Thank you.!


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## oflynnp

Did you get this sorted out?
Depending on the model of the machine, there is a drain plug(nut) on the side of the transmission underneath the digger.
There is a mesh filter inside here ( + loads of transmission fluid)
If the mesh gets blocked the fluid cannot passthrough.

If your digger is moving forwards and backwards, but feels "weak" this may be it.
Rev the digger when driving and it should move faster.

If the digger has been sitting around, change this transmission fluid, clean the mesh and do the filter too.
This should sort the problem, if not then the plates inside the transmission may be worn.

Let us know how it goes, pics etc


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## oflynnp

Did you get this sorted out?
Depending on the model of the machine, there is a drain plug(nut) on the side of the transmission underneath the digger.
There is a mesh filter inside here ( + loads of transmission fluid)
If the mesh gets blocked the fluid cannot passthrough.

If your digger is moving forwards and backwards, but feels "weak" this may be it.
Rev the digger when driving and it should move faster.

If the digger has been sitting around, change this transmission fluid, clean the mesh and do the filter too.
This should sort the problem, if not then the plates inside the transmission may be worn.

Let us know how it goes, pics etc


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## ibrahim

what the caution sign on jcb 3cx bachhoe mean


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## ibrahim

ibrahim said:


> what the caution sign on jcb 3cx bachhoe mean


2002 model


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## Ballyman

hey EddieIreland,

what was the outcome of JCB. i've 409 and its doing exact same thing. The machine would go around the world in reverse but wouldnt cross the yard in forward


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## Shannon Hickey

eddieireland said:


> hello everyone i have a problem with my jcb 3cx it has full moving power in reverse but when its shuttle is placed for it to move forward it just revs up and wont move what so ever.i have cleaned the filter for the torque converter and replaced its fluids and this hasnt worked i dont want to go stripping it apart unless i have some clue as to where i should start stripping.
> the year of the machine is between 1986 and 1988 any help on this matter will go a long way thanks for reading my thread!


Hi my 1984 jcb 3cx not going forward only goes in reverse, only fuse I see is on top left side..how can o fix it.


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## Shannon Hickey

My jcb 3cx 1984 is not going forward n only can see few fuse on top left side. Need help


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## eon

Shannon Hickey said:


> My jcb 3cx 1984 is not going forward n only can see few fuse on top left side. Need help


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## eon

I had that problem with a rented 1985 3cx, back in the early 1990s. perfect in reverse, but would not go forward in any gear.
long time ago now. As far as I can remember the problem was damaged/worn splines on the shaft driving it forward.


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## Kenny+263774674249

eddieireland said:


> wel horse i put the new switch into the jcb and low and behold it didnt fix the problem!it still has full power in reverse but still nothing in when its time to move forward afraid to say we're back where we started unfortunitley


Greetings brother
Your problems seems to be electrical...check on top of your gearbox there is a direction solonoid it seems the forward side there is a problem it could be a loose connection on your solonoid or it's short circuiting...trace also your cable if your solonoid seems to be working fine...if you want to prove its your solonoid you can swap the 2 connections put the reverse connection on forward side of the solonoid u should get drive on front


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