JCB 530 - No Reverse

Tony Wells · Dec 17, 2020

OK, mostly this is a plea for a parts source. I believe I have narrowed this down to the F-N-R switch, or possibly the wiring. I get a good solid engagement in F, but nothing in R, regardless of speed selection. Opening up the speed switch, as far as I could without removing the steering wheel to access the wiring to the stalk (stoopid design, imo), I see that parts of the contact system is a bit crispy, so I will need to replace that. Once, while doing the jiggle test, it did engage firmly in R, so I'm pretty convinced it is not a solenoid or clutch/hydraulic issue. The operators said it was fine up until suddenly today R quit altogether.

I'd rather buy online than drive the 100 miles to the nearest dealer, so what I'm hoping for is that someone has access to a parts book. I found several online for JCB equipment, but only specified the OEM PN, which I do not have.

The tag is pretty washed out, so I can't say which is the SN, but here are all the numbers on it.

SLP53000VE0770458
844336C
449/061/3/00087
15479 1997
6000

skata · Dec 17, 2020

Not sure on the exact part number for yours. But you can buy them cheap on ebay.
Just search "jcb forward reverse"
Maybe you can just see which looks like yours.

lantraxco · Dec 17, 2020

Maybe?

https://www.johnconaty.com/701-52601-p/1946.htm

https://www.amazon.com/Signal-Switch-Forward-Reverse-52601/dp/B07GFD11TD

https://www.ebay.com/itm/701-52601-SWITCH-FWD-REV-SHUTTLE-TRANS-fits-JCB-/291813737252

lantraxco · Dec 17, 2020

Another

https://www.ebay.com/itm/Forward-Re...074247&hash=item2d05b41f2b:g:9WwAAOSwQz1bEkjk

Tony Wells · Dec 18, 2020

Well honestly they all look pretty much alike. I have not pulled mine yet to have a look at the connector, which is the most obvious difference in those you found. Some specify the model number machine they fit, and don't list the 530. One does, however, and shows the oem pn to be 701/52601. Do we agree that is the correct number?

lantraxco · Dec 18, 2020

Tony Wells said:
Well honestly they all look pretty much alike. I have not pulled mine yet to have a look at the connector, which is the most obvious difference in those you found. Some specify the model number machine they fit, and don't list the 530. One does, however, and shows the oem pn to be 701/52601. Do we agree that is the correct number?

Best guess without an actual parts book?

skata · Dec 18, 2020

Just pop the steering cover off and look. Take a minute to do.

Kiwi-truckwit · Dec 18, 2020

Maybe not the same issue, but I lost reverse on a Terex 4010 telehandler. It turned out to be a high resistance to ground from the selector. Why it only affected reverse, I don't know.
A new wire to ground solved the issue.

Tony Wells · Dec 18, 2020

lantraxco said:
Best guess without an actual parts book?

I ordered one that specified several variants of the 530 series. It was a little higher than some, but the lower cost ones were shipping from China, and I'd rather not wait on it longer than needed. This lift is very handy for it's purpose. We run a firewood cutting/splitting operation with 2 saw/splitters. This lift is equipped with a claw, so it's better than a standard forked lift that the guys are forced to use until this one is fixed.

Tony Wells · Dec 18, 2020

skata said:
Just pop the steering cover off and look. Take a minute to do.

Well, with the best intentions I'm sure, the engineers decided not to split the cover on the column on this one. The screws that secure the cover to the column are not accessible without removing the steering wheel. One nut holds it on. I didn't have my puller on the truck, so I'll have to get that look next trip. Removing the nut didn't allow me to pull the wheel. A little rusty I suppose. Same for replacing the switch. Has to be scattered a bit.

Tony Wells · Dec 18, 2020

Kiwi-truckwit said:
Maybe not the same issue, but I lost reverse on a Terex 4010 telehandler. It turned out to be a high resistance to ground from the selector. Why it only affected reverse, I don't know.
A new wire to ground solved the issue.

I'll be double checking all the wiring once I have the covers off. I would think the same ground circuit would be in play for both F and R, but who can say. Grounds are funny things sometimes.

Kiwi-truckwit · Dec 18, 2020

Tony Wells said:
I'll be double checking all the wiring once I have the covers off. I would think the same ground circuit would be in play for both F and R, but who can say. Grounds are funny things sometimes.

Best I could figure is that there was just enough current with the increase to activate the solenoid for forward travel. In reverse, with the additional load of the beeper & lights, there wasn't. But I'm no electrical guru.

Tony Wells · Dec 18, 2020

That's a possibility, especially if the machine was old enough to have incandescent bulb rather than LED lighting, but the backup alarm likely would draw more. Good thought.

On the JCB at least, and likely the Terex, the stalk switch only controls a relay, with the JCB relays mounted on the same board as all the fuses. I feel pretty good clicks with my finger on the F relay, but can't say for sure which is the R relay, since it doesn't work. I suppose I could swap the relays around, as I'm sure they are the same for shifting F/R. I didn't try that. Lost confidence in the stalk switch when discovering the crispy parts. Generally a bad sign on electrical parts.

skata · Dec 18, 2020

Tony Wells said:
Well, with the best intentions I'm sure, the engineers decided not to split the cover on the column on this one. The screws that secure the cover to the column are not accessible without removing the steering wheel. One nut holds it on. I didn't have my puller on the truck, so I'll have to get that look next trip. Removing the nut didn't allow me to pull the wheel. A little rusty I suppose. Same for replacing the switch. Has to be scattered a bit.

The steering wheels aren't that tight on the shaft. Pull on the steering wheel and hit the shaft with a hammer may break it loose. Keep the nut on the shaft end to prevent thread damage from hammer.

Vetech63 · Dec 18, 2020

Does this machine have a TCU?

Tony Wells · Dec 18, 2020

Skata, this one is, but it's just rust and I soaked it down before I left yesterday. It will come off easy enough.

Vetech, define TCU (Trans Control Unit?) If that's it, I haven't discovered it yet. Honestly, I didn't spend a lot of time with it. I just removed the internal snap ring on the stalk switch and had a look inside, punched the microswitches that the lever actuates, and tried briefly on the wheel. I have a habit of not working on my birthday, which was yesterday, but it sounded really urgent when the owner called, so I made a quick exception.

Vetech63 · Dec 18, 2020

Tony Wells said:
Skata, this one is, but it's just rust and I soaked it down before I left yesterday. It will come off easy enough.

Vetech, define TCU (Trans Control Unit?) If that's it, I haven't discovered it yet. Honestly, I didn't spend a lot of time with it. I just removed the internal snap ring on the stalk switch and had a look inside, punched the microswitches that the lever actuates, and tried briefly on the wheel. I have a habit of not working on my birthday, which was yesterday, but it sounded really urgent when the owner called, so I made a quick exception.

Correct! You can still have a TCU controller even with an electric shifter. There was a lot of older stuff back in the day that was electric shifted with and without a TCU. Do you know what make and model transmission you have? I’m working on a JCB 722 articulated truck right now with a TCU operated ZF.

skata · Dec 18, 2020

Vetech63 said:
Correct! You can still have a TCU controller even with an electric shifter. There was a lot of older stuff back in the day that was electric shifted with and without a TCU. Do you know what make and model transmission you have? I’m working on a JCB 722 articulated truck right now with a TCU operated ZF.

I don't think the telehandler transmission has a tcu. At least the older ones for sure didn't. The forward /reverse lever just triggered solenoids on the transmission.

Vetech63 · Dec 18, 2020

skata said:
I don't think the telehandler transmission has a tcu. At least the older ones for sure didn't. The forward /reverse lever just triggered solenoids on the transmission.

I wasn’t sure which system we are dealing with.

Tony Wells · Dec 18, 2020

I don't believe this model does. Just above the trans, there is a valve bank, for lack of a better term, that has some solenoids on it. I'm not sure how (yet) how it all works to give the machine 4 speeds, automatic style, with only a pair of solenoids, but there easily could be additional wiring connections on the trans. It does automatically upshift when the stalk switch it set to a higher gear than 1. Naturally, I've no service manual for it. Figured it's a simple machine and hoped not to need it. I actually have a yard full of telehandlers of various makes that were brought in from auctions. We have 2 or 3 that we use regularly, but this is the only JCB. So I can't make any meaningful comparisons of their workings.

Oh, and no, I don't know what trans is in it yet either. It was a fast service call.

JCB 530 - No Reverse

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