JCB 530 - No Reverse

Without the tcu it should be a pretty standard setup. 5 solenoids would be the most popular. There will be a forward solenoid and a reverse solenoid......then 3-4 other solenoids for your range speeds. It will take electrical power to a combination of specific solenoids to get the direction and the range selected by the shifter. If you can get the transmission make model and serial number of the transmission, I may be able to supply the solenoid diagram for you which will help in the troubleshooting.

I'll try to get that Monday. Would be nice to have that diagram. I'll probably have to give it a washdown just to locate the tag, if it's still on there. It's probably encoded in the SN, and if necessary I can call Shreveport, the nearest dealer and plead my case. Just never know how helpful the guys will be.

Is there an Operating Manual in the machine? It should tell you relay locations.

Pull the Reverse relay and test for voltage. If the test light doesn’t light up, it’s either the shifter switch on the column, or the wire between the shifter switch and the relay.

No, unfortunately there is not. Many of the machines we have come from auctions, where a lot of companies dispose of problem machines. Although cheap most of the time, some have serious issues. It's a rare thing to get much in the way of documentation, ops manuals or even rarer service manuals. I end up buying a few if if the repairs are going to be extensive or specialized.
I cannot at this time positively identify the specific relay for R. If I could, I could check for supply voltage as well as switching, plus swap relays from the F circuit. Those I can ID by finger touch while engaging the transmission, but since the R shift is completely unresponsive I cannot. There are about 10-12 relays in the panel. Not identified, of course.

https://www.servicemanualbit.com/
I found this website googling at work when I needed a manual for a Nissan forklift. Had my job buy them to make sure it wasn’t a scam. Purchased a few from this site so far and haven’t had any issues. We’re pretty cheap too.

Thanks Jeff. I bought the 530 manual for 15 bucks and downloaded it along with a supplement. Total of something like 1700 pages I believe. I appear to cover this model.

Holiday shipping slowed the parts coming in but I can check and verify the relays and a few other things before they get here now. I think I'll go to Kinko's or somewhere and get it printed and bound. And keep a copy on lappie as well of course.

The problem turned out rather elementary. One of the control solenoids on the transmission had come mostly unplugged, despite the retainer. It's awkward, and tough to access, but managed to do a wiggle test and found it. Plugged it all the way in and it's fixed. I don't know why the engineers didn't put an access panel on this machine so you could actually see these valves, but they didn't. Poor service thinking.

Apologies for the late update, but the book it closed on this one, for now. It has some leaking cylinders, but they are going to wait a bit. This machine is equipped with a 60" claw/grapple and the guys are unloading timber for two firewood processors. After the season dies down, then it will get some seal attention.

Thanks for all the help, guys!

Thanks for the update

And some guy probably unloaded that machine at an auction thinking it was going to need an expensive transmission overhaul.

Vetech63 said:

And some guy probably unloaded that machine at an auction thinking it was going to need an expensive transmission overhaul.

Click to expand...

Very likely the case. This is part of the auction game. As I recall, we got this machine rather cheap, so that seems like a reasonable explanation. The previous owner may not have had anyone capable of troubleshooting it or chose not to get someone who could, or perhaps if someone did have a look, either didn't find it or just told the guy it needed a new trans. Probably never know, but this was a zero parts cost fix, other than the F-N-R switch which did have some burned contacts that gave it erratic upshifts in forward, but that cost less than a hundred bucks and fixed what had been more of a nuisance than anything. The no reverse problem was not affected by that part replacement anyway. This one was nearly pure labor, and not really that much time.

skata The thing about fora in general is that when someone posts up a problem and everyone tries to help, one of the worst things (to me) is that the readers, for possibly years in the future, never know the results. Was it fixed? Which suggestion was the correct solution? How does the story end? I used to lurk a lot of fora on different topics, and when I searched for previously presented problems, finding hanging threads was always frustrating to me. Even if the story didn't have a happy ending, at least the readers should know what happened. Maybe the machine burned to the ground....but we'd never know unless it was a closed thread. I promise to try and never leave an open thread here, although it may happen despite my efforts. I'm only human, and have typically a dozen running projects, some spread out a good bit, time-wise. It's not like a shop where I can just start a repair and not do much else until that one is complete. I jump around a lot, and some of it is not even heavy machinery related. I worked on a cardboard baler last week. And not all are presented here as trouble assistance pleas, but there is a lot to keep up with and my memory isn't what it used to be.

But you're most welcome.