Caterpillar Transmission

Hi, I was wondering if anyone had any ideas about what is causing us a headache, our Cat TH62 when you put the shuttle either in forward or reverse it occasionally won't do anything but when you change gear usually when you select 2nd or 4th it will go with a little jolt and will work ok whether you change gear afterwards be it 1st, 2nd, 3rd or 4th and may not do it again for a while even moving between forward and reverse but then it will. sometimes it will go after a few seconds and sometimes if you switch between forward, neutral and reverse.

As such myself and an engineer that i spoke with over here thought it sounded like the shuttle lever itself was the culprit especially as the reverse light seems to stay on all the time be it in reverse or not but today my dad made me question if it was that as he seemed to think that it played up more when it got hot and when he left it for a bit it would act up a lot less but I'm not sure if that is because he turned the handler off most of the times he waited and whether that has a bearing on it. It just has me stumped.

Very likely the issue of failing to select gears correctly and the reverse light not going off could be related to each other. Does the backup alarm function work correctly..?

If you want the Electrical Schematic then send me a PM with your e-mail address and the machine Serial Number. There are 2 possible S/N prefixes (4TM & 3LN) and a number of separate groups within each S/N prefix, so lot's of chances to get it wrong by guessing.

I tried it this morning and the alarm didn't work after I reconnected it as we disconnect it during lambing due the fact it sounds like a foghorn and with our neighbours right next to the yard and us working late I was threatened with strangulation by the boss of our family (she makes Marlon Brando look like a little toddler).

I noticed this morning before taking the radiator off to get it recored due to the wonder of the reoccurring piddley leak that although I didn't think it made any difference what temperature it was running at occasionally when you had it in first and either in forward or reverse it would move really slowly like when you have it running at idle and take your foot of the brake on the flat but wouldn't actually go if you changed gear or came to slope or bump until you got it to actually fully go into gear.

Looking at the schematic I sent to you the backup alarm and the reverse light are both supplied using the 321 Brown wire from the transmission control. If the reverse lights stay on that would appear to indicate that the micro switch inside the control that energizes wire 321 must be staying closed even if you are not in reverse. Another indication that the control might be dodgy. At the risk of upsetting SWMBO I suggest you do a brief test and see whether or not the backup alarm stays on all the time when the reversing lights are on - it should. That would be the clincher. Basically if the transmission control thinks you are in reverse and you are wanting to go forward it's going to end up totally confused.

Be warned if the (non-serviceable) speed/direction control is bad it's not a cheap fix. I'm showing a price of about £365............and TBH I doubt if you would get one from Finning for that.
I'm not saying you can't disassemble the control, just that even if you do and find something broken there are no spare parts available for it, it's a new control or nothing.

our TH460B had similar issues. A little more basic. sometimes it would not engage at all.

turning the machine on and off a couple of time and it would then work.

it finally went kaput.

turned out to be in the ECM/Trans control module. About a $4000 fix including the service call to the job site.

Hi,

I have a very similar problem with my CAT TH330b.

Originally the forklift would sometimes not find forth gear and the machine would default to neutral. Now 50% of the time, when I go to use the forklift the shuttle will not work at all in any gear. The rear reversing beeper does come on but the machine will not move.

I removed the shuttle lever but it seems like it only has 4 or 5 wires which is not enough for power, earth, gear1/2/3/4 and forward and back so I'm guessing it may use some "clever" electronics to send info to the ECM??

I was thinking about buying one of these diagnosing machines to see what the status of the lever is when the machine is on.

http://www.aliexpress.com/item/nexi...62,searchweb201560_6,searchweb1451318400_6149

A new lever is over £700 and a second hand one is £300. yikes..

If you're any good with electrics post the Serial Number and ask someone to send you the electrical schematic. In the case of the OP of this thread it was found that the directional shift control lever was faulty. You can troubleshoot the lever with no more than a digital multimeter if you have the schematic.

Even considering the price (remember the Cat logo on the box is worth a fortune in itself) I would not buy a used one of unknown provenance myself.