I watched the voltmeter gauge closely in my RT60S crane. I have noticed that the battery, with the engine at idle, only has 12.5 or so volts. If I rev the engine up, then voltage goes up to respectable 13.5 volts. So, as it is, the crane does not charge the batteries very well. I had a similar situation with my 30,000 lbs forklift a while ago, the only way I could resolve it was by making a custom smaller diameter pulley to speed up the alternator. I made it on my lathe. Here, I am wondering "what is normal" and whether a change of alternator could improve the charging situation. I do happen to have a spare rebuilt alternator, so cost wise it would not amount to much money. Any comments? Is it normal to not charge at idle? thanks
I would load test the batteries first off.
If you have an aftermarket alternator installed or if the belts have been reorganized, you are probably on the right path with under speed. My father owned a NAPA for over 40 years and would see equipment replacement alternators that would need a min engine speed anywhere from 900-1200 engine rpm to start charging which is above most idle speeds. He would keep small v belt pullys in stock or in you case, just make one. But grandpa is right, I would charge up the battery's (if I remember correctly, 12.5 v is around 85-90% charged), load test them, recharge them if they test ok and see if that makes a difference, some alternators require a good feedback voltage from the battery to charge. Also 13.5 volts is on the low end of ok if the batterys are not fully charged, it should be around mid 14s right after starting and slowly go down to 13s after the battery are charged, so may want to test the alternator also.
Check for a voltage drop between the alternator and the battery. Positive and negative sides. If my brain is still working right I believe it is a 0.5 volt drop max over the whole charge circuit. (somebody chip in here if I'm wrong please) If your not sure what I am talking about check out this link http://www.fluke.com/fluke/uses/com...articlecategories/electrical/diagnosevoltdrop It gives you a good idea of what to look for. I would clean up ALL the connections between the alternator and the battery and all the grounds. It doesn't take much to make things not work right. Run a resistance check on your wires, there might be some corrosion in the system Check to see what the voltage is right at the alternator Also, is your gauge reading properly. Is this a new problem or has it been coming on for some time. If machine was charging fine before, I see no reason why you would need to change up the pulley. Honestly, a new pulley would be about my last option, not saying it doesn't happen, but in 40 years of pulling wrenches I have only had one series of engine where I had to resize the alternator pulley. Dimes gets you doughnuts it is a wiring problem
OK, about batteries: I know for a fact that they are in very poor condition. They are two 4D's and replacing them is not cheap. I did buy, recently, a solar battery maintainer by PulseTech. It may be that at low speed, alternator was making electricity, and charging partially discharged batteries, but just not enough to raise the system voltage. I hate 4D batteries and am thinking about replacing them with two or three Group 31's.
I've seen lots of equipment like that. As long as it's charging it works. Make sure your batteries are fully charged and roll with it.
Also, check the specified engine idle speed. Works both ways, some people will turn the idle down a bit for smoother transmission engagements, better low speed control on hydraulics, etc., but lose the charge at idle. I "repaired" one loader that after the engine warmed up, the reverser refused to go into gear. After a bit of twenty questions I learned the owner had turned the idle up a bit because the generator (yep, old iron) was not charging well at idle. Dropped the idle by a hundred rpm and the transmission was magically healed. Go figure.
But, making a smaller pulley would be pretty ideal, as long as it is not so small as to trash the belt, no?
Depends, if your wiring has too much voltage drop you're only going to put off fixing it for a little bit, and maybe start a fire in the meantime. If you have bad batteries, it will by you some time. If the problem is that it runs for only a short time and at idle, and/or there is drain while running, then the smaller pulley should help. The low voltage at idle is not normal, it should be easy to fix without a new pulley. Is this a one wire alternator? Have you checked the amps at idle, and the voltage at the alternator?
Could be you've lost one winding out of the three typically used, is the alternator heating up?
OK, a little update. I bought two brand new 4D 12V batteries. I also added a solargizer solar charger to them so that they get slowly recharged from the sun and de-sulfated. (highly recommended on rarely used equipment) Ran the crane. It does, of course, start very easily in summer with new batteries. When I ran the crane, I realized that the alternator does not charge at all, neither at idle, nor at higher engine speed. No matter, I have a replacement alternator laying around and I will put it in when I open up the engine cover. It needs some additional work: - Alternator - Flexible exhaust tubing - Engine is leaking oil from the top cover and I have a replacement, I will replace it. Another question: this crane has a manual parking brake cable lever. (in additional to air parking brake) Does anyone know how it works exactly? Is that a brake on transmission?
Manual cable would be your swing brake.
I also thought so. But I read my manual and on page 45 it says it is a mechanical parking brake: http://igor.chudov.com/manuals/Grove-Rough-Terrain-Crane/Grove-RT60S-Operators-Handbook.pdf
I've never seen or heard of that. Seems like it would have to be hyd or air controlled to get it through the swivel.
Near as I can tell, if it's a 60S it should have air parking brake only, if it's a 60 it should have mechanical break over lever to the left of the seat for park brake only. I don't see any model that has both? Swing lock is a lever to the right of the seat next to the hand throttle? Pictures? LOL
I've seen cables run through the center of a swivel, with a mechanical swivel, not sure about these machines though.
pictures of parking brake?