I am having starter issues on this machine (an early D3 Cat Mitsubishi) and have pulled the starter to get it looked at. Strange as I got it off and found the starter was sealed up with some silicone to the flywheel housing and also found the flywheel housing is full of gear lube or oil. I called my Cat parts man and he says there is a paper gasket for the starter so I gusee the starter drive and flywheel are wet? Anybody know anything about this because I have never seen a wet starter drive and flywheel housing on anything I've ever worked on. Oh yeah the starter seems to hang up and also spins loose at times. Hanging up means it will keep cranking after I turn the key and let it loose and will contiue to crank until I finally have to pull the battery cables off or the battery goes to nothing and the cables start cooking, not the best thing I can say for sure. I already had it rebuilt a week or so ago so now I am taking it back as something is not right. It will also crank the engine over a revolution or so and completely go dead at times. My battery is good and keeps up above 10 volts while cranking (12 volt system) Thanks for any help.
Sounds like you have some electrical problems, maybe a sticking relay or solenoid. There are several Cat machines with a wet convertor housing, and they use a scavenge pump to pull the oil from the convertor housing back into the tranny.
Well, this one's kinda tricky. Yes, there's been a lot of "wet" convertor housings out there. Most of the time, it's a design to lubricate bearings of pumps and shafts that drive off of convertor gear. The oil usually comes from transmission sump. The starter does use a paper gasket to seal where it bolts to housing, unless your fond of using Silicone, which I'm not. Also, it has to be a sealed starter for wet housings, or you'll get oil inside your starter. As for the starter staying engaged, that's the tricky part. Just because you've had starter rebuilt is no guaranty that it's a good starter. You could also have a rough flywheel ring gear that won't let go of the starter drive gear when it's engaged. It could also have the wrong drive gear on it from some repair in the past. I've seen that before. The starter would have a 10 tooth drive gear when in fact it was supposed to have a 9 tooth. Other things that could cause the problem are a faulty ignition switch or a starter relay sticks. Not easy to determine what's the problem with this one.
I'll just add , make sure you use a gasket when you put it back . A gasket between metal parts not only seals , but acts like a clutch plate between a flywheel and pressure plate . A truck axle or diff center etc. insalled using Silicone alone can work loose , they need the friction that a gasket provides . Your problem must be electrical and not mechanical as pulling a lead will let the starter disengage . I would say it is a bad solenoid , sometimes they will click but not make a contact accross the Copper bolts in the cap which will make it spin but not engage . Other times it may stick to the Copper bolts in the cap , engage and then keep on spinning . Was the solenoid looked at or replaced when the starter was rebuilt ?
I'm right there with you. If it uses a gasket...it get's a gasket. Silicone is something I use rarely and sparingly. I don't disagree that the starter problem is most likely an electrical problem. But you can't say it's "not mechanical as pulling a lead will let it disengage", for this reason; if it's a starter that when the solenoid is engaged and contacts the conductor plate to power starter motor, at the same time the solenoid moves a lever that engages the drive gear into the flywheel ring gear. If that ring gear "hangs onto" the drive gear, it is still holding the conductor plate engaged in the solenoid via the drive engagement lever. That thing will keep turning until you take away the power driving the starter motor. It's normally an electrical problem, I'm just advising chasman of the number of possible problems.
I'm sorry if that sounded like i was saying your post was wrong , i did not mean it that way . I was just airing my thoughts on what it might be .
Whoa Iron Horse, I did not take that you implied my post was wrong, or for that matter, your post was incorrect, I will not challenge a senoir member in that way. I, as a mechanic, am all about accurate information to persons having problems. I don't claim to know everything, but I try with due dilligence to learn all I can about everything and pass on that knowledge to others. That's why I enjoy being alive and breathing, it's a blast!
Wet Case's ... Very Common. Try Jumping the starter by hand and take it from there. If the starter has No Ground lead then it's Bolted to a dry case.
Thanks for all the ideas and keep it coming. I see that they did replace the solenoid and I had them bench test it before I picked it up and it seemed to work fine except for exploding the first time they cranked it. It made a pretty good bang so they pulled the endcap off and some smoke came out. They said it was the paint fumes from respraying the internals as it was pretty rusted up inside, the endcap of the motor housing is what they repainted from what I saw. This is a decent shop that I have used before but more and more lately I try to get away from rebuilds as I've had problems in the past, just not sure how much a new starter would run me for this machine. I've bought a few new Delco knock off Chinese starters for bigger Cat 3304's and 3306's and have decent luck with them and they are cheap but hven't looked for the Mitsubishi starter as of yet. There is something else strange about this starter as it looks to have some sorta wire feeding the motor windings that feeds from the solenoid start signal terminal wire. But, whenever the stater motor cranks it feeds 12 volts back up to the solenoid for some reason which makes me think that is what is making it stay engaged? I was told it gives the motor a boost and when I disconnected it the starter seemed to act normal, would'nt hang up like before. It is backfeeding into the solenoid in other words. Am I making any sense? Sorry to be so long winded here....
Ive heard some wild stories from guys trying to cover their butts , but never exploding paint inside a starter......I think they have stuffed up . Why don't you try it for a while with that wire off ?
I can't help it, I'm getting a pretty good chuckle out of an exploding starter! I'd say those starter rebuilders about jumped out of their skin.
I do not recall D3's having a wet flywheel housing, but I never did much with the very early models. I agree with the bad solenoid option, or possibly a faulty ignition switch.
Yes something is not right with this starter. The wire I am talking about is external and goes to a terminal on the side of the starter motor. I disconnected it from the solenoid start terminal and it is getting 12 volts from the starter motor while it is cranking, doesn't make sense as that would keep the starter solenoid enegized as long as it would keep cranking. Maybe there is a bad diode in the starter motor? If I disconnect it the starter seems to behave as it should. I am gonna take it back to the rebuilder in the morning and see if they can sort it out. I am really not sure what to think about the explosion while bench testing, I do know it was not an everyday occurrence as pretty much the whole shop and a few office joes came out to the shop to see what the hell happened. LOL The main thing is I feel tons better knowing that the flywheel housing is apparently supposed to have oil in it, if not I'd have a huge job depressing job ahead of me. I've already had this thing in the shop for three months doing pretty much all that could be done to it and want it out ASAP.
Sounds like those guys at the starter shop had been huffing paint fumes.............
When you take that starter back to the starter shop, be sure and warn them "this starter could explode for no appearant reason!" :lmao
The starters on the D3's are Nipondenzo (spelling??). That seems to be a pretty good unit. As far as buying a rebuilt off of the shelf I found that I have been doing a whole lot better on both starter and alternator life since I have started taking everything to a smal owner operated rebuild shop where the Boss takes care of all of my units himself. That is where I learned the difference between a chinese knockoff solenoid and an American made Delco. The price of the Delco was $80.00 vs $42.00 for the knockoff. I lost a day of machine downtime between taking starter off, taking it in, getting it back on etc. Makes an $80.00 solenoid look pretty inexpensive here.
Well it looks as if they got it figured out for me, it had a bad field coil. Works like it should now. Need to figure out a bit of the starter wiring though as it looks like there are two solenoids, one on the starter (bendix) and another one before that, fired off the key switch I guess to get higher amperage juice to engage the bendix and feed the boost field on the starter motor. Now I am trying to get the alternator to charge, bought a new regulator and had the alternator rebuilt by the same fellas and guess what, it is not charging. I need to make sure it is wired correctly so does anybody know where I can get a wiring diagram for my machine? An early D379U? Thanks.
you got her right on the bloody nose there. two solenoids to make it go. Celebrate with one of these.:drinkup
I am also having a starter issue in our D3. Can someone tell me how you are supposed to get the starter out? I took the end cover off and oil came out of the starter. I don't believe this is supposed to happen. Any help on this would be greatly appreciated
Hi there, I just got through fixing my 931b with a densco starter, when i pulled it out oil came out, i was not expecting that. I had purchased a repair kit online. A friend told me to take it to a starter/ generator place in Falcon, NC. They installed the parts, cked the field and cleaned it up, all in one day and a friday to boot. I had removed it once to put the switch mag. one, so putting it back was easy the second time, with the help of a sling from the lift arm, in an out from the top. My problem was a draging starter, I had found a bad wire on the red wire coming out of the harness, had to run a new one. One celanoide you can take the plastic cap off and reverce the connector bolts, just turn them 180%, could make your connection better.
I don't think oil should come out of the front cap, the brushes are in there, 4, if you have oil there then the seals must need replaceing. I had the pans off the loader so it was easy to get to the bolts, a stuby box in 9/16 wrench with thin walls to get the bolt next to the frame, and a regular boxin to get the bolts loose. Good luck , sam
not sure if yours is the same type, but some of the later CAT starters have a multi-fit nose cone with x2 sets of bolt holes in the front (mounting) section of the starter which is held onto the body of the start motor with some cap head bolts fron the inside of the mounting face reward of the main mounting bolts (if that makes sense) don't have access to SIS @ home for a screen shot as there is another set of bolt holes in the front housing which arent used the oil leaks out past the case (no matter how much silicon you put in there) CAT stock a small round rubber ball "plug" p/n 3T-3434 which seal them up good (along with the paper gasket)
That was to funni...Willie.........
Starter
Ive delt with the same issue having starters rebuilt. I learned thru falure which shops were good and which ones wernt. Too often I pulled a rebuilt starter out I just put in and had to replace it. One shop comes to mind, going there over and over. Never again. Good luck with your issue, hope its an easy fix.
I have an earlier D3 also . The starter is a Bietch to get off , can't be done from the top om my machine , I have to drop the belly pan and there is one bolt thats almost impossible to remove without modifying a wrench. As for your alt. issue, I changed over to a Delco One wire unit . All you need is a hot wire from the battery and thats it, no more stupid regulators crapping out or wireing issues .