Starter Solenoid

[greywynd]

Here's the scoop. On occasion the dually has been sluggish turning over, crank a few seconds, the starter picks up speed, and then it'll fire. Look over the battery cable connections etc last night, they all seem good, no sign of cables overheating etc, grounds are clean, booster cables from battery to battery made no difference. I look at the connection at the solenoid, it's so-so, not dirty enough that it is jumping out as the culprit, but, enough that I decide to pull it apart to clean it. As I go to undo it, the plastic end on the starter solenoid tries to turn. I use a piece of wood to block it to prevent turning, take the cable off, clean it all up, and put it back on. I try starting it, and it turns over slower than before? Usually I leave the starter solenoids and starters themselves to an automotive electrical guy nearby, so I don't know what/how the connections are inside this thing. With it having spun like that, is it toast, or repairable, or what? Does it make sense that there could be a connection in the solenoid causing the lazy starter issue? Batteries are a matched set approx 14 months old, I put the charger on them to top them up just in case, and will check voltage in both before trying again (maybe later this evening). I don't have a load tester, or I would test them that way too, just in case a cell has puked, if it does turn out to be a battery issue, at least they are still under warranty.

[kenpobuck]

I would replace that solenoid myself. Also check the connection pionts at the fender. Make sure they are clean and tight as well.

[greywynd]

Yep, I cleaned the connections at the solenoid on the fender. I was hoping I would find an obvious poor spot, but no such luck.

[kenpobuck]

It could also be corrosion inside the cables themselves. Rupe just had that problem. Also check both grounds from the battery - post to the block.

[greywynd]

Yea, I was just thinking a bit ago that I could try an ohm meter from the cable end to cable end to see if they show an increased resistance. I should look to see what I have for spare cables, I know the one parts truck they are junk, but I may have a decent spare in my parts collection.

[kenpobuck]

I went to the upull it this morning to snag my core support and the truck I pulled it from had those cheap clamp on cable ends. I wonder how long those pos things lasted lol?

[Dave Sponaugle]

I actually find that the starter problems are usually the starter mounted solenoid, not the starter.
On a few I have seen the connection from the solenoid into the starter melt, which a new solenoid would not correct.

Those contacts in the solenoid do get cooked/pitted.
When you turned the post, now they are not making a great connection since the wear patterns on the contacts are not lining up.

But since I bought a lifetime warranty starter, changing the solenoid would void the warranty.
So when mine starts getting weak, I just get a new starter.

[poocher pup]

I agree with what dave said as my last starter problem was between the solenoid and starter motor itself.

[87crewdually]

This is actually Toyota but same principle. When you turn your key the electro-magnet pulls in the plunger of the solinoid which then has a disk that makes the contact for the starter motor. If the contacts are burnt or shifted the starter will drag as you describe.

[greywynd]

Okay, since I just had this rebuilt a couple years ago, I'll pull it off and see if I can throw a spare one on for a test. If that seems to help/fix the problem, I'll take it back to my rebuilder and get him to swap the solenoid. I didn't get a chance to do anything with it last night, so when I do get back to it, I'll also try checking the battery cables out too.

[greywynd]

So tonight I checked all the battery cables with an ohmmeter, from the negative terminal on each battery to the top of the AC compressor was 0 ohms, and from each positve terminal to the small wire on the fender solenoid was also 0. (This was with the positive cables disconnected from the batteries.) Dug out my spare starter, looks like it's quite possibly an original starter, filthy dirty, connections were rusty, mounting surface corroded and caked with a scale of some sort.

Cleaned it all up, and put the two side by side, and grabbed my booster cables to do some testing. The one I took off? It turned so slow you could hear the reduction gear teeth 'chattering'. The spare starter almost torqued itself off the bench! Tested the solenoid on the spare before putting it on, (nothing worse than getting something on and it not work!) and seemed ok.

Fought to get it back into position (wouldn't an extra 1/2" of room lengthwise be a whole lot nicer??) and got it bolted in. Hopped in the truck, let the glow plugs cycle a few seconds, and it fired right up!

So.... someday next week that starter will be going to visit the rebuilder again...... I do have to wonder if maybe there is something dragging in the gear reduction side though the way it sounds.

[Dave Sponaugle]

If you look at the two outer contacts in that picture you can see exactly where the problem is.

The contact on the left is worn so thin and only has a tiny bright spot that was actually making contact.

I bet that one was really dragging before the tear down.

[tjc transport]

i have found that when the starter speeds up as it cranks, that the starter itself is usually bad.

[greywynd]

Well, I don't know if it is the starter or the solenoid, I'll take it out to him one day this week and hang out while he tears it down to find out. What I do know is it's good to know that the cables etc are good still, and it's running again!

[elinmon1976]

I have seen those reduction gears sheared off or sometimes shattered all todether. It is rare, but then again I have built more than my share of these starters....