Engine/Transmission (1994 - 1998) My truck is cranking slow...

[dieselburner]

I replaced the batteries about 6 months ago because they were shot. Engine was cranking great with the new batteries. About 1 week ago, the engine started turning over real slow. I thought the new ones had gone bad already so I replaced them and I still have a slow cranking problem. I have 245K miles on this starter and it has had the Larry B contacts put into it at around 100K. I was going to check all of the cables this weekend. Any other ideas?

 

[CCiatteo]

Have the starter load tested? I had the starter on my truck act the same way. I also suspected that my redtop optima's had failed me, but they checked out fine. I pulled the starter had it bench tested and sure enough it was dead. If the grounds and other battery cables check out, I'd look at the starter.

Chris

 

[Vaughn MacKenzie]

Yep I think your starter is dying, happened to me too. There's been quite a few instances of this same scenario I've read about here on TDR, where a starter starts cranking slowly within a year of doing Larry B contacts then the starter dies. That's not to say there's a problem with the Larry B contacts, I think they're a great upgrade, but maybe the new contacts increase starting current which causes an aging starter to die more quickly.

 

[Cummins12V98]

98 12V 100k put in the Larry B contacts. About 300k the starter was turning slow, called Larry and had him ship a new factory starter with the large contacts installed. So at that rate I may be calling him at 600k!

 

[dieselburner]

Well I checked all of the cables and everything is tight and clean. Kicked on the aircraft landing lights which pull 100 amps and only measured a voltage differential of 2 millivolts between the negative post and the block on each battery so I know I have good grounds. Checked the positive wires also and the starter cable. All cables are good. I ordered a brand new Bosch starter for 203 dollars with free shipping from partstrain. They were list price of 660 something dollars. Should be here in a couple days.

 

[dieselburner]

Starter was here by 2pm. Less than 24 hours and free shipping. Looks great. 100% brand new Bosch.

 

[Cummins12V98]

Just curious, where is it made?

 

[dieselburner]

Don't know where Bosch builds there parts. Probably China like all others.

 

[Cummins12V98]

Thanks for the reply. I wish you luck, in my experience it is worth the extra money and get your factory starter professionally rebuilt or do like I did and buy a new Denso starter from Larry B with the big contacts installed. $300 for 300k is worth it to me.

 

[dieselburner]

I am going to pull the old one out today and replace it. After I am done, I am going to take the old one apart and check out the brushes. If thats all it needs, I'm going to swap them out and put the old starter in my boony box.

 

[dieselburner]

New starter works great! Top bolt was a pain though. :-laf

 

[surfbeetle]

Another option to a new starter...

I had the same issue in the past, did the Larry B contacts and then after quite a bit more miles, ended up just having the starter rebuilt by the company that services starters and alternators for my uncles repair shop. It was all of $100. 00 to have it rebuilt. As for the top bolt, you need a swivel socket or swivel adapter, 6 inch extension and a socket, piece of cake to get it out. The other option is to put in allen head bolts in place of the original bolts.

 

[ksoren24]

I bought a denso rebuild kit and had an electric motor shop rebuild mine. It works awesome but it still costed $200, but it should last as long as I have the truck. I found a denso rebuild kit on ebay for $50.

 

[JJanetka]

I put the denso kit in mine not long ago. The brushes were worn so bad I am surprised it turned over at all. Now I am back to firing up in what seems like one revolution. The kit was complete with bearings and wasn't difficult to install but you do have to solder the brush leads.