03 LB7 Starter freespins

[R_F_F]

I have a 2003 GMC Sierra LB7 Allison 4x4 118k miles

I was having problem that about every 10-30th start the starter would freespin. Turn the key off and back on and it would almost always fire right up. More often when cold and damp. And was becoming more frequently.

Replaced it with a reman AC Delco. New starter turns engine over much better.. But free spins more frequently. And almost always does it a second, even third time.

I've searched and searched and found many people with this problem, and no people with a solution. Many say they've replaced flexplate and tried different starters and still same problem. If its the flex plate why would it spin then grab just fine the second try? I will replace the flexplate but I don't want to go through all the time to do it if its not going to fix it.

Has anyone ever found a solution? I want to fix it but don't want to spend more money and time on parts that wont fix it.

Thanks a lot!
Stephen

 

[JoshH]

Unless you have some teeth missing from your flywheel (which is unlikely), you have a problem with your starter.

 

[R_F_F]

I know new parts arent always good parts, but why would old and new have same problem? And if teeth are missing, why does it freespin without turning engine and then the next try turn over like nothings wrong? Just really confusing and frustraiting. :S

I guess I'll try to get a chance tomorrow to try it till it spins, then pull the starter out and look at the flywheel in that area...

 

[seth999]

Take the new starter to a starter shop and have them check it sounds like its not lined up right somehow or more likely just spinning in place not engaging

 

[S Phinney]

If the bolts have loosened up on the starter it will do that also. I have one that has done that two times now.

 

[maxaholic]

I had the same problem with my '06 zf6 truck. I know it's gonna be like comparing apples to oranges but maybe it will help. When I put my first dual disc clutch in the ring gear grove was cut just a little to deep. About a 1/16" to deep. It was fine for about 3 months until it started doing the exact same thing you are talking about. It didn't bother me until it got to doing it more and more often. So I changed the starter and it kept doing it. Finally made the call to Valair and Dan had me come up so we change the flywheel and refresh the clutch. We measured new against old and found the depth difference immediately. I don't know how well this applies to an Allison flywheel but I figured it might help.

 

[Vrabel]

a bad ground may be enough to spin starter, but not enough to power up electromagnet for starter drive to engage.

 

[WTF]

I had that happen once then the starter bolts broke if it was me I would check the whole flexplate over and test the starter and check the silanoide and kick out

 

[jheyob]

I had this exact problem on my lb7.........

Went through 5 different reman starters and a flexplate before I gave in and bought the Isuzu reman from the dealer. The Isuzu reman has yet to act up. All the others I could get to grind after 20-30 cranks. You get what you pay for.

 

[R_F_F]

Well I bought an AC Delco thinking you get what you pay for. Apparently I need the Isuzu reman though? Is that the $800 one the dealer sells? Whatever it takes to fix. Like I said I don't mind putting a flywheel or whatever in it. But I don't want to do anything that isn't required.

Load tested both batteries individually both tested excellent.

Ran a jumper cable from starter body to frame and from the positive post of the starter to positive terminal. Same story. Then I took the cable from the frame and put it directly to the negative side of the battery to elliminate a bad ground from the batteries to the truck. Same story.

Of all the posts I've read online, the only ones that really seem to come back and say it's fixed are the ones who bought the Isuzu one. Would you guys agree that is probably the way to go?

The teeth on the starter looked fine and what I could see of the flywheel looked fine. I may try starting it till it acts up today then pull the starter and look at the flywheel in that spot.

Thanks for all your help guys!

 

[duramaxdiesel]

I thought the OEM starter on our trucks were made by Hitachi??

Nick

 

[R_F_F]

Checked with the Chevrolet dealer today and they have a starter part number 97779551 for $619.96. Do any of you guys who bought a starter that worked from the dealer have your reciept so you could check the part number for me? They had a couple different options want to make sure it's the right one.

Starter that's on the truck right now is AC Delco 336-1737A.

Thanks guys. -Stephen

 

[JoshH]

I bought a reman starter from CarQuest Auto Parts and have not had one single problem in 3 years and 40k miles. I think it cost me in the neighborhood of $200.

 

[Ian J]

I actully need about 6 starters for heap of motors I have over here and was wondering which ones to go for as you can get some pretty cheap ones but being a AutoSparky theres some shit made too and in a lot of the time OEM manufacture is the best way to go but had no experience in the Dmax starters so would be good to know whats good and whats not:spit:

 

[jheyob]

Mine was $350 with a discount I'm sure so idk what it should have been. It might have originally been made by hitachi but it had a couple tags on it saying isuzu reman

 

[Durascrap02]

my lb7 did the same thing when i got it so i replaced the starter with a hitachi, same thing after that it randomly free spins now

 

[R_F_F]

Mine was $350 with a discount I'm sure so idk what it should have been. It might have originally been made by hitachi but it had a couple tags on it saying isuzu reman

Where did you get yours?

 

[R_F_F]

Started and shut off truck till it did the spin thing twice. Pulled starter off to exchange for new one (hopefully) flexplate looks good. Although, how deep is the starter supposed to go? Looks like its only using half (at most)the depth of the flexplate teeth (shiny) One tooth on starter is chipped.

Hopefully they will exchange it.. And hopefully the new one works! :thumb:

 

[jheyob]

Where did you get yours?

Dealer

 

[R_F_F]

New starter on that they exchanged.. Works better but still not fixed. I didn't have high hopes when I opened the box and saw "remanufactured in china" (first one was mexico) I asked if she had anything made here and she said she could get one but it would take a week and it was more money. I don't know why I didn't think to ask that in the first place.. Guess I think everything should be made here and shouldn't have to ask specifically..

Turned engine by hand to look at the flywheel.. A few places more worn than others.. But no broken or smashed teeth. Guess there's a remanned Isuzu calling my name!