Help!!!, 2 New Starters, Both Not Engaging??

[aboyer]

I can't seem to figure out what is wrong. I recently had an issue with my stock starter on my '68 C-10, 350 engine. A couple of weeks ago, my starter decided not to engage into the flywheel. I assumed it was the starter solenoid and I purchased a replacement starter.

My replacement starter was a 3hp mini starter. When I installed it, it would not engage into the fly wheel. I thought I had a bad starter and returned this to the manufacture. I figured that I would go back to the OEM starter from Napa and this would solve the issue.

I have now installed the new Napa starter and it will not engage either. I adjusted the flywheel to insure that the gear could engage properly and I tested out the battery at Napa to insure it was good. The battery is 1 year old and they did a proper load test and it passed

I am out of ideas and hoping that someone can give me some additional things to look for. Please help!!!

Thanks,
Adam

[big_al_71]

It seems to me that you have not shimmed the starter correctly...thats the first thought that came to my mind.

[aboyer]

The previous OEM starter was never shimmed before. Do you think I still need to shim it?

Any helpful hints on shimming the starter would be appreciated.

[big_al_71]

the drive gear of the starter should mesh well with the ring gear but not so much as it binds. if your old starter had any shims it is usually a good idea to put them back. if your starter is binding in the ring gear put a shim in. if it is grinding and tearing up drive gears take a shim out

Agood rule of thumb, begin with a new starter, install. If the ring gear and the drive gear sound tight, add a shim and test. However, if grinding occurs and you notice you're tearing up your ring gear, you need to bring your starter closer, this is done by adding a 1/2 shim to the outboard bolt, good luck!

[kwmech]

153 or 168 tooth flywheel

[Sammy]

Originally Posted by kwmech

153 or 168 tooth flywheel

First make sure the starter provided is correct for the flywheel. If the starter does the whizzing sound with out engagement it could very well be the incorrect one.

[Camaro_nut2001]

Check your grounds. Body to engine and battery grounded good to the motor. I ran into this once and it wound up being the battery to engine ground. Hope this helps.

[camaney]

did you unscrew the cables at the battery terminals and clean it good? i had the same problem and thats how i got it fix

[tim21391]

did u cross the wires on starter?

[Kayotic]

Hum!

Sounds like what you are saying is that everything seems normal up to the point of not spinning the engine.

Like as if the starter has no umph. Wonder if testing it by removing the plugs for reduced compression would make a difference.

Does the starter still make a noise if you hold the key after it engages the flywheel (like maybe a buzzing sound followed by getting extremely hot)?

Anything not seem right as you turned it by hand?

[bhoeger70]

If the soleniod is moving the starter drive out but the starter is not spinning check your electrical connections.

[chipflyer]

If the soleniod is moving the starter drive out but the starter is not spinning check your electrical connections.

I agree, start with your ground cable, make sure where it grounds to the block it is clean and secure. You said you charged the battery and had it tested at NAPA but did they load test it? Pretty common for a sick battery to show over 12 Volts and drop to almost nothing when you try to start it.

[68C15]

you were working on the choke trying to get it to start, did this involve a bunch of cranking? then the thing stopped cranking right?
I would do a voltage drop test on both cables and all connections. I suspect one or both were marginal before but you may have killed them with extended cranking.

[piecesparts]

Everyone has some questions of merit here. Let's try to put those questions together.
1. Does the starter turn over when you hit the ignition switch? If not, then look at the battery and wiring for your answer.

2. IF NOT, does it turn over if you jump from the hot post on the solenoid to the smaller wire connection (On the solenoind itself)? That would be the solenoind magnet contact. Are you on the right mounting post? Once again--if it turns over, then you have an electrical connection problem. If it does NOT turn over or engage, then you have a starter problem.

3. To ensure that the starter is engageing properly, I pull the lower dust cover between the engine and the tranny, so that I can see the drive gear and the flexplate. I then move the drive gear into the flexplate for measurement of the gap. You want a gap equivalent of a LARGE paperclip wire between the drive gear tooth and valley of the flexplate gear. I take the solenoid off of the starter and manually engage the starter to do this, however there are othere ways to do it.

4. YES, you should check EVERY starter for engagement gap--there is differences in all starter housings---it is NOT nuclear quality stuff, here. The shims are ususally sent with a starter for that reason.

5. Back to the 153 tooth and 168 tooth flexplates---one requires an offset bolt pattern and the other uses a straight across pattern on the starter mounting holes. Many GM blocks have both holes available, so it would be easy to mess this up. You can count the teeth by marking the plate and rotating it slowly. The offset mounting profile is for the larger number of teeth plate.

6. It is truly possible that your battery cables will need updating if they are not making good contact. The heavier duty the better. You do not want any loss of voltage here, ity is hard on the starter.

[rsavage]

One other possibility. Do you have an auto or manual trans? If manual, does your starter bolt to the bell housing with 3 bolts rather than the block? If you had some difficulty bolting the new starters up to the bell housing (if it is that type) check to make sure it is not cocked slightly. Many of the rebuilt starters for have new cast noses installed on them and they are thicker than the original noses were. Consequently, the starter hits the inside slope of the cast iron bell housing, and if not noticed, the starter won't be in straight and will not mesh with ring gear correctly.

[aboyer]

I will be trying out some ideas tomorrow.

Just to answer some of the outstanding questions.

1. My cables are in fairly good condition and heavy gauge, but will check these over. The ground to the battery is located on the exhaust manifold.

2. The solenoid pushes out the gear drive, but doesn't rotate the flywheel. It basically shoots out of the starter and doesn't do anything additional, no whinning or attempt to crank. I did have the battery load tested at Napa and they used two different testers (passed both). I initially thought it would be a weak battery, as it seems it doesn't want to crank, but it tested out.

3. I currently don't have the starter shimmed, but I will look this area over again.

4. The terminals are clean, but I will wire brush these. I also have ground straps at:
--Engine block to firewall
--Cab to frame
--Radiator mount to frame
--Passenger wheel well to frame

Basically, I will take everyone's input and double check everything
--Shims
--Cables
--Connections

I will let you know how the testing goes tomorrow. Thanks for the input, keep it coming!!

[piecesparts]

Suggestion: Move the ground strap from the exhaust manifold to a point at the front of the engine block. The manifold is prone to rust and could provide for problems some day. If the starter is engaging, but not turning, then you do have current path from your battery, however the power is not getting to the starter motor contact. you may have a bad solenoid on your new starter.

[Wrenchbender Ret]

I would pull the starter back off & bench test it. Hook some jumper cables to a battery. Ground the neg to the starter. Touch the pos. to the terms. that come out of the starter & hook to the selinoid. The motor should spin. Then hook it to the bat cable post on the selinoid. Jump from the bat post to the small term marked S. The drive should come forward & the starter should spin. I'm wondering if the connection from the starter to the seliniod is not good.

[aboyer]

Well, the problem was solved...

From what I can tell, it was the shimming of the starter. I cleaned all the battery terminals and contacts to insure everything had a good contact. I then backed down the starter, away from the flywheel and basically bench tested the starter.

From there, I found out that the start is working correctly. I then placed both shims on the bolt locations and looked at how it messed together with the flywheel. Everything looked correct, tested out fine, fired up engine... Problem Solved.

Thanks for everyone's help on this. This is the beauty of forums, it is like having 1000's of car/truck nuts to bounce ideas and problems off of. Thanks again!

Adam