83 Datsun 720 1 remanufactured starter a month.

[Fadeawayfree]

I have a 83 manual 4x4 Datsun 720 z24 I'm in the process of daily driving. This truck will not stop eating starters. It had a carquest starter when I bought it (not OEM). I had to replace it in the previous owners driveway because it had given out on him. I have since replaced with a mix of AutoZone, O'Reilly's, Advance, and junkyard starters. None have lasted longer than a month and a half. I've finally settled on NAPA starters, because they keep replacing the halfass reman I bought from them 3 starters ago. Is there something I'm doing wrong? I've heard about shimming them, I've heard I need to find an original OEM direct drive Hitachi and rebuild it. But how do I know if I come across an OEM in a junkyard or a Reman OE Hitachi? The first starter I got from NAPA actually sounded good starting my truck, no grinding. It was reman but I can tell the Nissan rising sun logo used to be on the head before it got sandblasted off. Idk if it means it's an original head and it doesn't need to be shimmed because of the geometry. But it still burned out. I kept that starter just because it was the only one that felt and sounded healthy when it was working. Should I try to completely rebuild this starter with new brushes/solenoid/Bendix/and armature? Or should I just spend the money on a junkyard OEM starter and go for there?

[]2eDeYe]

Your flywheel teeth are probably worn.

[Fadeawayfree]

If that was the case wouldn't the starters just be free spinning? Or have there Bendixs chewed up?

[Crashtd420]

My first thought is maybe that starters are not the issue.... i daily drive my 521 and have never had to replace my starter in 7 years and it's a remanufactured unit from autozone.... 

(Side note,I did once after about 5 years but it was not my issue... )

 

Did they ever test the starters or did they just give you a new one?

 

When you say burned out how are you determining that? 

 

Have you examined or replaced the battery power and ground cables, and the starter cable,  even the start signal from the key?

[ggzilla]

What exactly are the symptoms? Do you mean the teeth are grinding?

13 hours ago, Fadeawayfree said:

This truck will not stop eating starters

[datzenmike]

Does it start normally? by normal, I mean withing 3-4 seconds? 

Does it need 3 or 4 restarts from stalling?

This could be an engine tuning problem that adds extra wear on the starter.

 

Good point on the battery cables and even the battery. If not supplying a full 12v to the starter, starts will be slower and the starter will get hotter faster. With nothing to compare it to, the engine may be spinning much slower than normal. Could be the battery is tired or charging system is failing. Check the battery posts and the cable clamps are clean and tight then check the ground connection on the engine. Have to assume the positive connection has been inspected monthly.

 

One last thing. Is the ignition fully returning to the RUN position after release from the START position? The key might be but is it electrically disconnected? I drove a cargo truck once and like everyone assumed the key returned to the run position when released. Drove it 50 miles with the starter engaged all the way home. Take the Black/Red stripe start wire off the starter solenoid and put a meter on it. Turn to start a dozen times. Does it turn on and off with each try?

[banzai510(hainz)]

when it so called eats starters.what is it doing? I had hard starter clicking at selinoid. Kept swapping starters till i put a hot start relay. Then works fine. But vatozone oriley starters barely last 2/3yrs on daily drivers. Look at flywheel as redeye said. Shim starter?never head of this on datsuns.

[ggzilla]

35 minutes ago, banzai510(hainz) said:

Shim starter?never head of this on datsuns.

right on. 'shim the starter' is what is done when a classic Chevy starter grinds against the flywheel teeth -- because it bolts below the flywheel, shims will space it further away. That technique doesn't apply to traditional Ford, Chrysler or Datsun starters

[banzai510(hainz)]

try a HOT start relays set up  maybe.

 

Did you have the stater retested back at the store? It might work there as there is no load

[datzenmike]

On an L series, the starter is in front of the ring gear teeth and the solenoid pushes the star gear back to engage the starter ring. Shimming would move the starter forward decreasing the starter gear engagement. 

 

I'm wondering how multiple starter gears can wear out yet not wear out the ring gear on the flywheel.

 

Need a picture of the flywheel teeth. If it's worn then the starters won't engage properly.

 

 

The flywheel ring gear is friction fitted to the flywheel by heating the ring gear to 400F in an oven to expand it and freezing the flywheel to shrink it. The two are joined and allowed to cool/warm. If this flywheel was ever off to be resurfaced at a machine shop or during a rebuild  and was dropped, the ring gear may very well have moved out of proper alignment. All FSMs say to never drop a flywheel and this is why.

[ggzilla]

If the engine starts when cool, and only has problems when hot (after driving for a while on a hot day), then a hot-start relay can help. Otherwise it just adds complexity to the system

 

There is already a relay in the Datsun starter -- an electro-mechanical relay. That Eric Diaz diagram adds a relay to the ignition switch circuit, and doesn't bypass the starter relay. With the added relay, a much smaller current goes through the ignition switch than normal and would help in cases where the ignition switch has worn/dirty contacts

Edited April 8 by ggzilla

[]2eDeYe]

On 4/7/2025 at 7:50 AM, Fadeawayfree said:

If that was the case wouldn't the starters just be free spinning? Or have there Bendixs chewed up?

 

No the starter will just wear it's gear faster from binding just enough to stop working. 


 

[ggzilla]

With bad teeth on the flywheel, it causes a grinding problem. A really terrible sound. @Fadeawayfree, is that what your symptom is?

 

Binding is an issue with GM starters that need more shims. Symptoms are slow cranking or whining while cranking. Or it can result in grinding if it's bad enough. I never understood why Chevy used shims, even from the factory. Couldn't they just have made the starter with precision machining? Even worse, rebuilders would reface the edge of the starter mounting boss, making the problem worse. Sometimes they reface it not square, basically turning the starter to junk. It was a huge problem that no one else had (except other GM brands)

 

In any case, if the flywheel teeth are bad, then when you get a new starter with good teeth, the flywheel teeth grind those down too. You can see the flywheel teeth when the starter is out (rotate the engine to inspect the teeth, it will be worn in four places). On some Datsuns, you can unbolt the transmission dust cover and see them without removing the starter

[Fadeawayfree]

On 4/7/2025 at 2:30 PM, datzenmike said:

Does it start normally? by normal, I mean withing 3-4 seconds? 

Does it need 3 or 4 restarts from stalling?

This could be an engine tuning problem that adds extra wear on the starter.

 

Good point on the battery cables and even the battery. If not supplying a full 12v to the starter, starts will be slower and the starter will get hotter faster. With nothing to compare it to, the engine may be spinning much slower than normal. Could be the battery is tired or charging system is failing. Check the battery posts and the cable clamps are clean and tight then check the ground connection on the engine. Have to assume the positive connection has been inspected monthly.

 

One last thing. Is the ignition fully returning to the RUN position after release from the START position? The key might be but is it electrically disconnected? I drove a cargo truck once and like everyone assumed the key returned to the run position when released. Drove it 50 miles with the starter engaged all the way home. Take the Black/Red stripe start wire off the starter solenoid and put a meter on it. Turn to start a dozen times. Does it turn on and off with each try?

I sure the tune is wrong, I've got a Weber 32/36 DGEV installed and it's had hard/long starts, 10mpg, and stalling issues even before the install. I'm almost positive it's a vacuum leak, probably a crack in the manifold. I can get it to idle okay but it bounces a little and takes too long to return to idle, then under load at idle it (turning in neutral in a parking lot, or braking hard and clutching in it chuggs and dies). I'll run a smoke test for the leak soon. When I take this starter out I'll remove the flywheel inspection plate and test the wiring and ignition/key switch, And update with pictures. 

[datzenmike]

10 MPG???? have you checked that the choke is fully off when warmed up??

 

Poor idle:

Check ignition timing.

Check valve lash.

Take EGR valve off an wire brush clean. It should be closed at idle but if deposits are preventing it closing it will idle poorly.

Confirm the intake and exhaust side plugs are firing.

 

Your description of 'eating the starter' is lacking in information. If a replacement works, what happens during that time of use?  and what happens when it is 'eaten'? Does it grind? does it fail to engage the flywheel? Does it turn slower? Does the solenoid just click?

 

 

Hard starting or prolonged cranking of the engine on starts is not the fault of the starter. If the engine turns with the starter it should start. Prolonged cranking with the starter will shorten it's life. No one does this but every 15-20 seconds of cranking leave an equal time to cool down.

 

If there is obvious clashing of gears, (grinding) that could be the starter or the starter ring gear worn.  

 

A vacuum leak would not hamper a cold start as the choke is on. It will hamper idle when warmed up as this makes the mixture lean.

 

 

If the starter engages and turns the engine every time the key is turned you don't need a 'hot start relay' That is for when the starter intermittently engages with the starter whirring away with no engine turning, and if the starter repeatedly just clicks and then engages. This is from a weak start signal from the ignition switch and happens weather the engine is hot or cold.  

[Fadeawayfree]

EGR is gone, block off plate and a gasket, ignition timing is 3° BTDC. The electric choke has no instructions for adjustment and I've tried to guess the best adjustment but it basically seems like it's not warming up all the way. It seems basically open all the time or halfway closed at running temp, depending on the "setting". Most of the starters sound crunchy and violent, not like a steady vroum vroum vroum. The starter that just died started slowing down and now just makes a click. Most of them have done this, just click and nothing else. Bang with a hammer and the work for a few more starts then back to NAPA.

[ggzilla]

That's the oldest problem in the book

1 hour ago, Fadeawayfree said:

just died started slowing down and now just makes a click. Most of them have done this, just click and nothing else. Bang with a hammer and the work for a few more starts then back to NAPA.

 

and there was just another article today, the #1 problem with new cars & gasoline engines: battery problems

 

Clean the battery terminals and cables. Even if they appear fine, scrape them to shiny metal, then treat with thin coating of grease, oil or battery terminal coating. Three Ratsuners confirmed just in the last month

 

Every time people replace the battery or starter, the cable are retightened and so work for a while. But if you clean the cables & terminals every 6 months you'll never have a problem

[datzenmike]

7 hours ago, Fadeawayfree said:

EGR is gone, block off plate and a gasket, ignition timing is 3° BTDC. The electric choke has no instructions for adjustment and I've tried to guess the best adjustment but it basically seems like it's not warming up all the way. It seems basically open all the time or halfway closed at running temp, depending on the "setting". Most of the starters sound crunchy and violent, not like a steady vroum vroum vroum. The starter that just died started slowing down and now just makes a click. Most of them have done this, just click and nothing else. Bang with a hammer and the work for a few more starts then back to NAPA.

 

 

Half open is usually where the choke settles when it's warmed by engine heat instead of the electric choke heater working properly. I would check that the electric choke heater is being supplied with 12v. When cold and you step on the gas I bet it snaps closed fully.

 

Because of how the choke heater relay is designed it only gets 12v when the engine is running.

 

 

[Fadeawayfree]

So I pulled the starter and I found out why it was clicking the head broke off in the bell housing. How does this happen?

[datzenmike]

Post some pictures and include the flywheel teeth. Maybe we'll see something that you might think is normal.

[ggzilla]

pictures tell a thousand words

[Fadeawayfree]

The valve lash was set too tight on the clearance that solved the stalling and mpg issues. I can't figure out how to upload a photo in the comments, do I have to make a new post to upload the pictures?

 

[ggzilla]

perhaps you have to make 7 posts before you are allowed to "add files" to a reply?