Serious Delco starter problem
 

I put a reman Delco starter from Rock Auto on the 78 K5. It destroyed the flywheel gear. The old starter had done some slight damage but it " should have been ok". It did work for a while..

The reman starter was installed and shortly thereafter- severe flywheel gear damage.

Pulled the trans and flywheel and there was an odd damage pattern on the fly gear- damage at two different depths on the ring gear. No broken off teeth- the damage was angled and teeth ground down.

The reman starter was incorrectly assembled- shims had not been installed on the brush side of the reman starter so the armature shaft was free to slide in and out about 3/8 inch so when it slid back, the starter gear crashed into the the of the fly gear and destroyed the fly gear.

To check the starter, try pushing the spacer on the shaft back and forth- there shouldn't be more than a few 10 thousandth of an inch travel. It may be necessary to remove the solenoid (spring) to do the check.
Also the rear cover can be removed from the starter motor and shaft pushed forward then clearance between the back of the commutator and inside surface of the end cap ( or back of the motor case) measured.

R.A. may not know about this- it could just be a one- off failure but its a very, very bad one because that 465 trans and transfer case are HEAVY!

The crashing of the starter gear damaged the drive clutch. It turned roughly compared to a new one so at least it should be replaced with such a failure. The drive gear showed no signs of damage.

Another reman starter had a stack of 5 or 6 shim washers on the armature shaft- the defective one only had one.

K5 350 Starter disaster solved
 

Thanks to an incorrectly made Delco starter from Rock Auto, the flywheel gear was destroyed. Shims were not installed in the back of the armature and the shaft slid back and the drive gear crashed against the fly gear and destroyed it.

After 5 Delco and one racing starter from Summit, found a reman Delco thru GM that had the correct radial mesh. No shimming needed. The tooth clearance was very difficult to measure accurately with a wire gauge as it slipped around on the drive gear bevel instead of being between the teeth. 030". Used a torch tip cleaning set ( long grooved wires used to clean torch nozzles) to gauge clearance by inserting the wire back thru the teeth then sliding the wire across the teeth. The trick is to keep the wire aligned with the tooth crest.

None of the starters had anywhere near the correct axial alignment ( how far the drive gear extended towards the flywheel). They meshed about half way back into the fly gear and thats not good because there's only one tooth in mesh at a time.

The fix was to remove the front housing, remove the shim washers and spacer and wire ring then install the wire ring with the large black spacer backwards on the shaft between the wire ring and housing. This allowed the shaft to slide the ring toward the housing which allows the drive gear to pop out further. Then shims had to be added on the brush and of the armature shaft to compensate for the armature having been moved forward.

The drive gear assembly had the end of the drive gear teeth recessed. Changed it out with another 10MT drive gear assembly and that gained another 075" of mesh.

That resulted in the two gears meshing about 90% instead of about half.

It's SO quiet now! Cranked it with the trans tunnel out and could barely hear it. What they say about improper clearances causing noise is exactly right! It sounded like an old Chrysler before..

The racing starter was the worst- its gear extended a bit less than half way into the flywheel gear so it was returned to Summit.

The Delco starters are pathetic. They are poorly built. The one from GM had the stud on the end of the solenoid incorrectly installed ( stud that sends power to the motor). The one from GM had a new front housing and I assume thats why it didn't need shimming. It had a long solenoid on a short motor and no rubber gasket on the solenoid. It looks like whomever is assembling them has no idea what theyre doing, or they dont have correct parts.

Tried to post a pix of the modified Delco starter but the site won't work on Android. The upload page doesn't do anything.

Congrats. I'm sure you must have been pulling your hair out. Of all things to build so poorly; the starter!

Hair? Lol. It left as the flat spot on my forehead developed from beating it against the bench.

It's been a problem for years, I just didnt realize it as Id never owned Chevys. Chisler starters always had a whine so I didnt notice. But on the occasion of a wrecked flywheel, Id vowed to not put it back together till it was perfect. Too much work to change another flywheel gear!

So now this is the " permanent" starter and will have to be repaired when it quits. Fortunately this truck doesn't get many miles.

Well, " progress" might be a bit optimistic..

4 steps forward and 27 back ..

Update.

Reman Delco starter in and works perfectly.

Several tricks and details:

1. Delco starter # 323-255 GM 01876555 10 MT
2. MUCH easier to install and prove correct mesh with trans out.
3. Trans in this vehicle can be slid back without dropping it down. Made two angle steel pieces one bolted to each side of the frame, to set the crossmember ends down on then the whole trans and transfer case assembly slid back. The trans hits the floor pan but goes just far enough to clear the bellhouse for removal. The trans and transfer case assembly rested on the steel angles without needing to support the trans. 4 inch angle steel 2 feet long each.

4. The new starter appeared to have a new front housing. It was $140 ish. The other reman 10MT starters had different front housings. They were much less expensive.

5. The 10 MT diagram shows 28 different front housings. I assume all of them are not available today and that may be the reason for improper fit.

6. This starter came thru a GM dealer.

7. It had about the correct tooth to tooth clearance of about 030 inch. The original GM unit repair book for the 77 and the 10 MT says 020 clearance.

8 None of the other reman starters had anywhere near the correct engagement into the flywheel gear. They only engaged about half way and thats very bad as its a one tooth engagement drive.

9. The fix to give it full engagement was to remove the front housing and remove the drive gear and clutch and replace it with one without a protrusion on the front of the drive gear. I bought another drive gear assembly from a starter shop. Then the shim washers were removed and the black stop ring and wire clip were removed and reinstalled backwards. This allows the groove in the armature holding the ring is moved forward so that makes excessive clearance on the back of the armature at the end if the commutator which must be shimmed so the armature shaft wont slide back. I put nylon pieces on each end of the shaft for it to bear against.

The 10MT has a special washer that has a ridge that faces towards the end bearing. The ridge acts as a seal to keep debris out of the bearing. It was removed, hopefully the black ring will suffice.

After doing these mods the drive gear extended beyond the back of the flywheel gear slightly.

Moving the armature forward caused one brush to slightly hang over the end of the commutator. Should work OK.

10. The racing starter from Summit was the worst of all and no way to make it fit. Chinese crap.

11. The local Starter shop knew of tooth clearance problems and told me to just shim one side to tilt the starter in. Not acceptable. They also said incomplete depth of engagement was also common. So there's a supply problem.

12. The flywheel gear was ruined. DO NOT DO NOT use a torch to remove or install the gear as that will distort the parts. Cut a slot in a tooth root with a thin Dremel cutoff wheel then split the cut with a hammer and cold chisel. To install the new gear, heat it to 450 F in an oven for an hour and it just drops on the flywheel. This way the heat is even and there is no distortion in the gear.

13. Remove the solenoid before installing the starter to check the mesh. Be VERY careful that the drive gear doesnt slip forward and bind against the flywheel gear when installing the flywheel bolts. Then the solenoid plunger can be pushed with fingers to move the drive gear in and out.

14. Be VERY sure that the drive gear goes in and out of mesh with the flywheel gear and doesnt bind in the flywheel gear. So there are three critical things...tooth clearance, depth of engagement and lack of binding. It all must be right before reinstalling the transmission as its very difficult to work with it after the trans is in.

15. Avoid the in line bolt pattern as its less stable. The staggered pattern locates the drive gear in two directions.

16. Disassemble the back of the solenoid. That assembly wasnt put together correctly on my new starter. I remove the extra terminal thats there for the points ignition. Its useless and gets in the way of the battery cable.

17. Need more cranking power? Try a set of # 2 battery cables! I hand made a set. No voltage drop.

18. Loctite all the fastners especially the mounting bolts. I use medium strength and coat two threads.

19. There were two differences in truck starters- a rubber seal on the solenoid mounting surface and a SMALLER drive gear opening in the front housing to reduce the opening in which debris can enter. I dont off road so these are irrelevant to me.

20. The front housing could be milled to decrease the tooth mesh but on the other reman Delcos I saw, there wasn't much material there to mill off.

21. This starter has a threaded extension on the back of the case screw near the solenoid for a bracket from the starter to the engine block. My truck doesn't have the bracket and it works fine but it's also a low compression V8. For a high compression engine I'd install it.

22. Make sure to use the correct knurled bolts to mount the starter to the engine block. They help make correct alignment and strengthen the bolts.

Dave I am having the opposite issue. My starter gear is way too close to the flywheel and gets stuck and then grinds because it wont engage. I have the 4.3 Vortec 2005 Silverado. I have two shims on it with no luck. Do you think the GM original starter would work?

Terry


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4.3 Starter
 

I have no way of knowing, I cant see it.

Generally, the initial position of the starter drive gear (the one that meshes with the flywheel or pressure plate) is not determined by the starter.

Its determined by the Bendix (solenoid) . In my 350 starter, the solenoid plunger link is forced back on a spring to stop against the housing.

There should be a large clearance between the two gears when the drive gear is "out" so it cant fall in and crash- thats obvious.

The starter shimming wont have much effect on that clearance, the shims are thousandths of an inch

Youll just have to disassemble the starter and bendix to see whats happening- the Bendix plunger may be sticking or some foriegn object inside stopping it from pulling back.