Starter motor loosens recurrently - M1009 / Chevrolet Blazer K5 6,2 Diesel

[Elektroman99]

Dear Steel Soldier Community,

Starter motor loosens recurrently

The problem occurred after about 1 tank of gas.
The engine would not start because the starter drive gear was slipping on the flywheel, it was not engaging properly.

Analysis:
Both fixing screws were loose and the starter could be moved by hand with a play of 5 mm.
Action taken:
Screws tightened with ratchet, was enough for 2 starts.
Further measures:
Disassembled both screws one after the other, cleaned them completely and also cleaned threads in the engine block. Tightened with 30 Newtonmeter and secured with Lock Tide.

After another 4 starts, same problem.
Screws again cleaned and tightened with 40 Newtonmeter.
Interesting, front screw (screw towards cooler) loosens while tightening the rear. Distance to flywheel not checked.
2 starts, starter again completely loose.

OK, I found this video that explains the distance and how to check it, as well as the logical procedure with the shim washer.

I used a 1/8 inch Allen wrench. The measurement you want is .125 inch and that is same as 1/8 inch. A 1/8inch round drill bit would work also.

⅛-Zoll bzw 0.125 Zoll (= 3.2mm)

Now the question to the community:
What is the fault if the starter is tight for 1 to 2 starts, the starter pinion engages the flywheel cleanly and then comes loose? Now it sounds like the starter pinion is not engaging cleanly and spinning on the flywheel.

For general information, my M1009 did not have the rear support on the starter motor installed.
After a little research I now know it is the 28MT DELCO REDUCTION starter motor. ( Link to the corresponding YouTube video LINK )

What is the most expedient thing to do?
Please do not get me wrong. It's really frustrating to be afraid that the starter drive wheel will slip again on the flywheel every time you start the engine.

Please describe troubleshooting step by step and in plain English so I can minimize translation misunderstandings (errors).


Best regards
Elektroman99

 

[german m1008]

1. The starter support bracket is mounted?
2. Starter screws are intended for single use only…….. that means screwing it tight once ……and then you need new ones

 

[Elektroman99]

1. The starter support bracket is mounted?
-> No, my M1009 did not have the rear support on the starter motor.

 

[Barrman]

Get the support bracket and the proper new knurled starter bolts.

 

[Elektroman99]

Now be honest, do you think that's enough?


Just new retaining screws and the additional rear fastening?

Maybe one of the many experienced users can give me a simple step by step plan?
That would be a little easier for me.

I don't mean that in a "judgmental" way, but here is a specialist forum for exactly these vehicles and I think there are definitely one or two people who have a lot of experience with this and who may have had this exact error effect before.

The support bracket is ordered.

 

[german m1008]

………I didn’t want to react normally anymore….. Of course it could be something else, but that would be the first thing I would do…….someone must have played with or replaced the starter motor, otherwise the support bracket would not be missing………and I don't mean that in any disrespectful way………if they had as much knowledge as you………these may be the first mounting bolts after repeated use……….. sometimes things can be simple……. of course you can also wait for someone who tell‘s you……..
“you need a new engine anyway”

 

[Barrman]

Here is a video I made about the starters, the support bracket and the bolts:

 

[Sezzo]

German M1008 and Barrman are well experienced and they know what they are talking about. Do what they told you and never look back - your starter problem will be solved.

 

[Curtisje]

Yes Sir. The advice you have received is the correct course of action. 2 new bolts and the bracket should get your problem corrected.

I will add that the previous owner may have used a US bolt in the past, either too small or too large, which may have damaged the threads in the block.

I recommend that you clean up the threads with an M12 tap. When you do you will know if your threads are good or if you may need to repair them with a Helicoil kit.

Good luck!

 

[Elektroman99]

Guys...
I would like to thank you again for the answers and...
... apologize if some feel "offended" or personally "negatively" addressed, if I ask here so steadily and energetically.

So retaining screws are newly ordered and the support bracket also.
Probably I have to make then still something around to find the appropriate screws.

Now another question:
Do you have tips on how best to perform the assembly?
Disconnect batteries is clear, but from above I come - if I remember correctly - hardly to the starter, because the exhaust manifold is on the left side above.
Has anyone here made other experiences?

 

[gringeltaube]

I recommend that you clean up the threads with an M12 tap.

I'm sure you meant to say M10x1.5

 

[Barrman]

I do the entire procedure from underneath. I find it easier to unbolt the support bracket from the block with a 13 mm swivel joint socket. Then pull the two main starter to block bolts and set the starter on the font axle. Actually, balance the starter on the axle is a better description. Remove the two nuts that hold the wires on and then let it down to my chest to get out from under the truck.

 

[Elektroman99]

I do the [...] under the truck.

Thank you very much, yes, I had it already solved and then I was afraid that the wiring is not enough until I put the starter on the drive shaft. But I think it makes sense.
Now I just hope I can find the bolt hole in the engine block for the support bracket. I really have a little "respect" (fear) for it, but it has to work somehow.

So now I have the following To Do's:
- Wait until bolts, support bracket and additional inch bolts are here, then in the underground garage tighten the two bolts on the starter again.
- Hope that then the starter pinion grabs and then drive to my yard to remove the starter once, clean and then reinstall with support bracket and new bolts.

A question in the round:
How complicated is it to change the starter motor pinion (small gear). Some stores offer it and I'm thinking of changing it once I have the starter out then.



Best regards
Elektroman99

 

[cucvrus]

I affirm all the above actions. Without the starter support bracket in place, you are flirting with disaster. And not the kind Molly Hatchet sings about. I mean utter destruction of the fly wheel, starter and possibly the engine block. I saw where it twisted the starter and cracked/broke a chunk of the engine block mounting boss area. Not nice. I had one early on that I bought from DRMO and it was a low mileage M1028A1 with the starter hanging by the cable and trigger wire. I tried in vain to get the starter up there and ended up pulling the engine and taking it to a machine shop where they welded and repaired the block. It lasted 174K and I sold the truck after many years. But the issue was caused by an Army Mechanic not installing the starter support bracket. The ring gear was toast also. I would double check your ring gear before you call it fixed. It could have an area with a tooth or 2 missing or milled down. Easy to change now while you know it's bad. Or carry a 24MM socket and turn the engine when it is milling away and will not engage the starter. Good Luck. A standard direct drive starter support bracket can be cut and drilled to fit a gear reduction 28MT start and a small 3/4" by 3/4" steel angle can be V cut and welded and drilled to fit. Good Luck. I had a machine shop make me a few 20 years ago when GM discontinued the direct drive support brackets. It seemed like every truck I worked on was missing the support bracket. The Wild Weasel is missing the support bracket for now. Be Safe.

 

[Barrman]

The gear on the nose of the starter motor is often called “The Bendix” since I guess they made them at some point in time. They are relatively easy to change. There is a wire retaining clip that will drive you nuts removing and installing if you don’t have the special tool to do the job.

have you by chance looked at or downloaded the technical manuals for the CUCV vehicles? Most of your questions are answered in them. Especially, the -20. The separate HMMWV engine TM is excellent at explaining with pictures how to take a starter motor apart and put it back together.

 

[Elektroman99]

I have the document (TM9-2320-289-20) and yes it describes it. I just hope that I find the screws version on the engine and I have a screw that fits.

 

[WWRD99]

I have the document (TM9-2320-289-20) and yes it describes it. I just hope that I find the screws version on the engine and I have a screw that fits.

Are you looking for the bolt thread pitch and size that goes in the block for the starter brace? If I remember right it is a 8mm x 1.25 pitch 3/4 inch long.

Sent from my SM-S906U using Tapatalk

 

[cucvrus]

Are you looking for the bolt thread pitch and size that goes in the block for the starter brace? If I remember right it is a 8mm x 1.25 pitch 3/4 inch long.

Sent from my SM-S906U using Tapatalk

Now come on, if it is a metric bolt, it will be M8 x 1.25 x 19.1 mm you can mix metric with standard it will screw up everything. And believe me when I say I have seen many CUCV's directly from the military missing the starter support bracket and heat shield and they had 3/8" starter bolts holding the starter on, and they were all Code H vehicles and listed on the failures document was repeated starter problems.

 

[MarkM]

If you mix metric and sae bolts you are wondering if will screw up something?

 

[MarkM]

Sorry read it wrong. This is a confusing thread.

Mark