84 K20 breaks starter/ Missing brace?

[zoomad75]

I’ve actually got that exact same pic saved on my phone so I could get under the truck and compare. The truck I’m working on has that plug to the right of the mount but the raised section the mount is bolted to is completely absent.

Not to ask a stupid question, but do you have a small block in there or a 6.2 oil burner? I went back to the top to look and see if you mentioned it and didn't see anything posted. I assumed it was a SBC but the lack of the mounting boss for the bracket had me scratching my head.

 

[Buddha.]

Also this, but this is after cleaning it up. The grinding isn’t fresh and my flex plate looks tip top. Not sure what the story is here.

I guess I should mention that this truck has been on its last leg for ten years and is worth less than my boots. Just trying to get it through one more winter.

 

[Buddha.]

Not to ask a stupid question, but do you have a small block in there or a 6.2 oil burner? I went back to the top to look and see if you mentioned it and didn't see anything posted. I assumed it was a SBC but the lack of the mounting boss for the bracket had me scratching my head.

Its a small block Chevy. It’s an 86 truck and the engine is carbed. Definitely not the original engine.

 

[NatersXJ6]

View attachment 534785
Also this, but this is after cleaning it up. The grinding isn’t fresh and my flex plate looks tip top. Not sure what the story is here.

I guess I should mention that this truck has been on its last leg for ten years and is worth less than my boots. Just trying to get it through one more winter.

How long have you owned the truck? That had to be from a misaligned crank/blown out bearings or broken flex plate. Is your rear main simply pouring oil?

I’m guessing, you haven’t owned the truck more than 5-6 years. The previous owner wasted a flex plate, cracking the block in the process, they fixed and sold, and you, about 3 years ago began suffering mystery starter failures as they loosened and broke and that got you to here...

Am I close?

 

[Buddha.]

It doesn't leak much oil currently.
I guess it could have had some semi catastrophic engine failure and was put back in service with a cracked block at the starter bolts.

 

[zoomad75]

I had a 307 in my 69 Nova that over the period of a couple of years ate 6 or 7 starters. Went through all you've done. We shimmed the starter, even beveled the edge of the ring gear to de-burr the edge that the starters were chewing up. Even added the starter brace to the block. It would end up with the starter drive throwing the drive gear past the flex plate and it would hang up. I'd have to beat on the starter or get the crank to turn by turning the engine over by the fan belt. When it would go that way I'd get another starter and install it and it would work ok for a while. Ended up buying a lifetime warranty unit and used that warranty at least 3 times. I limped it through to the point of swapping the 307 for a 350 in college. Sure enough once we pulled that 307 out we found the problem. The flex plate had multiple cracks from the center hub radiating out. It allowed it to flex enough to allow the starter drive gear to be misaligned even with the proper gear to gear clearance. The 350 got a fresh flexplate when we put it in and it never ate a starter since. Surprisingly enough it did not crack the block where the bolts for the starter went in.

The problem is, the only way you are going to prove the flexplate is cracked is to yank the trans. You might be able to pull the cast inspection cover and look with a mirror/flashlight, but you can't get up around the hub and see very easy.

 

[zoomad75]

View attachment 534785
Also this, but this is after cleaning it up. The grinding isn’t fresh and my flex plate looks tip top. Not sure what the story is here.

I guess I should mention that this truck has been on its last leg for ten years and is worth less than my boots. Just trying to get it through one more winter.

I revise my last statement. Either the flexplate is cracked or the crank bolts are loose. There's no other way to have the flexplate grinding on the inside of that cover. That is worn pretty bad. That had to make some crazy racket when it was running.

 

[Buddha.]

I revise my last statement. Either the flexplate is cracked or the crank bolts are loose. There's no other way to have the flexplate grinding on the inside of that cover. That is worn pretty bad. That had to make some crazy racket when it was running.

I think those are old battle scars, my flex plate doesn’t have any wear on it to indicate it did this to that cast aluminum cover.

 

[Buliwyf]

We're still having starters fall off of brand new 5.0, 5.7, 3.0, and 8.8 GM's over here.

Same old same old. One bolt gets loose, then the other snaps. Drilling out the broken bolt is a nightmare with no room under the engine to work. Torque spec is ''finger tight''. So use thread lock and clean the bolts up real nice.

 

[Buddha.]

Yeah, I put the last starter on with greasy wore out starter bolts. Now that I know that's a problem hopefully I can keep a starter in it.

 

[Buddha.]

Alright, put it back together with clean bolts and a new starter. Also I threw a shim in it, seems quieter.

 

[Buddha.]

Broken again. Seems to be the drive/Bendix this time.
It does half a crank, the drive disengages/kicks out, you can hear the starter wind down to a stop like it's not driving the engine anymore.
Hopefully I can find the receipt for the old one.

I've read that too much timing causes kickback when starting and can break starters, maybe that's my problem. Also the block is still cracked where the starter bolts up.

Also it didn't have any shims with the last two starters, I added two when I added the most recently broken one.

 

[nitro_rat]

The better starters come with a stack of shims and a small rod to use as a gauge to set the gap. Gauge the starter against the flywheel in at least 3 places. If the gap isn't the same in all 3 places you have flexplate problems.

Don't forget to not only clean the starter and the bolts, get in there and clean up the ear on the block too. Use Loctite on the bolts after you get the shim stack correct.

 

[Buddha.]

Well I figured I’d update if anyone still cared.
Went the whole winter without any weirdness from the starter, also put a new battery in at the beginning of the winter. I think that was my problem.