84 K20 breaks starter/ Missing brace?

Buddha.

Lurker
This is our not road worthy beater plow truck. Starter was cracked last year, replaced it. Now I see it keeps coming loose, that's probably why it cracked. I replaced the starter bolts and fingers crossed that helps. I remember some of these old trucks had a starter brace but it doesn't look like I have any place to mount one on this rig. I do see that something is missing that used to be bolted to the torque converter cover(pic attached). I remember some of these trucks had long rod-like braces that went to... something. What was bolted here, and is the lack of it causing my starter problems?7C9D368F-801E-4B68-90C2-46FE50D9A697.jpeg
 

vargsmetal

Active member
My 90 had those braces. They went up to the engine block. Guessing it was to prevent the transmission case cracking with the extra weight of the transfer case on a 4wd.

The bolts could be backing out because the threads are dirty. They feel tight because they're binding up but with vibration they back out. Try cleaning the bolts and the holes in the block next time you have them out.

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shortbus4x4

Expedition Leader
Those bolts on the torque converter cover went up to the block or engine mounts, if I remember correctly, it has been a few years since I've done one. Your old starter bolts might have had the knurling on them worn off which could cause your bolts to back out. I think the starter brace was only on the diesels and big blocks but again it's been a few years since I've worked on these.
 

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NatersXJ6

Explorer
Those bolts hold braces to the engine mounts. A breaking starter probably begins when you aren’t properly shimmed, greasy bolts without clean holes, then you overtighten to get it to stay tight; beginning to crush the nose cone, which just takes you down a spiral of overtorque and crush plus kickback from the flywheel loosening it more.

IMHO, get a lightweight gear drive starter, shim it well, and your issues will go away.
 

Buddha.

Lurker
It's already grinding again, I've only started it twice. I Guess I'll pull out the bolts and clean them up. Maybe locktite?
 

NatersXJ6

Explorer
It's already grinding again, I've only started it twice. I Guess I'll pull out the bolts and clean them up. Maybe locktite?
What condition is your ring gear in? Did you shim the starter for proper clearance?

I’ve fought some of these seemingly for years before getting them right. Once you get the right nose cone and shim combo, never let it go.

Sometimes replacing the flex plate and ring gear can make a big difference. Is your flex plate cracked or cracking?
 

Buddha.

Lurker
It didn’t have shims in it before so I didn’t think it needed any.
Not sure about the flex plate.
 

Buddha.

Lurker
I took the starter off to get a good look at it and clean it up along with the bolts. Didn’t see any cracks, I was just about to put it back together and saw there was a crack that I missed. I didn’t realize the cast aluminum is that thin at the bolt hole. This is not where it cracked last time, I assume this cracked from me torking down on it too hard but I’m not sure.
 

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Buddha.

Lurker
Well the hits just keep coming. Engine block is cracked at the starter mount bolts.
Did the cracked block cause the starters to crack or was it the other way around? Or was it just worn out bolts?

Plan of attack now is to just keep putting free starters in it.
 

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NatersXJ6

Explorer
Sort of chicken/egg mystery in my experience. Either one can cause the other.

I think you’re completely screwed. The free starter plan won’t work well as that crack gets worse and eventually you are running one bolt starters.

I had a 78 eating so many starters when I was a kid that I actually made a plug-in harness for them so I could change faster.

Then so learned how to shim them properly and never had another problem.

Anytime you change the nose cone you need to check the shimming.

I also highly recommend the lightweight gear reduction starter...

And maybe something to try and fix that block crack?

Or a manual trans and do lots of clutch-dump starts? It makes finding parking into a fun new game.... where is a hill?
 

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Buddha.

Lurker
This may be the bracket you were looking for. Not sure that it would help the cracked block at the bolt hole though. GM Part #3965588
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.
 

Ocdfisher

Member
Depending on what size flywheel you are using, you could switch to the other style starter mount ( straight or diagonal mounting pattern. I had to drll and tap a new hole in a sbc block and swith to the other mounting pattern. Google difference in straight or diagonal starter mount. Good luck
 
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