Hello to all. Not really sure if this is the place to post this, actually not really sure at all about anything because this is my first post but... oh well.

I've got an 02 Z06 with ~150k miles I picked up for 13k after my C4 was salvaged out when a BMW hit me pulling out across 3 lanes from a neighborhood, but I'll digress. My Z has always driven and performed well (aside from the steering lock shenanigans persisting despite a bypass kit install), though I admit I haven't driven it nearly as much as I should be. I've only done basic maintenance, sleuthing to the forums with common questions about silly things, and so far I've done oil, brakes, and a head unit with only a couple other tiny things. However, I bought the car suspecting at some point it would need a clutch, as it had enough miles and no evidence of a new one. I could guess that somewhere along the line one had been changed out, but I don't know how far it's been or if that's ever happened. So, I bought a clutch, slave cylinder, bearings, and easy bleeder in preparation for doing the work, all for around $700 at the time, and I haven't ever gotten around to it. Now I'm facing other problems and need the cash to go towards more proactive things (unfortunately my corvette isn't the most proactive thing I spend my money on), and I have decided to sell the whole car. I haven't yet listed the car but have slowly been mentally preparing to let it go, arranging all the spare parts I've purchased to go with it to whoever buys, since now I wasn't planning on doing any intense work. Two weeks ago, I went to start the car at a friend's house and heard the starter not engaging. We bump-started it and I went on my merry way, parking it in the garage for later as I had gotten busy. Finally, coming back to the car two days ago I tore at it, I dropped the exhaust and pulled the starter out. I bought a new ACDelco one that I'm hoping will last a while for the new owner. As I went to install it, I noticed this:

(the picture is not mine, but from a z28 forum where it looks EXACTLY THE SAME I just can't get a good picture on mine)
The mounting hole for the starter had cracked and snapped almost all the way. I picked the cracked piece off of the block:

Thankfully it stayed on until I found it while working on the starter. After doing some more sleuthing, I've determined that it is an uncommon, yet not unheard of failure and the fix involves welding the threaded part back onto the engine block (obviously), which requires the engine to be removed. This is super bad news for me, I'm just trying to get rid of the car at this point, hopefully getting some money back, and now I've stumbled upon a cracked block. I'm stressed, but upon some research on metal fixes I found that JB Weld (yes, I know most people think this is a terrible idea) has the potential to repair metal and hold with a pretty decent amount of strength. I found quite a few people with broken blocks at the starter mounting bolt hole on the forums, but almost all of them have ended with either no resolution (or at least none posted) or everyone yelling that it needs to be pulled out and welded. I know the repair should be done right in order to make sure it's safe and proper, and that it doesn't happen again (turns out the starter didn't go bad, the mounting holes just became misaligned when the bolt fell out and it couldn't engage the flywheel). However, I was still wondering if anyone used JB weld to repair their starter motor specifically, so I did some research and found this video on : where this guy uses JB weld on his Acura Integra starter motor to fix the mounting position. This case is a little different, because the repair is done on the starter motor mounting bracket and not the engine block, so the main solution here would involve buying a new starter, AND the engine is less than a third of the size so there's probably not as much force acting on the mount. I figure I could take the engine out, take it to a shop, and have them repair the mounting hole properly, probably not costing me very much since it's not too big of a crack and not in a structural location, and at the same time I repair the rear main seal (it's been a little leaky lately), with a flywheel resurfacing and clutch change and adding the new slave cylinder and bleeder. It would be even easier with the engine out of the car, and it would probably add more value to the car to have that much work done to it. However, the amount of work involved just to get it ready to sell seems kind of crazy to me, especially if I won't make back much on my investment, which leads me to considering alternatives in the first place.

I found one more example of someone with the same problem on a similar engine: Axle's Garage is a YouTube channel, and in one video series (split into and ) he solves it with a "band-aid fix" by first tightening the bolts as good as possible, adding a third mounting hole with a bracket for a "three bolt starter" that screws into the same bolt hole where the oil dipstick is bolted on, and shimming the starter temporarily to drive on it while it's still broken, only getting about 3 or 4 starts before it's out of alignment again. He then makes the "permanent" fix by purchasing a kit installing a mounting bracket that lies in between the engine and bell housing and provides a mounting space for a front-mounted starter.


The video linked to an Amazon listing that was no longer available, so searching myself I found two; one for $246.99 from Classic Industries and the other for $163.95 from Woody's Hot Rods. This Bracket is designed for vehicles utilizing a newer automatic transmission with the old 350 block design, newer being newer than the old SBC, as the new engines have a spot for the starter on the block while the old ones have it on the bell housing, so this allows a mounting solution when none are present. The starter is therefore different as well, using three bolts instead of two, yet I can see no reason for why it wouldn't hold up well so long as it is compatible with the gearing on the LS6 flywheel and fits without interfering with the engine. Axle's Garage linked to two starter options on Amazon, one advertised for the Bel Air and other pickup trucks for $115.53 and another remanufactured for $76.99. My only concern is that it will either be incompatible with my engine or transmission; so far everything I've read up says that the bolt pattern for a 350 bell housing and the ls is the exact same besides the fact that one bolt hole goes unused, so I'm more worried that the starter's new position using this mounting plate would interfere with the engine or exhaust manifold somehow. Anyways, ideally I don't have to buy a new starter and can just fix it with some JB weld, but I'm not sure about any of these options and that's kind of my main thing to be addressed here. What do you guys think? Am I wrong for even entertaining the idea of a cheaper fix to welding the block? Does anyone have experience with a transmission-mounted starter on an LS block engine or is there any information out there that I haven't found? My plan is to document this process so that in the (near certain) event of someone experiencing a similar scenario in the future they can see what mistakes I'm probably about to make. One more thing: If I JB weld the mounting hole then I'll try to see about adding a third mounting bolt like Axle's Garage did in the video, though I'm doubtful of a bolt location conveniently lying right where a bracket for a three bolt starter existing at all on my LS6. I'm thinking that first I'll try to JB weld repair it as dang nab near perfect as I can, prepping the surface and clamping down hard to get the piece as close and as tight as possible (the grain matches very well already, so I have a fair amount of faith in this working) and simultaneously adding the third mounting hole if possible, then if that doesn't work trying to find a solution with this starter engine plate. Finally if that doesn't work, I'll resort to plan C of taking the engine out and driving it to a professional to get it done right. My dad thinks that the JB weld is a mistake, because if it doesn't end up working and snaps off or breaks loose during startup it'll mess up my chances of getting the weld right. Does anybody agree with that? I don't think it'll make the prospect of welding any easier, as if it's getting done out of the car there'll be more chances to clean up the spot during prep work and the grain won't need to match as perfectly because it'll be built up from the inside and need to be tapped and threaded again regardless, at least so my welder contact says haha.

TL;DR, engine block/starter mounting hole cracked and I've found potential quick-fix alternatives to welding the block, they are JB weld and a bell housing mounting bracket, or just take it out and get a shop to fix it.

Anyways, let me know what you think, and wish me luck! Hoping to be able to post something successful.

 

Quick update: Found a forum on LS1 Tech about this, seems like a lot of people went to 2nd Sucks Racing's store and bought his Starter Bridge, it's a $370 part that uses two bolts from the bell housing to make a new bracket for the stock starter, while many others made their own but described it as a PITA. Guess I should have looked on more LS1 sites instead cause the LS6 is less common, but seems like it would be more likely to happen to the Z06 since it's aluminum. Others who got the job done through a welder said they were told it "wasn't a permanent fix," despite the nature of a job being what you're supposed to do when something breaks I find it kind of crazy to think it will still probably break after getting a professional to repair it.

I'm no expert on fabrication and haven't touched a welder in years, but I don't see why it would be so hard to make my own bracket. Probably could sell them for a heck of a lot less than $370 and it looks like it would fix the whole problem in it's entirety. Does anybody have this happen to them still?

 

Went ahead and bought some new bolts, turns out the shorter one that's closer to the engine block was missing on mine (either because I misplaced it or it also fell out) and the bolt I have is all bent up.



I cleaned the surface with some electronics spray and installed the new starter (I figured I might as well put it in because it's a nice part and if it fails again it won't be the starter's fault) using the one remaining bolt hole. The starter went in on one bolt and was super solid already, barely wiggled at all when I pushed on it. I mixed up some JB weld and applied it to the chipped aluminum piece, then stuck it back onto the engine block where it came from. Honestly it feels super rigid also. I tightened the last bolt up and everything seemed pretty good,

made sure to spread out the few dribbles of JB weld that got out of the crack so it's pretty liberally coated, but I don't think there's too much on there.


Note that I also got a little bit on the threads, so taking it off might be a bit of a nightmare, but as long as it holds tight it shouldn't need to come off anytime soon.

Anyways, I'm planning on letting it sit until tomorrow so that when I start it the JB weld has fully cured, but I'll make an update then.