Starter to Flywheel Engagement 1997 5.7

"'97, 5.7L, A1, 2bbl
Replaced starter about 2 years ago. The new starter was aftermarket but I thought it was an exact match. (Didn't shim it.)
Starter started making some grinding noise again. Pulled it out, the mounting bolts were slightly bent. Nothing visibly wrong with the starter, looked at the internal gears, no issues.
The flywheel, however, is missing teeth.
Obviosly need to pull the engine and replace the flywheel.
But before I do all that work I want to understand what caused the problem.
Should the starter have been shimmed? And how does one go about determining the thickness of shim needed?"

"[b]"Obviosly need to pull

""Obviosly need to pull the engine and replace the flywheel."

Ayuh,... You need to change the Ring Gear, Not the Flywheel,...
It's a couple Hundred dollars difference...

The Bent bolts are the Problem,...
Most starters Don't need shimmin'..."

"When you have the motor out,

"When you have the motor out, and install the new ring gear " check out some junk yards " with new bolts installed in the starter check the gear line up between the starter and ring gear.

See aftermarket starters made in china might be off in the mounting surface of starter to block.

With the motor out will make it alot easier to see if in fact you need a shim.

I think when you installed the new starter the bolts were straight, so they bent cause they were loose? Loose enough to eat a couple of teeth off the flywheel gear and bend the bolts?

So did you ever tighten the bolts after install of the starter say a few weeks after install ? I do check any starter auto or boat i install on my stuff a few weeks after install. Did one on my sons mountaineer and the bolt turned another half to 3/4 turn. Why it does got me seen it before will probably see it again.

After all is said and done if this happens again or to head it off from happening again you may want to consider installing a front bracket on the starter to the block. Will stop the starter from vibrating loose the bolts.

Good luck !"

"Didn't see the ring gear

"Didn't see the ring gear as being a seperate piece. The merc manual doesn't show it, and the parts websites I've looked at so far don't show it. Any ideas for sources? Sure would rather pay a few hundred less than what a new flywheel goes for... damn, they're proud of those buggers!
How is the ring gear held on to the flywheel? Bolted, not riveted, I hope!

No, I didn't go back afterward and check the tightness of the starter mounting bolts. I guess that's one of the lessons learned here. But they weren't what I'd call loose when I pulled the starter yesterday... wouldn't take much misalignemnt to cause havoc though."

Friction fit.

A competent m

Friction fit.

A competent machine shop should be able to do the whole thing. Just bring your money with the old flywheel.

"[b]"Didn't see the ri

""Didn't see the ring gear as being a seperate piece. The merc manual doesn't show it, and the parts websites I've looked at so far don't show it. Any ideas for sources? Sure would rather pay a few hundred less than what a new flywheel goes for... damn, they're proud of those buggers!
How is the ring gear held on to the flywheel? Bolted, not riveted, I hope!"

Ayuh,... Napa, for under $50....

Knock the old 1 off with a hammer,+ punch...
Throw the new 1 into the oven for a few minutes on High...
Take it out, drop it on,+ it'll Fall into place...
Let cool,+ reinstall..."

"Sounds like a plan, thanks Bo

"Sounds like a plan, thanks Bondo."

"Make sure the wife ain't

"Make sure the wife ain't home bakin that flywheel they don't seem to appreciate it, I don't know why.

Got a junk yard near you, probably have a bunch, maybe 10 bucks for the whole shebang flywheel and ring gear together.

Rock auto maybe, if you live dead in the middle of the desert."

"My wife is pretty good about

"My wife is pretty good about tolerating engine parts in the oven, home brew cooking on top of the stove, and even the occassional pile of fish guts left in the sink."

"kewl.

Be careful alot of w

"kewl.

Be careful alot of weight that motor. Your gonna have it out anyway, paint everything 4-5 times.

Your going to have to check alignment e-bay has a guy with alignment bars real, real cheap now."

Yup... looking at all that now

Yup... looking at all that now. Lot's of stuff back there that can't be reached without pulling the engine.
Pretty sure there's a good sized striped bass somewhere under there too.

"Thats my fish, i was looking

"Thats my fish, i was looking for it all over."

Is there a rear starter to blo

Is there a rear starter to block bracket on that starter??? Several cars incorporate these brackets but I'm not sure if Mercruiser does.

"not oem, but the new starters

"not oem, but the new starters are having trouble snapping bolts. 3.0 original starters had front brackets to the block.

Then the new starters smaller and lighter uses less juice. Then the starter bolts started snapping. the
fix is to fabricate a front bracket to the block and freeze the front of the starter, to stop the vibration causing the bolts to come loose.

Guys my sons mountaineer is a 5.0 ford had the same problem i made up a front bracket, no more problem.

I'm just putting this out there some might not agree to the 5.0 and 5.7 chevy motors but the problem in my small band of friends is showing it's ugly head, my fix seems to solve the problem at least in the 3 i made up for friends. The one i made for me cause i kept snapping the bolts in the block. Total of 5.

What i call the front of the starter is the other end of the gear. Some might call it the rear.

Bob i hope i was clear maybe not."

"My gut feeling at the momment

"My gut feeling at the momment is that the bolts that came with the aftermarket starter are junk. I'm either going to buy a new set from Merc, or find suitable replacements... grade 8, B7 or B16 hardened steel.
Not 100% clear on what chiefalen is getting at with the added bracket... is it attached to the end of the starter motor?"

"Yea the end that does not hav

"Yea the end that does not have the gear that turns the flywheel i make up a bracket that connects the starter to the block.

Maybe it was the bolts were bad, in your case.

Good luck !"

"Ayuh,... Napa should have th

"Ayuh,... Napa should have the starter bolts with the knurled shanks,...

The supporting bracket Chief is talking about attaches to the foreward end of the starter, at 1 of the little studs,+ then up to the block, just above the pan rail..."

"Probably going to go with 170

"Probably going to go with 170ksi capscrews vice taking anymore chances with the bolts... got a few of those already. Plus I'll go with the added bracket. If that thing comes loose again, I sure wouldn't want to be anywhere close it!"

"OEM starter motor bolts do no

"OEM starter motor bolts do not necessarily work with a replacement PMGR or HTGR starter motor (if that is what you purchased).
Often the bolt length requirement is ever so slightly different.... hard to see it unless you are keen to it.

I'd check the actual bolt length against what the starter motor housing requires... and I'd compare the remaining thread length to the female thread depth in the engine block!
This may have been your issue with the bolts bending/breaking!

This is also one area where I am OK with the use of the Automotive version of Anti-Seize on the bolt threads. Years from now, someone will be removing these bolts again. Be kind! It may be YOU!

."

"Hey all. I replaced a starter

"Hey all. I replaced a starter (aftermarket) on my dads boat about a year ago. It came w new bolts. The new bolts were longer than the old ones, only by about 3/16 of an inch, but it caused them to bottom out in the block and not fully tighten the starter. I didnt notice anything was wrong when i installed it, bolts felt like they were tight. I happen to be looking at it the first time we tested to see if it worked and i noticed it moved a little. Thats when we found the bolts were longer. A couple flat washers and lock washer and it was good to go.
Check bolt length when changing starter!"

Re: Starter to Flywheel Engagement

Compared the original bolts to the bolts that came with the aftermarket starter... the aftermarket bolts are longer. And, the after market starter is about 1/16" thinner than the original. Pretty sure that's my smoking gun. As soon as the torrential downpours ease up, I want to measure the depth of the holes in the block.

Re: Starter to Flywheel Engagement

there were two types of starter pinion gears, one was 11 teeth and the other 9 from memorie make sure youve got the same number of teeth on the pinion gear, teeth snapping off the ring gear is due to the starter coming loose usually, i think its sierra who do a ring gear on its own and is easy to fit when off the engine, starter shouldn't be shimmed

Re: Starter to Flywheel Engagement

Troym, Make sure that the bolts you use are starter motor specific bolts.... I.E., are knurled as to form the dowel effect.... and are of the correct length as I explained earlier.

Whether a 9 or 11 tooth pinion, I beleive that the starter motor housing design, the center of pinion (or armature for non-PMGR/HTGR) and mounting bolt pattern is what dictates the size flywheel that the motor is intended to work with. Yes/No?
The 153 tooth ring gear will use the straight bolt pattern housing....., and the 168 tooth ring gear will use the staggered bolt pattern housing.

Shimming can be done, but requires that it be done while we can view from the AFT side of the engine. This usually means the engine will be out of the boat!

Just to reiterate here;
The ring gear is GM.
All are same between the 153 and 168 tooth count for the SBC.
The Sierra ring gear should be same as what GM would provide.

The bad gear is driven from the flywheel while cold. Just punch it off!
The new gear is carefully heated around the perimeter, and tapped into position being careful to NOT over-heat the steel.
The better shops will do this on a turn table!
This can be done while laying in position on the flywheel.
The heat will go to the ring gear, the flywheel will absorb the heat and will not expand at the same rate!
The fit is a "heat shrink" fit.... if done properly, it will not spin once cooled.
Some High Performance guys may tac weld them in several places..... I don't think you'll need to.
Any auto parts store or GM parts dealer can bring in a ring gear for you.

Re: Starter to Flywheel Engagement

The bad gear is driven from the flywheel while cold. Just punch it off!
The new gear is carefully heated around the perimeter, and tapped into position being careful to NOT over-heat the steel.
The better shops will do this on a turn table!
This can be done while laying in position on the flywheel.
The heat will go to the ring gear, the flywheel will absorb the heat and will not expand at the same rate!
The fit is a "heat shrink" fit.... if done properly, it will not spin once cooled.

Click to expand...

Ayuh,... You do it the Hard way Rick,...

Here's the Bondo method,....
Beat the old ring gear off with a hammer,+ punch...
Put the New ring gear in the ole lady's Oven set at 450° to 500°, for about 20 minutes...
Set the flywheel,all cleaned up, with the ring gear side Up, on the counter...
Open the oven, wearing welding gloves, grab the ring gear,+ drop it onto the flywheel,..

It'll quite literally Fall into place,...
After 10 minutes or less, it's cooled,+ ready for Installation.....

Re: Starter to Flywheel Engagement

I like the oven method much more than the torch method... takes the guess work out of making sure it heats evenly and not excessively.
Plan on puling the egine on Saturday. I'll post a few pics.
Thanks for all the input.

Re: Starter to Flywheel Engagement

Built the lift, pulled the engine, and replaced the ring gear... and the rear main seal, since it was right in front of me. Still have plenty of work to do before it's ready to be started, hopefully tomorrow. Pictures attached.