5.0 mercruiser chevy starter bolt holes stripped, helicoil or not

[onebighead]

My 1998 5.0 chevy has starter bolt holes somewhat stripped. As I was tightening the bolts, it seemed they never tightened down. I know what that means....stripped. I would like to hear opinions from you experienced mechs concerning trying helicoil vs tapping to a larger size. thanks

 

[Don S]

Re: 5.0 mercruiser chevy starter bolt holes stripped, helicoil or not

As long as you get it drilled out perfectly straight and re-tapped (perfectly straight) for the helicoil, then it should work fine. Be off on the angle and you will need a block.

 

[Barnacle_Bill]

Re: 5.0 mercruiser chevy starter bolt holes stripped, helicoil or not

You have to drill and tap for the helicoil so you just as well use a bigger bolt. But then you may have to enlarge the hole in the starter some.

 

[Don S]

Re: 5.0 mercruiser chevy starter bolt holes stripped, helicoil or not

You have to drill and tap for the helicoil so you just as well use a bigger bolt. But then you may have to enlarge the hole in the starter some.

Don't do that. Then you have to fix every starter you ever have to replace no matter why you have to fix it.

 

[Prophammer]

Re: 5.0 mercruiser chevy starter bolt holes stripped, helicoil or not

Heli Coils work very well when installed properly and may even result in stronger threads

 

[Bondo]

Re: 5.0 mercruiser chevy starter bolt holes stripped, helicoil or not

My 1998 5.0 chevy has starter bolt holes somewhat stripped. As I was tightening the bolts, it seemed they never tightened down. I know what that means....stripped. I would like to hear opinions from you experienced mechs concerning trying helicoil vs tapping to a larger size. thanks

Ayuh,... How badly are the threads on the bolts beat up,..??

As Don said, Don't go over-sized, the starter indexes on it's bolts,...

Use a New set of bolts, with the proper knurlin' on 'em...
Merc sells a Sweet set, with 1/2" extended heads, insteada the usual 9/16" short heads...
Much easier to wrench on...

 

[achris]

Re: 5.0 mercruiser chevy starter bolt holes stripped, helicoil or not

If you can get one bolt in reasonably, use the starter motor itself as a drilling guide. If not, have a couple of spotters so you get it square. And I'll add my agreement with NOT going oversize...

 

[tinkerguy70]

Re: 5.0 mercruiser chevy starter bolt holes stripped, helicoil or not

Heli Coils work very well when installed properly and may even result in stronger threads

Agreed. When used and installed properly they work just fine. I imagine it may be tough to get in there and drill the holes straight though.
I'd be tempted to try new bolts and run a tap up through the existing holes. You never know, you might get lucky.
Either way, it looks like you're going to need new bolts.

 

[BRG25]

Re: 5.0 mercruiser chevy starter bolt holes stripped, helicoil or not

Why not first try to run the correct sized tap through the hole then use new starter bolts? Maybe it's not stripped as bad as you think?

 

[achris]

Re: 5.0 mercruiser chevy starter bolt holes stripped, helicoil or not

Cast iron vs rolled steel bolts... I know what my money's on for stripping first...

 

[Bondo]

Re: 5.0 mercruiser chevy starter bolt holes stripped, helicoil or not

Cast iron vs rolled steel bolts... I know what my money's on for stripping first...

Ayuh,.... Generally I agree, except some of the stuff I've seen, these could be gr.2 rusted out hardware store bolts,....



From China......

 

[tinkerguy70]

Re: 5.0 mercruiser chevy starter bolt holes stripped, helicoil or not

I don't know if you've ever drilled into cast iron before but.... it ain't exactly like drilling mild steel.

 

[Prophammer]

Re: 5.0 mercruiser chevy starter bolt holes stripped, helicoil or not

[.......

 

[Prophammer]

Re: 5.0 mercruiser chevy starter bolt holes stripped, helicoil or not

I imagine it may be tough to get in there .

an angle head air drill may be able to get in there but its hard to say without looking at it

 

[achris]

Re: 5.0 mercruiser chevy starter bolt holes stripped, helicoil or not

Ayuh,.... Generally I agree, except some of the stuff I've seen, these could be gr.2 rusted out hardware store bolts,....



From China......

On a 1998 I would expect it to still be the original... But you never know... :facepalm:

On question nobody's asked.... OP. Is the engine still in the boat or do you have it out on the bench?

 

[onebighead]

Re: 5.0 mercruiser chevy starter bolt holes stripped, helicoil or not

Thanks for all the replies. This was a different block I was using during a rebuild and the stripped holes got past me, since I put starter on after engine in the boat. To answer a question, the engine is now hanging on a hoist since I plan to fix these holes and maybe change out the electric fuel pump. It seems these starter bolts are 3/8 x 16 threads. Hopefully the threads in the block are exactly that. thanks again

 

[Don S]

Re: 5.0 mercruiser chevy starter bolt holes stripped, helicoil or not

Now you know why I ALWAYS, run the engine on the floor before I ever think about putting it back in the boat.

 

[Bondo]

Re: 5.0 mercruiser chevy starter bolt holes stripped, helicoil or not

It seems these starter bolts are 3/8 x 16 threads. Hopefully the threads in the block are exactly that.

Ayuh,..... They should be...

 

[Prophammer]

Re: 5.0 mercruiser chevy starter bolt holes stripped, helicoil or not

I'd be tempted to try new bolts and run a tap up through the existing holes. You never know, you might get lucky.

You might get unlucky if the bolts won't hold, be sure they can withstand the required torque!

 

[tinkerguy70]

Re: 5.0 mercruiser chevy starter bolt holes stripped, helicoil or not

You might get unlucky if the bolts won't hold, be sure they can withstand the required torque!

Either they hold or they don't, there is zero risk in trying.

If they don't hold, going the heli-coil route would be the next option.
Heli-coils aren't exactly cheap, and buying a kit that you don't need is a waste of money.