Tom928

The 4.7L block I have has a helicoil for the long bolt that holds the alternator bracket on. It is a long channel with threads at the back.

The threads must have been damaged at some point as a helicoil was inserted - I can see the beginning edge and insertion tab at the back. The problem is I can't get the bolt to thread into the helicoil. My thought is that the helicoil is damaged.
I doubt it can be repaired so I thought I might drill it and try to put in a time-sert; however, I am not sure it will fit or if anyone has every tried to put a time-sert into a recessed hole on the 928 block.

Thoughts, ideas?

Thanks,

Jim Devine

Any chance that someone put an American thread
helicoil in it instead of a Metric?

Ed Scherer

Did you run a thread chaser through the threaded hole yet? That's assuming, of course, that you know for sure what the threads are in the hole (i.e., that it's not an incorrect size, as Jim wondered).

GregBBRD

Super common...that 8mm hole has a Helicoil in it, from the factory. Once it messes up, it generally can't be repaired with another 8mm thread repair.

I fix these all the time, by using a 10mm timesert. I covered this on my thread about the "restoration' of my son's '83. I'll not smart enough to know how to provide you with a direct link, but you can find this repair explained in detail by finding "Two valve (pre '85) Update/Freshen". Look at post # 250. If you need pictures, I could take some.

Maybe one of the others guys here can provide you with a direct link? Anybody want to do a separate thread about how to fix this problem? Edwards?

Tom928

Hi Greg,

I found the post and the write-up.
No need for pics, I can make some as I go and post them.

Just to confirm the insert is M10x1.5 22mm length?
I looked for 23mm length ( timesert website) but couldn't find.

Thanks for the help,

GregBBRD

Mine come from Wurth and they claim they are 23mm. They actually measure 24.7 end, to end. A few millimeters isn't going to matter. Get something, in that range.

Other than the fact the alternator rebuilders will have a hissy if you ever try to turn that alternator in for a core....this is a great repair and will solve your problems forever.

Koenig-Specials 928

Another reliable repair can be done using Guardserts (guardspecialist.com). My company uses these on pump rebuilds and they are permanent fixes.