Author Topic: Aluminum thread inserts or steel for thermostat housing bolts in aluminum 20R  (Read 773 times)

0 Members and 1 Guest are viewing this topic.


  • Offline Rock Master
  • ***
  • Turtle Points: 104
  • Male Posts: 184
  • Member since Sep '15
  • DD and trail rider
Looking for someone with more experience than me.....I've got one stripped out threads on my head where the thermostat housing goes.  I was thinking about using a helicoil or thread insert and then saw that they make aluminum ones that press fit in.  I guess you could either couter sink a little or just cut bigger bolt hole in gasket due to the collar around the top of the insert sitting proud of the surfaced head.  Anybody got any experience or opinion on these?  If you think I should use the steel ones would you recommend helicoil or the inserts?

Current situation is holding as threads are completely gone but pretty close.  I'm driving it everyday but believe I'm pushing my luck.

Here's some of the aluminum ones:
1980 long bed; 20R; L52; 3" OME; 30-spline Marfields; Marlin high steer; PS; AC


  • Offline Silver Turtle Award
  • *
  • Turtle Points: 5445
  • Male Posts: 3,398
  • Member since May '07
    • emsvitil's album
    • Buy me a soda
I would use steel threaded inserts.

You could just try going up a bolt size and enlarge the thermostat holes.     Might even be able to keep the same thread pitch.
86 SR5 XtraCab
22RE  W56B


  • Offline The 2.5K Group
  • ****
  • Turtle Points: 2583
  • Male Posts: 2,659
  • Member since Feb '05
    • Buy me a beer
If you don't already have the tool for inserts I would use a helicoil.
Time to go wheelin!


  • Offline The 2K Group
  • ***
  • Turtle Points: 6755
  • Male Posts: 2,422
  • Member since May '15
    • Buy me a beer
I would re drill and tap the next size. I believe they are 8mm now. Could step up to 10mm.
83 long bed 2wd sas, 3rz, w56, duals with 4.7 rear, 4.88 elock front, spartan rear, 39.5 iroks
01 double cab hunting truck
06 tacoma street truck


Related Topics

11 Replies
Last post May 24, 2006, 12:40:30 PM
by boggerunner
2 Replies
Last post Feb 15, 2007, 09:58:25 PM
by millertime_t1
36 Replies
Last post Dec 30, 2010, 06:57:12 PM
by stevesyota
54 Replies
Last post Jul 06, 2010, 04:16:48 PM
by superyoat
8 Replies
Last post Nov 13, 2011, 09:48:30 PM
by zebracrawler