8DC Posted June 18, 2012 Share Posted June 18, 2012 (edited) Attempted to move the thermostat housing from the old head to the rebuilt one I just installed. Of course the 2 bolts holding it on were corrosion locked and snapped off when I tried breaking them free, so now I need 2 new bolts. What size are these bolts and what are the chances that I will be able to find them at the hardware store? I also see that "reddat" sells the set of 4 (2 for the housing and 2 for the outlet) on eBay for $25, is that my best option? Edited June 18, 2012 by 8DC Quote Link to comment Share on other sites More sharing options...
rossman Posted June 18, 2012 Share Posted June 18, 2012 (edited) Take a pair of calipers and measure the shank diameter. Measure the depth of the housing + washer and add 2x diameter and round up to the nearest bolt length. Invest in a thread gauge or get a printable one online. I got mine from Harbor Freight. Go the McMaster.com (or one of the many other online bolt suppliers) and see what they got. Beware of reddat's shipping charges. He has gouged quite a few people on this board including me. Edited June 18, 2012 by rossman Quote Link to comment Share on other sites More sharing options...
OldAndyAndTheSea Posted June 18, 2012 Share Posted June 18, 2012 If I had a nickel for every thermostat housing bolt I've broken on L motors.... I'd have 30 cents! Good luck getting em out. Quote Link to comment Share on other sites More sharing options...
z240 Posted June 18, 2012 Share Posted June 18, 2012 The bolts are all 8x1.25mm thread. Length you can measure. Take the thickness of the hole in the cover, add 16mm, that's the length you want. Very common metric thread. Use anti-seize on them for next time... Please don't give "him" $25 for 4 bolts! Shipping will be almost as much on top of that. Quote Link to comment Share on other sites More sharing options...
8DC Posted June 18, 2012 Author Share Posted June 18, 2012 (edited) If I had a nickel for every thermostat housing bolt I've broken on L motors.... I'd have 30 cents! Good luck getting em out. Fortunately I don't have to worry about getting them out, new (rebuilt) head and I was lucky enough to find someone nearby that had a thermostat housing. I don't know what the previous owner did, not only have the bolts become one with the housing but also the housing looks like it was JB Welded (or something) to the head, there's no gasket that I can detect on there and I can't even chisel it apart (at risk of damaging both surfaces but I had exhausted all other options). Take a pair of calipers and measure the shank diameter. Measure the depth of the housing + washer and add 2x diameter and round up to the nearest bolt length. Invest in a thread gauge or get a printable one online. I got mine from Harbor Freight. Go the McMaster.com (or one of the many other online bolt suppliers) and see what they got. Yeah' date=' I will probably have to do that. I was hoping someone would know the exact length of the bolts though so I don't accidentally run one into the timing chain. Beware of reddat's shipping charges. He has gouged quite a few people on this board including me. The bolts are all 8x1.25mm thread. Length you can measure. Take the thickness of the hole in the cover, add 16mm, that's the length you want. Very common metric thread. Use anti-seize on them for next time... Please don't give "him" $25 for 4 bolts! Shipping will be almost as much on top of that. lol Okay, thanks! Edited June 18, 2012 by 8DC Quote Link to comment Share on other sites More sharing options...
8DC Posted June 18, 2012 Author Share Posted June 18, 2012 (edited) *post merged and deleted* Edited June 18, 2012 by 8DC Quote Link to comment Share on other sites More sharing options...
Leon Posted June 18, 2012 Share Posted June 18, 2012 Fortunately I don't have to worry about getting them out, new (rebuilt) head and I was lucky enough to find someone nearby that had a thermostat housing. I don't know what the previous owner did, not only have the bolts become one with the housing but also the housing looks like it was JB Welded (or something) to the head, there's no gasket that I can detect on there and I can't even chisel it apart (at risk of damaging both surfaces but I had exhausted all other options). Use a heat gun, it'll break down any adhesive that was used to glue that thing on there. Quote Link to comment Share on other sites More sharing options...
rejracer Posted June 19, 2012 Share Posted June 19, 2012 On the new bolts get stainless if you can. If stainless is not available then at least go for class 10.9 bolts. You don't really need the strength of a 10.9 bolt, but they are more corrosion resistant than a class 8.8 bolt due to the difference in the alloy they are made of. Quote Link to comment Share on other sites More sharing options...
Xnke Posted June 20, 2012 Share Posted June 20, 2012 Do not install stainless threaded fasteners into an aluminium female thread. You will have trouble trying to remove them after a few heat cycles, because the stainless will grab and tear the aluminum threads out. It will do this 7 times out of 9. It really, really sucks. The holes will look fine sometimes...but you will find chunks of the aluminum threads stuck in the stainless bolts/studs. In my experiance, even good quality copper anti-seize doesn't stop this from happening. Quote Link to comment Share on other sites More sharing options...
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