Thermostat housing studs backed out

[sakoluvr]

Installed new radiators in the 2002 and 97 today. When replacing the thermostat in the 97, 2 of the 3 studs backed out when unscrewing the nuts. I could not get the 3rd nut off without rounding it out.

I cleaned the 2 studs up and put a lock nut on it and screwed them back in with locktite.

I left the thermostat in for another day. No leaks after a road test.

Has anyone dealt with the studs backing out? Any suggestions for the nut that I could not remove? Guessing that stud will back out too.

 

[Twan]

I've had it happen. Two were fused together, 3rd one rounded and had to be cut off. New studs and nuts are cheap, and I just put some thread locker on when i screwed them into the block.

http://www.toyota-4runner.org/3rd-gen-t4rs/247710-common-t-stat-replacement.html

http://www.toyota-4runner.org/2908126-post24937.html

 

[sakoluvr]

Thank you. That helped a lot.

 

[sakoluvr]

I wonder why the engine side of the studs were not made with reverse threads.

Is using a lock nut the best approach when installing the studs? My biggest fear is breaking off the stud!

 

[alumarine]

I wonder why the engine side of the studs were not made with reverse threads.

Is using a lock nut the best approach when installing the studs? My biggest fear is breaking off the stud!

The studs holding the thermostat housing have come out on all my 4runners.
When reinstalling the studs finger tight or a smidge more is plenty tight.
A mild thread locker is ok but not needed.

Lock nuts are not needed.

 

[sakoluvr]

I've had it happen. Two were fused together, 3rd one rounded and had to be cut off. New studs and nuts are cheap, and I just put some thread locker on when i screwed them into the block.

http://www.toyota-4runner.org/3rd-gen-t4rs/247710-common-t-stat-replacement.html

http://www.toyota-4runner.org/2908126-post24937.html

Twan, I am not familiar with stud pullers. Who makes that?

 

[sakoluvr]

The studs holding the thermostat housing have come out on all my 4runners.
When reinstalling the studs finger tight or a smidge more is plenty tight.
A mild thread locker is ok but not needed.

Lock nuts are not needed.

alumarine, I am worried about breaking the bottom stud that I could not I couldn't get the nut off of. Going to have to get a socket for removing rounded nuts, but I am a little scared of breaking the stud if the nut or stud does not turn out. Thanks. It makes me feel better that others have seen this.

 

[Twan]

Twan, I am not familiar with stud pullers. Who makes that?

https://smile.amazon.com/gp/product/B0041ESF2G/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

That's the one I used. I've got the other acorn style too and haven't had any luck with it. The one I linked has yet to let me down.

When the nut on mine stripped(the one on the bottom, of course) I got in there with a dremel and cutting disk to split the nut. Pulled off the housing and used the stud puller on a ratchet with it.

 

[gamefreakgc]

Installed new radiators in the 2002 and 97 today. When replacing the thermostat in the 97, 2 of the 3 studs backed out when unscrewing the nuts. I could not get the 3rd nut off without rounding it out.

I cleaned the 2 studs up and put a lock nut on it and screwed them back in with locktite.

I left the thermostat in for another day. No leaks after a road test.

Has anyone dealt with the studs backing out? Any suggestions for the nut that I could not remove? Guessing that stud will back out too.

Like others said they are common to back out. As long as the nut is on there real tight just thread it back in when you are done. These studs are not holding immense pressure or anything (not like head gasket studs) so there's no need to replace the studs unless you really want to.

 

[sakoluvr]

Thanks guys.

 

[sakoluvr]

https://smile.amazon.com/gp/product/B0041ESF2G/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

That's the one I used. I've got the other acorn style too and haven't had any luck with it. The one I linked has yet to let me down.

When the nut on mine stripped(the one on the bottom, of course) I got in there with a dremel and cutting disk to split the nut. Pulled off the housing and used the stud puller on a ratchet with it.

Will I have enough room to use that remover on the t stat studs? It looks pretty big

 

[Twan]

It might be a tight fit if the housing is still on. I had the housing off after I cut off the nut and end of the stud, but it worked just fine grabbing it with the inch or so of stud that was still sticking out afterwards.

 

[alumarine]

Is there enough thread to get another nut against the rounded one?
If so, tighten both nuts against each other and you may be able to remove the stud.

Could try some heat on the stud in case someone use red Loctite on it.

 

[sakoluvr]

I sent off for studs and nuts. Not going to touch it until those parts come in. Added it to a valve cover gasket order.

Going to keep penetrating oil on the stud and nut until the new studs come in. Going to hit the nut with some heat and then candle wax. After that I am going to try an extractor type socket. I quit trying to remove it as soon as I saw signs of the nut rounding, so I have plenty of surface to work with. I just don't want to break the stud. I won't mind if it screws out.
I will cut the nut off if I have to.