Mixed Up Head Bolts! - Toyota Nation Forum : Toyota Car and Truck Forums

barthmonster · 12-29-2005, 06:45 PM

Okay I'm working on a Corolla ('91-4AFE), but the knowledge base over here in Camry-land seems bigger. I disassembled the engine and didn't keep track of the headbolts, now the Haynes manual insists these need to go back where they came from. Why??
Anyone sucessfully cleaned them with a tap & die set and still had problems??
I don't see why I can't clean them up and just install them as if they were new...

Thanks for the help...

Gary_602Z · 12-29-2005, 07:25 PM

Surprised that they don't recomend new head bolts as most manufacters do. Are they torqued to a certain spec or degreed in ( as in torgue to a spec then another 90 degrees or so)? Also most makers do not want you to put any oil or lube on the threads as that can affect your torque setting.

Gary

white90dx · 12-29-2005, 07:29 PM

Head bolts stretch when installed the first time. Its good practice to use new head bolts every time you put a head on a block, even if the manufacturer says they are reusable... Cheap insurance against blowing another head gasket.

-Charlie

barthmonster · 12-30-2005, 06:50 AM

Good, thanks for the advice. I'll buy new I think they're around $30-35.00. The Haynes manual actually said to clean the threads and oil them. Makes perfect sense to me to remove the 'running' torque from the torque readings that you get...

Thanks guys...

white90dx · 12-30-2005, 01:31 PM

Oiling the bolts is a general procedure for most cars...

Follow the Factory Service Manual exactly unless there is some updated technique (see Toyota 7m-ge/gte motors).

Oil or other lubricants will change the amount the bolt stretches/holds for a given torque significantly. There is a good write-up on the ARP website if you are interested.

If the bolts are that cheap, I would definitely just get new ones.

-Charlie