need help bad

[plumcrazy]

hello all,

just tried to replace my fan switch and thermostat in my baby with
with a 176 switch and 160 thermo. my problem is i got the switch
changed but the bolts for the neck are frozen up real bad and
i cant budge em at all and i am afraid i will snap them off in the
intake. does anyone have any ideas how to get these suckers out
any help would be so greatly appreciated.



i didnt try to get em out hot was told not to mess with them till the
engine cooled down cause of the intake being aluminum.

 

[Moonunit 451]

You could try a big squirt of PB Blaster, but I doubt it will do much. I busted one of mine when I was pulling the intake. I didn't reuse it so I never worried myself with it. As far as heat, I hope somone else will jump in, it may be your only option.

 

[The Car Whisperer]

You need to make sure the engine is cold before you try to remove the housing bolts. Aluminum expands at a greater rate than steel when heated; you could easily strip the threads in the aluminum manifold or snap the steel bolt because of the difference in expansion rates. Let everything cool off first. Use the penetrating oil as suggested, but if you can get a steel rod down on the bolt head tap it right on top nice and solid right after you spray the oil on it. This sets up a vibration that will help the oil penetrate and it may also help shake the trhreads of the bolt loose from the manifold bolts.

 

[drags1998]

DITTO!!!!!! JUST TAKE YOUR TIME!!!! GOOD LUCK!!!!

 

[cablexpert]

And don't forget to use anti sieze compound when you re install it...Good Luck

 

[plumcrazy]

thanks guys, i will let you know how i make out. and i got a big ole can of
grey permatex antisieze dont know why people dont use this stuff as much
as possible. it is a lifesaver.

 

[SPANISHVETTS]

You have a lot of good advice already. Here are a few tricks we use every day in the shop.

Try letting the penetrating oil set a few hours, squirt and tap it again, set a while, squirt, tap etc. Do this 4 or 5 times.

If one of the bolts snaps off try this before you drill it out. Arc weld a piece of 6 mm bar stock bent into a T handle to the remains of the bolt. The weld will be stronger than the bolt and the bolt heating up rapidly while the aluminum remains cool will break the threads loose. Wait for the bolt to cool completely before attempting farther removal.

If you do end up stripping the threads out of the head it’s no big deal. $0.50 worth of Helicoils and 5 min. with a tap will have you back on the road in no time.

 

[Radar]

You need to make sure the engine is cold before you try to remove the housing bolts. Aluminum expands at a greater rate than steel when heated; you could easily strip the threads in the aluminum manifold or snap the steel bolt because of the difference in expansion rates. Let everything cool off first. Use the penetrating oil as suggested, but if you can get a steel rod down on the bolt head tap it right on top nice and solid right after you spray the oil on it. This sets up a vibration that will help the oil penetrate and it may also help shake the trhreads of the bolt loose from the manifold bolts.

But if the aluminum intake manifold expands at a greater rate than the steel bolt, I would think working with hot aluminum would help, not hurt. The aluminum hole would be bigger making it easier to brake the bolt free.

Radar :confused

 

[berky2500]

Actually, as the aluminum expands, it isn't expanding from the hole outward, the metal around the hole is expanding, which in turn collapses the hole, making it tighter on the bolt (that is probably steel). That is why you never change plugs or any other steel part in an aluminum block or head when they are hot, or the threads will come out with the part being removed.

 

[The Car Whisperer]

Actually, as the aluminum expands, it isn't expanding from the hole outward, the metal around the hole is expanding, which in turn collapses the hole, making it tighter on the bolt (that is probably steel). That is why you never change plugs or any other steel part in an aluminum block or head when they are hot, or the threads will come out with the part being removed.

Thanks for adding that bit about the hole collapsing around the bolt, I didn't get that across. Anyhow, if you do end up stripping the threads you can install a Helicoil to repair the threads, it will end up being a better situation. A Helicoil is a Stainless Steel threaded insert that will replace the Aluminum threads. I don't know why they don't just install these on the Aluminum manifolds at the factory, you can torque down on a Helicoil without having to worry about the dis-similar metals problem.

 

[SPANISHVETTS]

On our clutch and gearbox cases we re-tap and install hardened steel thread inserts as soon as we receive a new unit. The inserts cost about $0.40 each and last a lifetime. I have never seen one of these inserts strip, freeze or come out of the casting, even when a Gorilla sized mechanic is going at it with a breaker bar in the middle of a race.

I don't know why they don't just install these on the Aluminum manifolds at the factory,

If the manufactures installed these inserts or helicoils when they built a motor it would probably add $50. to the cost of the car. We all know that the General is not about to give up a penny here or a penny there for something that will not cost him a dime during the warranty period so we are stuck extracting bolts and installing helicoils.

 

[plumcrazy]

thanks guys,
got em out had to pull the throttle body to get a good shot at frt one but
after soakin and beatin on em they came out with clean threads....

 

[Moonunit 451]

This is why I keep reading and reading and reading in these forums. You can learn a lot in a short period of time. Thanks for the great explanations guys

 

[SPANISHVETTS]

Well done!!!

 

[wro87]

oil

I have had a lot of success using KROIL Penetrating oil it is available in spry and liquid container. Like the others have said, tap it and let it set for a while, and then you might try to move it back and forth. Good Luck.