Heat on crossmember

[Oomomo]

I've read about not to heat the crossmember, someone was droping the rear one and was told not to heat the bolts...
So is that 100% true and does it apply only on the bolts?

Because I was about to change the front differential oil seal and I never take out a bolt without heating it, never... ask me why

BTW I've already heated up both fill bolts on the diff

 

[Poodles]

Why are you heating them up? Penetrating lubricant (giggidy) works fine and doesn't damage anything...

 

[Oomomo]

Guess I should try that but I've always been pleased by the efficiancy of heating...
Thanks for the tip

so what do you suggess as a penetrating lubricant cause I don't find anything about the giddidy....not jig a loo I presume?

 

[Pr0ject_Supra]

PB Blaster

 

[figgie]

focused heat. I use a jewelers torch for bolts. It gets them nice and expanded over the rust and crud of 220K+ miles and 21 years Sometimes no matter how much penetrating fluid you got, it won't "cut" it!

 

[TooGoode]

lol quagmire.....

 

[Poodles]

finally someone got it :rofl:

PB Blaster and a wire brush usually do the trick. Depends a LOT on how bad everything is, but heat can cause issues.

 

[figgie]

..but heat can cause issues.

Only if it is a broad flame.

A focused flame will not cause issues as the heat will not have time to conduct itself from the part being heated to the other part. As with everything else, takes experience to know when to pull the flame and start turning the bolt

 

[Poodles]

This is true. I've seen people basicly heattreat a bolt to the point where it was brittle and ended up shearing the head off.

 

[Doward]

Fire and a hammer will fix anything.

 

[Oomomo]

Man that giggidy thing cought me...googled that and got some weird stuff about great satisfation on sexual ..........awwww
I think I'm gonna order some PB Blaster, never know where that could be useful... like when I need to heat a bolt surrounded by rubber:icon_bigg

mhhh never forgot the smell

 

[Pr0ject_Supra]

I always coat with pb for a couple days if I know beforehand that I'm taking something off. Heat is always a last resort for me.

 

[Keros]

I R teh Nubz... please forgive the following blastphamy:

Why does heating the bolt help? I would have imagined heating the bolt would cause it to expand in the bore, making an interferance fit with the threads in the bore... IIRC, rusted steel requires 9 times the volume of normal steel... making the effect even more prevailant.

 

[Oomomo]

I'm also very curious of knowing that answer.
I always guess it was some kind of difference of temp and wathever between the bolts and the surrounding area...

 

[jetjock]

The answer isn't intuitive but still simple. What happens (when the materials are the same) is everything expands equally, making the clearance between fastener and thread larger. Think about it...