I have a 1991 jeep Cherokee, and I wanted to change the transfer case fluid. It has a 30mm bolt that I use a socket wrench to get of. However, the bolt is only half a centimeter high, and once I get the ratchet to stop slipping off, i cant get the bolt to budge not even with a metal pipe to make more torqe.

 

30mm is the correct size. Maybe it's time to try some heat.

 

How would I try some heat?

 

With a torch

 

If you are going to apply heat, make sure it is no hotter than a propane torch. Acetylene will melt aluminum. one thing you might have to do is grind the face of the socket flat. I have done this for those short hex heads. You will find it works much better

 

I don't think I have one, would a lighter work?
Also is wd-40 flammable?

 

Can you explain how you would do this? Also what part is the "face of the socket"

 

A lighter wouldn't work as it produces very little heat. WD-40 itself is flammable but not greatly once sprayed, the propellant that sprays it out of the can is but that is a dangerous idea if that's where you were heading with the question.

By the face of the socket, it means the end which you put over the nut/bolt head. Most sockets have a slight taper for 1-2mm before you hit the actual hexagonal bore which does the work. By grinding away that tapered edge, you get a bit of extra grip, especially on shallow headed bolts. If possible, it may be worth you taking that tapered edge off and then get someone to help you. One person trying to undo it and the other pushing the socket on to prevent it from slipping.

 

Just NO.... Don't even think this way.

Get a Propane torch or MAP torch, they sell them at the plumbing section or automotive section of most Home improvement/Hardware or Auto part retail stores. I really like my Dad's MAP kit with the auto lighting trigger. Another thing that's super helpful are things called "plumber pads" or "welding blankets"... these are cloth-like bits that you place around the area you're heating up to prevent accidentally heating nearby items like plastic wiring. Use these around the area, especially if there's electronic components nearby.
Then Apply the heat gently.. a little at first... try to loosen the plug... increase the heating a little each time before trying to loosen the plug. Enough heat and it WILL separate... the only problem is that it may melt everything else around it before you get there.

 

Representation of improvised fire

 

Here is a pic of one I did so I could remove electrodes form water heaters. The one on the left was faced, the one on the right is original. Removing the rounded face gives you more contact on the shallow nut

 

if you ever use flame under your car, have a fire extinguisher, or at least hose or bucket of water handy..no if or buts..do it outside

the ground socket is good

one way, place breaker bar & socket over bolt head, and apply strong pressure to retain it,

slip a trolley jack under the breaker bar handle and jack it using your free hand, boot, or whatever organ you want

This is how I undo truck Pinion Yoke bolts, I dont have any impact guns powerful enough to budge them

 

One of the things my Dad recommends (and I consider him a master of stuck part removal) is to soak the thing in Liquid Wrench/PB Blaster, any all penetrating oils you have on hand... then tap the stuck piece (in this case the plug itself) gently with a small hammer... just vibrate it a bit to help the penetrating oil work in. Then wait an hour or two, come back and repeat.... Soaking, tapping, waiting are the keys to getting the penetrating oil to work it's magic. Then come back after a day and try again.

 

Thanks, How would I grind it though? Would an angle grinder work?

 

another low tech way that works on big stuck things..need an assistant though

2 dudes, with ***** punches and hammers

simultaneously tap opposite corners of the fastener head

things have definitely gone pear-shaped if you resort to this, as it can (but should not be) destructive

I have got some nasty weird things loose this way

...and yes, an angle grinder will work to grind the socket flat