removing cradle bushings; an experiment etc.

[fiero308]

I am doing this separately from my other thread so people don't have to pour thru all the many pix etc.
I removed the rubber bushings from the front of the cradle today and did a bit of an experiment and documented it so people who are thinking about it might benefit.

My standard method is to soak the offending bushing in lacquer thinner for about 5 minutes, then IN CONTROLLED CIRCUMSTANCES apply flame (propane torch) all the while AIMING the bushing so that it will 'pop out' (explode out?!?!?) in a known direction into a known 'backstop'.

Keep in mind that I have had control arm bushings explode out and travel 20+ feet in the air...... yes, a molten and flaming blob of burning rubber that sticks to anything it touches. So that is your little 'thought provoker'....... PLAN ahead!!!

So the first pic is a standard, stock cradle bushing (front of course). Note that there is a BIG end and a not so big end. The rubber bushing will come out the big end. Makes sense, I guess.....

On the first one, I made a point of tapping a thin screwdriver in between the rubber material of the bushing and its steel sleeve. I am thinking this will help the lacquer thinner to 'penetrate' into the sleeve and coat or 'get around' the rubber a bit more.

I did this about 4-5 spots around the bushing.

[fiero308]

next I trimmed off an apple juice can so that the little 'tab' on the cradle (for the exhaust hanger I think) won't interfere and so that the bushing can be totally immersed in lacquer thinner.  This is a procedure I heard of and have tried on control arms (smaller bushings) with great success (and excitement  )

I let the bushing sit in the lacquer thinner (I reuse the same stuff over and over, by the way....) for about 5 minutes. Note the propane torch (it is lots hot enough!), the bucket of water and the hose (the water is ON) all VERY handy to the scene.

Safety glasses and gloves fill out the picture.

[fiero308]

Apply heat and try to apply it evenly all around; that is important or at least I think so.
You will get some smoke and flame with this particular approach, but it is minimal in my opinion.  I had to keep the torch on it for about 2-3 minutes, then the bushing popped out very softly and without too much force. GREAT.

You see the wetted-down corrugated cardboard backstop. There is nothing behind this that is going to be important if for some bizarre reason the bushing manages to get past this barrier.

And this is what happened. Very controllable and no ill effects. A quick shot of water and that was that. The bushing WILL remain hot for a long time and you will find out just how MESSY molten rubber becomes...... YUCHHHHH

[fiero308]

so here is the final result; the steel sleeve is FAIRLY clean; it will require a good wiping out with a varsol soaked rag or two and then a wire wheel in a drill and it is good to go.

This took about 8-10 minutes and I haven't really 'wasted' anything. I am reusing the same lacquer thinner and not using any tools of any sort.  The 'drilling out' of rubber is quite hard on drill bits; which might surprise you. Rubber and plastics is VERY bad at heat transfer and any sort of machine work on that stuff is hard on the tool bit.

And the last pic is the VERY messy molten rubber...... after it is cooled of course.

[fiero308]

One last point.
On the other side, I DID NOT use the screwdriver trick. Now maybe that made a difference and maybe it was fluke, but the bushing sat there and burned and smoked and didn't pop out and so after about 5 minutes of black smoke and stink I finally just put it out and let it cool a bit.

Then it DID tap out with a hammer very easily and left a pretty clean hole. But I prefer the first method; it was quicker and cleaner.

Again, the rubber 'bits' that come out; ie burned drippings from the bushing (unavoidable) are VERY very messy and impossible to handle or 'neutralize' in any way I can imagine, so select your work area with care.

hope this helps someone.
gp

[2ML67]

What I do is burn the crap out of them then use a 1/4" or so drill bit and drill it through all around the outside of rubber then slowly walk the bit around the whole outside. The bushing usually just pulls out with the drill at this point. Dan