Suspension bushings ... burn 'em out!!

Do what I did, TRADE HER IN!

 

I kept the car...

 

I know I'm super late to the party, but I thought it would be nice to put in my two cents. In my experience if you put the flame directly on the rubber you get that smell and smoke and flames. But if you instead heat the housing, you can break the bond between the rubber and metal shell and the bushing just pops out.

I took some detailed pictures and video and put it in an article:
How-To Burn out Suspension Bushings: The Right Way - AftermarketSuspensionParts.com

Now that it's been a few years (7), did anyone have any negative experiences with burning out bushings? Other than the stench.

 

Why not do it the right way, cut the welds and press the old ones out? If you burn them out you still have to remove the outer sleeve if you are going to fit proper OEM-spec replacements which anyone who respects their car and its design heritage would do.

 

+308

And moreover; I would be concerned to apply such an amount of heat on the A-arms. I simply wouldn't know what it does to the microstructure. I wouldn't want to soft-anneal the steel.
A Dremel tool to cut the welding spots. There's no several tons hydraulic press needed. A bench vise and two sockets of the right size do the job. Spotwelding of the new bushings can be outsourced to any workshop, if there's no welding equipment handy.

I have seen broken Alfa rear trailing links, where someone did the crude burning job in the past. Even on my '72 GTV I took my time removing the big rear bushings without heat. It works, it just takes patience and time.

Best Regards
Martin

 

I just replaced all the A-arm bushings (85 -308). I used the propane torch method as described in the F Chat forum. I used a sawzall to cut the bushing off and then burned the rubber out. It does put out a lot of black smoke, but worked perfectly. The flame is not hot enough to damage the shell that is welded in place. I used the Poly bushings from Super Performance.
Next step is a 4 wheel alignment.

 

At that time someone whas working on his car to change the bushings, I did ask in a thread if it whas possible to keep the metal sleeves in place and remove the bushing with rubber at an other way. I suggested to cut the metal ring and burn or remove the rubber.
I feel sorry for our environment I brought this up....

Guido

 

did exactly that, it worked like a charm ! quick and easy ...

energy suspension poly bushings slid in smoothly

 

Experience has taught me the right tool for the job makes a huge difference. In this case, a press. Given the cost of a press you will not use often, which means it does not have to be industrial quality, it seems a low cost to pay to do the job right.

If you do not want to buy a press, there may be others, including FChatters, nearby willing to lend you one.

 

I have to say, since the A arms are off the car what's the big deal about grinding off the welds, pulling out the old outer bush shells and having the new ones welded in?

 

I wonder exactly the same. Moreover since this burning job is a huge mess and I doubt, that it's faster.
The possible too much heat thing for the steel microstructure of the A-arms also seems to be something, what's widely ignored. Because I know nothing about the probably necessary factory heat treatment of the A-arms after welding I simply stay away with heat from parts like those.
But since burning out rubber on stressed suspension components seems to be 'in vogue', I'm happy, that noone replaced the bushings on my car prior to my ownership.
They were shot and one of my very first jobs I had to deal with on my car.

Best Regards
Martin

 

But a bigger issue is, if the outer parts of the bushes are not removed, the proper replacements cant be fitted. On the OEM type bushes the rubber is bonded to the inner and outer metal sleeves. So you have to remove the welds and outer sleeves unless you are fitting the correct replacements. If replacements simply slide into the outer sleeves they are the wrong type for the design of the cars suspension which is designed to use bonded rubber bushes. They would surely rotate within the sleeves if the slide in.

Strange how in "American English" Bushes are called Bushings

 

Andy,
I try to write bush
I think, that procedure has something to do with using poly bushes, like manufactured by Energy Suspension, which are not bonded to the outer sleeve, and therefore one can use the old outer sleeve together with the new polyurethane bush and the inner sleeve.
Nevertheless there's a more cleaner and more elegant method to perform this job. Like, for example, Birdman describes it:

Replacing the 308/Mondial Suspension Bushings

A hydraulic press is nice and handy, but it would also work with a bench vise. I have a 20ton press, but I rarely use it. Most jobs work with my bench vise. I somehow have better feel.

 

Are the front and back the same size?

https://www.suspension.com/ferrari.htm

Looks like the fronts are 13.3101 x 8 and the rears are 13.3104 x 8 ??

 

Unless I have misunderstood, that method is appallingly bad.

Am I right in thinking that the new bushes are pressed into the old sleeves and they are actually lubricated so that they rotate within the old sleeve when the suspension moves? It seems to be the case.
It appears that the inner sleeve would be captive on the chassis and the outer sleeve would rotate directly on the plastic bush material.

In order for that to work, the material would need to be very hard (but would still wear). That means the bush would have no resiliency at all. The suspension would become like a race car. On solid jointed suspension its necessary to regularly inspect the suspension for cracks as there is no resiliency in the system. Are people fitting these going to do that?

The OEM bonded bushes also act as a rising-rate spring which stiffens the suspension. A bush which simply rotates would not do that so the suspension would be softer if the springs are unchanged.

I am sure if this were a Lotus forum someone from Lotus (who use the same type of suspension) would chime in with some strong words! Its a pity we cant get feedback from Ferrari on this type of matter.

 

Andy,
I'm glad YOU said it

Best Regards
Martin