Help! May have screwed up!
 

Need you engineering types opinions. I have the aluminum banana arms out of my 79 SC replacing the OE bushings. If you have done this before, you know the rubber bushing comes out easily, leaving the steel inner sleeve inside the trailing arm. I was using a hacksaw, trying to carefully make a kerf along the axis of the bushing to help facilitate the removal of the steel sleeve. Well, I got the sleeve out, but I didn't realize I had cut through the sleeve and slightly kerfed the inner surface of the trailing arm, about 1/16-3/32 deep.

Did I ruin the trailing arm, or would a Mig/Tig bead solve my problem?

Thanks for your input. :(

For my 2 cents I don't think you did any major damage, only to your pride... I think you start welding in there you might create more of a problem. I hope this is right, maybe someone else will chime in and render a more experience opinion.

Just take off the sharp edges and get it back on the road...

No welding ,heat will distort the inside diameter . Dont think you have anything to worry about .the new bushing / monoball is a lite press fit .

I agree with the above -- dont weld it -- you'll lose the heat treat of the aluminum locally. Just debur it nicely and install the bushings.

Thanks, guys for your input and encouragement. My first P Car, decided to tackle complete suspension rebuild on my 79 SC. Went along pretty well until now. Can't wait to get it back together and drive it like I stole it!

i froze new bushing before slamming it in.

thanks, Ronin

I was was wondering about the old freezer trick. Will do. by the way, a local wrench told me the arms needed to be in a loaded position before tightening the bolt that goes through the bushing and secures the front of the banana arm.

Can this be right?

this is a copy of a PM I sent to you.


all i did was guess as to the arm position with car sitting normally.

for a more real world answer contact your local PCA tech advisor

the porsche workshop manual on page R76 says

"the hex bolt may be tightned only after the vehicle has been placed on its wheels since otherwise the twisting capability of the flanblocks would be exceeded. Nominal torque is 12mkp[86.8lb-ft]"

I have seen people raise both ends of the car, and sit it on car ramps, so they can do the "loaded" tightening torque specs. Just a thought, if you have not already done this. Good luck!! Tony.

I agree, file the edges of the kerf, trying to make things burr free and eased. I froze my monoballs and put the arm in the oven. Slipped in like a glove.

I think the monoballs require no special assembly tightening, but stock bushings do.

Thanks Gentlemen for your helpful comments. I do appreciate it very much. I went with Elephant PB in front from our host and OEM rubber bush in back as the car is mostly street with a hopeful track day occaisionally in the future just for the grin factor. Not interested in TTOD.

Thanks again to all. Folks like you make this board a great place!