Surface rust on front torsion bars
07-11-2005, 02:06 PM
#1
Rennlist Member
Thread Starter
Surface rust on front torsion bars
I am restoring a 1974 Carrera and I am cleaning up the suspension before I reinstall it and I have noticed on one of the front torsion bars some surface rust. Is it advisable to to wire brush off the rust and paint the bar with a rust encapsulating paint, or should the torsion bars be replaced? Thanks for your help.
Gratuitous picture attached
Aaron
Gratuitous picture attached
Aaron
07-11-2005, 04:56 PM
#2
Rennlist Member
Definitely clean them up and repaint. The rust could cause stress cracks and possibly a broken torsion bar. This is very bad. If you are not replacing your front a-arm bushings as part of your restoration, you may want to do this also as the sagging of these bushings causes the torsion bar to rub against the torsion bar tube creating a similar breakage risk (Paint is scraped away and rust forms on the torsion bar).
Your car looks like it will be very nice when complete. Nice work so far!
Your car looks like it will be very nice when complete. Nice work so far!
07-11-2005, 05:45 PM
#4
same answer as on Pelican - I don't think cleaning them up will remove the cracks. It is risky and probably unsafe to use them. The rust has _already_ caused microscopic cracks. And these are the equal of stress cracks - all they need is to grow and then shear the bar on a curve or a bump.
I agree re the bushings.
I agree re the bushings.
07-12-2005, 09:17 AM
#5
Burning Brakes
One other thing about painting them (even w/ POR, etc.). Some bars come painted, some don't (like my Sanders), and I was going to paint mine before installation. I asked a VERY reliable source (on this board) about this, and he recommended that a coating of grease was necessary (even if they are painted), and is all you need to do to keep rust from forming.
Keith
Keith
07-12-2005, 02:03 PM
#7
RL Technical Advisor
Hi Aaron:
Nice car (I too, have a '74 Carrera that I bought brand new),...
I'd concur with Randy on this; given that the stresses of a torsion bar are greatest at the surface and that you cannot accurately assess the damage caused by the "tinworm", I'd suggest replacing the front torsion bars.
When these do break, the wheels contact the fenders and that almost always burns holes-strips in the paint. Given the trouble you have gone to thus far, new T-bars are a small expense on the overall scale.
I would also agree that new bushings are strongly recommended. Your 30 year old rubber ones are at the end of life and they have usually sagged enough to degrade suspension performance and will allow the front bars to rub inside the A-arms.
Nice car (I too, have a '74 Carrera that I bought brand new),...
I'd concur with Randy on this; given that the stresses of a torsion bar are greatest at the surface and that you cannot accurately assess the damage caused by the "tinworm", I'd suggest replacing the front torsion bars.
When these do break, the wheels contact the fenders and that almost always burns holes-strips in the paint. Given the trouble you have gone to thus far, new T-bars are a small expense on the overall scale.
I would also agree that new bushings are strongly recommended. Your 30 year old rubber ones are at the end of life and they have usually sagged enough to degrade suspension performance and will allow the front bars to rub inside the A-arms.
