I live in Chicago, where most years we see a lot of snow and a lot of salt. This rusts stuff under the car... the longer you own the car the more rusted the bolts get. I had a 22 year old Celica that ran just great, body was like new, but needed suspension maintenance (new shocks, new stabilizer links and so on-) and no one could get the old parts off, and an attempt to do so cracked the front sub-frame....

I tend to keep cars for YEARS - I only put 3,500 miles a year on a car, so my 2013 G37x with 38,000 miles on it won't hit 100,000 miles until the year 2034! I am a fanatic about regularly changing fluids, but is there anything I can do to make sure that this car can remain REASONABLY MAINTAINABLE? I got that Celica washed with under-chassis spray every other week in the winter, but every bolt in the suspension was still rust-welded.

Should I loosen and re-torque a strategic list of bolts every 3~5 years? Coat with some kind of wax? The car is garaged, but the winter streets here EAT metal, and then potholes wear things out

 

hit the bolts with Fluid Film twice a year?

 

You can use copper-based anti seize on bolt threads, especially if you ever replace any exhaust, brake, and suspension parts.

 

I've never seen a car from places that have actual winter that didn't get rusted out underneath to some degree. There's not anything practical to do to prevent it that I'm aware of. Short of moving somewhere where there's not winter or removing every fastener and liberally applying anti seize compound like Brad mentioned.

 

I wonder if replacing key fasteners in the suspension system with stainless equivalents would work.

Stainless fasteners don't rust; but the assembly they are fastening is often steel, which does rust.

Stainless bolt coated with anti-seize torqued into a threaded hole in a steel plate....

Replacing steel fasteners with stainless equivalents might be practical, especially for nut/bolt pairs. We're not talking about everything that holds the car together, I'm just considering the fasteners that hold the "consumable" suspension parts to the car.

Exhaust system, well, most of that you can just cut off if you have to when replacing pipes or back boxes. You've got no vehicle dynamics stress-carrying subframes involved in the exhaust system, it's just plumbing fixed to the car. So maybe that's not as much of a concern.

But the various parts of the suspension that wear- ball joints, shocks, anti-sway bars / bushings, and so, which have to be replaced at a fairly high mileage point- these might be amenable to fitting with stainless fasteners, which could be done while the existing steel fasteners are still able to be removed.


Hmmmm.

Thanks for kicking these ideas around with me.

 

Have you tried spraying a rust inhibitor such as LPS3 on your bolts? I haven't used the complete underbody coating solutions (e.g. Ziebart, Krown, POR15, etc.) but understand that it might do the trick. It's available at your neighborhood Granger store if you have one locally.

Link to product: http://www.lpslabs.com/product-details/612

ETA: when I say spray on the bolts I don't mean on the threads -- I don't know if a lubricant like LPS3 would mess up your torque values.