MX-5 chassis rust advice please!

[Sheeve]

Hi All,

Long time lurker first time poster.

6 months ago I picked up a '99 MX-5. Unforunately I checked the sills instead of the front chassis rails for rust. The time has come for MOT and it has failed on chassis rail rust.

Can anyone advise if this rust is terminal?


nearside



offside

Edited by Sheeve on Friday 10th April 23:41

Edited by Sheeve on Saturday 11th April 18:47

[wildoliver]

It isn't fatal, I've just repaired one that was worse, you do have several options ranging from barely better than bodges up to the frankly absurd option of fitting new Mazda chassis rails. But repair panels are available and the job is far easier than most people make out, I can do both sides on most MX5s in a day with another day to paint up and protect and reassemble the area. It's a good weekend job basically and is possible for a home enthusiast with a half decent welder/angle grinder and basic tools.

[MX-5 Lazza]

You can get repair panels from Wayne (Mazda mender). Ask on Mazdamenders.net.

[Sheeve]

Thanks for the responses.

I have seen replacement panels on themx5restorer.co.uk that look good.

I got a small hammer out and starter to tap out loose rust. Metal I previously thought was good has crumbled away.

Can you advise if these are still repairable? (This is my first time doing more than filters and fluids)



Also when attempting to remove the sway bar to get better access to the rust after a good double soaking with 3-in-1 the bolt head sheared clean off with little effort



Any further advice is much appreciated.

[Perseverant]

I can't remember whether it was here or on the MX5 Owners' site, but I did chassis repairs a few years ago. With the radiator out, there was enough space to squeeze in the space in front of the engine to wield welder and angle grinder. I made new sections forward of the subframe mounts where the rust seemed to have stopped and put it all back together. The roll bar came off as well, so I could clean up its mounts, and I also fitted new captive nuts (i.e. Welded on the INSIDE - the caps are because I made one side back to front - a test of patience and vocabulary!) It's a rotten design there with the double layer construction, but at least with the front off and the bumper mounts also, you can protect inside the rails without too much trouble. Passed MOT again today anyway - no probs!