Rust Warning (1986 107's)

[Strife]

If you have an earlier than 1986 SL, you should check the front of the fender above the headlight pockets. I am going through my 85 380 and rustproofing it additionally for the winter as well as touching up some stuff. I kid you not, I pulled about 3/4 LB of wet, nasty dirt from the LH side and about 1/2 LB from the RH side in this area. It's a lot harder to get at the RH side because the vacuum resevoir is in the way. After doing this and letting it dry, I POR-15'd this area and while that was drying overcoated it with rubberized undercoat.The RH would have been much easier with the vacuum reservoir out of the way but it's held in with screws and not studs and it would take removing the water bottles and maybe 3 hands to remove it.

If you've ever seen a rusty SL with rust above the aluminum eyebrow trim, this is how it got that way. 86+ cars are fairly immune to this because of the plastic wheelwell liners. I got a set of these locally from a car being stripped, but they aren't that easy to install, because the studs to mount them aren't there and blind-drilling into the inside fender is NOT RECOMMENDED (I'd have to basically remove everything mounted on both sides before starting on this).

[jdhill]

Here's another area to check and another reason to install the inner fender panels. I bought mine from MBz, 2 years ago, they were $50 apiece. They couldn't have designed a better rust trap if they tried. Apparently I already posted the photo befor and can't do it again. See" does anybody have a good splash/dirt shield to sell"

[ttnguyen23]

Originally Posted by Strife

If you have an earlier than 1986 SL, you should check the front of the fender above the headlight pockets. I am going through my 85 380 and rustproofing it additionally for the winter as well as touching up some stuff. I kid you not, I pulled about 3/4 LB of wet, nasty dirt from the LH side and about 1/2 LB from the RH side in this area. It's a lot harder to get at the RH side because the vacuum resevoir is in the way. After doing this and letting it dry, I POR-15'd this area and while that was drying overcoated it with rubberized undercoat.The RH would have been much easier with the vacuum reservoir out of the way but it's held in with screws and not studs and it would take removing the water bottles and maybe 3 hands to remove it.

If you've ever seen a rusty SL with rust above the aluminum eyebrow trim, this is how it got that way. 86+ cars are fairly immune to this because of the plastic wheelwell liners. I got a set of these locally from a car being stripped, but they aren't that easy to install, because the studs to mount them aren't there and blind-drilling into the inside fender is NOT RECOMMENDED (I'd have to basically remove everything mounted on both sides before starting on this).

I found on the rusted section of my front passenger side frame under the ABS system and under the right headlights.
I do not know how can I get into the section to repair the rust unless I have to remove the ABS unit. But I am worry if I remove the ABS unit the ABS option might not be work any more. Any one know?

[Strife]

Another ugly surprise I found while looking over my car with a can of SEM POR-15 equivalent (with a known shelf life) was the battery compartment, which I found by accident while changing a taillight bulb.

What happened was that the trunk seal channel had rusted (known when I bought the car), and the trunk seal had failed. The battery compartment was a "low spot", and all the water wound up under the plastic battery box. I had fixed the channel and gasket when I bought the car, but never saw any rustuntil now. Although this area has two drains (one for the battery box, really a drain/vent), and a regular water drain, these drains have a rim where I don't think they will really drain small, continuous amounts of water. The rust was old and dry, but after removing the (very heavy) battery and moving the box out of the way (a PITA to remove the cables) and removing the rubber drains, I wire-brushed, vacuumed, POR-15d, and undercoated the area and I'm confident that that's the end of the problem.

While you are in there, consider the condition of the battery box and its straps. The box and straps have a safety purpose, and it would not be a good idea to have a really large generator of explosive gases and source of electrical arcing bouncing around in your trunk in an accident. The straps tend to get bent and weakened by flexing; the battery box itself can crack, either in an accident (even a minor one like my 560 was in before I bought the car) or from age.