Snow buildup above under-floor panels

[LotusSeven]

Last Friday I drove the 05' LGT wagon for (2) hours during a moderate snowstorm. The snow was wet and heavy but only 5 inches deep, and driving was no problem with Subaru AWD and LM-25 Blizzacks. As one would expect, there was a lot of snow build-up in the wheel wells, on the splashguards and on the bottom of the rocker panels.

 

After the car was parked overnight in the garage and all the snow was melted from the wheel-wells, I noticed that the plastic cover under the passenger side floor (the long, aerodynamic cover/stone shield) was hanging down about 3 inches below the car's floor and the space above the plastic cover was packed with snow. Three of the plastic snap fasteners that normally hold the cover right up to the metal floor were broken off. I started scooping out the snow and ice with a long wooden stick, and removed (2) large snow shovels full (probably 35 or 40 pounds of very hard packed snow.

 

Upon close inspection I determined that the foam gasket at the front of the plastic cover had apparently been pushed back by the force of the snow being thrown off the front tire and had allowed snow to enter through the I/2 in high by 6 inch wide opening. As more snow filled the space, it pushed the cover downward and popped three retaining clips, allowing the cover to drop even further and allowing more snow to pack in the space.

 

The gasket that Subaru uses to seal the front of the cover (which is just behind the front wheel and is directly in the path of anything that gets thrown off the front wheel) is a piece of very low-density foam which is 5/8 inch square and about 9 inches long. It's held in place by a layer of double-sided clear plastic tape which mounts it to the plastic cover only. On my car the plastic tape let go and allowed the gasket to fold back and opened up the space above the plastic cover to the heavy snow spray from the front tire. The factory gasket is very light and the attachment method (double sided tape) is clearly not strong enough to withstand the pressure of a moderate snow spray.

 

I reinstalled the cover with new snap fasteners and made up a new front gasket using a length of 1-1/2 inch dia. Heavy expanded polyethylene foam. I cemented the new, thick gasket to the plastic cover and the metal floor using heavy duty weather-strip adhesive.

 

If you regularly drive in heavy snow, mud or gravel roads, you might want to check that it's not getting into the space above the "aero-covers" Note: These covers are not the lower engine compartment cover, but are the (2) 18 in. by 6 ft. covers under the passenger compartment.

[Gohmer1]

Cliffs notes?

[Visualfx]

Cliffs notes?

+1

[mwiener2]

Pics?

 

 

moved to exterior

[LotusSeven]

Pics?

 

Sorry. Didn't take any since removing the snow/ice/salt and then cementing the new gasket in with trim adhesive is a really messy job. The only practical way to get the trim adhesive in where it needs to go is with your fingers leaving your fingers covered in sticky goo.

 

It's possible to check that the front gasket is in place by feeling just above the leading edge of the plastic floor covering panels which are just behind the wheels and inboard of the rocker panels. If the gasket is gone and you can feel an opening between the plastic and the metal floor of the car, you have a potential problem.

 

The high-density closed cell foam I used (which seems to work well and is much stronger than the OEM gasket) was the stuff sold in hardware and home centers to insulate water pipes. I used 1-1/2 inch OD./ 3/4 inch ID. pipe insulation, which when crushed flat fits very tightly between the metal floor and the edge of the plastic cover panel and does a good job of properly sealing the opening.