The horizontal tailgate on the 80 Series is prone to damage of the inside skin when one kneels on the middle of the lowered gate. Post 95 models did get some extra bracing but it still does not alleviate the problem.
To check your tailgate, look along the forward of edge of the horizontal width of the lowered gate. It should be flat. If it is bowing in the centre, you've been kneeling on it.
If it is badly bowed, the inside face pulls away from the weather strip and will allow the ingress of dust and water (when it's that deep). You may also notice exhaust fumes in the vehicle. If it's that bad, you will have to speak to your Toyota rep, even if it's out of warranty. They need to rectify this problem at the factory. They may come to the party with another lower tailgate if you scream loud enough. The current cost in Australia is ~$1,200 so it is worth your while to scream.
Your other option is to have it repaired, but most body shops will not touch this sort of job.
> Please give me the clues as well if you could please. I too
have a slightly
> bent tailgate. not letting too much in yet.
You will need to remove the carpet from the tailgate. It should be pried off gently as it's held on with plastic clips. then remove the metal plates, from memory there are two, so as to gain access to the tailgate.
The parts you will need are a piece of timber 2"x1" approx 8 inches long, a bolt with any eye on the end of it (as in a turnbuckle) a washer and nut that fits the bolt, some glue and a ratchet strap.
Now the fun begins ... drill a hole in the timber on the 2" side so that the bolt will pass through. Glue the washer and nut to the timber. When dry, insert the timber into the tailgate, you will see the holes that you have to match up with on the lower edge of the tailgate, now insert the bolt and presto you now have a way to pull out the tailgate. A little bit at a time and move the timber around to the other holes.
I used the ratchet strap to attach to the bolt and then to a limb of a tree .... and you will need to sit on the tailgate to stop it trying to close. :-)