what might be the cause of the speedometer stopping and transmission being stuck in first gear on a 1999 dodge caravan with 33,ooo miles?
also on a 2001 Lexus, the new tires seem to lose air, have had 2 sets that do the same thing; dealer says my aluminum wheels are corroded and need replacing?
On the tires loosing air, rims can be porous, but they would have leaked since day one. I have never seen alloy rims corrode enough at the bead to leak. In any event, steel wool and a coat of paint would smooth and seal them for a lot less money than replacing the rims.
Have you sprayed soapy water in and around the valve stems, and everywhere else, for that matter, to see where the air is getting out?
P.S. The paint would go on the inside, not on the visible part of the rim.
On the Caravan, VSS (speed sensor).
I agree with Tardis that your Caravan needs to have the VSS replaced. What you have described are classic symptoms of this problem.
I think tire shops can apply a sealer to help with leaky bead seals. The tire would have to be remounted on the rim in order to apply the sealer.