Trans OverhaulQ. I have a '49 Merc with a big-block Ford and a C6 automatic transmission. The transmission works fine if I drive it every couple of days, but it acts like it's low on fluid when I start the engine and put it in gear after it sits for a week or so. In some cases, if it sits for a really long time-like a couple of weeks-there will be a puddle of fluid under the car. What's happening? And what's the fix?Tim MansonVia the Internet
A. If it makes you feel any better, we've got one that does exactly the same thing, and it means we both have transmissions that need to be overhauled.
Zack Farah and the guys at Gear Star Performance call this condition "morning sickness." According to Zack, "The rubber piston that seals in the clutch drums are hardening or crystallizing due to heat and age, allowing the ATF to bypass the piston rubber seals, thus causing this delayed engagement when cold."
Since your seals are of a square-cut design and not a lip seal style, Tim, this makes your problem more pronounced. "This has been a typical Ford problem for years and will progressively get worse," Zack continued. "The fix is a complete overhaul using the updated drum pistons and seals."
That's probably not what you wanted to hear, but these guys know what they're talking about
The delay in engagement is caused because it takes a short period of time after the engine starts for the clutch packs to fill with fluid-then the transmission works normally. After an extended period of time, so much fluid drains back that the fluid level rises to the point it leaks out somewhere-like in the dipstick tube O-ring or the shift lever seal-which means they're in need of replacement too.
This is all part of the transmission rebuilds that are in both our futures.