changing tranny fluid

[chevy art]

how often do the racers change the tranny fluid in a drag car, mine is a 383 with glide and comes through the traps at 7800 rpms . has tranny cooler and deep pan; car runs cool, but in past it overheated once or twice. i dont think i ever changed the fluid after the overheating. i run castrol type F in there. dont mind changing it tomorrow if concensus of opinion is to do so, its been in there for probably 4 or 5 ye. sure would appreciate advice on this. PS should i add an additive with the fluid change if i do change it. or maybe just add an additive to the old fluid. thanks Art

[F-BIRD'88]

The biggest issue with ATF is heat.
Excess heat is what kills ATF and auto transmissions.
Yup well due for a ATF change.

Remember just draining the trans pan leaves a ton of the old fluid in the torque converter. If your converter does not have a drain plug on it pull the converter and drain it.
Can take it to a trans shop. They will install a drain plug on your converter and can flush it for you.
Heat-overheated ATF is not your friend.

[engineguyBill]

High-stall torque converter generates a ton of heat, even though you are running a trans cooler. Like T-Bird has pointed out, heat is an instant killer where your AFT is concerned. You are probably running a small diameter torque converter, but it still should be drained. You are way past due for transmission service, I would recommend changing fluid in the transmission and torque converter at least once a year, regardless of the number of passes made. Don't worry about transmission fluid additive, just run good quality ATF and all will be good . . . . .

[F-BIRD'88]

Another good thing you can do to get your drag car ready for this racing season is clean ALL the electrical ground points on the car.. These ground point connections ( engine, ignition box, dely box, relays, fuel pump, engine to car body) corrode over time especially on cars in winter storage.
They need to be cleaned annually.
Drain and refill and bleed the brake system too.
Tends to attract moisture over the winter.
Remove and clean the connection of the big Positive battery cable on your starter motor too.
This connection is critical and tends to degrade over the winter... The whole electrical system and starter will tank you..

[BOOT]

Can't rem where I read it but it was suggested to change your fluid before storage(if you do it every season) so the contaminates don't settle and varnish up the trans.

[Schurkey]

Take the hose/tube off the cooler outlet, install a temporary hose or tube that empties into a drain pan that'll hold 15+ quarts.

Start engine, at the first sign of low pressure into the drain pan, shut off engine. Drop pan, replace filter, clean pan, reinstall. You've already mostly emptied the pan, so it won't be that messy to remove it.

Add 5 qts of fluid through the dipstick tube. Open another 3--5--7 depending on trans capacity. Have a helper start the engine, you dump fluid down the dipstick tube until the fluid coming out into the drain pan looks virgin-fresh. Shut off engine. Reconnect cooler hose or cooler tube.

Top off fluid as needed. Have a beer. You've just changed all the fluid in the trans except what's trapped in the clutches and accumulators and geartrain, flushed the converter, flushed the cooler, and installed a fresh trans filter, all without having to go to the local trans shop.

Type F is popular as a "high performance" trans fluid, but Dexron takes heat better, AND lubricates better. Synthetic is better-still.

[tenxal]

Yes, you're due for a change. With a cooler, you can empty the convertor as suggested by taking a line off and running it.

Amzoil's Super Shift trans fluid is a very good product that's recommended by many of the racing trans and convertor builders. We've been using it for years in our stuff with excellent service.

[dannobee]

The cooler hose into the drain pan trick works for me. I learned another trick from my old coworker who races a super stock ford. If you put a remote engine oil filter in line near the trans cooler, it'll even filter out the clutch material and keep the fluid a lot cleaner than just the screen. Change the filter when you flush out the fluid and cut it open to verify that there's no surprises in there when you're done servicing the trans.

Allison's have a filter boss built into the case, and "servicing" consists of changing the screw-on filter and topping off the fluid.

[Geoff2]

Reading all this, with buckets of fluid going everywhere, I am veeeeeeeery glad I had a drain plug fitted to me converter [ a la Chrysler ]....