Tranny Fluid Change Question
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,387
Likes: 123
From: CA.
Tranny Fluid Change Question
want to change fluid on my th400. got a 454 ,dont know if that matters but how is it done? i also want to change filter. i know i drain fluid and unbolt filter i think. are there any tricks or something im not aware of? i remember when i was younger they used to tie gasket with string. should i do this and do i use a sealer too. also what filter and fluid should i get? thanks, nutsy.
Instructor
Joined: Mar 2006
Posts: 246
Likes: 1
From: west melbourne florida
get the gasket and filter and fluid dexron or dexron 2 remove the tranny pan .then remove the 2 strainer screws for the filter. replace filter.install new gasket. you can use indian head gasket sealer small thin film. to hold new gasket onto pan. bolt pan up fill with fluid about 20 pints. then road test and check for leaks
Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
If you only remove the pan, you are getting less than half the fluid.
If the torque converter has a drain plug you should drain it too. If not then it gets more difficult.
Better with a helper.
Do the pan thing,
Then disconnect the return line from the radiator to the tranny,
Start the engine at put in drive and watch the fluid run into an empty bucket. Stop and refill thru the dipstick tube. Repeat until the fluid into the bucket is clean fluid.
Reconnect the return line and check the level.
It helps to know the total capacity and keep track of how much you are putting in as you go.
With this method all the fluid is changed.
If the torque converter has a drain plug you should drain it too. If not then it gets more difficult.
Better with a helper.
Do the pan thing,
Then disconnect the return line from the radiator to the tranny,
Start the engine at put in drive and watch the fluid run into an empty bucket. Stop and refill thru the dipstick tube. Repeat until the fluid into the bucket is clean fluid.
Reconnect the return line and check the level.
It helps to know the total capacity and keep track of how much you are putting in as you go.
With this method all the fluid is changed.
Race Director
Joined: Sep 2001
Posts: 10,560
Likes: 439
From: Wellington, FL
St. Jude Donor '11 thru '25
I would use a slight coating of RTV on both sides of the gasket rather than anything else. This stuff makes a great seal and very easily peals off when you want to change the gasket next time. I would also recommend Mobil 1 synthetic ATF as it can handle heat much better. If the fluid doesn't have a burnt smell and appears to have the fairly normal red tone to it, I wouldn't bother changing the fluid in the torque converter. If the fluid is old, that's another story. This is a simple job that you can do yourself. BTW, I don't think Dexron or Dexron ll is available any more. Most of it is lll or higher today but the synthetic is great and will mix fine with whatever Dexron you are running. 
Burning Brakes
Joined: Feb 2006
Posts: 1,024
Likes: 1
From: AL
if your going to replace all the fluid, i'd recommend to not disconnect at the radiator, but at one of the hose connections of the cooling line return. this way, you don't take any chances with the threads in the radiator.
you can also let the engine run and fill the tranny at the same time, just need to get the fill rate about the same as empty rate. make graduations on your dump can so that you don't get more than a quart off. it usually doesn't take much more than the total normal fill amount before clear fluid begins to discharge . . .
you can also let the engine run and fill the tranny at the same time, just need to get the fill rate about the same as empty rate. make graduations on your dump can so that you don't get more than a quart off. it usually doesn't take much more than the total normal fill amount before clear fluid begins to discharge . . .
