::95 Blazer::Tranny Flush Advice
cleanshavenrsx
12-12-2005, 01:38 PM
I have a delemma... i need a trans service bad.... the fluid smells bad while driving dark almost black... yesterday it was really cold out and i couldnt get reverse... it was fine today tho.... now the problem i was going to get it done at my work but i knoiw nothing bout the tranny all i can do is say it has 202000 miles on it because i dont know if it was changed rebuilt ever had gaskets done... soo.. if i do a\ full flush i could destroy the tranny...... what should i do??? any one in sepa good with trans that can help me out???
wolfox
12-12-2005, 03:02 PM
Get a Wix tranny filter and pan gasket kit with a revised rubber on metal filter collar. It will cost you about $15 to get one. Grab up about 6 quarts of your favorite ATF. If you are not mechanically inclined, enlist the help of friends that are. If that fluid's BLACK as you say, get more ATF than the 6 quarts...I would get 10-12 quarts.
Siphon/suck out all of the tranny fluid you can from the filler neck with a long hose. Add in 3 quarts of ATF, and then check the level according to your manual:
"After the engine is hot, and you have driven the truck for more than 15 miles at highway speeds, place the transmission in Neutral and withdraw the fill-tube dipstick."
Make sure that the fluid when hot and the truck's in neutral with the e-brake on - is between the low and full-hot marks on the dipstick. Drive the truck around a little more to allow time for the fresh ATF to circulate and start unplugging and cleaning things up.
After a few dozen more miles of leisurely, highway like driving, return to your service area, and drop the tranny pan. If you have a 4x4, belly armor and a tranny crossmember have to be removed. Keep the transmission upright and in place when you remove the cross member by using a small floor jack to hold it near the output shaft housing.
Remove the pan and let it drain out. Pull the old filter out, and extract the seal that fits around the neck of the filter inside of the valve body housing either using an extractor tool, or a blunt, small blade screwdriver to crush the sides a little, then using needle-nose plier to remove the old seal. Drive the new seal that came in the box up into the filter bore with a socket that just fits the hole with *very light* taps until it seats. Push the new filter into place into the hole you drove the seal up into with *firm* pressure. It will literally *pop* up into place when it's fully seated.
Clean and flush the tranny pan with brake cleaner, it leaves no residue. Make sure that the little magnet in the corner of the pan is clean too, wipe it with a rag soaked in brake cleaner to get all of the "clay" looking gunk off of it. Inspect magnet and bottom of the pan for large slivers of steel or tips of gear teeth. A small amount of metallic grey clay-looking powder is okay....half moons of silver-like steel the size of pinky nail clippings is not.
Scrape all of the old gasket off of the body of the tranny and the pan using the crushed end of copper tubing, 1/4" reference tube used for A/C systems in permanent installations is perfect for this. Pound the end flat on your workbench with a steel hammer to make a flat, broad head and use that to scrape remaining gasket gunk off. Finish the cleaning of the seal surfaces with a rag soaked in acetone. You do not want anything on the metal between these surfaces, nor gouges/rough edges.
To help hold the undoubtably curled up seal a little easier, you may insert a few bolts into the holes of the pan and gasket. Or, if the holes in the gasket are too large to use this trick, spray the side of the gasket that will meet the pan face with a copper sealant. It will dry tacky after a minute or two, and you can lay the gasket on the pan's lip like a sticker.
Bolt her back up, about 13 foot pounds of torque in a cross-wise fashion will be more than snug enough. Too tight, and you'll crush and bite through the gasket. (A good excuse to buy a torque wrench here!) Refill the tranny with 3 quarts of fluid, start the engine and with your foot on the brake; cycle through each gear range slowly. Put the tranny into each position and pause, letting it sit there for ten seconds, from park to Low-1, and back to Park. Then, place the tranny in Neutral, apply the parking brake and get a look at your dipstick.
If all is good thus far, you should not see any leaks under the truck, and the fluid will be to the level of "Low/Cold" just below the hash marks. Drive her good and steady for at least 15-20 minutes down the highway, and re-check the fluid again - in Neutral, with the truck on *level* ground. It should be 3/4's to right up to the top of the "Full/HOT" mark at the top of the haskmarks. If NOT, add small amounts of fresh ATF until it is.
In 7000 miles, suction out as much ATF as you can through the fill tube, replenish and check the same as I have described above. Inspect the fluid - expect it to still be a little dark, but show improvement. Also, discharging the fluid into a shallow collection pan will help you spot if the tranny's shredding itself up, you'll see small, suspended sparkly metallic bits in the fluid if it's coming apart. Otherwise, keep on driving it, drawing off your tranny fluid every 2-3 oil changes and replenishing it, then replacing the filter every 35,000 miles or 3 years will pretty much see to it that it goes a bit longer than 202k Miles. Good luck!
Siphon/suck out all of the tranny fluid you can from the filler neck with a long hose. Add in 3 quarts of ATF, and then check the level according to your manual:
"After the engine is hot, and you have driven the truck for more than 15 miles at highway speeds, place the transmission in Neutral and withdraw the fill-tube dipstick."
Make sure that the fluid when hot and the truck's in neutral with the e-brake on - is between the low and full-hot marks on the dipstick. Drive the truck around a little more to allow time for the fresh ATF to circulate and start unplugging and cleaning things up.
After a few dozen more miles of leisurely, highway like driving, return to your service area, and drop the tranny pan. If you have a 4x4, belly armor and a tranny crossmember have to be removed. Keep the transmission upright and in place when you remove the cross member by using a small floor jack to hold it near the output shaft housing.
Remove the pan and let it drain out. Pull the old filter out, and extract the seal that fits around the neck of the filter inside of the valve body housing either using an extractor tool, or a blunt, small blade screwdriver to crush the sides a little, then using needle-nose plier to remove the old seal. Drive the new seal that came in the box up into the filter bore with a socket that just fits the hole with *very light* taps until it seats. Push the new filter into place into the hole you drove the seal up into with *firm* pressure. It will literally *pop* up into place when it's fully seated.
Clean and flush the tranny pan with brake cleaner, it leaves no residue. Make sure that the little magnet in the corner of the pan is clean too, wipe it with a rag soaked in brake cleaner to get all of the "clay" looking gunk off of it. Inspect magnet and bottom of the pan for large slivers of steel or tips of gear teeth. A small amount of metallic grey clay-looking powder is okay....half moons of silver-like steel the size of pinky nail clippings is not.
Scrape all of the old gasket off of the body of the tranny and the pan using the crushed end of copper tubing, 1/4" reference tube used for A/C systems in permanent installations is perfect for this. Pound the end flat on your workbench with a steel hammer to make a flat, broad head and use that to scrape remaining gasket gunk off. Finish the cleaning of the seal surfaces with a rag soaked in acetone. You do not want anything on the metal between these surfaces, nor gouges/rough edges.
To help hold the undoubtably curled up seal a little easier, you may insert a few bolts into the holes of the pan and gasket. Or, if the holes in the gasket are too large to use this trick, spray the side of the gasket that will meet the pan face with a copper sealant. It will dry tacky after a minute or two, and you can lay the gasket on the pan's lip like a sticker.
Bolt her back up, about 13 foot pounds of torque in a cross-wise fashion will be more than snug enough. Too tight, and you'll crush and bite through the gasket. (A good excuse to buy a torque wrench here!) Refill the tranny with 3 quarts of fluid, start the engine and with your foot on the brake; cycle through each gear range slowly. Put the tranny into each position and pause, letting it sit there for ten seconds, from park to Low-1, and back to Park. Then, place the tranny in Neutral, apply the parking brake and get a look at your dipstick.
If all is good thus far, you should not see any leaks under the truck, and the fluid will be to the level of "Low/Cold" just below the hash marks. Drive her good and steady for at least 15-20 minutes down the highway, and re-check the fluid again - in Neutral, with the truck on *level* ground. It should be 3/4's to right up to the top of the "Full/HOT" mark at the top of the haskmarks. If NOT, add small amounts of fresh ATF until it is.
In 7000 miles, suction out as much ATF as you can through the fill tube, replenish and check the same as I have described above. Inspect the fluid - expect it to still be a little dark, but show improvement. Also, discharging the fluid into a shallow collection pan will help you spot if the tranny's shredding itself up, you'll see small, suspended sparkly metallic bits in the fluid if it's coming apart. Otherwise, keep on driving it, drawing off your tranny fluid every 2-3 oil changes and replenishing it, then replacing the filter every 35,000 miles or 3 years will pretty much see to it that it goes a bit longer than 202k Miles. Good luck!
cleanshavenrsx
12-12-2005, 03:27 PM
good write up... so you wouldnt reccommend getting it flushed?
wolfox
12-12-2005, 10:47 PM
No, not at all. Just a few, short intervals of changed fluids. You'll not be able to get ALL of the fluid out, but a few, quick partial changes will begin to fortify the old, used up fluid and start cleaning parts slowly. Flushing can knock crap loose, especially on neglected trannies that can lodge elsewhere and cause even greater problems. Slow, easy, methodical is the key. If the tranny survives, it didn't need anything more than clean fluid and clean filters. Keeping up with clean fluid and filters is the best thing you can do to it in the long run rather than "shock treating" it sporadically, IMO. After three-4 changes grabbing what you can from suctioning the pan out and changing the filter halfway through it all, you'll be on your way to a cleaner, happier gearbox.
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