I'm getting ready to do a fluid change on my tranny. As far as I know it's never been done before. I bought the truck in 2004 with 164,000 kms it now has 223,000.

From the reading I've done, I don't want a "flush". I'm planning on changing the fluid myself and installing a drain plug, I will also use the plug to mount the sensor for my temp gauge.

I've heard that there is a danger of a catastrophic failure when changing the fluid an older tranny with and unknown history. I've used the truck to pull my 5th wheel since getting it. Nothing excessive and not too frequently. It doesn't appear that the previous owners used it to tow with.

I know when you change the fluid in the pan, you are only changing about 75% of it. I plan on getting a larger capacity pan in a couple of months so I'll be changing the fluid again at that time.

Does this sound like a safe plan?

How about using synthetic vs. regular ATF?

Thanks,
Dave

My truck got its first trans oil change at 270000kms. there has been no negative effect from it. My truck has did some trailer towing but the oil was still good and the bottom of pan was also clean. I also don't think that flushing a trans is a good idea especially a high miler that hasn't been changed before. your plan sounds good but I would wait until you get the big pan and just change the oil once. I believe if I remember correctly the trans complete system is 15 quarts(plus whatever extra your new big pan holds) approx 12 quarts will come out of the pan the rest is in the converter. You can get the rest of the oil out of the converter by refilling the pan and trans with the required amount 12 quarts plus the extra amout for the big pan. Then unhook the trans cooler feed line at the rad ( I believe the top one) hook a clear plastic hose on the trans line with the other end into a large pop bottle. Start the engine and idle for approx 30 second, stop and measure oil in bottle and then add oil to trans. Redue this until you have approx 3 quarts out the oil will start to run nice and clear. Stop recheck level. you will have completely changed the trans oil.

I have heard synthetic is the oil of choice, wish I had used it, the trans will run a little cooler with it. It is very expensive but the way of changing the oil as I described will save some money.

Hope you are changing the filter while your at it, if your truck has a rubber gasket on the pan reuse it as they are good for approx 6 oil changes and is much better than cork and such . A new rubber gasket is about 60$ so becareful when removing not to hurt it.

Tracy,

Thanks for the info. Maybe you're right. I'll just wait until I get the new tranny pan.

One question. When draining the fluid from the cooler line. Does the vehicle have to be put in gear to get it to pump out or just in park?

I'm going to keep my eye on the Canadian Tire flyer to see if they put synthetic tranny fluid on sale.

Dave

if the fluid is that dirty and old, change it. but i would change it again two more times within a week or two, just to make sure you dont get a blockage of crud.

if the fluid is that dirty and old, change it. but i would change it again two more times within a week or two, just to make sure you dont get a blockage of crud.


That sounds expensive, but cheaper than a new transmission I guess!

Dave

if the fluid is that dirty and old, change it. but i would change it again two more times within a week or two, just to make sure you dont get a blockage of crud.


I was pretty amazed at how clean my oil was and just a little bit of band material in the bottom of the pan and that was after 270,000kms. Maybe i was just lucky.

I can't remember for sure If I had it in park or neutral, I think park.

i bought a friends 96 3/4 ton truck with 150k miles on it. he never changed the trans fluid.
the old fluid came out black. so i installed a drain plug, and changed the fluid a couple more times to try and get all the old fluid and crud out.
the truck has 200k miles now, and the trans shifts like new still.

I have always wanted to go synthetic in mine. That stuff is expensive though! I have heard that the 4L80E will hold about 14 quarts with TC. I want to run a deeper pan so I would be looking at around 18 to 19 quarts total. Plus I also have a fairly large auxillary cooler which will probably put me around 20 quarts. I figure it would cost me almost $200 to put Amsoil Synthetic Torque-Drive in my truck. I haven't decided if that is the route I want yet or not. My transmission is on a new rebuild. Now would be the time to do it.

As for Tracy's post, this is what I would recommend. This procedure is actually given out by Amsoil although they suggest filling as it is running and just keep an eye on how fast it is coming out and fill around the same speed.

I don't know about trucks, my background is all cars.... this input may be useful though.

On my 1989 V6 Toyota Camry, I changed the (neglected) trans fluid and it whined forever after. I later learned on a BMW forum that when you suddenly change the trans fluid that the new fluid with its fresh detergents break loose all the crud and the crud clogs stuff up. When it was time to change the fluid in my 1985 BMW 524 turbo diesel I was worried. What I did was drian it into a clean pan, filter it the used fluid through a 1 micron bag filter and re-used 1/2 the old fluid. I replaced the filter and ran it like that until the next oil change when I replaced all the fluid that came out the drain and used another new filter.
It worked great and I plan on doing the same on my '93 3500 with 130K miles.

4L80E is agreat trans and i beleive 04 has a reusable pan gasket as long as it wasn't overtightend previously you should be good tourque to 98in pds or 8ft pounds my experience with drain plugs is to have a bung welded in on passenger side of pan it might cost more but all the other own's i have seen leak as far as synethic it all comes down to personal choice

Just changed the fluid (probably original) in my 96 K3500 with 65000 miles. Used RP Max ATF. In response to an earlier post, pop the return line AT the tranny and after 1-2 quarts, shut down, refill, do again until clean fluid.