Amsoil ATF is not Mercon V. Amsoil ATF is "multi-vehicle". Some people think that Amsoil is perfect for everything. Amsoil is more expensive than Mercon V. Mercon V is sold by several different brands. I prefer to use Mercon V, as opposed to a "multi-vehicle" ATF. I don't care about branding, and I will use any brand Mercon V.



Find a good shop in your area. Discuss it with them. See what they have to say about their process for transmission fluid exchange. Some people believe that it's imperative to drop the pan, change the filter, clean off the magnet, and inspect the transmission for wear and damage. Then they go about exchanging the remainder of the transmission fluid. Other people simply hook up the cooling and return lines to their machines, and believe that you should be fine once the contaminated fluid has been exchanged. This process does not remove the metal shavings stuck to the magnet in the pan.

You can exchange the fluid yourself.

I have a Mag Hytec pan which has a magnetic drain plug. When I drain the pan, I am able to clean the metal shavings off the drain plug. I disconnect a transmission hose at the transmission cooler, turn on the engine, and allow the fluid to flow into a bucket. A few quarts pump out, I turn the ignition off. Add a few quarts through the dipstick tube. Then repeat until the clean fluid is flowing out the line. Now I know that all the contaminated fluid has been removed and the transmission is filled with clean fluid. Reconnect the transmission hose, turn the car on, check the dipstick, and add fluid to fill line.

A good shop will install Mercon V, which they should have in stock, or can get delivered from their distributor. Some shops stock Amsoil fluids and will try to steer you in that direction. There may be shops who insist on using their own preferred boutique brand of ATF. Any shop who insist on installing their own proprietary "multi-vehicle" ATF, something in a 55 gallon drum which they use on every car, you may want to avoid.

 

Fifty150, thanks for clearing up the issue of clearing up the fluid.

 

If you haven't serviced the transmission before, you are way overdue. What you are describing sounds like very contaminated fluid. Get fresh fluid in there, and see if it clears up. Then follow the maintenance schedule. You could actually change the ATF before the recommended service interval. All that it would do is keep fresh fluid in your transmission. Won't hurt the transmission to have fresh fluid.
Change Your ATF

 

Update:

I had the trans fluid changed two weeks ago. The mechanic said the fluid looks fine, but it was time for a change. He dropped the pan and changed the filter. Miles on the truck at time of change 59k.

I do not drive the truck every day so I've had limited opportunities, but I have not recreated the rumble strip sound since the fluid change.
So far the fluid change appears to have done the trick. I did not get a chance to remove the tune and put it back to stock.

 

Only the fluid in the pan was exchanged? The mechanic did not completely flush the system?

You put fresh fluid in the pan. Contaminated fluid is still inside of the transmission. The new fluid does not "freshen up" the old fluid. The opposite happens. The old fluid contaminates the new fluid. Some will argue that a pan drop and 5 quarts is just fine. Other people will say that you should always perform a complete fluid exchange.

Would you only change half of your engine oil?

 

Yes, only the fluid in the pan was exchanged. I asked my mechanic if he knew of a good place to do a full exchange and he just advised against doing a full exchange. I still do not know of a good place in Milwaukee area to do the exchange. Some of them just stick a tube down the dip stick and suck the fluid out. How can that be any different than dropping the pan? I can still do a fully loaded exchange should I find a place I'm happy with.

 

A proper exchange uses a machine that taps into the cooler lines. It doesn't suck the fluid out the dipstick. You fill the machine with fresh fluid, connect it, and start the engine. The transmission pump pumps the old fluid into a reservoir on the machine and draws in fresh fluid to replace it.

Dealers, good independent shops, chain auto repair shops, quick lubes, and transmission shops should all have the machine. It's almost a necessity these days for proper servicing. Last time I had this done, which admittedly was 15 years ago, it was at a Jiffy Lube.

NOTE: A lot of the machines you will find use air pressure or an internal pump to do the exchange. This is not desirable and you do not want to use any flush chemicals or backflush the transmission. That's probably why your mechanic advised against it.

 

At least your mechanic is honest with you. He's advising you, to the best of his knowledge. Your mechanic did the best thing, that he knew how to do.

My dad always dropped the pan, and refilled. He did that with every car he ever owned. His wisdom was based on flush machines doing more damage than good. And that was true, with the older machines. The old flush machines actually flushed. They pushed chemicals into the transmission. Those flushing chemical agents under pressure, did damage the transmission internals and seals.

Refer to what GLC wrote, in regards to the new machines simply being a receptacle for the old fluid, and a source for fresh fluid.

Even Jiffy Lube has the new machine. I know because I've brought my company truck to a Jiffy Lube for transmission fluid exchange. The problem with most of the chain shops is that they tend to use a multi-vehicle ATF, which you do not want. Go talk to the shops. Just about anywhere in the country, you should be able to find an AAMCO, FireStone, Sears, Jiffy Lube......or whatever good independent shop, that has a machine. Ask them if they can service your car with Mercon V. Even offer to pay them just for their labor and use of the machine, if you supply the Mercon V. But your first stop should be a dealership. Prices are higher, but dealership techs only work on Ford, are trained to service Ford, and will perform the service correctly.

When you drop the pan, you actually get to see what's in the pan. Is it just fine metal particulate stuck to the filter? Or are there larger pieces of metal, and or other materials floating around in there? You get to clean off the magnet. You get to change the filter.

Now here is what you can do in your own garage or driveway. Disconnect the transmission return line from the oil cooler. Place a 5 gallon bucket, with measurement markings, underneath where you just disconnected the line. Turn on the truck and pump out a gallon into the bucket. Add 4 fresh quarts of transmission fluid through the dipstick tube. Repeat this until you see fresh fluid being pumped out. Now reconnect the transmission return line, turn the truck on, check the dipstick level, and top off with enough fluid to the proper fill level. This process just completely exchanged your transmission fluid.

If you like your mechanic, and trust him, ask him if he could do that for you,.

My ex was working at a location 280 miles from home. She had to take an apartment in that area, as nobody commutes for 5 hours each way. Between me going there on my days off, and her driving back here on her days off, we put a lot of miles on the cars. Her apartment was right across the street from the local police department, and next to the shop which performed fleet service for all of the vehicles in that small town. One day, I was changing the oil on our cars while she was at work. The police lieutenant came over to talk to me. He introduced me to the guy in the shop, who happened to be his cousin, and explained that we were commuting thousands of miles a week between us. No problem. Just bring the cars into the shop. No charge, since you are doing the work yourself & supplying your own oils & filters. At least I'm not doing it out on the street. That's when he saw me perform the poor man's transmission flush. They had been sending all the city vehicles to the dealership 40 miles away for transmission service. He couldn't believe how simple it was to just disconnect a return line, pump out contaminated fluid, and add fresh fluid. He got the city manager to approve the work, and added an extra $250 per car in revenue to his billing. After that, I hung around the shop and helped out where I wanted, and the corner garage guy did everything on my ex-girlfriend's car for free. Free labor. I paid for parts, bought from him at his mark-up, which is still a great deal.