I have 145,000 miles on my 1998 F-150 (my dad had it before me) and I dont think he ever changed the transmission fluid. (automatic, does E40D sound right?) I got it with 76,000 miles on it, and I have been scared to change the fluid ever since. I have heard that changeing the fluid this late in the game would loosen some of the grime and clog the orafices in the tranny. The engine has been overheated one time and I know that this degrades transmission fluid. But I am worried that if anyone messes with it, that it will never be the same again, and it runs great right now. If I replace it, I am going to use royal purple fluid. Thanks in advance for the help.

 

this is always a topic of conversation on this board. you will get 20 different opinions on what to do. i tend to agree that if the transmission oil is flushed under pressure that things can loosen up and flow into the orifices or spools as you suggest. i have always thought it was a good idea to drop the transmission pan, change the filter and scrape the deposits off the bottom of the pan and valve body. i then reinstall the pan and add about 5 quarts of oil. note that you are only getting about 35% of the oil changed, but you get the crud out below the filter, get a new filter, improve the oil 35% and have a general idea what things look like inside. i tend to change the oil this way every 2-3 years.

 

The problem with changing is NOT clogging orifices, rather if the fluid is burnt, the clutch faces may go away, but this is rare. If that is the case, a power flushing poses a much greater risk of making this happen than does a simple drain and fill.

Such neglect most definitely shortens transmission life. For every 10 degrees above normal temperature that the ATF reaches, the life of the fluid is cut in half. Since the vehicle has been overheated, certainly your fluid and most likely your transmission are on borrowed time.

Have you smelled of the fluid? What does it smell like?

Good luck,
Doc

 

Have it power flushed. These trannys last a long time when properly maintained. I recommend it every 60,000 miles.

 

I to got my 98 4x4 F-150 exstended cab from my dad when he passed away.It had 72,000 on it but very well maintained.Never a trans flush though.That was the first thing I had done to it at Ford.Never a problem.If anything it felt better.

GO FOR IT! Steve

 

Not changing the fluid will do more damage than changing it. If the transmission is in good shape to begin with, fresh fluid will only prolong the life of the transmission. If the transmission is damaged or worn out it will eventually give out anyway.

 

Thanks guys! I appreciate the help. If anyone knows something that has not been said here, tell me, I want to know. Thanks again!

 

Someone in the thread recommended power flushing. If the fluid smells burnt, power flushing can very easily wash away the clutch linings and the truck won't even be capable of backing out of the stall on it's own power.

If the fluid is NOT burnt then power flushing is a WASTE OF MONEY.

Power flushing has one SIGNIFICANT advantage. That advantage is that it puts lots of money in the pockets of the shops that use it and the companies that sell/promote it and the service advisors that are pushing it.

Unfortunately most modern automatics no longer provide a means of draining the converter. That means that you can only drain part of the fluid. If that is done regularly, that will suffice because you are replenishing the drained fluid with fresh fluid with fresh additives.

I have heard all sorts of methods of how to drain modern torque converters but I pay no attention to them. Although I am certified on automatic transmissions, I try to stay as far away from them as possible. I don't like driving them and I don't like working on them. For those of you who do like them, that's fine, but you should be servicing them REGULARLY and PROPERLY.

Best of luck,
Doc

 

These trucks have a drain plug in the converter. Power flushing changes all of the fluid in the tranny including the lines and coolers. Fluid breaks down over time. It may ne be burnt, but the detergents and other additives need to be replaced. It's a little thing called preventative maintenance. You don't wait until your engine sludges up before changing the oil do you? Flushing the fluid every 60,000 mile swill not only revive the fluid, but also remove all of the floating debris from the tranny such as the normal wear of the clutches and will also keep the converter lock up clutch from chattering.
I don't think that $120 every 60,000 miles is too much to pay to keep a $2500 tranny in good shape.

 

Just had mine done @ 103,000 MILES. It's more responsive and feels smother shifting.

A ounce of prevention is better then a pound of cure!

 

All of the transmission machines I've seen connect between the transmission oil cooler line and the cooler. The machine takes the fluid going to the cooler and places it in a container and feeds fresh fluid to the transmission pan through the oil cooler. No power flush to speak of, just a fluid exchange. With 145,000 miles on the transmission a filter change and complete flush would be the best way to go. IMO

 

They call it a power flush, but that is how it's done.

 

change yes, flush no! I have bought and sold a ton of these trucks and most with over 100k only 2 I have had flushes done and both trannys went within 1500 miles. Disconnect trans line on radiator start truck and allow fluid to be pumped out of converter, but shut truck off immediately when fluid starts to slow down. change filter and refill with merc v, after servicing in this manner have never had another problem, and have even had it cure what I thought were going to be big problems. (shudder, slip rough shift etc.)

 

My Ford dealer did mine 10,000 miles ago. No problems yet.

 

both trannys that went in ours after flush had between 135k and 150k. its always a possibility there were pre existing unkown problems starting. from experience, i would not have another high mileage truck flushed, especially not were a flushing agent is used. transmission oils have such high detergents that the transmission should get clean from the fluid change. also from previous post, there is a drain plug on the bottom of converter. remove round black rubber cap and there it is.