So, I bought my F-350 recently and it's almost at 170k miles. I am no longer in contact with the seller. I called Ford to inquire about servicing the transmission. The Ford service manager related since I do not know how long its been, if ever, since the transmission was last serviced, he recommends I do not service it and leave the existing fluid in there. I asked him, "So, if I drive this truck another 300,000 miles on the existing tranny fluid, thats ok?" He replied, "Yes."

Apparently, if a Ford transmission has over 100k miles and has never been serviced, its safer to not service it for fear of it being damaged or something like that.

Whats this all about??? The thought of never flushing my transmission is crazy to me.

 

Well, you’re certainly not the first one in this and many other forums to have brought this question forward.

You can find numerous threads here wherein the discussion has presented itself. Moreover, we (FTE) have a former Ford Transmission Engineer who chimes in from time to time on many issues, this being one of them.

I suppose it lends itself to two theories of thought. One being that:

New fluid in a transmission not maintained loosens deposits causing harm in the system and it would fail sooner rather than later.

The other being that new fluid can’t be bad for the system and can help extend its life. And, if it fails, it would have failed regardless.

While I probably won’t be purchasing a vehicle since retirement like ours again, I would say that when I did purchase vehicles,maintenance records of some sort were always a must before I paid out the dollars. The mere fact the owner has some type of records places them in a minority. A minority I seek when spending money. Lesson Learned.

In my opinion, I have always done a complete factory maintenance when I purchased a vehicle even if the owner had records indicates such. That maintenance included the transmission fluid and filter. I personally have not had an issue with my current transmission nor have any other I performed maintenance on following purchasing.

However, (just as the service manager) many have. Coincidence? Perhaps. Concerns of liability? Maybe. Nonetheless, I personally can’t see where fresh fluid and filter (if for no other reason to inspect the pan’s contents for contaminates) could shorten the life of the transmission, that’s me.

What follows is a process used by many here and written by a former Ford Transmission Design Engineer.

TOOLS: Container for 17 Qts of Transmission Fluid, Socket, Ratchet, Pliers, Rags, Clear Tubing, assistant (optional, but encouraged).

I’ve done this alone. It’s easier with a second person, and sometimes helps prevent spills. - Kovalsky

1. Things you need to get started:

a. The E4OD and 4R100 transmission system holds almost 18 quarts of ATF, and you must waste a couple of quarts to be sure you get it all purged and replaced, so buy 20 quarts of MERCON ATF [For the 4R100, use MERCON V]. You may use either conventional or synthetic, as long as it meets the above requirements. The 4R70W transmission system holds about 14 quarts of ATF. The 4R70W uses MERCON V, and the MERCON V can be used on older 4R70W transmissions that were factory filled with MERCON.

b. I replace the transmission filter every other fluid change. Note that Ford does not recommend ever changing the filter. I’ve opened filters with over 300,000 miles that were not even close to being clogged.

c. Don’t buy a new pan gasket. The original is reusable.

d. A 10 foot length of clear tubing and one hose clamp, sized to fit over your cooler hose. There have been different size cooler lines over the years, so check before buying!

e. If you don’t already have a special funnel that fits into the transmission dipstick tube, then you will need one of those, too.

2. If you are changing the filter, drain the pan if your pan has a drain plug. If you are not changing the filter, jump to step 4.

a. If you don’t have a drain plug, go to step 4 to pump out the pan, preventing an ATF shower! Return here after step 4 and one pass through step 5a.

b. Remove the pan and clean the pan and gasket, including the magnet on the bottom of the pan. Fuzz on the magnet is normal, that’s why it is there!

c. Change the filter. It just pulls out, there are no bolts that hold it. It is held in place by the pan. Make sure that the O-ring is removed, too. Sometimes it does not come out with the filter.

d. Replace the pan, using the reusable gasket.

e. At this point you can drain the torque converter. Some people think it is necessary, but I don’t. Running the engine in the next steps will pump the fluid out of the torque converter. If your transmission was built after August 2001, you don’t have a drain plug in the torque converter.

f. To drain the torque converter remove the shield (or the rubber plug in some models) and turn the flywheel until you see the drain plug. If you also drain the torque converter, then the old ATF will not come out the return line until after the torque converter has filled.

3. If you drained the pan, pour new ATF into the filler [dipstick] tube until you have added about as much as you earlier drained from the pan. At this point overfilling by no more than one quart won’t hurt anything.

4. Disconnect the transmission-fluid return line at the transmission – from where the ATF returns to the transmission from the cooler. This is the line towards the rear of the transmission. Clamp the clear tubing over the line that you removed from the transmission. This is where the fluid comes out.

5. This is where the second person comes in handy. One person starts the engine, while the other holds the line over the drain bucket. A clothes pin can replace the person holding the line in the bucket. Run the engine until you see some air in the clear tubing. As soon as you see air shut off the engine. Refill through the dipstick tube with the same amount as you just pumped out.

NOTE: If you drained the pan and the torque converter, fluid will not run out until you fill the pan a second time. Run the engine for 30 seconds, then stop and add six more quarts.

6. Repeat step 5 until you have added 19 quarts with of new ATF to the system with an E4OD or 4R100. Repeat until you have added 13 quarts with the 4R70W. At least one time while the engine is running move the shifter through each position from P to 1, pausing about 5 seconds at each position. This will change some fluid that would otherwise be trapped in the valve body, accumulators, and clutches.

7. Remove the clear line and reconnect the cooler line to the transmission.

8. Check the fluid level and use the last quart to top off.

9. Properly dispose of the used transmission fluid.

10. Congratulate yourself! And your engine starter/killer person.

Hope this helps,


Tom

 

Keep in mind he'd rather sell you a new transmission than change the fluid in that one.

Me, too.

There is a tiny thread of truth here. Often a trans that has never been serviced and is WAY over where it should have been serviced will fail right after changing the fluid.

It has NOTHING to do with new fluid breaking loose deposits that cause it to fail. That does not happen. People make that up because it seems to make sense. It doesn't make sense to me. It has NOTHING to do with the new fluid "shocking" the transmission. It has NOTHING to do with the junk in the old fluid holding the transmission together. That's ludicrous!

What does happen is that the trans is ignored until a problem shows up. Then they decide to service the trans, maybe that will fix the problem. No, it will not. The problem is that it has been ignored and the old fluid has destroyed the trans. Now it needs a new trans, and only changing the fluid won't repair the damage and the trans fails. I maintain that the trans would have also failed if the fluid wasn't changed, but now they blame the new fluid, not the 170,000 miles of abuse from not changing the worn out fluid.

 

i bought my 02 diesel with 140,000 on the clock. first thing i did was take it to the local ford dealer for oil change and trans service. dealer said don't do it. i told them to do it. they then said there is no gaurentee it will hold. i told him do it or i will get someone else to do it, i am not listening to you because you want to sell me a new trans.
i have since changed it again, and it is due for service again in 9,000 miles.
read the owners manual, it says trans should be serviced every 30-35k miles.
i have transmissions in vehicles i maintain that get serviced every 30k miles that have over 400,000 miles on them.
then i hear people beefing because they need a trans at 100-150k miles, because it has the factory fluid in it.

 

Thanks all for the responses. I located the sellers contact info and spoke to him. He related he serviced the tranny every 40,000 miles. Truck just rolled over 169k, and its been 4 years since the last service at 160k miles. So, Ill make an appointment and have it done.


Thanks again!

 

Super! I not only changed mine at 141k when I first got it, I did the flush described above and have gotten an additional 80k out of it w/o issue.

I am convinced now that the PO did not do the scheduled maint on anything which runs contra to what he said.

Thank you Mark K for your response and the original instructions. Your response verifies what I have suspected for a long time.