[latitude500]

I'm a little confused at the moment this is my first F350 and it has a rebuild tranny on it with 160k. But some people are telling me to change out the tranny fluid every 20k and others are telling me not to touch it just add more. I'm under the understanding that doing maintenance on the truck is going to be alot cheaper then repairing the tranny again.

 

[RT]

There are two ways you can do this - a complete and total transmission flush every 30K or so, or you can do like most of us do - more frequent partial changes.

Here's my routine - every 15K (every 3rd oil change) I drain the transmission, drop the pan - clean the magnet - inspect the filter - put it all back together and refill it. It takes about 8 quarts that way. I also put a new Magnefine filter inline everytime I do this. This technique "refreshes" the additives and allows me more frequent inspections of anything that might be building up. i.e. dropping the pan and finding metal shavings or too much clutch material.

I use Castrol Dex/Merc - available at WallyWorld. The gasket is re-usable. Doing this, I can service my transmission for about $35.

You don't mention what year your truck is - the earlier converters had a drain plug - if I had that, I'd drain it too - since I dont - oh well..

 

[txgp17]

CHANGE THE FLUID AND THE FILTER.

I'd also suggest you add a deep sump oil pan which increases oil capacity, and decrease fluid temperature a little. B&M makes a nice model for $180 from Summit Racing. And here are the installation instructions.

If you want to look at some more models, here's everything they have to offer.

Here's some videos showing you how drain and refill the transmission without making a mess. If you want to install the extra inline filter that he recommends, it can be found at NAPA, but you'll need some extra parts to install. But Ford makes a kit with everything in one bag, part # xc3z-7b155-e. My wife's Honda Pilot had no transmission filter at all, and I added one to it for peace of mine.

 

[Mark Kovalsky]

I recommend changing the fluid every 30k miles. Here's how I recommend doing it: http://www.thedieselstop.com/forums/f47/changing-atf-7-3l-powerstroke-engine-4r100-automatic-transmission-198641/#post1564217

I don't recommend deep sump pans. They cost a lot of money for very little benefit. If you want the trans cooler a better transmission cooler is WAY more effective than any pan on the market.

 

[txgp17]

I don't recommend deep sump pans. They cost a lot of money for very little benefit.

A 31 row 6.0 transmission cooler will run you at least $350 retail, but it's still a fraction of the cost a rebuild. The B&M deep pan is half that, and easier to install. Adding more fluid provides more stable temperatures. Allison offers deep sumps on almost all of their transmissions, I'm certain their engineers have good reason for that. The only trucks getting shallow sumps on Allisons are those with ground clearance issues.

If you want the trans cooler a better transmission cooler is WAY more effective than any pan on the market.

No argument there, as I never said, nor implied that a deep pan was better at cooling than a cooler. For the record, I wrote it would "decrease fluid temperature a little."

There's no question that excessive heat causes more transmissions to fail than anything else. But the deep pan is a lot easier to install. I vote for both.

I have a 99' GMC K-3500. Some simple upgrades like

• A deep sump,
• the largest cooler offered by B&M,
• Mobil 1 fluid, and
• an external filter

helped it last 180,000 miles. That's when the torque converter went out. The hard parts showed no signs of wear, and the you could still read the factory print on all the clutches.

 

[whd507]

When I was running 100-150k miles a year with my 97s, (when they were new) I would drain pan and converter at the 30k mark, add a B&M pan for the extra three quarts and the drain plug. I would switch to Mobil 1 fluid, and take samples to send off to Blackstone every 30k along with the oil sample, The fluid would always stay clear, and by 90k I would flush it out with new, even though Blackstone gave the fluid a clean bill of health, I just re-used it as hydraulic fluid in leaky equipment. But I was hitting 90k in like 8-9 months, so the oil wasn't old age-wise. I still prefer Mobil 1 fluid, but I don't do oil samples very often anymore, since I don't drive anywhere near as much, so I change at the 30k mark as recommended.

 

[SmokeyWren]

CHANGE THE FLUID AND THE FILTER.

That guy on powerstrokehelp.com tries hard, and he's pretty good on a lot of his advice. The first three of the youtube videos are pretty good. But he fell down on the final one.

If you follow his advice, he says you will change about 10 quarts of ATF. And if you have a 4R100 tranny made after August, 2001, then you don't have a drain plug in the torque converter, so you will change less than 8 quarts of the ATF. The tranny system holds over 17 quarts of ATF, so if you drain the torque converter, you will change only about 60% of the ATF. If you don't drain the torque converter then you'll change less than half of the ATF. That's like taking a bath in 60% clean water mixed with 40 percent sewage. Not for me, thanks. Instead I used Mark's procedures and changed almost all of the ATF each time.

 

[RT]

Ha! Nice analogy. Except I'm not bathing my transmission - I'm trying to keep the additive levels and viscocity at a level that won't harm my transmission. Think about it this way - I'm taking a sponge bath every night as opposed to you taking a really, really good bath once a week. Who smells better?

To all you readers out there - I hold Smokey in the top three most honored positions in Texas. His word is next to gospel. He helped me with every modification I have on my truck - so even if I think I'm right - take his advice over mine.

 

[txgp17]

...so if you drain the torque converter, you will change only about 60% of the ATF. If you don't drain the torque converter then you'll change less than half of the ATF. That's like taking a bath in 60% clean water mixed with 40 percent sewage. Not for me, thanks. Instead I used Mark's procedures and changed almost all of the ATF each time.

Again, excellent advice, the more fluid you get out, the better. And I think it supports the idea of a deeper pan as well, because you're increasing the percentage of fluid that you change.

I serviced my 4L80E last week, and after draining, used compressed air to purge the cooling and filter system of additional fluid. The refill took 12 quarts.

 

[jasons 99 powerstroke]

I agree with others, I've always ( if applicable ) drained the trans pan every 15k and serviced with filter every 30k. Always use a good quality fluid. Valvoline has always done me very well. And yes the good thing about the early models is you can drain the convertor so thats like changing almost 100% of the fluid only thing you arent chaning is whats in the lines and cooler. I've owed MANY vehicle over the years and NEVER had a trans failure at all. Always serviced regularly and checked levels frequently. But I would change no matter what. These auto trans are pretty darn tuff, Like my dad always said a vehicle is like a women if you don't take care of her she'll put you walking. :thumbsup:

 

[SmokeyWren]

And yes the good thing about the early models is you can drain the convertor so thats like changing almost 100% of the fluid only thing you arent chaning is whats in the lines and cooler.

No. You severely underestimate the volume of ATF that won't drain, because it's trapped in the cooling and operating passages inside the 4R100 tranny, as well as the smaller amount in the coolers and lines. The total system holds over 17 quarts of ATF. About 7 quarts are in the stock pan and another 3 in the torque converter for a total of about 10 quarts that will drain. So in PSDs built before August, 2001, the ATF in the coolers and lines and the cooling and operating passsages inside the tranny totals about 7 quarts. That's over 40 percent of the ATF that won't drain. In most 2002 and later models built after August 2001, only about 40 percent will drain from the pan, leaving about 60 percent nasty old ATF to mix with the 40 percent of new ATF.

.

 

[latitude500]

Thanks for your help, looks like I'm going to be replacing the fluid and filter. I'm wondering how bad that magnet looks.

 

[jstrauss]

On my old 2000 F250 V10 that I don't have anymore, when I drained the pan and the converter, it took 15 qts. to refill it. I did that every 25k miles.