Replacement Transmission for 2000 Ford Super Duty

Mackinaw, if this is the first time it's done it, and after it cooled down it quick leaking your probably fine. I had the same happen to me a few years ago on my 2003 F250 V10 4R100 powered truck. Towed 150 miles into the campground, stopped to unhook the boat, pulled forward and had to back up a 5-7% hill to get into my spot, and of course it took me 2-3 tries to get it right where I wanted. Got all done, looked down, and sure enough I had trans fluid dripping just as you experienced.

That evening I called a good friend whom is one of the most reputable local trans builders and had a chat with him. He said not to worry about it, more than likely it was just the front seal leaking and when it cooled it would likely stop. His explanation was; basically your trans was at full temp when you pulled into the campground, you then proceed to back uphill a coupe times, and you then had very little air going thru the trans cooler. In reverse your torque converter won't lock under those circumstances and you'll overheat the fluid around the torque converter, this causes the front seal to get soft, expand a bit, and starts leaking until it cools down. He even asked if I noticed if my gauge moved and told him that I didn't see it move which he noted that in this case often times it won't show on the gauge since only that fluid right around the torque converter is what is overheated unless you continue to push it. He did tell me that since mine was 4 wheel drive, that if your maneuvering heavy trailers at slow speeds, lock it in four low and it'll take enough stress off the trans that it'll keep it from doing the same in most cases.

He was spot on with everything he said. I ended up taking mine in that summer anyway and had the trans freshened, a HD torque converter, and new seal installed and 4.56s gears put in front and back diffs. Frankly, it made for a good excuse to the wife to get my truck bullet proofed like I wanted, ha ha. Truck had about 65k on it at the time and was 7 years old. The guy at the shop said all of the original parts, gears, clutch plates, everything looked like brand new. Heck they even joked that one of the younger guys wanted to save the fluid for him self. Point being, the trans was fine and still in great shape even after my small incident.

Good luck, if nothing else it can be used as a good excuse with the wife that you "need" to get it fixed and that you should probably upgrade a few things so it doesn't happen again. Good luck

MackinawMan wrote:
We just got back from our big Mackinaw trip yesterday, over 1000 mile round trip towing. The old 2000 Ford F350 7.3L PSD truck towed beautifully, but as I was backing the travel trailer up beside the garage (a rather steep hill which puts a lot of strain on the transmission with a 9,000 lb. camper) my wife noticed a red liquid in the driveway, and sure enough when I got out I noticed that the transmission was leaking transmission fluid. The 500 mile straight tow combined with backing up the hill really heated up the transmission and it started dumping a bit of fluid.

Rather than look into a repair for that, I think it might be time just to replace the Achilles Heel of those model year Super Duty's....which was the junk from the factory 4R100 tranmission. With 130,000 miles on my truck, I knew it was just a matter of time before the transmission issues started. So rather than put any money into that transmission, I'm thinking of putting in a superior aftermarket one.

So...with that in mind, does anybody have any suggestions on manufacturers? We're looking for a solid transmission that can handle the towing. Thanks for any help.

I had a Ford automatic (AX4S) puke fluid once when it got really hot. I was told there is actually a valve designed to dump the fluid in specific overheat situations. After letting the transmission cool, then warming back up to operating temp, I found the fluid level to be in range, so it might have been slightly overfilled before the event.

Moral of the story is I drove that vehicle for another two years 25K+ miles without another peep from the tranny, before selling it for unrelated reasons.

If you really want to replace the tranny, go for it, but just keep in mind that there may not be any 'real' damage done.

Hey MackinawMan now is the time to decide your long term plans for the truck.
If you love it forever and plan to keep it another 10 years get the BTS tranny. The BTS is bullet proof If you just want to patch it together which I doubt just replace the seal Tranny maybe OK.
If you want to ensure everything is reliable for the next few years get a rebuild or another 4R100. A 4R100 will last another 100k. Which may meet your needs.
I rebuilt the trannies in both of my prior 7.3 PSD's. funny thing is stock rebuilt only lasted 100K
The big issue is the truck is 15 years old. If I remember the truck was in great condition. How much do you want to invest in it at this point.

I ad the tranny temp light come on my 2500 Chev 6.0 pulling my 5th wheel while going up Monarch Pass. There were lots of bicyclists and I was slowing and going.

The book said to pull over and let it idle to cool down. I followed the advice and pulled over at the first pull off (right before the summit). When I got home 1000 miles later, the fluid looked great, wasn't burned.

130K on the trans now and it just starting to have issues. Yes it maybe OK, but at that milage you should condsider an upgrade. There are several reputable builders out there many recognized in the diesel magazines, sun/suncoast is one of them. You should probably get a built one with a good torque converter while at it. Many now are billet to take extra stress, time to maybe upgrade the rad/oil cooler while you are at it.

The standard trans has been noted over in the ford websites as being the weak link in the system. depending on what you buy look at 4-5K investment. Still lots cheaper than a new $70k truck with payments. With an upgraded trans you can also have some tuning upgrades done, new Y pipe to replace the 7.3 exhaust donuts etc. I think these come from BPD not sure. There have been several articles in diesel world/power magazines on what to do for the 7.3 one is on a dually from tennessee last month or so.

My 2000 Ford F350 (same thing) has the radiator internal cooler.

It also has the oem 9 plate external cooler.
When driving normal in 90 degrees it would be at 180.
When towing up a 10 mile grade 7-8% at almost full throttle 65mph it would reach 220 at the top of the hill.

Removed the 9 plate and installed a 2003-2006 6.0 liter trans cooler with 32 plates.....it was freakin huge!!

Now normal driving 140, towing up the same mountain with 7K trailer is 165-170 MAX.

I never had to back up a hill, but the cooler should handle it.

If this was the first time that your trans puked through the seal then it will most likely be fine once cooled back down. The fix is actually a very cheap new front seal made from Viton (I think that's the correct spelling), the expense is getting to that easy to replace seal, about $400 for a shop to slide the trans back to do it. As long as the torque convertor hub where that seal rides is NOT scored at all the new seal will fix the problem and be more reliable in the same situation. If that TC hub is scored, then you are buying a new TC as that score will chew up even the new seal and leak again.
Expect to pay about $4500+ for either the BTS or John Woods trans, they are awesome units but you have to pay for it. The very good 4R100HD from Ford will save you some money if you decide to replace your still good trans.
As pointed out earlier some '00 7.3's did not have the trans cooler loop in the radiator, make sure that your does or upgrade to that radiator. Also the 7.3 had the smallest trans cooler of any motor in the SD/EX product line, the 5.4/6.8 gasser coolers where nearly double the 7.3's size and the 6.0 was almost twice the size over those. Both the BTS and JW trans come with a new 6.0 cooler last time I checked.
As for an idea to reduce the chance of repeating the fluid leak consider using 2 wheel drive low range for reversing up slopes in the future. If you have manual hubs it is very easy to do, simply leave them unlocked and shift the transfer case to LOW. With the AUTO hubs you will need to either unplug the vacuum actuator switch under the hood that send the vacuum pulse to the hubs or wire in a switch (and replay) to have it cut out on demand of 2WD LOW. The better (deeper) LOW range gear ratio will put less stress on the trans and will build heat more slowly.

Damage has already been done, so I think it is a good idea to replace it, but also address the root cause which PUCamping describes.

BTS is and John Woods both have a great reputation for durable upgraded 4R100's.

Ford also sells a HD version of the 4R100 (reman), and that seems to be a good unit too. Maybe not quite up to what those other guys built, but usually more convenient since any dealer can order and install them.

Your transmission is likely OK, and the weak link is not necessarily the transmission itself but the cooling. In this case, replacing the transmission will not solve the problem and you are likely to get a repeat.

Do you have the stock radiator? If so you likely do NOT have the transmission cooling loop in the bottom of the radiator, but only the air/oil stacked plate cooler. It is easy to check, just follow the lines from the transmission. Do they go to the radiator, or just a cooler behind the condenser and back? For a year or so someone at Ford decided this was a good idea before recognizing the error of their ways. Unfortunately, many trucks were shipped with this configuration. It generally only becomes an issue when towing heavy.

The oil/water cooler in the bottom of the radiator always provides cooling at any speed and is very effective at heat transfer. The air/oil cooler is not as efficient and does almost nothing when backing up or pulling a steep hill slowly, when you need it most! It is good for secondary cooling but NOT as a primary!

The result is exactly what you experienced. Fluid heats up FAST and eventually the front input shaft seal expands too much and starts to leak. Once cool it will seal back up and be fine, well the first couple times it happens anyway, eventually it will continue to leak and then it will need the shaft seal replaced.

The solution is pretty simple, replace the radiator with a slightly later version that has the loop in the bottom and add a couple lengths of hose. If you want you can also add the 6.0 air/oil cooler for additional cooling. No air/oil cooler can compete with the effectiveness of the radiator loop especially at low speed, which you unfortunately are missing. But this is cheaper than a new transmission.

I had this EXACT issue with my 04 explorer because Ford did the same thing, no radiator loop. I did a ton of research on it before discovering what was going on. I then read that it was also an issue on 2000 7.3 autos, because they removed the radiator loop. Let me know if you want more details. You can also try PM member Mark Kovolsky who is a former Ford transmission engineer. He can tell you anything you need to know.