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.

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.

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.

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.

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.

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.

Replacement Transmission for 2000 Ford Super Duty

19 Replies

hotpepperkid
Explorer
Jul 22, 2015
It will heat up really fast backing. I use 4X4 low range with the hubs unlocked for backing and never have an issue
Lantley
Nomad
Jul 19, 2015
smkettner wrote:
New cooler and new fluid is all I would do.
Get a stacked plate cooler with a fan for best cooling at low speed and reverse.

Mac,
I agree with the above. I installed a new cooler on my PSD X and it made a noticeable difference.
If the fluid did overheat above 240º than It is a good idea to change it. I don't think I would go the BTS or John Woods route just yet.
RAS43
Explorer III
Jul 17, 2015
Mac,
In my opinion you are on borrowed time. My '99s transmission failed at 47000 miles even after I changed some valving, switched the external cooler to the 6.0 cooler, added a larger oil pan and ran synthetic oil. The planetary gears are a weak point which failed on me while on a trip. And it never heated up even while towing over one of our Colorado mountain passes but failed 40 miles from the pass on level ground.
I put a Jasper heavy duty rebuid in it and a month later traded the truck off as this was the second breakdown that year.
looks like you are doing good research so I hope you have better luck then I did.
LarryJM
Explorer II
Jul 17, 2015
TXiceman wrote:
Best option for a replacement is a BTS or Brian's tranny from Arkansas. Also add a large external stacked plate oil cooler, a heavier duty torque converter and run synthetic tranny fluid.

Ken

All three of those are included in Brian's tranny and he now uses the 6.0 cooler as I understand it.

As already mentioned the two best "head and shoulders above the rest" options are John Woods and BTS. However, unless things have changed John Woods only does inhouse work out of SoCal and doesn't ship. Brian does have a few dealers and will ship out a rebuilt tranny, but by far the best way is to go to Lead Hill and have him do it inhouse. Yes expensive, but his cost is IMO worth every penny and is the ONLY 100% GURANTEED FIX for any and all tranny issues.

His tannies are so good than I know of several folks that have actually swappped one of his trannies with many more miles on it for a factory or rebuild one when changing vehicles for heavy use.

Larry
time2roll
Nomad
Jul 17, 2015
New cooler and new fluid is all I would do.
Get a stacked plate cooler with a fan for best cooling at low speed and reverse.
TXiceman
Explorer II
Jul 17, 2015
Best option for a replacement is a BTS or Brian's tranny from Arkansas. Also add a large external stacked plate oil cooler, a heavier duty torque converter and run synthetic tranny fluid.

Ken
Hank85713
Explorer
Jul 17, 2015
look here for the articles I refered to:

http://www.dieselworldmag.com/project-work-truck-part-2-simple-transmission-upgrades-towing-hauling
MackinawMan
Explorer
Jul 17, 2015
Wow guys, thanks for all the replies. A little update as I've been researching the past day.

First and foremost, I posted this on the Ford Truck Enthusiast website as well, and curiously got a reply similar to SLE's post where a guy with a Class C that ran the Ford engine/transmission did a similar thing when backinup up a somewhat steep grade after driving all day. He was told by a local Ford dealer/mechanic that the Fords that run the similar setup as my F350 can "vent" transmission fluid that way. It sounds like I might have been premature on things.

After a local trip yesterday I checked the transmission fluid level and it was right at the top of safe range. I also have repeatedly checked the area where the fluid was leaking out (it literally looks like a designed vent hole) and it's as dry as a bone....not even a drop of fluid. The truck is driving and shifting fine.

Now, my concern is what might happen under a load like towing our Eagle. I do have to tow it to our local fairgrounds in a week for the county fair...however that is only a 10 mile trip. That rounds out the camping trips for this season. I think what I'm going to do is just keep an eye on it. We're taking a short trip to Madison, WI in mid-August (not taking the TT though, as it's just a few days) to visit our oldest son, so that will be a long drive (albeit without towing a TT).

Come next spring, I might look into upgrading the tranmission cooler. Right now the lines do go into the radiator. It looks like some people have switched over to the 6.0 cooler for the 7.3L. Sounds like it's a serious upgrade.

Lantley, yes this F350 is in very good shape. We had some body work done on it last year to bring it back to looking sharp. Given the price of diesel trucks these days, used or new, I plan on keeping this one a long time..especially since it's paid off. I do think if we do anything it will be to go with a remanned transmission. Can the current 4R100 in the truck be rebuilt and "toughened up" to the standards of the HD models? (not the KBS and John Woods versions, but the HD model Ford currently sells)
elkhorn98
Explorer
Jul 17, 2015
I used to have a 2000 f250 and it started leaking on a trip at high temp. Got home and went to a Trans shop and he said the front seal ford used was garbage. Changed it and then no problems. Probably only had 30-40k on it then.
majorgator
Explorer
Jul 17, 2015
If it were me...
The John Wood or BTS are nice, but very costly. If you have the extra money and you want to keep the truck, go for it. But for me, that's kinda like something I'd do when/if I had to.

So, if it were me, I'd keep running with what you have and lose the concern over this one time incident. Drain and replace the fluid at the same time you're adding a transmission cooler. If your SD is one of those that doesn't route to a separate cooler or to the radiator, then you'll need to purchase a bypass valve kit and new SD cooler lines. In my opinion, skip the 6.0 cooler and go with a much more affordable Tru-Cool Max (for less than half the price). This is a relatively simple mod, but you'll lose fluid in the process, which is why I recommend changing it at that time.

With my 96 F350 E4OD, I haven't seen 180 degrees since installing the Tru-Cool Max, regardless of what I've hauled or what the ambient temp is.