I just bought a truck at 142,000miles. 2002 f250 with the 7.3. Ive heard the stories about the 4r100 and wanted to get a good discussion about it. How bad are these transmissions really?

The previous owner had just had the transmission rebuilt before I bought it. He said it was starting to slip in 2nd.

So let's talk about how you use your trucks and how (if at all) your transmission needed work, and any tips to extend the life of them.

 

I'm the guy who voted 250k plus w/o work. But I don't want to invoke the bad juju that will follow if I discuss my good luck.

By the way, I just towed through Ventura after staying at Port Hueneme for a week.

 

I will do my best to stop the bad juju. What do you pull? And you should have stopped by and said hi! haha

 

My factory transmission died at 143,761 miles. I had it rebuilt locally with stronger parts and a Transgo Tugger kit. They also added a Tru Cool supplemental cooler.

I don't know what failed on the original unit but I can tell you that my replacement is still going strong with just under 270k on the odometer. Shifts are still firm, temps are in line, fluid looks good and the lab sample says that everything is good.

So, if I was to venture out on a ledge with a blanket statement.....
I would say that adding a supplemental cooler is imperative if you want to tow. Keeping the fluid cool will substantially increase the life of the trans. I think there are some mechanical areas of concern as well (some of that depends on the year of your trans). A nice strong rebuild can result in a very strong transmission indeed.

Perhaps you can talk to the shop that the previous owner used and see if they did anything special or just performed a rebuild using standard parts. There are a few guys on here that are very familiar with how these work and what is necessary to increase their strength. I think the 4R100 can be a very sturdy trans if the builder knows how to work on these units.

Just my $.02....

 

I plan on doing just that. The guy he went to is VERY well known in our area as one of the best. The owner said he used better parts and he spent $3000 for the rebuild. I do plan on finding out what he did to it.

 

I had Brian at (BTS) build my trans at 130,000 miles because of the mods I am running now. When he took my trans apart, he couldn't find anything wrong with my trans. Thats ok, because I have a BTS now and don't have to worry like I was before.

 

I got a hokey rebuild and I'm still worrying...
My trans went south at just over 230k. Roughly 25k on the rebuild and its showing signs of weakness. BUT this time I'm saving all of my pennies for a BTS.

 

Mine went out before I bought it at about 10K. It was the lovely "diode" version.

 

I'm not familiar with the "diode" term. Care to explain.

 

Some 4R100s had a one-way "mechanical diode" and the tabs in the "mechanical diode" would break.

Pics of "mechanical diode" LINK

Here's some info I have saved:

Mechanical Diode Tranny Build Dates
2001 vehicles equipped with 4R100 transmission, having a transmission build date between
7/27/2000 and 3/23/2001.

Roland (mueckster) 04-15-2008
The trans does have its own build date located on the tag on the trans case (left side ,rear).
4th line down should show BD- #Letter##. This is the build date year/ month/ day.
Example : BD-1D28 1=2001 D=April (A=Jan, B=Feb...12=Dec) 28=Day of Month.
Using his example tranny Build Date is Jan 28, 2001

Mark Kovalsky 01-03-2009
The mechanical diode was in the diesels from the start of 2001 model year (July, 2000) and left production in March, 2001.

Cody (cleatus12r) 01-03-2009
If anyone is still interested, the "mechanical diode" was the replacement for the one way roller clutch previously (Intermediate one way clutch) used in the E4OD and 4R100s. After Ford found out that the diode wouldn't work in the gasser trucks (they exploded when shifted at 5300 RPM), they decided that they should stick with the proven and slightly more robust design. It is a mechanical device that allows rotation in one direction but not the other. It is used for the 1-2 shift when in drive range. When the "diode" was used, it replaced the roller clutch with a sprag that is inherently weaker. High power/high RPM 1-2 shifts are what kills the intermediate one way in the diesels.

Mark Kovalsky 01-03-2009
The gas engine trucks blew up the diode at 4600 RPM if the driver lifted his right foot just as the WOT 1-2 shift started, then put it right back on the floor. The person that discovered this was able to do it on 100% of the trucks he tried it on. That's why they left it in the diesels, they couldn't run 4600 RPM.

 

Got Brian at BTS to build mine @260000..still driveable but would shutter on a hard 3-4 shift....tow a 31ft TT reguraly and anything i can hook to it fron time to time....

 

I swapped my trans with a BTS unit at 90K. Nothing wrong with the old unit but since I'm going to be buried in this truck, I figured that it was money well spent.

Plus, the truck PO was a construction company that wasn't very nice to it.

 

I would recommend a valve body from John Woods or BTS. I got my BTS VB at 180k. Truck tows constantly right around 22k gross.

I'm at 304k now. The trans is getting ready to go out tho. My temp fluctuates in town now. But no slipping yet...

 

This is a good post. Any way to tell if your trans has been rebuilt once before? or if it has a good valve body on it already?

 

I'm going to do a filter system and a cooler. I'm thinking I'll stiff the bill for the 6.0 Cooler. Anyone know of any good filtration kits? I've seen a couple just wanna hear what you guys have to say