"01 Mechanical diode trans.
Laughing Gas
Joined: Aug 2008
Posts: 823
Likes: 5
From: Dallas, Oregon
Check your build date on the doorpost tag. If it was built after 3/23/2001 you are highly unlikely to have the diode, since that was the last date they were known to be installed. Check out TSB 01-13-6 in the Recalls/TSB's section of this site. If the search function was working better, I would tell you to search for "diode" in the 7.3 forum. Maybe later. I have a diode and have almost 270,000 miles on it, but they are a known weak point.
Hook it, I'll pull it.
Joined: May 2007
Posts: 15,037
Likes: 4
From: Grand Lake, La.
We have close to the same truck. Look in my sig and you will see what mods I have. I have the Diode in my trans and it is still going strong with 125,000 miles. I don't know what the problem is with my trans but I launch my truck at 20# boost in 4wd and I keep going. Like the monkey.
Frmr Ford Trans Engr
Joined: Aug 1999
Posts: 24,739
Likes: 2,669
From: SE Florida
The mechanical diode is a trade name for a type of one way clutch. Ford changed to this one way clutch in all 4R100s for the start of the 2001 model year. At the launch it was discovered that they failed in the gas engine trucks with a certain trick at 4600 RPM. Since the diesels couldn't run that fast the decision was made to only remove them from the gas engines until they could make enough for all transmissions.
There were thousands of gas engine trucks that had their transmissions replaced before they left the assembly plant. Allegedly NO gas engine trucks made it to dealers with the mechanical diode. All diesels had it until March 23, 2001, when the mechanical diode was replaced by the one way clutch it replaced.
There were thousands of gas engine trucks that had their transmissions replaced before they left the assembly plant. Allegedly NO gas engine trucks made it to dealers with the mechanical diode. All diesels had it until March 23, 2001, when the mechanical diode was replaced by the one way clutch it replaced.
Thread Starter
|
Senior User
Joined: Oct 2008
Posts: 466
Likes: 0
From: Ontario, CAN
Trending Topics
Frmr Ford Trans Engr
Joined: Aug 1999
Posts: 24,739
Likes: 2,669
From: SE Florida
The improved part is a sprag type one way clutch. It replaces the mechanical diode. There is no improved diode for a 4R100.
I know that's picking nits, but that's the way I am! It's the engineering training.
I know that's picking nits, but that's the way I am! It's the engineering training.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Lead Driver
Joined: Jun 2003
Posts: 8,298
Likes: 25
From: Damon (South East Texas)
Hook it, I'll pull it.
Joined: May 2007
Posts: 15,037
Likes: 4
From: Grand Lake, La.
Thanks Mark, I like how you keep us straight. lol. Is my Diode trans much worse then the trans without? I mean, can I for sure know it will go out because of the Diode? I would rather go ahead and drive the truck to BTS instead of haul it there. In your wisdom, should I go ahead and get the trans rebuilt now?
Lead Driver
Joined: Jun 2003
Posts: 8,298
Likes: 25
From: Damon (South East Texas)
Thanks Mark, I like how you keep us straight. lol. Is my Diode trans much worse then the trans without? I mean, can I for sure know it will go out because of the Diode? I would rather go ahead and drive the truck to BTS instead of haul it there. In your wisdom, should I go ahead and get the trans rebuilt now?
has, you might be seeing Brian a little quicker than most. 
Elder User
Joined: Jun 2006
Posts: 764
Likes: 1
From: Gulfport/Biloxi, MS
Wow, I had to have my trans replaced last year and it sounds like I def had the diode. Why didnt ford have a recall on this. It p****s me off that ford knew about the problem and I had to pay over 2k to have it fixed.
Hook it, I'll pull it.
Joined: May 2007
Posts: 15,037
Likes: 4
From: Grand Lake, La.
. I just wish I knew when it would go out so I can drive there, instead of haul it there.
Lead Driver
Joined: Jun 2003
Posts: 8,298
Likes: 25
From: Damon (South East Texas)
It had to do with rpm. The diesels didn't turn the rpm that the gassers did when the "diode" failure occurred.
Lead Driver
Joined: Jun 2003
Posts: 8,298
Likes: 25
From: Damon (South East Texas)
