Hello friends, how do I find a thread to run down the symptoms that I now have.
I have a 2001 7.3. Superduty

Jumped in my truck three days ago and starts fine, idles fine. Took off down the road and it seemed that it was having trouble in shifting up gears. The RPMs were a lot higher to shift and the truck seemed to have a 'lack of power'and go back and forth in every gear on the way up. I run a Super Chip and was in HI-Performence mode. I changed it over to Stock and checked for codes. No codes came up. I have 106,000 on the motor and have done no maintenance on the transmission. All fluid levels (trans, motor, ect.) fine. Driving in Stock mode, the transmission shifts fine, but not with the 'crispness' of before, and I believe that the RPMs are slightly highter when shifting. The engine idles good and runs good, but seems now to have a lack of power in driving. The 'engine' just seems to run 'weaker' down the road than when I was driving it a week ago. There is no 'bad smoke' out the tail pipe and all cylinders seem to running fine. The MPG have dropped way off to the point that it is alarming.

I let my son in law drove my truck to haul some stuff last week. I topped it off where I usually do before this trip and knew that the trip would be 400 miles. Well with in the range of the tanks.I told him not to fill it up as I would when he got back. He filled it up any way, don't know where or what kind. He is a good kid but would really be offended if I told him my truck runs like junk after he used it...

I will run out the Diesel that he put in there and see if it changes. But in the mean time, could someone post up a thread from the past that I can go through on others that may have had these issues.

I don't think that transmission is now the problem, but it sure makes you sit up and notice when it is acting like it is searching for the next gear.

All suggestions will be thankfully run down.

Thank-you
Brother Les

 

How do you know it is fine if you have done no maintenance? How do you know there there is no debris at the bottom of the pan? Not sure why people leave trans maintenance off their list but that is kinda like asking for problems.

First thing to do is to drop the pan and see what is at the bottom. Since you have an 01, it could be the diode giving your problems.

 

X2 what aklim said.

The first thing you should do is flush and fill the tranny using the Kavolsky Method.

 

Thank-you for your response. No, I am not 100% sure that there is not a problem with the tranmission. I talked to my brother in law, who is a diesel mechanic and owns the same truck that I do, but in a 2002 model year. He suggested to not drop the pan or replace the filter, but have it flushed out. He suggested that if it is already slipping that the damage is already done and that the best aproach would be to not rebuild the one on the truck but to buy a remanufactured one.

I am taking it to another mechanic tonight who has a diagnostic machine and will go over it. I have told him the same things as I posted above and just wanted to get as much information as I could before I took it over to him.

What is the diode issue to look at? I am a novice at most of this.

Thank-you

Brother Les

 

PaysonPDS

Thank-you for the transmision flush post. I will do that no matter what as it is time to flush it.

What about the diode question and what is the torque of the pan bolts?

Thank-you
Brother Les

 

Here's the info I have about the Mechanical Diode.

Thanks to all the posters for this info.

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

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

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.

Pan bolts I believe are 10 ft/lbs

 

Without dropping the pan, you can't see what is in the pan. There could be all sorts of debris in the pan. Why don't you give Brians Truck Shop a call? They can tell you if it is the diode or what you need better than we can

In 01, Ford changed the way the trans was built and put a diode in it. Well, that went over like a lead balloon and it would lock up and do strange things. Feels like you have the e-brake on and it won't shift out of gear 2 or other things like that. When the diode gives a problem is hard to say.

Depending on what you intend to do with the truck, there are 3 routes open to you, IMO.

1. If you are selling the truck, get whomever you want to rebuild it for as little as possible. You aren't going to get more for the truck.

2. If you are keeping it for a couple of years, get a Ford reman and don't mod it or you could endanger your warranty.

3. If you are keeping it for a long period, get a BTS trans and he will fix it for as long as you own it for free. You pay shipping./

 

The first thing I'd suggest is check all of your intercooler boots. I don't know if you have a boost gauge but it sounds like a blown boot to me.

 

I will print off everything stated today and take it to the mechanic who will look at my truck tonight. I plan on keep the truck 'forever'.... I think that the build date on the truck is very late '01.

Thanks, any more comments are much welcome.

Brother Les

 

Here's a LINK to pics of the mechanical diode. Toward the bottom are pics of the ring that the tangs lock into and the ring with the tangs. Good illustration of the "one-way" locking feature of the mechanical diode. Just 4 small tangs. Definitely a weak point.

Probably TMI, but thought it was interesting.

 

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The tag on the transmission (back, drivers side) had BD 1F08

I am not sure why there is a 'Zero' after the 'F', as it would be strange to have a 'zero' month?


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Are these the blue short hoses that are on the the foil coverd pipes going to the back of the top of the engine? I could find no leaks on these hoses, with the truck off or running.

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The pan on the bottom of the transmission has a drain plug and the pan looks to be very easy to take off. I will use the url you suggested to flush and refill the transmission after I have looked to see if there is anything in the bottom of the panKavolsky Method.


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Les, if your truck was built late '01, you may not have the diode. My trans was built the day before my truck build date. I am going to BTS soon, and I want Brian to build my trans, that came on my truck.

 

There's also 2 black ones going into and out of the intercooler up by the radiator. Those are typically the ones that blow off.

 

And you know this how? By having them blow off when you are in the middle of BFE? BTW, I had it blow off twice. Didn't do it right the first time but it was dark and the weather, of course, SUCKED

 

I need to learn how to do 'quotes' better


I am now questioning myself on the build date... for some reason I thought that I knew it.... and that it was on the vin #.....which I have duh... I go to the 'spec' sheet and no date.... (Is the date on the front door sticker?)

https://www.ford-trucks.com/forums/498954-super-duty-and-heavy-duty-______super-duty-tech-folder_____.html



I will check those out tonight. The engine does sound a little different than a week ago and that may be the place.



The transmission flush is still at the top of my list and I will look for those boot leaks again.


Thank-you for the posts.

Les