1999 7.3l poor shifting shifts when let off gas

[014x4cc7.3]

Originally Posted by SCstroker

I just found out that my problem was the mechanical diode in transmission! 1k later and I will be up and running.

Wish to heck I had gotten by that cheap. Everywhere I checked told me the only fix was a complete rebuild. I spent 2800, if it had only been 1K it would have taken a week to wipe the smile off of my face. Like others here have said, you either love these trucks or hate them. If mine will continue to behave I will be one of the one's that loves it, if not............

[SCstroker]

Tranny-man still needs to get inside to make sure that is whats wrong. He stated that it was something Ford tried out for 2001. I am sure it was some bright designers idea. He really was pushing nothing else for an add-on. I pushed and he said maybe a trans-cooler only. No change in the torq-converter. Nice guy!!

[PaulyP]

I have a 99 2 wheel drive auto with 200,000 mls on it. I am having a problem with what I had believed to be the trannie.I initially brought the truck in to have the front seal leak repaired. I would also have an ocasional problem with the third gear shift reving out a tiny bit and then shifting hard. I would always get a p304 code (3rd gear ratio problem)so I had the transmission looked at.I took my trannie guys advice and had a new convertor put in.He said he found a broken accumulator spring that would account for the shift problem, They fixed it and the seal and installed the convertor. Thirty miles after picking up the truck I exited the hwy,stopped at the light, when I pulled away from the light the truck wouldn't shift It would just slip and or hang in low until the red line If I didn't peddle it.I returned to the shop with the truck. After three weeks of waiting they told me that they were certain it was a computer problem. I brought the truck to a friend at his dealership we tested the truck again and found 1st being the worst but 2nd and third gear were also effected. We ran most of the electronic and manual shift tests, Pressure tests and taste tests we could.We tested the unit with a different shift pak before taking it down and it did the same thing. The other tests showed some slippage and apparent wear on the unit.I figured I would go ahead and have the tranny overhauled(It had been 80.000 mls). After a complete go thru we found a few burnt discs and overdrive piston and even a little dirt internally(we believe to be from the previous guy's unclean dis-reassembly of the unit).We used the new converter the other guy's had installed, all new seals, frictions and sensors.I even replaced the speed and cam sensors for good measure. It was finished early friday morning. We hooked up the scan tool and went out for the road test. All pressure, shift and temp reading where right where the should be. However the drivability problems, eratic shifting and hanging in Low are exactly the same.Some shifts where even more aggresive due to the fact that there isn't any slip now.If I run it wide open to the red line it will shift. I was leaning towards a bad program from my Superchips programmer or a faulty pcu. I flashed the computer on monday. After clearing out the old program we reinstalled the factory program. Now the truck is undrivable it slips so bad in low you have to peddle it 4-5 times to make it shift, if It will shift at all. Some of the codes we've pulled are P0781 1-2 shift and a bunch of wiper control related B1450 B1438 B1428 and B1352 ignition key cuircut. After I picked up the truck from the first shop my shift arm ingagement was no longer positive. In fact I had to make several attempts to get it into drive. We are going to check the column wires to see if they are rubbing or shorting.Maybe this some how related to the problem and the B-codes. I'm now going to try another manual pressure test and a shift pak pin-point test.I'm $2600 into this unit. .................

After all of the above mentioned work and heart ache the truck sat for 5 days after I limped home from the re-programming. I started it up and drove it back to the shop. It never missed a shift point, never hung not a thing. I left it for my friend to test with a manual gauge for pressure bleed off in the case. He drove it for two days without a problem It drives like it was new.The pressures are dead on. I picked it up this morning and will be driving it all day or all week, to evaluate it. What the *#$% is going on here? ANY ONE? Thanks PaulyP Parasracing@nc.rr.com

[SCstroker]

Sorry, for all your troubles. My problem, from what my trannie man said, was related to the early 2001 mechanical diode trannie. I am suppose to pick truck up today. Hope I have no further problems. Best luck with your truck. You may want to call the guys in Arkansas, Brain's Transmission, if you continue to have problems. Nice people.

[Quack Attack]

For what it's worth, I have a 2000PSD and at 130,000 the trannny decided not to shift into 2nd gear. Let off the gas and it would go right to 3rd. Dropped the tranny(easy,45min)and tore apart. Found the bad diode(basically a one way clutch)and a burnt up clutch pack. Picked up aftermarket clutches and steels off E-Bay and the diode from Ford. total cost of rebuild 700.00. Definatley helps to have a friend who rebuilds trannys.

[AlamoShooter]

Originally Posted by SCstroker

I just found out that my problem was the mechanical diode in transmission! 1k later and I will be up and running.

? how did you "Find Out" that it was a mechanical Diode ?
?what did you have to do to locate the problem
Thanks

[Quack Attack]

I was lucky enough to have a close friend that works for a large Ford dealer and has seen this problem many times before. He also recommended not use Ford parts when rebuilding. So we ordered aftermarket parts online, and did the rebuild ourselve's. Have not had a problem since . Hope things go well.

[014x4cc7.3]

Originally Posted by SCstroker

I just found out that my problem was the mechanical diode in transmission! 1k later and I will be up and running.

I had the same at 80,000. Sucked.

[014x4cc7.3]

Originally Posted by AlamoShooter

? how did you "Find Out" that it was a mechanical Diode ?
?what did you have to do to locate the problem
Thanks

Local transmission shop had the Ford TSB and my truck fell within the build dates of the known defective one way clutch.

[Brian]

Originally Posted by Quack Attack

I was lucky enough to have a close friend that works for a large Ford dealer and has seen this problem many times before. He also recommended not use Ford parts when rebuilding. So we ordered aftermarket parts online, and did the rebuild ourselve's. Have not had a problem since . Hope things go well.

what parts did you put in it? just curious