I have a 4r100 on in a 99 7.3 4x4. The shifting problem I have appears to be intermittant. it seems loose after warm up especially at the 4th shift overdrive and passing gear. possibly due to low presures ? sometimes (lately more often than not) hunts back and forth between 4th and o.d when passing or hill climbing. Under normal driving it shifts somewhat firm with 4th being an exeption.I have changed my crank position sensor filters and fluids which had turned dark and improved slightly. When I pulled the pan and replaced the filter the pan was spotless. No residue or signs of plates or debris. There is about 100,000 miles on the tranny and 350,000 on the truck. Questions: Is there a tcm for this transmission and if so could it cause these problems? I'm considering a purchase of an unlocked 1705 superchip to change the shifting but unsure if this will work for my issues. Any suggestions or input .Thanks

 

Your transmission is a four speed. Fourth gear IS overdrive, so you can't be shifting between fourth and overdrive. It is most likely locking and unlocking the torque converter that you are feeling.

Sometimes frequent lock/unlock is caused by a restricted fuel or air filter. When the engine isn't making the proper torque it will affect the transmission operation.

There is no separate TCM in this truck. The PCM (Powertrain Control Module) controls both the engine and transmission.

 

Mark, thanks for the input. It was late when I wrote this but, yes 4 speed means only four gears. I will check for obstructions but, I did just change the filter which was overdue.The air filter service gauge shows okay but maybe upstream blockage I'll check. The only other issue is an oil leak near or under the turbo stand area.
my 6.9 had a screen at the intake. Do you know if there are any on the 7.3. I will purchase a manual today. Thanks again

 

I am curious about this issue too. My trans does the same thing when shifting from 3rd to 4th. Only does it when I am babying it. When the pedal is down it knows what gear to go into. Same transmission with a couple more miles on it. Is this something we need to be concerned with?
Thanks D

 

Same issue as mine. It's more than likely slipping worse than you think. Mine was anyway. There were also a couple codes . first was code po732 then. I changed the shift solenoid to see if it was the problem. It wasn't. Then I got another code p1744(manufacturer code tcc or torque converter clutch stuck in off position. This is the problem ,the converter loss of presure. Since my truck is 4x4 and a pain to remove I decided to tear the tranny down. Did that tonight and other than three dime sized hot spots on two of the direct clutch steels there wasn't any problem inside the transmission. As I stated on the first post there was zero debri in my pan and if yours is the same I would check the converter.There are some upgrades you should do however if you tear it down. Beware of the many transmission snakes.

 

Mine only does it every now and then. I have a 2003 F250 with the V10 by the way. Is my trans going to crap out on me or is this a simple fix? It will hunt for the gear for just a second or two. I am hoping i dont need a new transmission.

 

I'm no specialist, just a gearhead but ,I believe sometime in 03 ford went to a five speed tranny and yours may not be the 4r100 I'm dealing with even still the possibility is great your issue is the same. My issues started the same as yours slowly over time. One time a year ago for a split second and then just last week it got to where I needed to deal with the problem.

 

Just went and checked its the 4r100

 

Well it's worth a try and way less than a whole transmission. Good luck

 

What r the upgrades? So u think i just need a new TQ?

 

They make a couple heavier duty torque converters. I'm personally going to use the heavy duty type as opposed to the stock replacement that the supplier in my town has in stock. Wholesale 195.00 exch. Definately the most bragged about shift kit on here and around the phx area is the transgo hd-2(tugger) . Got mine for 109.00. The final part or mod I'm doing is the intermediate shaft. The stock is hollow where the flange meets the shaft and the aftermarket one I'm using is solid. I broke one on an e4od which is a very similar transmission. That's all I know of for upgrades but, may find more out tommorrow when I buy my kit and converter

 

Well, since he had the transmission torn down, he coulda' installed an entire Sure Cure kit from Sonnax.
http://www.sonnax.com/system/instruc...4R100HD-IN.pdf

The kit addresses some factory shortcomings, and makes it a little more "tough" than a stocker.

It's what I'll be doing if mine ever has to come down.

Mind you, it isn't the same as having one of the "Top Two" 4R100 builders go through it, but should help prevent the trans from dying a premature death caused by a possible original design deficiency.

Pop

 

Only with the 6.0L diesel. The V10 didn't get the five speed TorqShift transmission until 2005.

 

I just wasn't sure and didn't want to make a false claim.Thanks again Mark you were more helpful than four transmission shops that all just wanted a tranny rebuild or not smart enough to diagnose properly

 

Mark, I was looking for a way to ask a question but couldn`t find it. If i may, I have a 4r100 trany for my ford e250, i drop the accumalator body for inspection due to shift trouble. all the accumalator valves seet against the accumalator body except for the line pressure modulator which has free play in it. there is no spring tention on it. i quest the spring is worn out. please comment