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Discussion Starter #1
I've owned a 97 F250 reg cab auto 4x4 with 4.10 gears for the past 3 years and has shifted like a 5 speed since the day i bought it. Its shifting patterns are:

1. 0-15
2. 15-25
3. 25-32
4. 32-36
5. 36 +

I know, its geared really low. When it shifts at point 4 & 5 i can feel the torque converter is locked. At 32mph (4th shift) im cruising at about 1100rpm and i just lay my foot right into it (Torque:nod:) and build speed as soon as it shifts up again whenever I let up on it. I can get it to shift up again as soon as 36mph. I have no loss of power whats so ever and the truck runs 110%.

However when I'm driving normally it always seems to "upshift" at exactly 32mph almost like its splitting the gear. This upshift occurs even when i'm accelerating quick. When I punch it - i think it actually upshifts and then immediately downshifts again to keep up with what I'm demanding from the pedal.

My questions are can any harm result from this? Keep in mind I've been driving it like this for 3 years and never had the slightest problem. I usually drive like a grandma (MPG > Speed) with my foot just resting on the pedal when i drive. I think this shifting pattern helps with my 17mpg average (50/50). I also keep it under 2000rpms on the highway for the most part.

At the same time I plan on adding a tony wildman chip in the near future and want to know if the chip will interfere with my trucks shifting patterns. At the moment the truck is bone stock with just a 6637 air filter. Gauges, exhaust, and chip are all I want to do to the truck.

If I had my choice I'd prefer the way the truck shifts now - I dont street race too often and I like cruising at low rpms. But I want whats best for her. Any thoughts on what could be causing this early TC engagement? I have no CE light, a cleaned EBPS tube, and one meaningless code PO113 (low intake temperature). Any thoughts or opinions would be much appreciated.

Thanks!
 

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That 5th point is just the tc. Or the tc is locking somewhere before then. I can make mine lock in 2nd then it's just normal after that. You only have 4 gears

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Mine does the same thing. Don't know if its normal or not as this is the first diesel I've had. I just swapped my e4od out for a 4r100, but never drove the truck with the e4od in it as it was blown when I got it. But I've got a 4r100 behind my other trucks v10, and it definitely doesn't shift like that.... or maybe its just not as noticeable because it has 3:55 gears and not as much torque as my diesel with the 4:10's?? Either way, I'm still on a mission to find out if it really is normal or not, or if the TC is locking/unlocking when it is not supposed to be.
 

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Discussion Starter #4
I've determined it's defintely the TC because it ****s normal when it's cold. When it gets up to normal operating temperature though you can feel the TC engaging in 3rd at 32mph. I'm still in the process of trying to decide why it's engaging soon and how I can fix it.
 

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Does it engage at that speed every single time or just under certain conditions?
 

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Sounds like you drove my truck. Lol. Cept mine seems to move tc lockup not sure...
 

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I drove a 94 powerstroke over the weekend. It shifted normally through 4 gears. Then, if I let completely off the accelerator, it felt like it shifted once more. The RPM would drop another 500-600. As soon as I touched the accelerator, it felt like it shifted down, and the RPM increased 500-600. It acted the same way with the OD override engaged. Anybody have an explanation?
 

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My 96 does the same thing except my does it at 43 mph. Drop Down to 40 and it down shifts get up to 43 it shifts into OD then the TC locks up figured it was normal.
 

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Ok mine with a chip and being a 96 locks up no mater what gear at about 32-35 and will shift into OD at about 45. There is nothing wrong and it is perfectly normal. If you guys are used to driving Dodges they go 1-2-3-4-TC. Fords go 1-2-3-4 with TC happening at 30 something. If you calibrate for bigger tires it's still going to lockup at 30 something. It's this whole safety thing or they would lower it even more. Also my TC doesn't disengage until it drops below 30 or I touch the brakes. I wish it would only do it if it dropped below 30, but it's fine.


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Also my TC doesn't disengage until it drops below 30 or I touch the brakes. I wish it would only do it if it dropped below 30, but it's fine.


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You could defeat the brake unlocking the TC if you really wanted. My recollection is that early TC lock up vehicles didn't have this function and in a panic stop the engine was killed which affected power steering and brakes...and then there is the pesky locked engine/trans/rear wheels to tend with, all the while trying to avoid an accident.
 

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You could defeat the brake unlocking the TC if you really wanted. My recollection is that early TC lock up vehicles didn't have this function and in a panic stop the engine was killed which affected power steering and brakes...and then there is the pesky locked engine/trans/rear wheels to tend with, all the while trying to avoid an accident.
No, think if your hitting the brakes you are soon to be under 30mph. I know it works, cause my dads 99 24v has a Exhaust brake with transmission controller thats programable and you can ride the brakes with the tc locked all the way to what ever speed you have decided. It can lug, but stepping on the bakes that hard and fast will disengage the tc.
 
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