E4OD shifting problem.

thetintguy001

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Ok so this probably isnt a new thing, ive been doing some reading and ive seen a lot of different ideas of what can cause this but nothing for sure. I thought maybe i could try describing whats happening here.

First of this truck sat for about 3years. Recently we got it road worthy. (Long story.)

I replaced the trans filter and new fluid. The old fluid had started to gel in the bottom. I dropped the pan a 2nd time and refilled as a way to flush it.
Also added a bottle of transtune.

When i start the truck and put it in drive most of the time its in 1st sometimes it seems like 2nd. Ive been told these trucks start in 2nd....but that might be bad info. But regardless it will not shift to the next gear until its been held at a high rpm for awhile. Sometimes 5 seconds sometimes longer. When it goes to the next gear it hits pretty hard. But generally the nexts shifts are decent,and as long as the truck is running it will shift relatively good even from a stop. Not perfect, still hits a bit hard.
I read this could be the intermediate plates wearing out or the clutch packs wearing out on 1st.(I hope I dont sound dumb on this i dont know transmissions at all)

What is weird is that if i was to turn off the truck say at a drive through or something, it starts all over. 1st gear has to be revved high until it grabs and then it shifts decent through the rest.

Today i pulled all the connections on the tranny and cleaned them and used dielectric grease on all.

This seems to be an electronic issue but i may be wrong. Possibly a shift control solenoid.

This is a custom truck, the guy who did the wiring didnt mount the ob2 port, so im trying to find these wires and get it fixed. Also i have 2 computers for this truck and it acts the same regardless which one is used.

Thanks in advance.

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thetintguy001

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I failed to mention this is a 97 f250, and the transmission has been rebuilt by a previous owner.

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Mark Kovalsky

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Ive been told these trucks start in 2nd....but that might be bad info.
That's bad info. They start in first gear.

But regardless it will not shift to the next gear until its been held at a high rpm for awhile. Sometimes 5 seconds sometimes longer. When it goes to the next gear it hits pretty hard. But generally the nexts shifts are decent,and as long as the truck is running it will shift relatively good even from a stop. Not perfect, still hits a bit hard.
That's what it will do if it doesn't see a signal from the vehicle speed sensor.

I read this could be the intermediate plates wearing out or the clutch packs wearing out on 1st.(I hope I dont sound dumb on this i dont know transmissions at all)
Probably not either of those.

What is weird is that if i was to turn off the truck say at a drive through or something, it starts all over. 1st gear has to be revved high until it grabs and then it shifts decent through the rest.
If it doesn't have a vehicle speed signal, each time it's started it has to learn that all over again. So this also points towards a missing vehicle speed signal.

This is a custom truck, the guy who did the wiring didnt mount the ob2 port, so im trying to find these wires and get it fixed.
That's the first thing to do. Knowing what codes are stored could turn this from just guessing to actually knowing what to fix.
 

thetintguy001

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Ok, im going to prioritize getting this ob2 port hooked up (smh) and check on the speed sensor.

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8inchstroker

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Sounds like speed sensor in rearend . don't ask how i know. Does it have the donor trucks rear axle? I read your other post.

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thetintguy001

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All the running gear is 97 f250. Sterling 10.25 in the back i believe.
I just picked up the tranny speed sensor and the rear end one. Ill put them on as soon as i eat some dinner =) 👍

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thetintguy001

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Ok i grabbed a new rear diff VSS from autozone. Took it for a spin to a parking lot. Turned it off, back on and it did the same thing on the way back.

I read that part house VSS can be crap. Does anyone recommend a good brand? Oem maybe best best.

Side note i managed to locate the obd2 port so ill get someone with a capable scanner hit this thing soon.

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old man dave

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OEM is best for all electrical/electronic items.

Is your speedometer working? It uses the same VSS signal but after its processed by the PSOM module.
 

mandkole

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this is a wag, but a broken accumulator spring in a 4R70w acted almost exactly the same way. Good luck getting the OBD plug harness figured out.
 

thetintguy001

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Ok, here is a quick update. I managed to fix my data link port and get the truck over to suncoast to have them scan the codes.
I was told the ecm is searching for vss on the tranny and isnt finding it so its going into limp mode, thats why im getting a long delay until 2nd and its searching for gears when under heavy acceleration.
So they didn't add a vss to the tranny until 99+ so they are leaning towards my ecm is not correct for the truck or it has been damaged.

I pulled the ecm apart and noticed a few odd things on the board like something had been prying and scrapping around. Also it has a remanned sticker on it.
So the #on my current ecm is F7TF-12A650TB and after calling a few dealers to cross check they supplied me with this part number as the correct one.
F7TZ-12A650TB soi dont know the difference between the F and the Z but maybe this is the issue.

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Mark Kovalsky

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So they didn't add a vss to the tranny until 99+ so they are leaning towards my ecm is not correct for the truck or it has been damaged.
That's wrong. The VSS in the 99+ is on the rear diff, not the transmission.

The 99+ transmission did get a turbine speed sensor (TSS) and output speed sensor (OSS) but not a vehicle speed sensor (VSS.)
 

thetintguy001

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Ok so just an update. My shifting problem was the psom. Or the lack of one. 😃😂 this being a project truck, 78 supercab on a 97 f250 frame i didnt realize a psom was needing to convert the signal from the vss to the pcm! So i got my psom wired in and we have silky smooth shifts. 👍
The only thing im experiencing is under heavy throttle it seems to shift too fast into 3rd then shifts again and bogs hard. I have to feather the throttle to get it to kick back down and get on the power. A few things i was going to check is the rear end ring and make sure there is no junk throwing off the vss. Then check or replace the the tps.
Any other ideas?


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thetintguy001

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7d18f315adbfdce10c566ded9f441bfe.jpg


Here is the truck. Look I know its not everyones style or taste so save the bs comments 👍 and of course its not finished.

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