I have a '89 F250, 7.3 IDI with the E40D. The trans was rebuilt back in 2002 by PROFormance Powertrain Products, has right at 5,000-10,000 miles since rebuild. I purchased the truck last month and ever since I bought it, it has shifted hard. I am just now getting around to solving it. When driving normal it shifts and jerks into all gears. But, when I run around 2K+ RPM's, it shift just fine through all gears.. ?? So, when I run high RPM's it's fine, but between 1,100 and 1,800 RPM's it shift hard. ?
Help!!!

Also, it has an OD drive button on the dash, how do I use that? I know the purpose, but when do I use it?
I'm not to familiar with this generation of truck.

 

it could be the fipl/tps if it's shifting ok in the upper rpms.if the tps is waring out,getting a bad spot right where it's driven most of the time,this would make since.if it's got more than 50k miles on it,id replace it anyway as it's a medium ware item.

https://www.ford-trucks.com/forums/1...ions-only.html

 

So, this thing ? Standard Motor Products TH35 Throttle Position Sensor | eBay

 

My 89 IDI E4OD shifts super hard also. And it slips going from 2nd to 3rd. I'm just not going to fool with mine. When I find a ZF5 I'm throwing that POS out. Also the OD button obviously takes away the OD or 5th gear. It is used when pulling a load because it is not good on the trans and is a big no no to use overdrive when pulling a load.

 

thats the one.i can't confirm that particular part number but im sure you googled it to verify.that's what they look like though.you can buy them locally for about the same $ as that too.most parts stores carry them.
just remember there are several things that can cause the trans to shift firm.though that may be likely the cause,pulling codes and or testing it's sweep with a volt meter will let you know if it's bad for sure.

 

Well that's all wrong.

The transmission is a four speed. There is no fifth gear to take away. The OD OFF button locks out fourth gear, not fifth. You only want to turn off OD when you need more engine braking. You should also turn off OD if the trans is frequently shifting in and out of overdrive, which is fourth gear.

The system was designed to tow in overdrive. You do not have to turn off overdrive with a load.

 

I didn't know this.

Thanks Mark!

 

I beg to differ. The E4OD technically has 5 gears. After fourth gear it has a double overdrive, and when you press the OD button it turns off the double overdrive which would be 5th gear. And as previously stated early, never use the fifth gear or double overdrive while towing. You can look at this link here to better understand.
https://www.gearvendors.com/fdrive.html

 

You beg to differ? There is no double overdrive. Here are the transmission ratios:

First 2.71:1
Second 1.54:1
Third 1:1
Fourth 0.71:1

That's it. There are no more ratios. While I didn't major in math, I can count. That's four ratios, which makes it a four speed. What is the ratio of the magical fifth gear?

The double overdrive that you found on the Gear Vendors chart only happens when you attach a Gear Vendors transmission on the back of the stock E4OD. The E4OD does NOT have five ratios.

Can you see signatures on your browser? Can you see that I was a Ford automatic transmission engineer for 19 years? I know this trans inside and out. You do not.

 

my F-super duty wishes he was right when she reaches 50 mph.

 

Where is the TPS at on the truck??

 

it's mounted to the side of the injection pump.on the drivers side about midway.you'll see a 3-wire harness plugged into it.

oh and i missed your last question in the first post,though Marked answered it partly when replying to the other guy.
you use the od cancel switch when and if the trans hunts between 3-od.with the diesels this really doesn't happen like it can the gas engines due to our grunt.she pretty much remains in gear until she downshifts and remains there until its good and ready for od again (as long as the tps is set correctly.)
another reason to cancel od is when coming down steep grades.it aids in engine braking.once in a blue moon i use it.

 

Is the tps something I can just get from an O'Reilly?

 

yup.they sell them at all the parts stores.though you've probably found it online there by now or called.

 

Okay. I'll start looking. Another question, would you happen to know what would be the best and cheapest code reader I could buy to work on my truck. 89 f250 7.3