I wasn't sure whether to post this here or in the other truck forum.

'97 F350 CCLB DRW 7.3
Sam Wyse stage 1 transmission with maybe 4,000 miles on it, diesel site external trans filter, external cooler bypassing the radiatorPHP hydra with canned tunes but it's been running fine for a year untill yesterday

The problem: Yesterday on the way to work the truck made the shift into OD (at 35mph like it's done for the last 6 years with or without the tuner), but moments after it made the OD shift the truck acted like it was in neutral. I pulled over and it down shifted then momentarily acted as if the torque converter wasn't working. Light throttle got it to move, but then acted like it was in neutral again.

I checked the fluid level (good) and for leaks, none present. Continued on my way, but now the truck wouldn't even attempt the OD shift.

I've checked the MLPS, solenoid pack, and transmission wiring harness external plugs for loose pins, damage, corrosion, and have found nothing wrong. I checked the OD wiring in the column for bare spots - no issues. I scanned the truck even though the TCIL isn't flashing and still turns on and off - no codes.


So, now I'm looking for information although I spent a few hours yesterday doing research on the issue.

1) When is the OD shift supposed to happen? The truck has done it at 35 for the last 6 years, Sam says it's supposed to happen at 45-50.

2) Research is suggesting either a stuck valve or the solenoid pack isn't functioning properly (although it should throw a code), is there anything else I should be looking for?


Thanks in advance.

 

The shift to overdrive will happen at around 45 MPH. The torque converter will lock at 35 MPH. Are you sure that it is the overdrive shift and not the converter locking?

 

Quite positive as the truck seems to sort of "hang up" around 33-37mph like it is waiting for something. If it is the torque converter locking up it is the only time it does that you can physically feel it (to me anyways).

I can see the converter lock and unlock as the truck accelerates through the gears, but at 35 mph it certainly feels like a shift vs a converter lock.

 

What axle ratio do you have?

 

97' F350, 2006 axles, 4.10s. proper VSS
today the OD light finally began flashing but my scanner doesn't pick up a code from it unfortunately

 

I thought it was going to be a 4.10. That will lower shift speeds by 15%. That should make the 3-4 shift between 35 and 38 MPH.

I think Forscan will read all of the codes in these trucks.

 

So I tried to pull codes with 2 different apps on my phone as they have worked before for a flashing OD light, but it doesn't come up with anything.

Key on engine off: OD light functions as it should, no flashing
Key on engine on: OD light flashing
Driving tonight also seemed to have a firmer than usual shift and potentially torque converter lock but I didn't pay too close attention unfortunately. I'll see what tomorrow yields on the drive to work.

 

This was the culprit of my no overdrive issue. The planetary for the overdrive unit stripped somehow.

 

WoW! That doesn't look good. Mine shifts at 35 mph with light throttle.

 

Impressive carnage!

 

I was considering a SW transmission any ideas why this one grenaded ?

 

Warranty covers it?
After one year and 4000 miles.