4R70W not shifting into 3rd or OD

nickleman60

Registered User
Okay, save me some trouble of searching.

1994 4r70w, upgrade to 2000+ valve body, j-modded with 2800 stall converter. Took it for a spin last week, entered the ramp to the interstate and let her rip through 1st and 2nd., about that time I had to let off the throttle and let it ease into 3rd, reapplied the throttle to just cruise and no 3rd, revving like it was in neutral. Luckily I was able to coast to the 1st exit which is my exit, when I slowed down to turn off of the off ramp I was going slow enough for it to kick down into 2nd so I limped back to my house. I let it sit until today so I pulled it out of the garage and let it warm up to check the tranny fluid level and was a little low. Topped it off and took it for a spin around the neighborhood and no 3rd or OD, meaning gear selector in drive and tranny still in 2nd, not free revving like it did on the interstate. Any ideas on what possibly be the issue? I'm hoping it's a simple and inexpensive one but I'm not banking on it.

Found this:


This could be a small or large problem. We will start with a possible cause that would not require transmission removal. If the car shifts from first to second, and then stays in second, never shifting to third or OD it may have a number 2 shift solenoid that is failing to activate, or failing to seal when activated. This could be caused by a defective solenoid, wiring problem, or bad processor. If you have had any recent electrical problems one of the above problems is more likely. This same condition could also be caused by a stuck 1-2 shift solenoid in the valve body.

If your transmission shifts from first to second, seems to hold second longer than normal, and then finally neutrals out completely at the point where it would normally shift to OD then the most likely cause is a damaged Direct Clutch Pack. This would require transmission removal and disassembly to repair. The Direct Clutch pack is the last one to come out of the transmission during disassembly, so plan on a complete overhaul while it is apart. You may also want to upgrade your direct clutch using raybestos blues, or the alto direct clutch pack kit as listed in our AODE Product Section. Another possible cause of the same symptoms is a broken stub shaft. We also offer an upgraded version of this shaft.
 
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How long since rebuild

Rich,
Mine was doing the exact same thing just 4 weeks ago and mine ended up being some worn out valves in the valve body.

Upgraded to a late model case and valve body and all fixed, but you already have a late model VB, so not sure what it could be other than what you have learned so far. Sounds like the info is from PATC.

3rd could definitely be the direct clutch pack. Has this tranny it been raced? I have a sheet that tells the status of all the clutches and solenoids if you would like me to upload it for you? Or if you are still going to shootout I can bring with me.

Smitty
 
There are some changes to the valves that are helpful as well. It's been years since I did one, but I remember a spring being changed and the valve being changed as well. Can dig and see what the part numbers are....

The neutral safety switch was an issue with this, but generally it can be the direct clutches. F430 is the autozone part number. Probably check rockauto.com and get the Ford one.

Is the OD light flashing at all?

2-3 Accumulator the Bonded Rubber one? New spring for it as well?

For what it's worth this is what Alan posted about this issue over on TCCOA a few years ago:

Actually this is a VERY common problem when using the rubber direct accumulator piston and no spring. Use of the taller aftermarket 4 seal design piston is one way of preventing the issue. I have been salvaging the stiffner plate from early valvebodies and installing them on the late valvebodies with the late retainer and have not had the problem since. I like to measure the clearance between the plane of the case and the retainer at bottom then make sure I fill it completely. Welding a washer or 2 to the bottom side of the retainer has also proven to be useful. I used to just weld up the retainer at top but I just hate doing that.
The aftermarket piston is a sure fire preventative it is so tall you could probably leave the retainer out and still not have the issue but I wouldn't try it.
Alan

Good info article: http://forums.tccoa.com/showthread.php?t=142615&highlight=accumulator

No OD light and no codes I would think it was the TR sensor.
 
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If you have a trans pressure checker, check direct/3rd gear port pressure. If that's OK, then your valve body and case are OK, you burnt third/direct clutches. You need third clutch to go into overdrive.

I smoked third a bunch of times in the Mark VIII before I figured out the calibration was bad in 94/95 years. Only time I came close to breaking something was when I compressed a spring in the one way roller clutch. Then, I just replaced it with an mechanical diode.
 
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