Any experience with Superior's 4r70w OD "Super Servo"

[Centaurus5.0]

Dropping the the valvebody this weekend in my 96 5.0l Explorer and I was contemplating on whether to install this oversized OD servo or not. I tow 6,000lbs +2,000miles often with it.

Anyone have any first hand experience before/after of the increased shift feel on 3-4 engagement. You can install a washer and make it shift even harder. I imagine like a WOT shift into 2nd, but have no real clue if it would even make a noticeable improvement.

 

[CDW6212R]

Interesting, I didn't know there was room for improvement of the 4R. Which part is it exactly that is being made bigger. I'm used to the old AOD's and their OD servo/piston/spring.

 

[Centaurus5.0]

It is a 2.7 Overdrive Servo. I believe ours have a 2.5 with a sleeve. They also sell an adjustment pin. Curiously it does not come with a spring. I was thinking, why not just remove the stock spring like you would with 2-3 accumulator to make it engage faster?

TCCOA says the 2.5 is good up to 300hp, but that was figured for a car not a tow truck.


I had this ordered just a bit ago on ebay and then cancel it. Decided to see how it behaves with the new valvebody first. If 3-4 still feels a bit clunky, I’ll put it in on the next fluid change and set the adjustment pin to maximum and see what happens.

 

[transman304]

This transmission suffers the same pin bore wear as the 5R55S/W. This is just a bandaid. The only way to make the circuit correct is to bush it back to OE spec. Don't want to remove spring on the sevo not the same function as an accumulator. It uses fluid pressure on both sides where the accumulator works more like a shock absorber. Adjustable pin may be ok but I feel you may just be compensating for band and drum wear. JMO.

 

[CDW6212R]

I gotcha, and that should match the size of the 98+ 4R's, which I think have no outer sleeve? It's been years since I looked at the parts inside a 4R, and lost touch with the guru who spent a lot of time on the SCCOA forum. I just haven't gone there in a long time.

 

[Centaurus5.0]

Thanks for the input transman. I will leave the OD servo alone. My trans has 62,000miles on it. It's not acting up in any way, just want to get it shifting the best it can and fix any common problems with it.

 

[CDW6212R]

Oh yes that's a good one. Put an EPC on the list too when you do the fluid next time. I was told that the EPC bore is one of the main wear points to watch for in a 4R. Sometimes the EPC itself will get a little loose in the bore from its wear, and then the normal operation/vibration can wear the case bore faster. That is not a serviceable hole, so it's better to simply replace the EPC on a schedule, like every 60-100k miles.

 

[transman304]

Oh yes that's a good one. Put an EPC on the list too when you do the fluid next time. I was told that the EPC bore is one of the main wear points to watch for in a 4R. Sometimes the EPC itself will get a little loose in the bore from its wear, and then the normal operation/vibration can wear the case bore faster. That is not a serviceable hole, so it's better to simply replace the EPC on a schedule, like every 60-100k miles.

That's very interesting information. I was unaware of this. Makes sense,i will have to check out the next few I do. The only issues with the early units was shift solenoid problems and 3-4 molded piston coming apart. Also noted for a neutral-bang symptom when starting from a stop. If you are dropping the VB watch the way you torque it back up as they are finicky and like to be torqued down in a few steps and have even had some to need retorqued after driving. Just the earlier units not so on 2000 and up. Now they blow forward drums apart and punch holes in the separator plate and break the OD sevo piston snap ring and loose 4th gear.

 

[CDW6212R]

Good stuff brad. I learned from doing my own AOD's and shift kits for them. Now that I have cars that need the 4R70, I'm working towards building four. I'll do one 99 Explorer 4R for my work truck for a mild application. The other three need to have car VB's, so I hope to find 2-3 04 Mustang V6 4R70W's. For my 91 Lincoln and old Ranchero, I hope to find a decent AODE planetary set to make those close ratio. My keeper SUV needs the most I can get done with a 4R, starting with the right trans.