Transmission hydraulic issue - almost done with restoration

[KeithKinPhx]

Need advice. Bought a 4R70W conversion 7 years ago and finally installed. US Shift 4 controller. Went down the deep rabbit hole: Body lift, headers, exhaust, painted engine bay, FiTech, steering column, fuel system, rebuilt Dana 20, new interior. Add in a little renal cancer and other life issues to slow restoration down but I finally almost done.

Engine starts and runs fine. 800 RPM idle.

When I shift to drive then it runs rough. Shift to reverse the tires chirp and kills the engine. Called US Shift and they have me disconnect the solenoids and say I should still have 2nd and reverse. No changes. Same rough idle in drive and stall in reverse. They feel I have a hydraulic issue that may be caused by tranny sitting too long or improper rebuild. I did fill the torc converter with fluid before installing.

Called local transmission shop my brother has used here in Phoenix. Has me verify fluid levels at hot idle in park and that the cooling lines flow freely. Affirmative. Says the transmission has been modified and they have no idea what modifications the seller did. Basically if they take the pan off and can’t see something obvious then “Get ready to use your Visa Gold card. Going to be very expensive.”

Obviously I am very frustrated. At some point the cost to chase the problem down becomes a waste of time and money.

Decision time:
1) Having it towed to the shop ain’t cheap and now at mercy of shop owner but it is an option. Spending $500 to be told it is bad is an unrecoverable expense.
2) Easier to just buy another 4R70W and put it in?
3) Technology has advanced. Is there a better swap out now?
4) Park it, wait for the sweet quiet embrace of death and let my heirs deal with it?

Let me know your thoughts. God bless. Keith

 

[badandy73]

Couple of thoughts:

Have you updated your firmware on the controller and/or had them send you a new program based on your setup?

Are you running the TPS from the FiTech? Have you set/ adjusted it per the quick 4 instructions, 0% to WOT?

 

[Broncobowsher]

Couple of my thoughts.
What is it idling at IN GEAR? 800 in neutral is a touch fast. Which brings me to
I think you have a basic tune up issue with the engine. Do you have the vacuum advance connected to ported or manifold? What is the base timing set to? Do you have the right firing order?

 

[KeithKinPhx]

Couple of thoughts:

Have you updated your firmware on the controller and/or had them send you a new program based on your setup?

Are you running the TPS from the FiTech? Have you set/ adjusted it per the quick 4 instructions, 0% to WOT?

Thanks for the reply.
Nice folks at US Shift verified I had the latest firmware and were the first to say it was acting like an internal hydraulic issue. Not a transmission guy but something about an internal clutch/solenoid stuck. Even had me disconnect the Shift 4 to test that it was failing. Said the 4R70W give 100% to reverse if internal pressure is wrong. Hence the chirping of the tires.
I also bought the TPS direct from US shift and added to the FiTech. Did the TPS set up on the module per their instructions (not laptop). If I recall my readings were .54 on idle and 2.24 on full open throttle.

 

[KeithKinPhx]

Couple of my thoughts.
What is it idling at IN GEAR? 800 in neutral is a touch fast. Which brings me to
I think you have a basic tune up issue with the engine. Do you have the vacuum advance connected to ported or manifold? What is the base timing set to? Do you have the right firing order?

Thanks for helping.
800 is idle in neutral and park. I will try dropping it down to 700.
Vacuum advance is on the ported line on the back of the FiTech, not using manifold vacuum except to master brake cylinder. Timing is 12 degrees before TDC. Firing order is correct. Runs smooth and revs just fine in park and neutral.
When in drive it slows down the dies, about a 4 second process. Reverse engages, Bronco surges back, chirps tire and dies in about 1 second from engaging the gear.
Just really frustrated . And angry. And disappointed.

 

[badandy73]

Definitely sound like it's something inside the trans. Is there another reputable transmission shop in the area you could try? Seems like a good shop could drop the pan and diagnose with only burning a couple of hours of labor.

Once you get it figured out it'll be well worth it, mines been the best upgrade I've done to the truck.

 

[Broncobowsher]

I am still going with an engine issue. Can't be a clutch pack issue. You could appy every clutch and band inside the transmission and it will be locked solid. No different than if it is working perfect and you are in gear at a stop. That is the input shaft isn't moving and the torque convertor is slipping. The hard hit into reverse could be a transmission issue.
The closest it could be is internal to the torque convertor. Not sure how it could be extra tight?

 

[badandy73]

Do you remember seating the converter correctly when installing it; studs should have been pulled through the flexplate after the bell housing is bolted up to the back of the engine. If not, it can bind up and cause issues. Think it's more common for this to happen with the C4.