4R70W Lock-up problems

[Thatorange67]

To start off, I would just like to mention that I do not own a mercury, I have a 1967 mustang with a 5.0L coyote and a 1995 4R70W. But I am experiencing some issues with my transmission, I was talking to a few guys at Holley (that's where my EFI that runs my trans and engine is from) and they actually recommended this website because they said you guys were a wealth of knowledge on the 4R70W. I know mine is a bit older but at this point any help is helpful. My trans started going into lockup out of the blue. Drove it all summer and had no problems but now it just started doing it non stop. When I start it in neutral or park it runs perfect. Shift into reverse it run just fine. Shift it into 1st and it goes into lock up and the rpms plummet and the car stalls. Shift it into manual 1st or manual 2nd and it goes into lock up. It for sure is going into lock up and I don't think it's an actual forward clutch failure because before it started going into lockup non-stop it shifted fine. Upon taking the trans pan off and looking around, there seems to be no evidence of a burnt out clutch or broken parts. I ordered another tcc solenoid, the 0-3 ohms. I haven't received it yet so who knows if that will fix it.

Just some important takeaways:

4R70W out of a 1995 Lincoln mark VIII
The Holley EFI trans controller software and hardware are not commanding the trans to go into lock up when I shift into 1st
I have 2 trans manuals for the 4R70W and one says that 1st gear lockup is hydraulically disabled and the other says its electronically disabled

Do You guys have any suggestions on whats wrong? Even a manual that could show the oil flow diagrams through the trans so we could eliminate more variables. Or a schematic for the solenoid to know if it constantly has power or not to determine more likely answers.

Thanks guys. sorry for the long initial post.

[burt ragio]

contact 88grandmarq another member on site he can take care of your problem.

[blazen71]

You want to turn lockup completely off until a desired rpm. That way it will only lockup in OD. I like 60-65mph. Most do it around 45-55mph.

[justbob]

contact 88grandmarq another member on site he can take care of your problem.

This ^^ The guy really knows his stuff!

You could also try Blown3.8 (Chris) He’s a little more active here and tunes as well.

Both have built some stout 4R70’s and love to help.


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[justbob]

I found a nice little write up on lock up operation and fluid routing from Sonnax.

Scroll down to 4R70

https://www.sonnax.com/tech_resources/203-ford-bypass-converter-clutch-circuits


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[MyBlackBeasts]

I found a nice little write up on lock up operation and fluid routing from Sonnax.

Scroll down to 4R70

https://www.sonnax.com/tech_resources/203-ford-bypass-converter-clutch-circuits


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KEWL!!! Thanks for the share Bob!

[Thatorange67]

Thank you very much! extremely helpful!

[Thatorange67]

I found a nice little write up on lock up operation and fluid routing from Sonnax.

Scroll down to 4R70

https://www.sonnax.com/tech_resources/203-ford-bypass-converter-clutch-circuits


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I am adding this to my trans manual info, thank you very much.

[Blown3.8]

My 95 t bird uses a higher? (don't recall if its higher or lower) ohm TCC solenoid. Not sure if its the same for the mark 8 trans I would assume so. But im guessing you got the correct on since you mentioned it. I also don't think that would matter using the holley for control.

I don't know what your problem could be but my bird locks the converter at the top of 1st gear which is supposed to be impossible. It would also lock low in 2nd when i would leave the house and stop at the stop sign it would down shift and stay locked and drag the motor down, but would finally release.

I havent torn the trans down to see if anything is wonky in there. It should have been done long ago as the car has been out of commission for 8 years. I just planned to get a 99+ trans for it. But did also pick up a marauder valve body to put in my 95 trans to see if that fixed the issue.

I'm gonna reedirect you again lol. You can post over on TCCOA.com there is a wealth of 4r70w knowledge there.

Definitely let us know if you figure it out. I'm personally interested in the fix.