6L80 Tap shift issue

[tcDawg]

2004 LJ, LY6 with 6L80 trans

I originally used a Speartech module for tap shift on a switch, worked fine.

Swapped to a Winters Shifter with RADesigns tap shift connectors/resisters about 3 years ago and it has always worked fine. Worked great actually, it is the only way I wheeled...always in manual mode, it was great to always have the gear you wanted.

Recently did a Cam swap and higher stall torque converter(also new headers and exhuast). Took it for a Dyno tune and tap shift would not work at the tuners. Tuner did his tune, motor runs well and the trans shifts well in regular auto mode.

Went to trouble shooting the loss of tap shift yesterday and cannot figure out why the trans won't shift in manual mode:
- checked all the tap shift wires at the shifter and at pin 7 in the trans plug, they have the appropriate ohm rating per Rory(RADesign) and Speartech(can't remember the ohm rating at the moment but at the time of testing we had Rory on the phone and he confirmed our ohn rating was correct, something like 1.5 for down shift and 4.425 for upshift.
- checked with a snap on scan tool and when clicking a down shift or up shift, the scan tool showed that the trans was getting the signal to up or down shift but there was no physical shift of the gear
- put the old motor and trans tune on, it idled like **** but it ran. Same thing, no manual trans shift.

Anyone have any ideas on this?

 

[Lil ugly]

No help here as you obviously know that the issue is in the tranny. But I am following this as I am interested in learning the solution.

 

[RustyC]

Following as well for info as I'm working on the exact same build. I would think the cam and converter should be the trigger to the problem or any changes to the tune due to them.
Do you know if you lost tap shift prior to the tuner connecting to the ecm,pcm? or as you stated didn't find out until it was on the dyno itself.

 

[tcDawg]

Following as well for info as I'm working on the exact same build. I would think the cam and converter should be the trigger to the problem or any changes to the tune due to them.
Do you know if you lost tap shift prior to the tuner connecting to the ecm,pcm? or as you stated didn't find out until it was on the dyno itself.

The tuner said tap shift was not working prior to any tune work.

Update to the original post....

Trans tune requires that you set a range(where the transmission is shifted) for Tap Shift to work. In my tune is was set at D5. D6 is auto mode, pull the shifter down on slot into D5 and that activates tap shift mode. The shifter itself was dropping down into the position for D5 just fine but we found out that the linkage wasn't actually moving the transmission into D5. An adjustment to the shift linkage allowed for for the transmission to move to D5 and now tap shift works.

Fixed. Big thanks to Justin at Rock Solid Fab on this one. He was helping me trouble shoot it and finally figured it out.

 

[RustyC]

Thanks for the update. It is amazing how it can help others down the road. Build thread?

 

[paradisepwoffrd]

Just for future reference, are you just using the RADesigns with Winters shifter now, or need that plus the speartech module to get auto plus tap shift?

 

[Lil ugly]

Good information. It always seems to be a small detail that doesnt stand out for alot of this tuning fixes.

 

[tcDawg]

Just for future reference, are you just using the RADesigns with Winters shifter now, or need that plus the speartech module to get auto plus tap shift?

Yes, using the Winters shifter with the RADesgins tap shift wiring. I love it.

I had the speartech module on a momentary "up/down" switch and didn't like it. The Speartech module worked correctly, but the switch was cumersome

 

[tcDawg]

Thanks for the update. It is amazing how it can help others down the road. Build thread?

I don't really have a build thread.