Slip between 5th and 6th?

[high mileage]

Sometimes under light throttle I get what can only be described as a slip between 5th and 6th gear. It revs for a split second then engages. Hard to make it happen consistently but it's there. Am I looking a a new trans or is this some quirk I'm unaware of?

Trans is a rebuilt with like maybe 3 years on it.

 

[LSxBakakos]

Considering the trans is decently fresh id take it back to whoever rebuilt it and have them diag it. Very well could be something as simple as something sticking in the valve body that requires a ream, swollen check ball etc.

If its tuned you can probably adjust the oncoming/offcoming adaptives to remove the "flare" but id only do so as a last resort

 

[Joseph Garcia]

If you have access to a quality bi-directional scanner, some live data would be helpful in troubleshooting your issue.

@NickTransmissions is our resident transmission expert, and he will chime in with his thoughts and perspectives.

 

[high mileage]

I have access to a terrible scanner, but it may do live data.

 

[NickTransmissions]

Sometimes under light throttle I get what can only be described as a slip between 5th and 6th gear. It revs for a split second then engages. Hard to make it happen consistently but it's there. Am I looking a a new trans or is this some quirk I'm unaware of?

Trans is a rebuilt with like maybe 3 years on it.

Was your TEHCM replaced when the transmission was rebuilt last? What about the valve body - was it vac tested and a valve body correction kit installed (example would be the Sonnax Zip kit). Take a look at your paperwork if not sure.

If you do have a scanner, you'll be looking at pressure switch data to see if all of the TEHCM's switches are coming on and off timely as they need to. Flares as well as slamming into gear can be attributed to cracked diaphragms, worn/hardened seals or pressure switches themselves going bad.

If everything is ok w/the TEHCM and your flare is only occurring during a 5-6 upshift then I'd be inclined to suspect worn 456 clutch pack and another rebuild.

 

[high mileage]

Was your TEHCM replaced when the transmission was rebuilt last? What about the valve body - was it vac tested and a valve body correction kit installed (example would be the Sonnax Zip kit). Take a look at your paperwork if not sure.

If you do have a scanner, you'll be looking at pressure switch data to see if all of the TEHCM's switches are coming on and off timely as they need to. Flares as well as slamming into gear can be attributed to cracked diaphragms, worn/hardened seals or pressure switches themselves going bad.

If everything is ok w/the TEHCM and your flare is only occurring during a 5-6 upshift then I'd be inclined to suspect worn 456 clutch pack and another rebuild.

Ok cool thanks. The guy who replaced it is kind enough to do it again. Will update.