Hard Trany shifts. Q’s for the pros

[Dirty30]

Hello 1st post here. Came to seek some info on my transmission and ask for advice. My 16 Yukon XL has been shifting hard from 1-2 & 2-1, and sometimes feels like it’s slow to engage and start rolling in 1st, revs a lil and jumps into gear if you don’t give it a sec to engage. Took to dealer & said I needed a whole new trans ($6k) That was almost a year ago. So my question was, if this is a common problem and “just replace this part/that part” or if I need a full replacement or rebuild? Also if so does anyone recommend a certain company or parts to use? I’m thinking I will be buying a new Yukon for family and keeping this for back up or trade this in for the new rig. I’ve had valves replaced and AMF deleted. So with a new tranny do you think it’s smart to keep around or are there other issues know to come up around that 150k mark?
Thank you for any help or insight.

2016 Yukon XL Denali; 128k I have owned since 20k and has been wife’s car and family road trips, no towing, no racing, have replaced trany oil 2-3 times with the last time being the recommended Mobile 1.

 

[donjetman]

Hello 1st post here. Came to seek some info on my transmission and ask for advice. My 16 Yukon XL has been shifting hard from 1-2 & 2-1, and sometimes feels like it’s slow to engage and start rolling in 1st, revs a lil and jumps into gear if you don’t give it a sec to engage. Took to dealer & said I needed a whole new trans ($6k) That was almost a year ago. So my question was, if this is a common problem and “just replace this part/that part” or if I need a full replacement or rebuild? Also if so does anyone recommend a certain company or parts to use? I’m thinking I will be buying a new Yukon for family and keeping this for back up or trade this in for the new rig. I’ve had valves replaced and AMF deleted. So with a new tranny do you think it’s smart to keep around or are there other issues know to come up around that 150k mark?
Thank you for any help or insight.

2016 Yukon XL Denali; 128k I have owned since 20k and has been wife’s car and family road trips, no towing, no racing, have replaced trany oil 2-3 times with the last time being the recommended Mobile 1.

U posted in the 2007-2014 area?

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

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

 

[blackelky]

If you're anywhere near vegas driving distance just take it to @NickTransmissions he is a gm transmission guru.

 

[NickTransmissions]

Hello 1st post here. Came to seek some info on my transmission and ask for advice. My 16 Yukon XL has been shifting hard from 1-2 & 2-1, and sometimes feels like it’s slow to engage and start rolling in 1st, revs a lil and jumps into gear if you don’t give it a sec to engage. Took to dealer & said I needed a whole new trans ($6k) That was almost a year ago. So my question was, if this is a common problem and “just replace this part/that part” or if I need a full replacement or rebuild? Also if so does anyone recommend a certain company or parts to use? I’m thinking I will be buying a new Yukon for family and keeping this for back up or trade this in for the new rig. I’ve had valves replaced and AMF deleted. So with a new tranny do you think it’s smart to keep around or are there other issues know to come up around that 150k mark?
Thank you for any help or insight.

2016 Yukon XL Denali; 128k I have owned since 20k and has been wife’s car and family road trips, no towing, no racing, have replaced trany oil 2-3 times with the last time being the recommended Mobile 1.

Sounds like either your rear sprag is starting to roll over or 1-2-3-4 piston is cracking...Could also be valve body, pump (worn PR valve), TEHCM and/or torque converter (the TCC is active in gears 2-6 and may not be releasing properly upon the 2-1 downshift).

It will need a full diag work up starting with a test drive w/bi-directional scan tool plugged in to confirm the drivability symptoms as being caused by the trans (Dealer likely already did this, hence their diagnosis) then trans will have to come out, valve body and TEHCM bench tested, TC cut open and trans torn down and inspected.

I can't speak to other, non-transmission related issues other than AFM/DOD, cam bearing and lifter failure are somewhat common for LSX engines north of 175k so if you plan on keeping it for the long haul, I'd do some engine testing/diagnosis to determine if you'll soon need major work there as well before committing to the transmission job.

 

[Dirty30]

U posted in the 2007-2014 area?

Whoops

 

[Fless]

Whoops

No worries. Fixed.

 

[Dirty30]

No worries. Fixed.

Thank you.
Does anyone one know of a company that sells remans with upgraded weak points for these trans? I read that GM replacements don’t address the weak points with their replacements? My Transmission shops near me are very limited so I feel I might try and do it myself as long as I’m not tearing into the insides on the tranny. Replace TC and trans at same time?
Anyone heard of Go-Powertrain? Free shipping and core returns!

 

[NickTransmissions]

Thank you.
Does anyone one know of a company that sells remans with upgraded weak points for these trans? I read that GM replacements don’t address the weak points with their replacements? My Transmission shops near me are very limited so I feel I might try and do it myself as long as I’m not tearing into the insides on the tranny. Replace TC and trans at same time?
Anyone heard of Go-Powertrain? Free shipping and core reruns!

Why are you hesitant to rebuild the transmission?

Per your drivablility symptoms, it's a least 50/50 you'll need to get into the case and overhaul it.

Never heard of Go-powertrain. Post a link to one of their 8L90 remans and ill take a look, give my thoughts.

 

[Dirty30]

Why are you hesitant to rebuild the transmission?

Per your drivablility symptoms, it's a least 50/50 you'll need to get into the case and overhaul it.

Never heard of Go-powertrain. Post a link to one of their 6L80 remans and ill take a look, give my thoughts.

OE Replacement Remanufactured Transmission 2015-2017 Chevrolet GMC Yukon Silverado Escalade 6.2L 5.3L V8 8L90 GPT1NN943328936AA

Looking for Online Wholesale Remanufactured Engines, Replacement Transmission, Transfer Cases & engines Distributor? Powertrain provides High quality large automotive parts with Good performance at Competitive Price.

go-powertrain.com

Reason I’m hesitant, is I guess I’ve never been involved in digging into one and wouldn’t know what I’m looking for. I’ve done a decent amount of backyard mechanic work just nothing with trans.