05 Yukon SLT Autoride

[dadwagon95]

Yo yo yo dadwagon here... Got the new mule in and she's got a little issue just want some opinions from y'all knowledgeable fellas.. so I'm pretty sure it has a transmission issue before I forget it's a 2005 GMC Yukon SLT Auto ride 4x4, it's fully loaded all the bells and whistles. You can take off and drive before the transmission warms up and it'll shift fine although it seems like it slips third a little bit.. after about 5-10 minutes it feels like the acceleration is sluggish and I have to drop it into the first gear manually to get it to go and then shift to second and it never grabs third or fourth. However I try to engaging the four low it does work but it also feels like it shifts through all the gears. Very odd I just don't want to jump the gun on the transmission and it be something totally different like possibly a transfer case or maybe a differential not working properly.

 

[rockola1971]

Yo yo yo dadwagon here... Got the new mule in and she's got a little issue just want some opinions from y'all knowledgeable fellas.. so I'm pretty sure it has a transmission issue before I forget it's a 2005 GMC Yukon SLT Auto ride 4x4, it's fully loaded all the bells and whistles. You can take off and drive before the transmission warms up and it'll shift fine although it seems like it slips third a little bit.. after about 5-10 minutes it feels like the acceleration is sluggish and I have to drop it into the first gear manually to get it to go and then shift to second and it never grabs third or fourth. However I try to engaging the four low it does work but it also feels like it shifts through all the gears. Very odd I just don't want to jump the gun on the transmission and it be something totally different like possibly a transfer case or maybe a differential not working properly.

First check your fluid level and condition in your Tcase. The 246E Tcase commonly develops a pump rub in its rear half case and slowly leak its fluid out until its too low or bone dry. Do you have an Auto 4wd button on your dash?

 

[Joseph Garcia]

@NickTransmissions is our resident transmissions expert, and he may have some troubleshooting advice for you.

 

[NickTransmissions]

Yo yo yo dadwagon here... Got the new mule in and she's got a little issue just want some opinions from y'all knowledgeable fellas.. so I'm pretty sure it has a transmission issue before I forget it's a 2005 GMC Yukon SLT Auto ride 4x4, it's fully loaded all the bells and whistles. You can take off and drive before the transmission warms up and it'll shift fine although it seems like it slips third a little bit.. after about 5-10 minutes it feels like the acceleration is sluggish and I have to drop it into the first gear manually to get it to go and then shift to second and it never grabs third or fourth. However I try to engaging the four low it does work but it also feels like it shifts through all the gears. Very odd I just don't want to jump the gun on the transmission and it be something totally different like possibly a transfer case or maybe a differential not working properly.

Agree w/ @rockola1971 - check fluid levels and TCase...Your symptoms sound like 3-4 clutch failure, which accounts for roughly 85-90% of all 4L60E transmission failures. I've never been in 4L in my 03 Z71 outside of occasional rough trail use so never got it anywhere near fast enough to shift into 3rd gear so I'd double check...

Unplug the transmission fuse or the large, round case connector then fire up the vehicle - put it in drive and see if it will move forward on it's own...This test puts the transmission into limp mode, maxes out the line pressure and gives you only third gear and reverse...While it's not foolproof, if you can move forward and drive a bit (don't drive far like this!) it would tell me your 3-4 pack is at least function to the extent that can be determined via this test.

If it goes nowhere, drop the pan - see the bottom...If you see a lot of black, burnt clutch material put the pan back on with a few bolts and yank it out for overhaul.

 

[dadwagon95]

First check your fluid level and condition in your Tcase. The 246E Tcase commonly develops a pump rub in its rear half case and slowly leak its fluid out until its too low or bone dry. Do you have an Auto 4wd button on your dash?

It is all wheel drive. Only three buttons one looks like traction control? 4low and the middle one I'm not sure

 

[dadwagon95]

Agree w/ @rockola1971 - check fluid levels and TCase...Your symptoms sound like 3-4 clutch failure, which accounts for roughly 85-90% of all 4L60E transmission failures. I've never been in 4L in my 03 Z71 outside of occasional rough trail use so never got it anywhere near fast enough to shift into 3rd gear so I'd double check...

Unplug the transmission fuse or the large, round case connector then fire up the vehicle - put it in drive and see if it will move forward on it's own...This test puts the transmission into limp mode, maxes out the line pressure and gives you only third gear and reverse...While it's not foolproof, if you can move forward and drive a bit (don't drive far like this!) it would tell me your 3-4 pack is at least function to the extent that can be determined via this test.

If it goes nowhere, drop the pan - see the bottom...If you see a lot of black, burnt clutch material put the pan back on with a few bolts and yank it out for overhaul.

Thank you buddy! So if it moves I have something else going on? I was told potentially a torque converter but it doesn't act as if it's a torque converter and the symptoms really don't follow with it I was under the impression torque converters will stall a vehicle

 

[rockola1971]

It is all wheel drive. Only three buttons one looks like traction control? 4low and the middle one I'm not sure

Since its got AWD, you have a Borg Warner Tcase and they dont have the same pump rub problem that the 246E Tcase has. Sounds like you have clutches burnt up in your tranny. The shifting fine until warmed up is almost a dead giveaway. Pull your tranny dipstick. Smell it! Does it smell a nasty burnt smell? What color is the fluid? It should be pink to pinkish. Not orange to brownish. I suspect you will find out that the fluid is burnt from the excessive clutch slippage. If burnt then confirm by dropping the pan (or just take it to a shop for a rebuild at this point). Have a look in the bottom of the tranny pan and I suspect you will find all kinds of clutch material laying in the bottom of the pan and maybe even notice some metal glitter or even metal chunks. You may not want to drop that tranny pan in your driveway or especially your garage. That burnt fluid smell is very strong and lingers.