Real fast question for someone out there... does anyone know what model transmission is under the 2011 GMC sierra Z71. Mine has the 5.3l v8 engine and i want to ...

Real fast question for someone out there... does anyone know what model transmission is under the 2011 GMC sierra Z71. Mine has the 5.3l v8 engine and i want to do some more research on the transmission and using my blackbear performance autocal tuner on both the engine and transmission. does anyone know the model or possibly have any webpages that might help me dig a little deeper into whats in my truck... or even possibly have any information about whether or not the blackbear tuner would do my new baby any good? Thanks in advance for the info.

Go to GM Powertrain web site, they have all the data on the transmissions and engines you download. You will need your engine option code from RPO label in glove box to select the correct trans for the engine,, e.g. LC9, LMG

http://www.gmpowertrain.com/PowertrainOverview.aspx

http://www.gmpowertrain.com/VehicleEngi ... d=66&pid=2

im currently in Afghanistan and the truck is home in a garage... is there any other way to figure out what is in the truck? I do have the VIN with me if there is anyway to figure it out off of that. On a side note... does anyone know if the fluids and oil from factory are synthetic? I usually run full synthetics through the whole vehicle and i actually meant to ask the salesman but i totally forgot. Just trying to figure out what i need to change if anything when i get another break several months from now. Sorry for the hassle im new to sierra's im typically a jeep kinda guy heh.

The engine and trans fluids are not synthetic but they could be a semi-synthetic as it would have to be to meet dexos1.

Both differentials are synthetic and have been for many years.

The engine is coded in the VIN, the 8th digit

0 - LMG 5.3L flex-fuel iron block
3 - LC9 5.3L flex-fuel aluminum block

Basically its going to be the same transmission under all of them, what could be different is the program they are running for shift control etc.

2011 GMC TRUCKS SIERRA 1500 PICKUP 5.3L 8-cyl Engine Code [3] LC9 Flex-fuel

Good possibility you have the 6 speed HD 6L80. Thus far has proven to be a good tranny. You could have the 4 speed also.

By the way, thanks for your service to the United States of America.

Plug the VIN intohttp://www.compnine.com/vid.php

That should tell you what was installed in your truck at the factory.

Jim

is it a 4 speed or 6 speed. 4 speed 4l60E 6 speed 6L80. the 6 speed has the shift buttons on the gear select lever

He's got a 2011 5.3 so he has the 6 speed, the 4 speed on only offered on the 4.3 v-6 and 4.8 v-8. I think in 2010 they started using these transmission setups.

Jim08SLE wrote:Plug the VIN intohttp://www.compnine.com/vid.php

That should tell you what was installed in your truck at the factory.

Jim

The compnine site is only updated through 2009 (and some early 2010) models. The OP has a 2011.