8.1L with Allison?

[ALarsh]

So after reading some information on a plowing forum, many people have said that all 8.1L Chevy's & GMC's come with an Allison?

 

Is this true? I'm asking because I am looking at a GMC 2500 HD with the 8.1L and was wondering if it has the Allison in it?

 

Thanks

[Scyry]

Yes, it has an Allison, in all trucks. The 2500 Subarbans have a beefed up 4l80.

[ALarsh]

Yes, it has an Allison, in all trucks.  The 2500 Subarbans have a beefed up 4l80.

 

<{POST_SNAPBACK}>

 

 

 

Thanks Scyry.

 

Would 4l80 mean Allison?

 

Sorry, new to Chevy/GMC.

[Shaners]

Yes, it has an Allison, in all trucks.  The 2500 Subarbans have a beefed up 4l80.

 

<{POST_SNAPBACK}>

 

 

 

Thanks Scyry.

 

Would 4l80 mean Allison?

 

Sorry, new to Chevy/GMC.

 

<{POST_SNAPBACK}>

 

 

 

 

 

No, the 4L80E is not the Allison trnsmission. (I don't recall what the Ally RPO code is).

 

The only 2 trucks that I know of that GM puts the 4L80E behind the BB 8.1L is the 2500 Suburban and the 2500 Avalanche. It is also the tranny that is behind the 6.0L small block in the HD series trucks.

 

All other automatic equipped trucks (8.1L and the 6.6 Duramax) have the Allison tranny behind it.

[ALarsh]

Thanks for your help.

[Draenor]

If my memory servers me right...correct me if im wrong

 

4=Speeds

L=Longitudinally positioned

80=8000 lbs. GVW

E=Electronically controlled

[dewfpo]

The trans in the suburban behind the 8.1L is the 4L85E, a beefed up 4L80E.

 

DEWFPO

[Cheekster96]

Hey gang...i specifically wanted a regular cab 2500 HD with the big block and Allison, so, they do make em...

 

Picked it up today and boy, let me tell you...coming from a 4.8 to the big block...all i can say is.....NIIIIICE!!!

 

the six speed Allison, with the 4.10s and the big block, cruises effortlessly at 70 mph, turning only 2000rpm!

 

Rear end easily comes out with too much gas applied, and is hard to stay off of it!

 

The truck has 200 miles on it, under 10 hours on the engine, and i have only had it for a day...AND LOVE IT!!

 

more to come.

Lee

[silverado3500]

RPO for the Allison is MT1