4l80e gearing

[Will L.]

I know there are places rebuilding the 4l80e into a 6 speed to help freeway geared trucks with better acceleration. Does anyone know are there options for more top end? Maybe 35% od instead of 25%?

I don't need to do anything with it now, just thinking ahead for when it's time to rebuild what options might be out there.

Has anyone put an allison behind thier 6.5 and what are the ratios available there?

The wife already hates this rig, I wonder what she'd think of an nv4500. That would take some serious linkage magic.

Thanks for any input.

 

[WarWagon]

The 6 speed is using the OD clutches to split gears. It also has a lower first gear ratio that TCI made for it. 2.97, 2.31, 1.57, 1.18, 1.00, and 0.75

The Allison has more drag and thus wastes power. Not worth it behind the 6.5. It is more fun behind a Duramax. This is the conversion you should be planning... The 4L80E is just a step down, but, a tough design except for compression braking. That is it's weakness as the overrun clutches will burn off easy with compression braking. (Done that.) The 4L80E is behind the van Duramax engines...

You may consider a Gear Vendors over/under drive that would give you better ratios on both ends.

 

[Will L.]

Yeah, I just dont have the room to fit in the gearvendor. Full time 4wd is a pain in that aspect also.
I'm really happy with the gearing of the tranny getting up to speed, towing and off road. Just wondering if that ".75" od is possible to go to a ".70" .

Also you mentioned there is a tranny shop in Az. that was good at a good price iirc from a different post. Care to share info for my records? Lots of good shops for regular work here, nut bo tranny places I recomend.

 

[WarWagon]

http://www.allstatetransmission.net/
They have had me OTD for $1200 with new OD gears and a full rebuild. They can build higher power units, but, for the 6.5 towing I can't complain.

 

[Will L.]

Thanks!:thumbsup:

 

[handcannon]

The 4L80E is just a step down, but, a tough design except for compression braking. That is it's weakness as the overrun clutches will burn off easy with compression braking. (Done that.) The 4L80E is behind the van Duramax engines...

Is there a work around/upgrade that will work for this?

Don