Built 04 lb7 tranny fit in my 05 LLY??

[Duramaxin]

Like the title says.. Do yall know if a built 04 lb7 transmission fit in my truck?? Will i run into any problems with this down the road??

 

[bullfrogjohnson]

The valve body and internal harness will have to be swapped, other than that you should be fine.

 

[Mike L.]

No changes necessary. All '04 Alli's had the G solenoid. It is a direct fit.

 

[bullfrogjohnson]

No changes necessary. All '04 Alli's had the G solenoid. It is a direct fit.

Damn, learn something new everyday.

Whats the purpose of the G-solenoid? With all the other hard parts being the same in the in the 5spd, is there a benefit?

 

[Duramaxin]

Thanks man. I really appreciate it.

 

[Mike L.]

Damn, learn something new everyday.

Whats the purpose of the G-solenoid? With all the other hard parts being the same in the in the 5spd, is there a benefit?

G solenoid drops mainline pressure at below 8% throttle by 150 psi. It raises it back again above 7% throttle. This is done by the TCM so the trans runs cooler at idle. All '04 and some late '03 had it installed but it wasn't lit up. In '04 they lit the G solenoid in the LLY's and 8.1's but not the LB7's. You can use the '05 G solenoid valve body in any 5 speed as that is all Allison sells now for replacement. You cannot use a non G valve body in the later ones because it will set a code and the engine will run ruff.

 

[THEFERMANATOR]

You cannot use a non G valve body in the later ones because it will set a code and the engine will run ruff.

Can't you swap in a LB7 TCM or flash in a LB7 TCM OS into your TCM and do away with it?

 

[Mike L.]

Can't you swap in a LB7 TCM or flash in a LB7 TCM OS into your TCM and do away with it?

Yes

 

[BoostJunkie622]

I will be doing the same, my buddy is selling his built lb7 trans and I am gonna throw it in my lly! super pumped!!
:woott: