M1084 Allison transmission problem

[Unimog66]

Hi
I have a m1084 with an Allison transmission , I’ve already changed the oil . it gives little jerks between the second and third , all the all gears shift smoothly . Any ideas what it could be

thanks

 

[Ronmar]

how much weight you got in it? any codes stored(press both arrows to enter diag mode use mode button to step thru the 5 memory locations).

3rd is where lockup is engaged, and with the 2:1 hubs, the trans has a real mechanical advantage so it satisfies lockup requirements almost immediately/in conjunction with the the 2-3 shift. put 2 tons on the back and see how it shifts...

 

[Unimog66]

how much weight you got in it? any codes stored(press both arrows to enter diag mode use mode button to step thru the 5 memory locations).

3rd is where lockup is engaged, and with the 2:1 hubs, the trans has a real mechanical advantage so it satisfies lockup requirements almost immediately/in conjunction with the the 2-3 shift. put 2 tons on the back and see how it shifts...

Perfect I will put 2 tons in the box and get back to you
thank you

 

[Ronmar]

Yea the 2-3 shift is brutal in an empty truck. Getting rid of the 2:1 hubs also calms it down.