Allison 5sp: Tranny pops in and out of netural

[daltongd]

I recently did an extended repair on the engine where I had the transmission computer disconnected for 3 to 4 weeks. This problem started after putting it back together. During the repair I started the engine without connecting the transmission computer two or three times. 2002 Lb7 engine all stock.

When i accelerate slow from a start the transmission will momentarily pop into and out of neutral right after shifting from 1st to 2nd and sometimes 2nd to 3rd. The only way I know it does it is because I can hear he engine momentarily rev up. It's very quick.

When i accelerate through the shifting it doesn't do it all.

Any idea what's going on?

 

[darkness]

any codes? this is a question for whomever chimes in but could the tcm have reset being unpluged that long the trans is re-learning?

 

[juddski88]

Recheck connection tightness. Use some electric grease and zip ties. If it still does it report back

 

[daltongd]

No codes. I will re-mate the connector and report back

 

[daltongd]

I re-mated the connections with some dielectric grease and it still doing it. There is no way to use tie wraps to secure the connection.

 

[juddski88]

Are they loosening up visibly? Another possibility is the nsbu connection

 

[daltongd]

No they don't seem to be loose at all

 

[blk smoke lb7]

Not sure if related but a friend of mine had problems with his 01 jumping in and out of neutral and it wound up being the transfercase as the drive power has to go thru the t case.We thought it was the trans also.