Spool up

[vk2ss55 Senior Member Find all posts View Profile Close vk2ss55]

G'day

I've got an 09 D4D auto and have noticed that there seems to be a bit of spool up of the transmission before it actually starts to drive after an over run condition . Typically this will be going down hill on no throttle , then when some throttle is applied the trans seems to spool up and then drive . I wonder if it's something to do with the trans holding a lower gear on a hill descent but then having a little think about it before actuallty driving again ?
Any ideas ?

Cheers

Ross

[gxl_d4d Advanced Member Find all posts View Profile Close gxl_d4d]

Re: Spool up

I've got an 08 d4d. Mine does the same.

[WBY 1 Senior Member Find all posts View Profile Close WBY 1]

Re: Spool up

some autos will do this as the auto thinks about what gear it should be in. Most noticeably occurs in the scenario you said due to the sudden change in speed/momentum and throttle input. dpends on the auto transmission and manufacturer etc.