Auto box change up

dandywarhol · Post by **dandywarhol** » Sat Feb 09, 2008 6:15 pm

I've been bleating on about my autobox holding onto gears a little bit too long and kickdown happening too early so I thought I'd better do something about it. Changing the gearbox oil and cleaning the filter last year really helped a lot but it still downshifted 2 gears at a time at inopertune moments, resulting in a lot of revs and getting nowhere fast when overtaking

On the fuel pump there's a Throttle Positioning Sensor which signals the autobox change up times depending on throttle position.

Mine was set quite far to the clockwise position of the adjustment so I marked the position, loosened the screws and turned it about 2mm anticlock - tried the Bongo and found I had turned it too far - it wouldn't kickdown above 60mph.

Turned it back 1mm and tried again. Seems to be good now - the upchanges on light throttle are smoother and earlier (but still revs to 4500 before changeup on full throttle) and doesn't drop 2 gears when kickdown is demanded at 60 mph.

I'm sure there's a setting somewhere for the TPS by using an ohmeter but I can't find it.............

moonshine · Post by **moonshine** » Sat Feb 09, 2008 6:40 pm

A useful bit of info there Dandy. I am sure others have posted previously about high revs, and mine is slightly on the high side when using kickdown too. I might just try that adjustment, as mine sometimes kicks down when it doesn't really need to.

roosteruk · Post by **roosteruk** » Sat Feb 09, 2008 8:11 pm

That is a great bit of info there Dandy.
I have been meaning to have a look at mine and see what I can do, so its a gearbox service and a fiddle with the unit.
Cheers

Karl

mikeonb4c · Post by **mikeonb4c** » Sat Feb 09, 2008 8:14 pm

Wow, what an excellent tip that is, should I need it. Thanks+++ DW

bigdaddycain · Post by **bigdaddycain** » Sat Feb 09, 2008 9:17 pm

Good man dandy

Invaluable bit of info there!

(you use kickdown at 60???

)

cheffy34 · Post by **cheffy34** » Sat Feb 09, 2008 11:47 pm

Top banana

another good tip

Ralph · Post by **Ralph** » Sun Feb 10, 2008 3:40 pm

Did the same a few months back it smooths things out a bit
and seems to stop a few unnecessary change downs.

bighairypict · Post by **bighairypict** » Thu Feb 14, 2008 9:33 pm

I think I need to get round to this

would this also account for an idle speed that seems a little on the high side? My Creep mode is rather more of a Brisk Walk

Peg leg Pete · Post by **Peg leg Pete** » Thu Feb 14, 2008 11:30 pm

Cheers Dandy, good advice

dandywarhol · Post by **dandywarhol** » Thu Feb 14, 2008 11:33 pm

bighairypict wrote:I think I need to get round to this

would this also account for an idle speed that seems a little on the high side? My Creep mode is rather more of a Brisk Walk

No BHP - first set the idle speed then try the TPS adjustment. I've got mine set to where I want it now - nice smooth upchanges and better kickdown response.