Page 1 of 2

auto box lock-up operation

Posted: Sat Apr 30, 2011 8:46 pm
by nicstrike
i know that the auto box & all its quirks have been discussed over & over , but can anyone describe , solely , the proper & correct operation of the lock-up aspect of the auto box? i know it should kick in at around 37-40mph but other than that i am unsure how it should function & what is (or not) correct behaviour. is there a particular speed at which it should stay locked (other than in kick-down)? i am asking because on our bongo the lock-up seems to drop out & then back in if you back off the the throttle fully & then re-apply (as on twisty b road cruising etc) it was very pronounced & agressive but i have made it a little less "in your face" by tweaking the tps a touch but dont want to over-do it and mess up the change pattern too much. i would like to understand fully what it should be doing before i get too carried away with it.

Re: auto box lock-up operation

Posted: Sat Apr 30, 2011 9:31 pm
by francophile1947
That sounds normal to me 8) Mine also seems to go out of lock-up when on overrun, but re-engages as soon as you start to accelerate again.

Re: auto box lock-up operation

Posted: Sat Apr 30, 2011 10:58 pm
by bigdaddycain
The lock up is noticeably less noticeable :D After an ATF fluid change... might be worth considering perhaps? You'll be amazed at the difference! :wink:

Re: auto box lock-up operation

Posted: Sun May 01, 2011 10:23 am
by nicstrike
thats being done this week , so hopefully that will do the trick!

Re: auto box lock-up operation

Posted: Mon May 02, 2011 9:38 am
by nicstrike
just read a quote from alacrity in another "gearbox" post & it would seem that our 'box is probably working as it should , just maybe not as smoothly as it could. gear changes themselves are pretty smooth but the lock-up could be quite pronounced , though a little less so since i played with the tps.

Re: auto box lock-up operation

Posted: Thu May 05, 2011 7:31 pm
by nicstrike
WOW.......we now have a new truck. what a difference a good service has made! atf & strainer change has really smoothed out the lock-up jolt. new drive belts mean we no longer have a demented mouse at idle , and new front arb bushes and drop links have stopped it sounding like an old cart rattling over cobbles. the old bus is driving really well now!

Re: auto box lock-up operation

Posted: Thu May 05, 2011 7:38 pm
by westonwarrior
Thats good to hear

Re: auto box lock-up operation

Posted: Thu May 05, 2011 8:06 pm
by nicstrike
dead chuffed. aparantly the atf was like soup. happy days.

Re: auto box lock-up operation

Posted: Fri May 06, 2011 11:18 am
by Alacrity
Just seen this post as I have been away. If the ATF was 'like soup' then one oil change will not be enough, you only get out about 2/3rds of the oil when you drain it, the converter stays full. I would strongly recommend you change it again if it was that bad.

Re: auto box lock-up operation

Posted: Fri May 06, 2011 6:26 pm
by nicstrike
cant have been far off , he got best part of 6 litres back in.

Re: auto box lock-up operation

Posted: Sun May 08, 2011 8:36 pm
by Alacrity
I assure you if, as he says it was 'like soup' you need to double flush, you will NOT have changed more than about 2/3rds of the oil. It's your choice though but oil is cheap compared to a transmission rebuild.

Re: auto box lock-up operation

Posted: Sun May 08, 2011 9:49 pm
by nicstrike
i'll double check with the grease monkey.

Re: auto box lock-up operation

Posted: Mon May 09, 2011 10:40 pm
by nicstrike
grease monkey interrogated & all well.

Re: auto box lock-up operation

Posted: Mon May 09, 2011 10:44 pm
by jaylee
nicstrike wrote:grease monkey interrogated & all well.
I bet he never expected that....

Image

Re: auto box lock-up operation

Posted: Mon May 09, 2011 10:51 pm
by Bongoplod
nicstrike wrote:grease monkey interrogated & all well.
Ah,but does your greasemonkey know his Bongos??

There are plenty of Bongo owners on here who THOUGHT their greasemonkeys did when they informed they had bled their Bongo correctly......then got a bit miffed when it cost them £1500 to re...!!! place the head!!!

Brian