automatic gearbox problems

[Ghost14]

if i accelerate slowly in D, when it changes into 4th at rougly 30mph the engine revs seem to drop and the gearbox judders. it doesn't happen if i accelerate quickly so that it changes at a higher speed. any ideas? it's a ZF4HP22

[LRDISCOVERY]

if i accelerate slowly in D, when it changes into 4th at rougly 30mph the engine revs seem to drop and the gearbox judders. it doesn't happen if i accelerate quickly so that it changes at a higher speed. any ideas? it's a ZF4HP22

are you sure it is changing into 4th it shouldn't get into 4th until 50mph?

[Ghost14]

yea i'm sure. i know it should change at 50, that's the problem..... it's changing too early

[piper109]

You may want to try adjusting the kickdown cable where it attaches to the throttle. By tightening it up a little you should be able to get it to hold in each gear longer before it changes up. The overdrive however is controlled by a spring and a plunger in the valve block inside the transmission. If its been a long time since the transmission was serviced, a change of filter and a flush may be called for.

Steve

[steve b]

Sounds like the kickdown cable needs adjusting. Changing up really early = too slack , hanging on to a gear up to high engine revs = too tight.

hth

Steveb

[hebislander]

Hi everyone,

I'm new to this forum joined yesterday. I think I have the oposite as my auto is hanging on to 3rd gear for ages and you can never tell when it is going to change up.Some times slightly reducing revs prompts it to change but not all the time. I'm interested in the kickdown cable theory but where is it? and where is the adjuster? and lastly how do you increase and reduce the affect required.I'm sure I could attempt this myself with a little help from the forum, maybe some pics if pos.

Cheers Heb

[teabag]

are you sure it is changing into 4th it shouldn't get into 4th until 50mph?

You can be in top gear at 30 it depends on engine load and road speed it's the torque converter that locks up around 54mph, I can stay out of top gear up to 80+ when pushed hard with the peddle to the metal

[piper109]

Hi everyone,

I'm new to this forum joined yesterday. I think I have the oposite as my auto is hanging on to 3rd gear for ages and you can never tell when it is going to change up.Some times slightly reducing revs prompts it to change but not all the time. I'm interested in the kickdown cable theory but where is it? and where is the adjuster? and lastly how do you increase and reduce the affect required.I'm sure I could attempt this myself with a little help from the forum, maybe some pics if pos.

Cheers Heb

You havent said what engine you had but I am going to guess 300tdi. The kickdown cable should be attached to the arm on the injection pump and the adjuster should be clear. The throttle cable will be visible as the cable that goes to a place beside the brake booster. The transmission cable disappears down to the left hand side of the transmission.

On the V8 it is attached to the bracket that supports the outer part of the throttle cable and I would guess the 300tdi is similar.

Steve

[Ghost14]

Right i've adjusted my kickdown cable as tight as it can go and it's better but still not fixed, it doesn't seem to change the speed at gear changes up during normal slow acceleration but changes when it changes down to accelerate.

how do I change the filter??? anyone know of a link to a guide or has any pics???

[LRDISCOVERY]

4TH engages around 50mph with light throttle lockup of torque convertor is almost simutaneous kickdown would allow higher speeds before change.

[WHO?]

right fella's ive got a similar problem, im getting juddering at 54mph so it cant be kickdown cable as its behaving as it should but the spring plunger in the valve block sounds like it could be the culprit, as said above if accelerated hard it behaves its self until its time to change into 4th, so i should get it flushed and a fresh filter and all should be well?

Hugh