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auto tranny problem


dwi

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Hi all,

Ok I have a 1996 300tdi with auto box. 100,000 miles on the clock and until 70,000 fully L/R serviced, gearbox was last serviced at 75,000

The problem is the box won't change up normally it just revs and revs stuck in gear.

In order to get the box to change up I have to take my foot off the throttle, the engine revs drop, and the box happily changes up. I then power on through the next gear until I get to a point just beyond where it normally change up on its own, then back off the throttle and the next up change occurs.

Down changes are no problem.

There is no slippage.

Any ideas grwatfully recieved.

Thanks,

Dave.

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Hi all,

Ok I have a 1996 300tdi with auto box. 100,000 miles on the clock and until 70,000 fully L/R serviced, gearbox was last serviced at 75,000

The problem is the box won't change up normally it just revs and revs stuck in gear.

In order to get the box to change up I have to take my foot off the throttle, the engine revs drop, and the box happily changes up. I then power on through the next gear until I get to a point just beyond where it normally change up on its own, then back off the throttle and the next up change occurs.

Down changes are no problem.

There is no slippage.

Any ideas grwatfully recieved.

Thanks,

Dave.

Dave,

In cold Auto can do weird if not enough oil (or bad quality).

Is it only when gearbox is cold? Gets warm after 1 hour of driving, is it then back to normal?

On a cold engine (and gearbox) try to check level of gearbox while engine is iddling.

First change to all gears (1,2,3,D,N,R,P) then shift back to neutral and check level.

If thas is alright,...change filter and oil?.....

(Please let me now the results)

Fred

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Dave,

In cold Auto can do weird if not enough oil (or bad quality).

Is it only when gearbox is cold? Gets warm after 1 hour of driving, is it then back to normal?

On a cold engine (and gearbox) try to check level of gearbox while engine is iddling.

First change to all gears (1,2,3,D,N,R,P) then shift back to neutral and check level.

If thas is alright,...change filter and oil?.....

(Please let me now the results)

Fred

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Dave,

In cold Auto can do weird if not enough oil (or bad quality).

Is it only when gearbox is cold? Gets warm after 1 hour of driving, is it then back to normal?

On a cold engine (and gearbox) try to check level of gearbox while engine is iddling.

First change to all gears (1,2,3,D,N,R,P) then shift back to neutral and check level.

If thas is alright,...change filter and oil?.....

(Please let me now the results)

Fred

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Hi thanks,

The fluid appears clean and fresh, it has done about 30,000 miles on this fluid. The level checked on the dip stick is where it should be. And warm or cold makes no difference.

Does that help?

Thanks,

dave

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that sounds femiluar that problem, my grandad had a p38 rangie and he it serviced and gearoils changed and after that it did what you explained and it couldnt work out what gear it wanted to be in, which was rather strange. i think it might be that you have to tell the comushift that you changed the oils (if it can be done) or rest it? just a thought.

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Hi all,

Ok I have a 1996 300tdi with auto box. 100,000 miles on the clock and until 70,000 fully L/R serviced, gearbox was last serviced at 75,000

The problem is the box won't change up normally it just revs and revs stuck in gear.

In order to get the box to change up I have to take my foot off the throttle, the engine revs drop, and the box happily changes up. I then power on through the next gear until I get to a point just beyond where it normally change up on its own, then back off the throttle and the next up change occurs.

Down changes are no problem.

There is no slippage.

Any ideas grwatfully recieved.

Thanks,

Dave.

Hi Dave, just a quick thought, you do know that the gear change points are dependant on the throttle position ie light throttle they change earlier, heavy throttle and they change later??

Cheers

Dave

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Guest DiscoTD4

Hi there

The auto box is purely mechanical with no electronic/ECU controls. Up shifts are determined by road speed and throttle position (supposed load). The gearbox determines the throttle position via the 'kick down' cable, which is linked to the throttle cable under the bonnet via lever crank arm.

On my auto I like a lazy drive with up shifts low down in the rev range - I don't like the standard setup and find it kicks down unnecessarily and makes for a fussy drive :(

So I slackened off the kick down cable sufficiently to ensure she up shifts at 1750-2000 RPM, even under relatively wide open throttle. Indeed if you disconnect the kick down cable completely she will up shift at 1750 RPM even under wide open throttle.

The kick down cable not only does what it says on the tin, it also extends the up shift point further up the rev range in tandem with road speed, so I wonder if your kick down cable adjustment has become too 'tight' or the cable slack has been removed some how, which would cause teh symptoms you describe ?

As an experiment I would disconnect the kick down cable at the crank arm under the bonnet - it's easily done as there is a clip on the end of the cable that can be swiveled out of the way to allow the cable to be temporarly disconnected. easy peezy job and will cut straight to the chase.

Having done this see how the gearbox responds, it should change up at around 1750 RPM even under wide open throttle. You'l have no kick down at all, so don't try any overtaking on the test run <_<

Please report back and good luck

Cheers

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I'll try that with the kickdown cable, sounds like a good diagnostic. As an aside; I had thought it 'kicked down' too easily so you might have something there.

Thinking about that, if it had been kicking down too easily would that be a sign that the cable was too tight or too slack?, too tight I suspect. It's hard for me to figure out how it could be getting tighter as it wears? but a brilliant idea to start with.

I've never looked at the workings of this box it sounds very similar (identical) to my old THM350 and 400s and 700R4 with a spinning governer in the side and either a vacuum modulator to the manifold (petrol) or a throttle position sensor on the pump (diesel)

Thanks,

Dave.

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Guest DiscoTD4

Your welcome, it's always worth trying the simple cheap things first ^_^

The more you tighten the kick down cable, the more readily she will kick down and also move the up shifts higher up the rev range. Basically the gearbox thinks you are pressing the accelerator pedal down further and are demanding greater acceleration / torque.

If this makes no difference then before commencing major surgery, one last shot would be to check the filter screen for blockages. If it looks clean then it's probably box out for further investigation and if it looks dirty and blocked then worth cleaning and refitting to see if it makes any difference. However if it's that blocked, this would be evidence of severe wear in the clutches/bands and so you may be on borrowed time anyway.

Good luck

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Disco TD4.

WOW that's amazing.

I disconected the the kick down as you suggested. What a difference. I doubt I'll ever re-connect it.

Wonderful lazy changes up and down. What an amazing improvement.

If I want kick down I'll slip it manually into 3rd and give it some throttle.

After giving her a test drive with the kick down disconected I tried to reconnect the cable and get it balanced but I just couldn't get it right; so disconnected it remains.

I'll write more later but now have to go and teach the wife to drive her 'new' gearbox.

Many many thanks,

Dave.

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Guest DiscoTD4
Disco TD4.

WOW that's amazing.

I disconected the the kick down as you suggested. What a difference. I doubt I'll ever re-connect it.

Wonderful lazy changes up and down. What an amazing improvement.

If I want kick down I'll slip it manually into 3rd and give it some throttle.

After giving her a test drive with the kick down disconected I tried to reconnect the cable and get it balanced but I just couldn't get it right; so disconnected it remains.

I'll write more later but now have to go and teach the wife to drive her 'new' gearbox.

Many many thanks,

Dave.

Excellent news, your welcome. I have found on mine it's possible to adjust the cable with enough slack so that I can still get kick down on the accelerator pedal (just about), but still maintain a nice lazy up shift characteristic.

It could well be the kick down cable is frayed inside or sticking or not attached correctly at the box end. I think on the EDC autos the cable terminates externally on the box.

I'm thinking of making a solenoid control on the crank arm so I can have a 'sport / winter' setting switch on the dash to select either mode, but that's a job for another day... <_<

Anyway enjoy your 'new Disco'

Cheers - Martin

There is one caveate I would add and that is possible negative consequence on the clutch bands

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Excellent news, your welcome. I have found on mine it's possible to adjust the cable with enough slack so that I can still get kick down on the accelerator pedal (just about), but still maintain a nice lazy up shift characteristic.

It could well be the kick down cable is frayed inside or sticking or not attached correctly at the box end. I think on the EDC autos the cable terminates externally on the box.

I'm thinking of making a solenoid control on the crank arm so I can have a 'sport / winter' setting switch on the dash to select either mode, but that's a job for another day... <_<

Anyway enjoy your 'new Disco'

Cheers - Martin

There is one caveate I would add and that is possible negative consequence on the clutch bands

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Thanks, I did wonder about the 'new' change style and the clutch bands, still it's never driven hard and the land bruiser does all my towing.

I did try and readjust the kickdown last night but couldn't get a balance. I did notice (I'd never seen this before) a coarse adjustment on the trotle control cable on the other side of the see-saw lever that actuates the kick down cable. I'm wondering if movement there might have been the cause as the car had just come back from the garage having it's poor starting in the cold checked out.

This weekend I'll re-connect the cable and try and balance it so kick down is near the bottom of the peddle position.

many thanks again,

Dave.

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Thanks, I did wonder about the 'new' change style and the clutch bands, still it's never driven hard and the land bruiser does all my towing.

I did try and readjust the kickdown last night but couldn't get a balance. I did notice (I'd never seen this before) a coarse adjustment on the trotle control cable on the other side of the see-saw lever that actuates the kick down cable. I'm wondering if movement there might have been the cause as the car had just come back from the garage having it's poor starting in the cold checked out.

This weekend I'll re-connect the cable and try and balance it so kick down is near the bottom of the peddle position.

many thanks again,

Dave.

Dwi,

Nice to hear that it is working again.

is it possible for u to take a few pictures of the kickdown cable (the end that u can disconnect)

Cheers and good luck adjusting it,

Fred

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I'll try Fred, not sure about uploading pictures but I'll try.

It's the fine detail you don't notice, I didn't see the coarse adustment on the trottle cable till afterwards, it's well disguised!

These things are so common you'd be better off finding one and flipping the bonnet to have a look.

All the best,

Dave

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I'll try Fred, not sure about uploading pictures but I'll try.

It's the fine detail you don't notice, I didn't see the coarse adustment on the trottle cable till afterwards, it's well disguised!

These things are so common you'd be better off finding one and flipping the bonnet to have a look.

All the best,

Dave

Hi Dave, I hope you don't mind but I'm after a bit of info before I go and have a look on my motor as the kick-down needs adjusting on it. I can't picture where this adjustment/cable is? I'm imagining looking into the engine bay, seeing the brake servo and master cylinder - so where is it in relation to them please, and what does it look like.

I know this must sound really lame but the weather is really cold here at the mo' so I want to be in and out as quick as poss, if you understand me.

Cheers & Merry Christmas

Dave

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Guest DiscoTD4

hi Dave

on the EDC model TDi300 trace the accelerator cable where it comes out of the bulk head, you'll see it connects to one end of a fulcrum arm, which sits behind the air conditioning pump (if fitted) The other end of the fulcrum has a cable connecting to the gear box (the kick down cable). It's pretty big and you want miss it.

Both of these can be adjusted by twisting the course knurled adjuster nut where the cable passes through the mounting bracket, or by unlocking the lock nut and turning the ferule in a traditional manner.

First adjust the accelerator cable to remove slack where it connects to the fulcrum arm, then you can adjust the kick down cable as required.

Regards

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Guest DiscoTD4
Thanks, I did wonder about the 'new' change style and the clutch bands, still it's never driven hard and the land bruiser does all my towing.

I did try and readjust the kickdown last night but couldn't get a balance. I did notice (I'd never seen this before) a coarse adjustment on the trotle control cable on the other side of the see-saw lever that actuates the kick down cable. I'm wondering if movement there might have been the cause as the car had just come back from the garage having it's poor starting in the cold checked out.

This weekend I'll re-connect the cable and try and balance it so kick down is near the bottom of the peddle position.

many thanks again,

Dave.

Yes this definitely could cause a problem, the accelerator adjustment will affect the kick down cable. They may have wound the accelerator cable out without then re-adjusting the kick down cable.

Basically the accelerator pedal cable just needs to be adjusted FIRST to give a slight clearance/slack at the crank arm, you then adjust the kick down cable SECOND as required.

Best wishes

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hi Dave

on the EDC model TDi300 trace the accelerator cable where it comes out of the bulk head, you'll see it connects to one end of a fulcrum arm, which sits behind the air conditioning pump (if fitted) The other end of the fulcrum has a cable connecting to the gear box (the kick down cable). It's pretty big and you want miss it.

Both of these can be adjusted by twisting the course knurled adjuster nut where the cable passes through the mounting bracket, or by unlocking the lock nut and turning the ferule in a traditional manner.

First adjust the accelerator cable to remove slack where it connects to the fulcrum arm, then you can adjust the kick down cable as required.

Regards

Thanks very much for that, I'll have a look tommorrow morning, we're off out now to the Notaires to sign for some more land !!! More money NOT being spent on Landys - boohoo :blink:

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