Auto Gearbox

eldescans · Dec 3, 2009

Hi as you may have seen on my previous threads I am experiencing heavy gear changes what I have now noticed is that it appears to do a double change into top gear the first change is when I get a very heavy change and the revs drop and then go back up and the second change is reasonably smooth I am thinking of taking the valve block out to see if I can see anything wrong I have also sent for some Lucas transmission fix to try if it will improve the changes Has anyone any ideas what might be causing this problem

Datatek · Dec 3, 2009

eldescans said:
Hi as you may have seen on my previous threads I am experiencing heavy gear changes what I have now noticed is that it appears to do a double change into top gear the first change is when I get a very heavy change and the revs drop and then go back up and the second change is reasonably smooth I am thinking of taking the valve block out to see if I can see anything wrong I have also sent for some Lucas transmission fix to try if it will improve the changes Has anyone any ideas what might be causing this problem

If it's a P38, have the faults read, could be that the auto ECU is not calling for reduced torque from the engine or the engine ECU not responding to torque reduction call at the point when the gearchange is happening

lanmjdun · Dec 3, 2009

Isn't the last change the torque convertor locking up, usually happens about 48mph, it changes to 4th between 30-40mph.

Refurbing the valve block is a tricky job I would say, doing it under anything other than a spotlessly clean work environment is asking for trouble.

andyb66 · Dec 3, 2009

^^^ Yep ^^^ second 'shift' is the TC locking up.

Again "if it's a P38A".........the shift pressure (harshness of shift) is changed with respect to the throttle setting. I would suggest cleaning the TPS connections at the throttle pedal or unplugging the TPS and seeing if that makes a difference.

fett · Dec 3, 2009

Where are you located?, after a long learning curve on my classics autobox I now have a very good expert local to me. I now would not go anywhere else!

Beast o Bodmin · Dec 3, 2009

fit manual.bomb proof.

arron beast unleashed · Dec 3, 2009

^^^^^^^i second that, its not that hard changing gear for yourself.

eldescans · Dec 4, 2009

Hi thanks for the replies yes it is a P38 diesel I live in Spain so it is not very easy to get the faults read I have read on this forum that guys have taken this valve block out and have said its a fairly easy job to strip and check so I am concerned when you say I am probably asking for trouble I will try the TPS sensor when I get chance can you tell me the difference it would make if I disconnect it like you suggest any other thoughts would be very much appreciated

Canyon · Dec 4, 2009

is there a noise when the torque converter locks up or starts to lock up?, I sometimes get to 48-50mph and the power seems to flatline and a whirring noise occurs, after 50mph it just drives and accelerates as normal up to 70mph.
Not so much of a problem that is noticed when flooring it.

goonarmy · Dec 4, 2009

Canyon said:
is there a noise when the torque converter locks up or starts to lock up?, I sometimes get to 48-50mph and the power seems to flatline and a whirring noise occurs, after 50mph it just drives and accelerates as normal up to 70mph.
Not so much of a problem that is noticed when flooring it.

mine sounds like another gear change, the revs drop a little, but not as much as on a gear change.Id be worried about a whine....

gemsdad · Dec 4, 2009

arron beast unleashed said:
^^^^^^^i second that, its not that hard changing gear for yourself.

change gear oneself,unheard off.the driver or the butler do those sort of things.

eldescans · Dec 4, 2009

Hi have looked for TPS but cannot find it the only switch I can find by the throttle is the brake light switch can you tell me where it is I am now having problems with reverse I put it into reverse but nothing happens despite revving it I then need to go into D and drive forward a few times before reverse will work. I have never been able to get sport since I have had the car does anyone know the answer to this I have read on later forums that most guys at 70mph say there rev counter is saying about 2600 rpm I checked mine today and mine is doing 3600rpm do you think it might be stuck in sport or a lower gear I would be interested in your opinions

Datatek · Dec 5, 2009

eldescans said:
Hi have looked for TPS but cannot find it the only switch I can find by the throttle is the brake light switch can you tell me where it is I am now having problems with reverse I put it into reverse but nothing happens despite revving it I then need to go into D and drive forward a few times before reverse will work. I have never been able to get sport since I have had the car does anyone know the answer to this I have read on later forums that most guys at 70mph say there rev counter is saying about 2600 rpm I checked mine today and mine is doing 3600rpm do you think it might be stuck in sport or a lower gear I would be interested in your opinions

Don't know what your accelaration is like, but it does sound as if it could be in limp home mode, ie locked in 3rd.

Can you actually select 1st, 2nd and 3rd manually and see the revs drop as the change occurs? Have you checked that you have oil in the gearbox?

eldescans · Dec 7, 2009

Hi thanks for your replies update on my gearbox problem I now do not have any drive in reverse in high or low ratio would also still like to know answers to my other questions if possible please help if you can

fett · Dec 7, 2009

Have you had a look under FAQs on the ashcroft transmissions website?

They normally are pretty helpfull, its normaly the news that makes your wallet cry though, I know its happned to me!

(I got the wife to pay though lol

)

andyb66 · Dec 7, 2009

eldescans said:
Hi thanks for your replies update on my gearbox problem I now do not have any drive in reverse in high or low ratio would also still like to know answers to my other questions if possible please help if you can

Check fluid level and refill if low. That would be the first step. A complete flush may also help.

Worst case it is clutch pack or pump failure. Do fluid check first tho'......not so painful on the wallet

Auto Gearbox

eldescans

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Datatek

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lanmjdun

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andyb66

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fett

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Beast o Bodmin

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arron beast unleashed

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eldescans

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Canyon

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goonarmy

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gemsdad

NOT BOTHERED.

eldescans

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Datatek

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eldescans

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fett

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andyb66

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