Problem with my auto gearbox

robearner · 10th December 2012, 21:43

I have a 2 litre 75 Tourer club 2002 that has a problem with its auto gearbox. When changing both up and down it thunks and feels as if it is pushing the car forward slightly as it roughly engages. There is no slippage, all gears are accessible and the kick down works as expected.

I have changed the gear oil with the appropriate oil from Rimmers, but this brought about no improvement. Does anyone have any idea what could be causing this and if so what I need to do to remedy it? Am I facing a new or replacement box or is it likely to be one of the sensors that I can change/

I have a 2000 Conny 2.5 auto as well, maybe one solution would be to swap the auto boxes, but I am unsure whether they would be compatible or not. Anyone have any idea about this too?

Thanks,

Rob

SD1too · 10th December 2012, 22:04

Rob,

It might be a faulty solenoid. This has been discussed before, so a search should bring up the relevant data.

The gear ratios for the 2.5 litre engine are not the same as for the 2.0 V6 so it's not advisable to swap transmissions.

I hope that you bought ATF specified as a direct replacement for 'N402'.

Simon.

rover54 · 10th December 2012, 23:10

Quote:

Originally Posted by robearner

I have a 2 litre 75 Tourer club 2002 that has a problem with its auto gearbox. When changing both up and down it thunks and feels as if it is pushing the car forward slightly as it roughly engages. There is no slippage, all gears are accessible and the kick down works as expected.

I have changed the gear oil with the appropriate oil from Rimmers, but this brought about no improvement. Does anyone have any idea what could be causing this and if so what I need to do to remedy it? Am I facing a new or replacement box or is it likely to be one of the sensors that I can change/

I have a 2000 Conny 2.5 auto as well, maybe one solution would be to swap the auto boxes, but I am unsure whether they would be compatible or not. Anyone have any idea about this too?

Thanks,

Rob

Solenoids are the same between both boxes. Do a resistance test via the mutliplug, the thud jerky shift is if IIRC solenoid C which is the 2/4 brake drum or 2/4 duty solenoid. Solenoids are around £45 and are available http://www.the75andztclub.co.uk/foru...63&postcount=1

robearner · 11th December 2012, 08:26

Simon,

Thanks for the reply. I didn't think they would be transferable, but thanks for confirming that. I also did use the N402 fluid supplied by Rimmers, about 4 litres for the change.

I'll look into a replacement solenoid before condemning the box! Any idea how difficult identifying the faulty unit and replacing it might be - any experience of this?

Cheers,

Rob

robearner · 11th December 2012, 08:40

Thanks for that really informative reply - I'll certainly look into replacing the solenoid c before condemning the box. As I already said, the unit seems to work normally, changing both up and down at the right engine speeds, etc - if it were not for that "thud jerky shift"
. love the term by the way, really sums up what is happening!!

A local mechanic on the Island took the car to a 'transmission specialist' whose diagnosis was a less than complimentary 'it is shot' or stronger words to that effect. He also went on to condemn the Jatco box as 'that Japanese Rubbish', saying that you couldn't do any work on them as they are sealed units and once they start playing up you simply have to get rid. I would like to think that this diagnosis is too premature, certainly on the forum people seem to have had experience of replacing many items and ending up with a perfectly functioning box....

How easy is it to assess the working of the solenoids and then to replace. Are there any guidelines out there - I see some people have been talking about a Jatco manual....

Any help or pointers in the right direction will be more than gratefully received!!

Rob

rover54 · 11th December 2012, 09:19

Quote:

Originally Posted by robearner

Thanks for that really informative reply - I'll certainly look into replacing the solenoid c before condemning the box. As I already said, the unit seems to work normally, changing both up and down at the right engine speeds, etc - if it were not for that "thud jerky shift"
. love the term by the way, really sums up what is happening!!

A local mechanic on the Island took the car to a 'transmission specialist' whose diagnosis was a less than complimentary 'it is shot' or stronger words to that effect. He also went on to condemn the Jatco box as 'that Japanese Rubbish', saying that you couldn't do any work on them as they are sealed units and once they start playing up you simply have to get rid. I would like to think that this diagnosis is too premature, certainly on the forum people seem to have had experience of replacing many items and ending up with a perfectly functioning box....

How easy is it to assess the working of the solenoids and then to replace. Are there any guidelines out there - I see some people have been talking about a Jatco manual....

Any help or pointers in the right direction will be more than gratefully received!!

Rob

Solenoids are just under the black cover at the front of the box, all you need to do is remove the air box to get to it. Test their resistance at the gearbox electrical plug which is a break-away connector about a foot along the wiring from the gearbox.

Solenoid layout can be found in the Jatco section of this publication http://macassemble.com/lrm/freelande...%20(2001+).pdf. Nothing to stop you swapping solenoids between the two cars to see if your problem goes away.

mh007 · 11th December 2012, 09:26

Hi
First of all, the Jatco box is fantastic when working well & they're very reliable.
Have you checked the lower engine mount/tie for wear ?
if this is ok, either check the resistances on the solenoids with the diagram above or have the box scanned with a compatible scanner (it doesn't have to be a T4)
From experience, harsh changes are down to the 2/4 Brake Duty Solenoid.
This is one of the 9 solenoids in behind the front cover of the box.
All solenoids are accessible by removing the front cover (you may lose a small amount of oil) & the solenoid mentioned is 2nd from bottom whilst looking from the front of the car.
Removal of the front cover is a little fiddly but can be done.
Be careful when prising off the front cover & there is no gasket, just sealant.
Good luck with this.

SD1too · 11th December 2012, 10:50

Quote:

Originally Posted by robearner

How easy is it to assess the working of the solenoids and then to replace. Are there any guidelines out there ...

Rob,

Beinet1 did a superb repair on his automatic box, and posted lots of photographs.

http://www.the75andztclub.co.uk/foru...d.php?t=122171

Simon.

robearner · 11th December 2012, 12:02

Sounds worth trying. Apparently the sensors on my Conny 2.5 and Club 2.0 are interchangeable, so I might just open them both up and switch the sensors about and see what happens! I could also change the line pressure solenoid valve, too, as this could also explain the harsh changes....

What sort of sealant would you recommend I use when replacing the front cover? After removing the twenty bolts holding the cover to the gearbox casing, does the cover just prise off easily or is it held tightly?

Again, thanks for this invaluable advice.....

wuzerk · 11th December 2012, 12:08

I would repeat the question from mh007. Have you checked the lower engine mount?

10th December 2012, 21:43	#1
robearner Avid contributor Rover 75 Join Date: Aug 2012 Location: Castletown Posts: 104 Thanks: 8 Thanked 2 Times in 2 Posts	Problem with my auto gearbox I have a 2 litre 75 Tourer club 2002 that has a problem with its auto gearbox. When changing both up and down it thunks and feels as if it is pushing the car forward slightly as it roughly engages. There is no slippage, all gears are accessible and the kick down works as expected. I have changed the gear oil with the appropriate oil from Rimmers, but this brought about no improvement. Does anyone have any idea what could be causing this and if so what I need to do to remedy it? Am I facing a new or replacement box or is it likely to be one of the sensors that I can change/ I have a 2000 Conny 2.5 auto as well, maybe one solution would be to swap the auto boxes, but I am unsure whether they would be compatible or not. Anyone have any idea about this too? Thanks, Rob

10th December 2012, 22:04	#2
SD1too Doesn't do things by halves Rover 75 2.5 Connoisseur Auto (1999) Dealer launch model. Join Date: Mar 2007 Location: Former Middlesex Posts: 20,382 Thanks: 1,587 Thanked 3,749 Times in 3,181 Posts	Rob, It might be a faulty solenoid. This has been discussed before, so a search should bring up the relevant data. The gear ratios for the 2.5 litre engine are not the same as for the 2.0 V6 so it's not advisable to swap transmissions. I hope that you bought ATF specified as a direct replacement for 'N402'. Simon. __________________ "Whatever is rightly done, however humble, is noble." Sir Henry Royce.

11th December 2012, 12:02	#9
robearner Avid contributor Rover 75 Join Date: Aug 2012 Location: Castletown Posts: 104 Thanks: 8 Thanked 2 Times in 2 Posts	Thanks for the info, MH007! Sounds worth trying. Apparently the sensors on my Conny 2.5 and Club 2.0 are interchangeable, so I might just open them both up and switch the sensors about and see what happens! I could also change the line pressure solenoid valve, too, as this could also explain the harsh changes.... What sort of sealant would you recommend I use when replacing the front cover? After removing the twenty bolts holding the cover to the gearbox casing, does the cover just prise off easily or is it held tightly? Again, thanks for this invaluable advice.....

11th December 2012, 12:08	#10
wuzerk Passed Away Rover 75 CDT 03 auto Conn. SE Join Date: May 2009 Location: London Posts: 2,885 Thanks: 104 Thanked 254 Times in 204 Posts	Auto jerk I would repeat the question from mh007. Have you checked the lower engine mount?

11th December 2012, 08:26	#4
robearner Avid contributor Rover 75 Join Date: Aug 2012 Location: Castletown Posts: 104 Thanks: 8 Thanked 2 Times in 2 Posts	Simon, Thanks for the reply. I didn't think they would be transferable, but thanks for confirming that. I also did use the N402 fluid supplied by Rimmers, about 4 litres for the change. I'll look into a replacement solenoid before condemning the box! Any idea how difficult identifying the faulty unit and replacing it might be - any experience of this? Cheers, Rob

11th December 2012, 08:40	#5
robearner Avid contributor Rover 75 Join Date: Aug 2012 Location: Castletown Posts: 104 Thanks: 8 Thanked 2 Times in 2 Posts	Thanks for that really informative reply - I'll certainly look into replacing the solenoid c before condemning the box. As I already said, the unit seems to work normally, changing both up and down at the right engine speeds, etc - if it were not for that "thud jerky shift" . love the term by the way, really sums up what is happening!! A local mechanic on the Island took the car to a 'transmission specialist' whose diagnosis was a less than complimentary 'it is shot' or stronger words to that effect. He also went on to condemn the Jatco box as 'that Japanese Rubbish', saying that you couldn't do any work on them as they are sealed units and once they start playing up you simply have to get rid. I would like to think that this diagnosis is too premature, certainly on the forum people seem to have had experience of replacing many items and ending up with a perfectly functioning box.... How easy is it to assess the working of the solenoids and then to replace. Are there any guidelines out there - I see some people have been talking about a Jatco manual.... Any help or pointers in the right direction will be more than gratefully received!! Rob

11th December 2012, 09:26	#7
mh007 This is my second home MG ZT260 SE, MG ZT190+, MG ZTT 160, R75 Conn SE 2.0, R75 Conn SE 2.5 X 3, R75 Club SE 1.8, P5B Coupe Join Date: Jul 2009 Location: Keynsham, Bristol Posts: 4,211 Thanks: 65 Thanked 635 Times in 499 Posts	Hi First of all, the Jatco box is fantastic when working well & they're very reliable. Have you checked the lower engine mount/tie for wear ? if this is ok, either check the resistances on the solenoids with the diagram above or have the box scanned with a compatible scanner (it doesn't have to be a T4) From experience, harsh changes are down to the 2/4 Brake Duty Solenoid. This is one of the 9 solenoids in behind the front cover of the box. All solenoids are accessible by removing the front cover (you may lose a small amount of oil) & the solenoid mentioned is 2nd from bottom whilst looking from the front of the car. Removal of the front cover is a little fiddly but can be done. Be careful when prising off the front cover & there is no gasket, just sealant. Good luck with this.