Auto box fault - Page 2

SD1too · 3rd March 2015, 07:02

Shaun; I wouldn't do that if I were you. You could easily end up with a transmission from a scrapped car (and the wrong one for your engine) with even more serious problems than you have now. Besides, we don't have a diagnosis yet.

Your solenoid valves appear to be fine, so check the fluid level next and assess its condition. You can do this at the correct temperature using your meter on the connector you used for the solenoid checks.

What's the service history of the car? How many miles? Has the fluid ever been changed? Has the car been used for towing?

Simon

debo · 3rd March 2015, 07:27

I will try and answer a few of these. The fluid is good and it was changed 3000 miles ago. It has done 230,000 miles. There's no towbar fitted so don't think its towed and as for service history there is none.
Could the solenoids give a false reading as the problem is intermittent and normally only after 15-20 miles so I expect when the gearbox has warmed up

SD1too · 3rd March 2015, 07:33

Quote:

Originally Posted by debo

Could the solenoids give a false reading as the problem is intermittent and normally only after 15-20 miles so I expect when the gearbox has warmed up

Well, there's one way to find out!

Check them again when the fault has presented itself.

Quote:

The fluid is good and it was changed 3000 miles ago.

Who did it? Was fluid to spec. N402 used? Have you checked the level since the fault occurred?

Simon

debo · 3rd March 2015, 08:08

The fault was there before the oil change which I done myself with carlube atf-u it just made the other gear changes better

SD1too · 3rd March 2015, 08:50

OK Shaun, that's good to hear. I would still check the level though, using the MGR procedure. It would be crazy to start dismantling a gearbox without checking the fluid level first.

I do see that the car has covered a very high mileage.

Simon

RN3212 · 3rd March 2015, 10:45

I might be stating the obvious but the Battery needs to be disconnected to do the resistance test on the Solenoids.

SD1too · 3rd March 2015, 10:51

Quote:

Originally Posted by pat hanley

... the Battery needs to be disconnected to do the resistance test on the Solenoids.

Does it? According to the wiring diagram, when the 18 pin connector is separated to measure the resistances, all the solenoids are electrically isolated.

Simon

rrobson · 4th March 2015, 00:25

I've never disconnected the battery checking them. Like Simon says, surely if it's unplugged its isolated? And your measuring resistance and that won't change even if there is a voltage applied.

SD1too · 4th March 2015, 07:13

Quote:

Originally Posted by rrobson

And your measuring resistance and that won't change even if there is a voltage applied.

Ah, no Reece, because of the way that the multimeter works, you cannot properly measure resistance unless the circuit under test is electrically isolated.

Just to clarify, unless you can be certain of this, Pat is correct to say that the vehicle's battery should be disconnected. However in the specific case of the automatic transmission solenoids, it is clear from the wiring diagram that separating the 18 pin connector is all that is necessary. Sorry if my previous post has caused confusion with anyone.

Simon

debo · 4th March 2015, 15:16

i think soon its about time i just bite the bullet and take it to my local gearbox centre to see if they can figure it out if they cant i will be on the look out for a good second hand gearbox to fit

3rd March 2015, 07:02	#11
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: 20,531 Thanks: 1,587 Thanked 3,749 Times in 3,181 Posts	Shaun; I wouldn't do that if I were you. You could easily end up with a transmission from a scrapped car (and the wrong one for your engine) with even more serious problems than you have now. Besides, we don't have a diagnosis yet. Your solenoid valves appear to be fine, so check the fluid level next and assess its condition. You can do this at the correct temperature using your meter on the connector you used for the solenoid checks. What's the service history of the car? How many miles? Has the fluid ever been changed? Has the car been used for towing? Simon __________________ "Whatever is rightly done, however humble, is noble." Sir Henry Royce.

3rd March 2015, 08:50	#15
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: 20,531 Thanks: 1,587 Thanked 3,749 Times in 3,181 Posts	OK Shaun, that's good to hear. I would still check the level though, using the MGR procedure. It would be crazy to start dismantling a gearbox without checking the fluid level first. I do see that the car has covered a very high mileage. Simon __________________ "Whatever is rightly done, however humble, is noble." Sir Henry Royce.

3rd March 2015, 10:45	#16
RN3212 Gets stuck in Rover 75 Classic SE 2.0V6 Auto Moonstone Green Join Date: Sep 2008 Location: Roscommon Posts: 839 Thanks: 315 Thanked 46 Times in 34 Posts	I might be stating the obvious but the Battery needs to be disconnected to do the resistance test on the Solenoids. __________________ [SIGPIC][/SIGPIC]

4th March 2015, 00:25	#18
rrobson I really should get out more....... 75 tourer cdti, MG ZS 180, nissan terrano & 1.8t rover 25 Join Date: Feb 2010 Location: Pontefract Posts: 2,647 Thanks: 17 Thanked 295 Times in 218 Posts	I've never disconnected the battery checking them. Like Simon says, surely if it's unplugged its isolated? And your measuring resistance and that won't change even if there is a voltage applied. __________________ How to view a car - everything you need to help you inspect a used car VIS motor tester avalible to local members Injector removal tool and auto gearbox pressure tester now available

3rd March 2015, 07:27	#12
debo Regular poster rover 75 saloon Join Date: Nov 2013 Location: great yarmouth Posts: 74 Thanks: 13 Thanked 3 Times in 3 Posts	I will try and answer a few of these. The fluid is good and it was changed 3000 miles ago. It has done 230,000 miles. There's no towbar fitted so don't think its towed and as for service history there is none. Could the solenoids give a false reading as the problem is intermittent and normally only after 15-20 miles so I expect when the gearbox has warmed up

3rd March 2015, 08:08	#14
debo Regular poster rover 75 saloon Join Date: Nov 2013 Location: great yarmouth Posts: 74 Thanks: 13 Thanked 3 Times in 3 Posts	The fault was there before the oil change which I done myself with carlube atf-u it just made the other gear changes better

4th March 2015, 15:16	#20
debo Regular poster rover 75 saloon Join Date: Nov 2013 Location: great yarmouth Posts: 74 Thanks: 13 Thanked 3 Times in 3 Posts	i think soon its about time i just bite the bullet and take it to my local gearbox centre to see if they can figure it out if they cant i will be on the look out for a good second hand gearbox to fit