Jerk when changing from 2nd to 3rd (2.5 auto)

Forestgreen · 11th August 2017, 18:27

2.5V6 auto Connie SE.

Quite out of the blue a few days ago there was a pretty noticeable "clunk" when shifting from drive to reverse (or maybe it was the other way round) as I was parking and having to go back and forwards. A bit alarming but never thought any more about it.

Until today. Every time I gently accelerate through 20mph, changing between what I think must be from second gear into third there's a short sharp jerk. But if I accelerate rapidly from standstill so that the gear change is delayed until closer to 30mph (this is easier if I put the gears into Sports mode), the gear change from 2nd to 3rd is quite smooth. I should add that I'm not a speed freak and normally only accelerate gently.

There were no clunks between any other gears, including reverse, today.

Auto box fluid was last changed about 4 years ago, since when I've driven about 30,000 miles. Car has done a total of 80,000 miles since new.

Any suggestions would be appreciated, especially as I'm intending to take the car on a driving holiday next week and am due to cover around 500 miles. Doubt I'll have chance to have it looked at before then - is this something that I can live with a bit longer, especially as it doesn't seem to happen if I accelerate rapidly through the 2-3 change?

Chuckles · 12th August 2017, 06:29

I would first check ALL engine and gearbox mountings.
have someone look at the engine when going from Neutral to reverse then back to drive to see if the engine moves excessively.

DMGRS · 12th August 2017, 17:06

As above, mounts first!

If no joy, check the resistance of the gearbox solenoids with a multimeter - a useful guide here as to what they should all measure:

The usual cause is the 2/4 Brake Duty Solenoid - this one:
https://www.dmgrs.co.uk/products/r75...mission-jf506e

Good luck!

mikmoz · 13th August 2017, 11:00

i have recently had a similar problem,but only when selecting drive or reverse from stationary,so reading this thread followed advice and just been out and checked engine mounts and the bottom one looks goosed,engine really moves when selecting either forward or reverse,so will get engine mounts ordered,so thanks to OP and sorry to hi jack thread,cheers

Forestgreen · 13th August 2017, 14:25

Thanks for contributions, this forum is always so helpful!

In the event I spoke to Terry Shaw in Stourbridge who very kindly offered to see me the next day. Initial checks were all normal - mounts all fine and T4 had no fault codes showing -though he did point out that I'd ben driving around for goodness only knows how long with a broken front offside spring. Thankfully the spring protectors he had previously fitted had prevented any damage and he sourced a new one right away rather than have me drive around any longer. Just as well given the MOT is due next week.

He drove himself around a bit and noticed the jerking between 2nd and 3rd gears, so suggested we change the oil (he'd last done it 30,000 miles an four years ago). Out came thick slimy chocolate soup, to be replaced with clear dilute Ribena (not literally, but best analogy I could come up with).

Initial impressions driving home are that (a) the car feels ever so slightly softer and bouncier than before which I guess is the difference between driving around with a knackered spring or not, and (b) the gear change between 2 and 3 around 20mph is still slightly less smooth than the others but significantly better than before. So it sounds like I need to keep an eye on it over the next thousand or so miles and take off to a Rover 75 gearbox guru at the first sign of any deterioration (terry doesn't do solenoids any longer).

Terry201 · 11th August 2019, 06:51

My problem has been fairly similar. I have a Rover 75 2.5 l V6 automatic. When starting I get a jerking sensation in the car. This will happen every time the car changes gear, whether going up or down. It is more noticeable in the lower gears and when I start off in drive it jerks twice. I took it to a garage and they will be investigating. From what I've read it would seem there are three possible solutions: one to check the solenoids and replace if faulty; the second is to change the oil; third is the possibility that it might be a fault in the torque converter. Any suggestions anyone? Also if anyone knows of a short video that will help my garage, which is a non specialist gearbox garage, to deal with this problem, that would be really good.

SD1too · 11th August 2019, 07:08

Hello Terry and

to the forum.

Your problem might have nothing to do with the automatic transmission at all. For smooth, correct operation they rely upon engine tune, so the first thing I would do in your shoes is to check things like the sparking plug gaps and their condition, air filter, vacuum and breather hoses for security, exhaust system for leaks, etc. The gear changing technology is actually quite complex. On changing up, the engine's torque is reduced by altering the ignition timing. This gives the 'soft' quality to the change which can sound like a well executed manual gear change.

I would next consider the automatic transmission fluid. When was it last changed? If it has been, was the correct N402 spec fluid used? Is the level correct?

The other possibility is a problem with the multiplex communication system between the engine and automatic transmission ECUs. T4 could help with that.

Your symptoms don't match those of the solenoid failures we've encountered although anything is possible.

The chances of a torque converter fault are extremely remote.

Simon

kaiser · 11th August 2019, 10:08

If the box jerks only when changing from 2 to 3, it has little to do with engine mountings or engine tune.

An oil change is likely the most important thing and easier to do than looking at solenoids, for starters.
Owing to the large amount of fuel not being changed, I would not hesitate to do another change, to get more fresh fluid in there. ( a lot of oil in the converter will not be changed)
I had exactly such a jerk in my box, and it was completely cured, after a fluid change.

SD1too · 11th August 2019, 21:48

Quote:

Originally Posted by kaiser

If the box jerks only when changing from 2 to 3, it has little to do with engine mountings or engine tune.

You're replying to ForestGreen who started the thread two years ago.

I am replying to Terry201 who says something completely different:

Quote:

Originally Posted by Terry201

This will happen every time the car changes gear, whether going up or down.

So your

is misplaced I feel.

Simon

kaiser · 12th August 2019, 05:16

You have a point there Simon.
https://www.youtube.com/watch?v=_WcmftJlkYs

11th August 2017, 18:27	#1
Forestgreen Gets stuck in Rover 75 Connoisseur SE 2.5 V6 saloon Join Date: Dec 2011 Location: Birmingham Posts: 770 Thanks: 47 Thanked 105 Times in 54 Posts	Jerk when changing from 2nd to 3rd (2.5 auto) 2.5V6 auto Connie SE. Quite out of the blue a few days ago there was a pretty noticeable "clunk" when shifting from drive to reverse (or maybe it was the other way round) as I was parking and having to go back and forwards. A bit alarming but never thought any more about it. Until today. Every time I gently accelerate through 20mph, changing between what I think must be from second gear into third there's a short sharp jerk. But if I accelerate rapidly from standstill so that the gear change is delayed until closer to 30mph (this is easier if I put the gears into Sports mode), the gear change from 2nd to 3rd is quite smooth. I should add that I'm not a speed freak and normally only accelerate gently. There were no clunks between any other gears, including reverse, today. Auto box fluid was last changed about 4 years ago, since when I've driven about 30,000 miles. Car has done a total of 80,000 miles since new. Any suggestions would be appreciated, especially as I'm intending to take the car on a driving holiday next week and am due to cover around 500 miles. Doubt I'll have chance to have it looked at before then - is this something that I can live with a bit longer, especially as it doesn't seem to happen if I accelerate rapidly through the 2-3 change?

12th August 2017, 06:29	#2
Chuckles Gets stuck in NOW a Club Tourer was 1999 - 75 2.0Ltr Connoisseur SE petrol Saloon Join Date: Jan 2012 Location: Iwerne Minster, Dorset Posts: 552 Thanks: 63 Thanked 54 Times in 47 Posts	I would first check ALL engine and gearbox mountings. have someone look at the engine when going from Neutral to reverse then back to drive to see if the engine moves excessively. __________________ Chuck Nth. Dorset. UK Membership #1896 Don't take life so seriously.... it is not permanent!

12th August 2017, 17:06	#3
DMGRS Discount MG Rover Spares Rover 75 CDTi, 2x MG ZS180 Join Date: Jun 2011 Location: Hythe, Southampton Posts: 11,320 Thanks: 456 Thanked 3,377 Times in 2,027 Posts	As above, mounts first! If no joy, check the resistance of the gearbox solenoids with a multimeter - a useful guide here as to what they should all measure: The usual cause is the 2/4 Brake Duty Solenoid - this one: https://www.dmgrs.co.uk/products/r75...mission-jf506e Good luck! __________________ Your trusted MG Rover specialist! Tel: 02380 001133 / Email: [email protected] We now have a 'chat' function on our site for even quicker replies. Give it a try! Remember - discount code FORUM5 for 5% off

11th August 2019, 06:51	#6
Terry201 Newbie Rover 75 Join Date: Aug 2019 Location: Winkleigh Posts: 1 Thanks: 0 Thanked 0 Times in 0 Posts	Rover 75 2.5 l V6 automatic transmission jerking sensation when gears change My problem has been fairly similar. I have a Rover 75 2.5 l V6 automatic. When starting I get a jerking sensation in the car. This will happen every time the car changes gear, whether going up or down. It is more noticeable in the lower gears and when I start off in drive it jerks twice. I took it to a garage and they will be investigating. From what I've read it would seem there are three possible solutions: one to check the solenoids and replace if faulty; the second is to change the oil; third is the possibility that it might be a fault in the torque converter. Any suggestions anyone? Also if anyone knows of a short video that will help my garage, which is a non specialist gearbox garage, to deal with this problem, that would be really good.

11th August 2019, 07:08	#7
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: 20,344 Thanks: 1,587 Thanked 3,749 Times in 3,181 Posts	Hello Terry and to the forum. Your problem might have nothing to do with the automatic transmission at all. For smooth, correct operation they rely upon engine tune, so the first thing I would do in your shoes is to check things like the sparking plug gaps and their condition, air filter, vacuum and breather hoses for security, exhaust system for leaks, etc. The gear changing technology is actually quite complex. On changing up, the engine's torque is reduced by altering the ignition timing. This gives the 'soft' quality to the change which can sound like a well executed manual gear change. I would next consider the automatic transmission fluid. When was it last changed? If it has been, was the correct N402 spec fluid used? Is the level correct? The other possibility is a problem with the multiplex communication system between the engine and automatic transmission ECUs. T4 could help with that. Your symptoms don't match those of the solenoid failures we've encountered although anything is possible. The chances of a torque converter fault are extremely remote. Simon __________________ "Whatever is rightly done, however humble, is noble." Sir Henry Royce.

13th August 2017, 11:00	#4
mikmoz Loves to post Rover 75 Tourer cdti/75 v6 2.5 Join Date: Sep 2016 Location: manchester Posts: 279 Thanks: 172 Thanked 45 Times in 35 Posts	i have recently had a similar problem,but only when selecting drive or reverse from stationary,so reading this thread followed advice and just been out and checked engine mounts and the bottom one looks goosed,engine really moves when selecting either forward or reverse,so will get engine mounts ordered,so thanks to OP and sorry to hi jack thread,cheers

13th August 2017, 14:25	#5
Forestgreen Gets stuck in Rover 75 Connoisseur SE 2.5 V6 saloon Join Date: Dec 2011 Location: Birmingham Posts: 770 Thanks: 47 Thanked 105 Times in 54 Posts	Thanks for contributions, this forum is always so helpful! In the event I spoke to Terry Shaw in Stourbridge who very kindly offered to see me the next day. Initial checks were all normal - mounts all fine and T4 had no fault codes showing -though he did point out that I'd ben driving around for goodness only knows how long with a broken front offside spring. Thankfully the spring protectors he had previously fitted had prevented any damage and he sourced a new one right away rather than have me drive around any longer. Just as well given the MOT is due next week. He drove himself around a bit and noticed the jerking between 2nd and 3rd gears, so suggested we change the oil (he'd last done it 30,000 miles an four years ago). Out came thick slimy chocolate soup, to be replaced with clear dilute Ribena (not literally, but best analogy I could come up with). Initial impressions driving home are that (a) the car feels ever so slightly softer and bouncier than before which I guess is the difference between driving around with a knackered spring or not, and (b) the gear change between 2 and 3 around 20mph is still slightly less smooth than the others but significantly better than before. So it sounds like I need to keep an eye on it over the next thousand or so miles and take off to a Rover 75 gearbox guru at the first sign of any deterioration (terry doesn't do solenoids any longer).

11th August 2019, 10:08	#8
kaiser This is my second home 75 Tourer 2.5 Auto, 1.8T, 75V8ZT Join Date: Jun 2007 Location: Johannesburg ZA Posts: 6,200 Thanks: 1 Thanked 859 Times in 613 Posts	If the box jerks only when changing from 2 to 3, it has little to do with engine mountings or engine tune. An oil change is likely the most important thing and easier to do than looking at solenoids, for starters. Owing to the large amount of fuel not being changed, I would not hesitate to do another change, to get more fresh fluid in there. ( a lot of oil in the converter will not be changed) I had exactly such a jerk in my box, and it was completely cured, after a fluid change. __________________ Worth his V8 in gold

12th August 2019, 05:16	#10
kaiser This is my second home 75 Tourer 2.5 Auto, 1.8T, 75V8ZT Join Date: Jun 2007 Location: Johannesburg ZA Posts: 6,200 Thanks: 1 Thanked 859 Times in 613 Posts	You have a point there Simon. https://www.youtube.com/watch?v=_WcmftJlkYs __________________ Worth his V8 in gold Last edited by kaiser; 12th August 2019 at 05:22..