Driving forward seems.. not right - gearbox?

Mattias · 4th August 2021, 19:37

Hello!

I recently bought myself a Rover 75 (absoluteley gorgeous car in my view) with a suspected headgasket failure (don't worry, I bought it r e a l l y cheap). Turns out, it wasn't anything wrong with the headgasket, but due to the suspicion I didn't drive it more than around the block at the time of purchase, but then all seemed fine with the issue at hand (lower down).

I've gone thru the car and the overheating issue was due to the replacement Kenlowe fan controlling unit failing.

I've replaced the transmission fluid (only 2.5l came out) and with the excellent help from a lot of threads on this forum I've manage to rectify most things without much effort, as it seems. There was a grinding noise in the gearbox before I changed and topped up the oil level in the gearbox which greatly reduced the noise, to the point where it is almoast completely gone. I think I accidently let out to much oil though when I did the level check as I had the engine turned off before putting the plug in - I will re-do this task soon.

However - When I have started the car and put it in Drive (automatic obviously) it doesn't seem to me to work properly. It's like it doesn't really want to go forward. It behaves like it is a lot less hp than its 177. In reverse it behaves much more agile, and it goes as soon as I let go of the brake, but in Drive I have to rev up to at least 1500rpm before it even starts to move, and then it's still very tired. Haven't driven it more than that, since the new controll unit for the fan is still in the postal system and I don't want to overheat it again.

I've checked the gearbox solenoids connector for resistance, and everything was within spec.

Can anyone point me in the right direction?

Thanks for an awesome forum! One of the best I've ever attended. This is the first question I had to ask, since I didn't really find an answer to thru searching.

Kindly,
Mattias from Sweden

trikey · 4th August 2021, 19:49

Hi Mattias,

I would drain the fluid and do another refill, don't forget to run the engine and select every gear for a few second with your foot on the brake.

Once you have done that, remove the level plug and let the fluid drain with the engine running.

vitesse · 4th August 2021, 20:49

As you only got 2.5 ltrs out you might like to look at this thread: https://www.the75andztclub.co.uk/for...d.php?t=124816

Regards

Ps. https://www.facebook.com/groups/1800705170206717 (Rover 75 Swedish group)

Mattias · 5th August 2021, 08:54

Thank you for the replies!

I've read Beinet's thread already, but it seems that you both suggest the oil as the culpret?

As never having had an automatic gearbox before, how would this affect the propelling forward?

I just want to add aswell, that I put in 5.5 litres when i changed and levelled the oil. The amount that came out too much wasn't more than about 2 decilitres.

Once again, thank you for the advise!

Mattias

pletevl · 5th August 2021, 14:34

Wouldn't this be the classic cracked reverse piston in the gearbox ? reverse is ok, but as good as no forward motion.

Pete.

Mattias · 6th August 2021, 23:21

I tested a little bit more today on the driveway. Reverse works fine. Drive very poorly. Putting it in 2 makes it go forward like it should. 3 and 4 makes it go forward, but not as good as 2, but not as poor as Drive. 4 also worse than 3.

It is also very, very rough when going into the forward gears with the selector. Sort of jerking the entire car - like it's slamming the gears in.

Should i still try to change the oil first, or is it just as well to tear it apart?

Does it seem like the reverse piston problem?

My car was made in 2000.

Kindly,

Mattias

xsport · 7th August 2021, 14:52

please listen to the advice that you are being given. change the fuid to the correct recommended type EXACTLY. make sure the level is CORRECT at the correct TEMPERATURE by following the how to on this website. please read again and again what i have just told you word for word. this is your starting point . then see what happens and report back on here with your findings. ...

xsport · 7th August 2021, 15:31

[QUOTE=Mattias;2894385]

I just want to add aswell, that I put in 5.5 litres when i changed and levelled the oil. The amount that came out too much wasn't more than about 2 decilitres.

............. well i hope you are useing the correct drainbolt. as the box could be overfull. there is one near to the drainplug that can be mistaken for it. this bolt if removed will need a complete stripdown to be rectified. hope not. the engine must run to get the level correct and left running whilst hot to get the fluid level correct whilst going and holding through the gears .as in the how to. use the xpart recommended fluid or the ravenol for your fluid change and see where you go from there. make sure you follow the fluid change how to on here. . good luck !!!

Mattias · 15th August 2021, 15:10

So:

I did read most threads about possible problems and the "How to" before I started doing anything at all. I have now done a second fluid change, and there's no difference in performance. R and 2 works as intended, but 3, 4 and D won't go forward unless the gas pedal is pushed. On 2 and R the brakes only need to be released and the car goes forward (and backwards obviously) with stringency. All this tested on a flat surface of course.

As I previously mentioned I have already tested the solenoids thru the contact with a multimeter, but I'll check them once more just to be sure.

Is it probably the reverse piston that has cracked or could something else be the problem?

Teardown of the gearbox next or should I get a second hand one and fit that instead?

Kindly,

Mattias

mbonwick · 15th August 2021, 17:26

This honestly sounds like a fluid issue, rather than reverse piston/solenoid.
D/4/3/2 only inhibits the top gear that will be selected, not the "starting" gear - i.e. in all cases the 'box is physically in 1st gear when pulling away from a stand.
For me that rules out reverse piston failure, and I can't believe you'd have multiple failed solenoids either.

Needing revs to get it moving would definitely have me investigating the fluid levels/the fluid used. Did you use the correct N402 type?

However you've mentioned noises from the gearbox when you bought the car, which is not usually a good sign so it's possible that there's major damage inside (I'm thinking disintegrated brake/clutch bands from being run with low fluid).

4th August 2021, 19:37	#1
Mattias Newbie Rover 75 saloon Join Date: Jul 2021 Location: Vänersborg Posts: 10 Thanks: 1 Thanked 3 Times in 1 Post	Driving forward seems.. not right - gearbox? Hello! I recently bought myself a Rover 75 (absoluteley gorgeous car in my view) with a suspected headgasket failure (don't worry, I bought it r e a l l y cheap). Turns out, it wasn't anything wrong with the headgasket, but due to the suspicion I didn't drive it more than around the block at the time of purchase, but then all seemed fine with the issue at hand (lower down). I've gone thru the car and the overheating issue was due to the replacement Kenlowe fan controlling unit failing. I've replaced the transmission fluid (only 2.5l came out) and with the excellent help from a lot of threads on this forum I've manage to rectify most things without much effort, as it seems. There was a grinding noise in the gearbox before I changed and topped up the oil level in the gearbox which greatly reduced the noise, to the point where it is almoast completely gone. I think I accidently let out to much oil though when I did the level check as I had the engine turned off before putting the plug in - I will re-do this task soon. However - When I have started the car and put it in Drive (automatic obviously) it doesn't seem to me to work properly. It's like it doesn't really want to go forward. It behaves like it is a lot less hp than its 177. In reverse it behaves much more agile, and it goes as soon as I let go of the brake, but in Drive I have to rev up to at least 1500rpm before it even starts to move, and then it's still very tired. Haven't driven it more than that, since the new controll unit for the fan is still in the postal system and I don't want to overheat it again. I've checked the gearbox solenoids connector for resistance, and everything was within spec. Can anyone point me in the right direction? Thanks for an awesome forum! One of the best I've ever attended. This is the first question I had to ask, since I didn't really find an answer to thru searching. Kindly, Mattias from Sweden Last edited by Mattias; 4th August 2021 at 20:23..

4th August 2021, 19:49	#2
trikey Premium Trader Rover 75 Join Date: Nov 2010 Location: Devon Posts: 33,766 Thanks: 8,837 Thanked 14,831 Times in 8,030 Posts	Hi Mattias, I would drain the fluid and do another refill, don't forget to run the engine and select every gear for a few second with your foot on the brake. Once you have done that, remove the level plug and let the fluid drain with the engine running. __________________ Lest we forget..

7th August 2021, 15:31	#8
xsport Posted a thing or two rover 75 club se Join Date: Apr 2011 Location: Leicester Posts: 1,644 Thanks: 358 Thanked 419 Times in 310 Posts	drain plug hexagon bolt or hexagon key ? [QUOTE=Mattias;2894385] I just want to add aswell, that I put in 5.5 litres when i changed and levelled the oil. The amount that came out too much wasn't more than about 2 decilitres. ............. well i hope you are useing the correct drainbolt. as the box could be overfull. there is one near to the drainplug that can be mistaken for it. this bolt if removed will need a complete stripdown to be rectified. hope not. the engine must run to get the level correct and left running whilst hot to get the fluid level correct whilst going and holding through the gears .as in the how to. use the xpart recommended fluid or the ravenol for your fluid change and see where you go from there. make sure you follow the fluid change how to on here. . good luck !!! Last edited by xsport; 7th August 2021 at 15:36..

15th August 2021, 15:10	#9
Mattias Newbie Rover 75 saloon Join Date: Jul 2021 Location: Vänersborg Posts: 10 Thanks: 1 Thanked 3 Times in 1 Post	So: I did read most threads about possible problems and the "How to" before I started doing anything at all. I have now done a second fluid change, and there's no difference in performance. R and 2 works as intended, but 3, 4 and D won't go forward unless the gas pedal is pushed. On 2 and R the brakes only need to be released and the car goes forward (and backwards obviously) with stringency. All this tested on a flat surface of course. As I previously mentioned I have already tested the solenoids thru the contact with a multimeter, but I'll check them once more just to be sure. Is it probably the reverse piston that has cracked or could something else be the problem? Teardown of the gearbox next or should I get a second hand one and fit that instead? Kindly, Mattias Last edited by Mattias; 15th August 2021 at 15:13..

4th August 2021, 20:49	#3
vitesse I really should get out more....... Rover 75 Saloon Join Date: Jul 2011 Location: Gävle Posts: 2,531 Thanks: 395 Thanked 823 Times in 652 Posts	As you only got 2.5 ltrs out you might like to look at this thread: https://www.the75andztclub.co.uk/for...d.php?t=124816 Regards Ps. https://www.facebook.com/groups/1800705170206717 (Rover 75 Swedish group)

5th August 2021, 08:54	#4
Mattias Newbie Rover 75 saloon Join Date: Jul 2021 Location: Vänersborg Posts: 10 Thanks: 1 Thanked 3 Times in 1 Post	Thank you for the replies! I've read Beinet's thread already, but it seems that you both suggest the oil as the culpret? As never having had an automatic gearbox before, how would this affect the propelling forward? I just want to add aswell, that I put in 5.5 litres when i changed and levelled the oil. The amount that came out too much wasn't more than about 2 decilitres. Once again, thank you for the advise! Mattias

5th August 2021, 14:34	#5
pletevl Posted a thing or two rover 75 cdti(rhd), MG ZR(lhd), MG TF(lhd), MG TF(rhd), mini mpi (lhd), Renault megane III (awful) Join Date: Mar 2014 Location: East of France Posts: 1,282 Thanks: 124 Thanked 114 Times in 93 Posts	Wouldn't this be the classic cracked reverse piston in the gearbox ? reverse is ok, but as good as no forward motion. Pete.

6th August 2021, 23:21	#6
Mattias Newbie Rover 75 saloon Join Date: Jul 2021 Location: Vänersborg Posts: 10 Thanks: 1 Thanked 3 Times in 1 Post	I tested a little bit more today on the driveway. Reverse works fine. Drive very poorly. Putting it in 2 makes it go forward like it should. 3 and 4 makes it go forward, but not as good as 2, but not as poor as Drive. 4 also worse than 3. It is also very, very rough when going into the forward gears with the selector. Sort of jerking the entire car - like it's slamming the gears in. Should i still try to change the oil first, or is it just as well to tear it apart? Does it seem like the reverse piston problem? My car was made in 2000. Kindly, Mattias

7th August 2021, 14:52	#7
xsport Posted a thing or two rover 75 club se Join Date: Apr 2011 Location: Leicester Posts: 1,644 Thanks: 358 Thanked 419 Times in 310 Posts	please listen to the advice that you are being given. change the fuid to the correct recommended type EXACTLY. make sure the level is CORRECT at the correct TEMPERATURE by following the how to on this website. please read again and again what i have just told you word for word. this is your starting point . then see what happens and report back on here with your findings. ...

15th August 2021, 17:26	#10
mbonwick Gets stuck in Connoisseur SE 1.8 Auto Saloon Join Date: Jul 2015 Location: Kendal Posts: 633 Thanks: 129 Thanked 176 Times in 147 Posts	This honestly sounds like a fluid issue, rather than reverse piston/solenoid. D/4/3/2 only inhibits the top gear that will be selected, not the "starting" gear - i.e. in all cases the 'box is physically in 1st gear when pulling away from a stand. For me that rules out reverse piston failure, and I can't believe you'd have multiple failed solenoids either. Needing revs to get it moving would definitely have me investigating the fluid levels/the fluid used. Did you use the correct N402 type? However you've mentioned noises from the gearbox when you bought the car, which is not usually a good sign so it's possible that there's major damage inside (I'm thinking disintegrated brake/clutch bands from being run with low fluid).