1 year old 4AT. Been observing this strange vibration and sound everytime I slow down to go over a hump or turn at a junction. If the gear changes from 3 to 2 and I step on the accelerator after it shows 2, most of the time I get the jerk and sound. If I slow down to 1 or maintain at 3 it doesn't happen.

Anybody else experienced this problem? Any advice?

 

I think the problem comes from my AT not down shifting properly. Today I observe that at slightly less than 20km/h when I let the car roll on after a hump, it was still maintaining on gear 3. When I tap on the accelerator then it suddenly switches to gear 2 at close to 1000rpm and that's when the "thud" sound is heard together with a big jolt. Anybody any advice?

 

hi sushifan, transmission engaging sound??? if yes, change your ATF.
best regard

 

I also have the same experience as Sushifan.
Hi amplify - what do you mean by changinf the ATF ? Pardon my inexperience, but what is ATF ? Tks a bundle.

 

I am driving the 4AT too but i do not have the same proble. I have changed my ATF within a month of getting my car to a synthetic one.

 

ATF -> auto transmission fluid. Been corresponding with other SMEs that I should change my ATF. I'm quite convinced that this is the problem. Anyway my servicing is also due this SAT so just nice.

 

dont know i a have a manny tranny. 6 gears and im lovin it!

 

Hello SushiFan

have you changed your ATF? if so, Did it help? what ATF oil did you use? and where did you do the change? I have the same problem and am getting worried it will damage the gearbox in the long term. Willl change it if it solves the problem.

 

My Car currently with my Warranty's workshop which happens to be an AT specialist. They are doing a detailed inspection (like drive shaft etc) apart from changing the ATF so I'll let you know when I get the car after Tues.

 

Thanks SushiFan

Hear from you soon.

 

Ok, just got my car back today. They changed the second gear's clutch after finding that it was a bit out of spec, i.e. did not have a good fit. He also changed the ATF fluid.

When I test drove my car, only very deliberate scenarios then I can reproduce the event. When I go back to my normal driving style on the slow speed scenario after that, so far 95 % of the time I dont get the jerk and sound anymore.

What I notice is also a difference during the slow speed gear change, it changes to gear 2 automatically (without me tapping the accelerator) much faster now once drop close to 20km/h vs last time it will hold at gear 3 for quite some time until I tap accelerator.

Will monitor the situation and update if anything significant.

 

SushiFan

What ATF did they use for your car?
My warranty is over, so not possible to do any gearbox service free. But the problem is starting to concern me more and more.

 

to me this is normal lor - it's actually the lag time of where you wanna go, ECU and gear change. once you get used to how your ecu thinks, this will change.

rem every little bit will affect responsiveness. e.g. i change from shell to caltex, response is different, so adjust accordingly.

btw i mad driver, so i use High Temp ATF from Redline

 

I think they maintained the stock ATF. But I will be changing the ATF in Dec after I come back from 2 months of overseas work in Australia (oct-Nov). I think you should have the problem checked out, its not worth waiting. Diagnostic shouldnt cost much then u see how much to solve the problem loh...certainly will be cheaper than if u keep at this mode and something else breaks.

 

Gfoo
I am not so concerned about the responsiveness. It is the clunking feel and sound that i am worried about. It feels like it is having difficulty in engaging 2nd gear, especially during downshift when accelerating at low speeds (20-30km/h), and upslope in MSCP.


SushiFan
I think you are right, but unless they know the gearbox well and take it out to check, i believe it is hard to diagnose. IF not done properly, the action of taking out and put back, will make it worse.
Not sure what to do now, but i probably will change the ATF oil.

 

FlyingAce, no harm bringing the car down to MG to have a look and ask for recommendation. The warranty company that tied up with MG is supposed to be an auto transmission specialist so I think you should be in good hands.

 

i see. alright i'll go see MG once i can. thanks

 

All the best.