Changing A/T fluid

[wt_know]

Re: Changing A/T fluid

did you experience gearbox jearking before ATF & differential flush/top-up?
not gearbox very smooth or you just did it at 60k milleage as a preventive maintenance ?

 

[tlkchew]

Re: Changing A/T fluid

There is a nitrile rubber seal around the torque converter. This seal keeps the oil flowing back from the torque converter within the gearbox. ATF enters the torque converter through the center stator shaft under high pressure and there are 2 metal seals there. Once it runs through the torque converter, it exits in a ring around the stator shaft. So when the oil is older, its viscosity goes down and the ATF flows with less "resistance" on its way back to the sump. The biggest fear with changing ATF in older trannies is the possibility of busting this seal. With age, the seal starts to sag and as the oil does have the same flow pressures caused by thinning, it does not leak. When new oil is introduced, the viscosity suddenly goes up.

At the shop, with every ATF change, we pour in a bottle of Lubegard ATF protectant that has some seal conditioning chemials to keep the seals soft. This helps to prevent any failures in transmissions. There are also a shit load of large diameter O rings in the clutches within the tranny too but i have yet to see these fail as they predominantly work in oil and thus have super low wear rates.

As for oil change intervals, i practice 40k km between ATF changes. with this frequency, i just drain the sump and refresh the oil. I have seen cars run upwards of 250k km without failure so far. Its is hard to quantify the additional "mileage" new oil gives but personally a lot of it has to do with driving styles.

cheers


BTW, the ZF trannies are designed with a 100k KM service life and that is their MTBF. So all they ask of the oil is to last the same amount of time.

ZF only 100k ah... like that must look for one to standby for mine already... 130k coming already.
yesterdy experienced a slip again 2nd time in 2 months.

 

[R2D]

Re: Changing A/T fluid

dun fret, there are a lot of instances that its just the valve body solenoids experiencing slower shifts and thus there is some slip, just a change of the solenoids may solve the problems.

cheers

 

[tlkchew]

Re: Changing A/T fluid

dun fret, there are a lot of instances that its just the valve body solenoids experiencing slower shifts and thus there is some slip, just a change of the solenoids may solve the problems.

cheers

Ah.. i see.. maybe that is it...it does change up alittle retarded sometimes. especially going up MSCP, it likes to stick in first gear and rev goes up to 3k+ and still dont feel like changing up.

Thanks Doc.

 

[R2D]

Re: Changing A/T fluid

The MSCP is a different thing. In the EGS, there is a gradient sensor and when it senes a gradient, the greabox holds on to gears longer with the same accelerator input. So when you go up the MSCP, the car knows that it is climbing a hill and it will not shift up cos the next gear will drop revs below the power band and that will be another downshift coming up. This gradient based logic also helps hold gears for downhill drives.

cheers

 

[tlkchew]

Re: Changing A/T fluid

The MSCP is a different thing. In the EGS, there is a gradient sensor and when it senes a gradient, the greabox holds on to gears longer with the same accelerator input. So when you go up the MSCP, the car knows that it is climbing a hill and it will not shift up cos the next gear will drop revs below the power band and that will be another downshift coming up. This gradient based logic also helps hold gears for downhill drives.

cheers

ah i see...more answers revealed... so this sensor holds it there for a while more even when car is in flat surface...

 

[delrosa81]

Re: Changing A/T fluid

Just to check what are good driving habits to preserve Automatic Transmission in the E90 320i?

What I practise:-

1) I will leave in N before shutting down the engine. Engage handbrake, release footbrake for any movement forwards or backwards before engaging P with the engine already Off.

2) I will use the steptronic from time to time, go high revs, when revs not enuf, drop one or two gears using the paddle shifters, bring the revs up, go to redline, shift up, etc. My more aggressive driving style.

3) Sometimes in either D or DS, I will be cruising then suddenly I will floor to drop gears to get enuf power to either overtake or to cut into another lane quickly.

I think for part 2 and 3 is harmful?

Any tips on driving styles to ensure a long life of the transmission?

 

[Red_Bean_Bun]

Re: Changing A/T fluid

Just to check what are good driving habits to preserve Automatic Transmission in the E90 320i?

What I practise:-

1) I will leave in N before shutting down the engine. Engage handbrake, release footbrake for any movement forwards or backwards before engaging P with the engine already Off.

2) I will use the steptronic from time to time, go high revs, when revs not enuf, drop one or two gears using the paddle shifters, bring the revs up, go to redline, shift up, etc. My more aggressive driving style.

3) Sometimes in either D or DS, I will be cruising then suddenly I will floor to drop gears to get enuf power to either overtake or to cut into another lane quickly.

I think for part 2 and 3 is harmful?

Any tips on driving styles to ensure a long life of the transmission?

I thought 2 & 3 is the reason one would drive a bmw ?

 

[delrosa81]

Re: Changing A/T fluid

I thought 2 & 3 is the reason one would drive a bmw ?

hahaha yeah I guess ya, but I think it affects the lifespan of the gearbox though

 

[Golf-mass]

Re: Changing A/T fluid

I'm getting my 520i tomorrow. It is a 2004 car but gone only 52k Km. I test drove it n the gear shift is quite smooth. Do I need to change the A/T fluid ? The PML technician said no need to , but if wants to , it will cost app $900 . Btw the way PML mention only less than 5% of their client change the A/T fluid . Any one out there can provide the answer whether to change or not ? Thks

 

[Red_Bean_Bun]

Re: Changing A/T fluid

I'm getting my 520i tomorrow. It is a 2004 car but gone only 52k Km. I test drove it n the gear shift is quite smooth. Do I need to change the A/T fluid ? The PML technician said no need to , but if wants to , it will cost app $900 . Btw the way PML mention only less than 5% of their client change the A/T fluid . Any one out there can provide the answer whether to change or not ? Thks

To change or not - they are some discussions about it. But for $900 by PML - it's way out of this world pricing.

 

[Golf-mass]

Re: Changing A/T fluid

Any recommendation for a wksp to replace the fluid ? Any idea how much it cost ? Thks

 

[davidtch]

Re: Changing A/T fluid

Any recommendation for a wksp to replace the fluid ? Any idea how much it cost ? Thks

My advice is to sent it to get everything check out & replace whatever that needs to be replace including ATF & differential oil. The last time i change, the oil is $100.

Pls don't ask which workshop to recommend. It is like which underwear is more comfortable.

 

[ac323]

Re: Changing A/T fluid

I'm getting my 520i tomorrow. It is a 2004 car but gone only 52k Km. I test drove it n the gear shift is quite smooth. Do I need to change the A/T fluid ? The PML technician said no need to , but if wants to , it will cost app $900 . Btw the way PML mention only less than 5% of their client change the A/T fluid . Any one out there can provide the answer whether to change or not ? Thks

Hi golf-mass,

usually is 80,000km to do ATF but for a piece of mind there's no harm to change it earlier (eg: i change engine oil every 5000km and do servicing every 10,000km /maybe i kiasu, hehe )....go do it at R2D better ( PML pricing is sky high )



cheers

 

[xeonm3]

Re: Changing A/T fluid

Hi there , I would like to know if anyone change to Redline AFT D4 ? If change it will be a mixture of redline ATF and ZF ATF... is there any issue with that ? thanks...

 

[Red_Bean_Bun]

Re: Changing A/T fluid

Any recommendation for a wksp to replace the fluid ? Any idea how much it cost ? Thks

Look for R2D. Should be more a little more than a third of PML's price.

 

[Golf-mass]

Re: Changing A/T fluid

Just change ATF with ZF @ $210 . One question , there is no dip stick. to indicate the correct volume of ATF to replace , therefore mechanic top up ATF via pump till overflow . Is that the correct way ? Anyone out can share ? Thks

 

[wt_know]

Re: Changing A/T fluid

overflow is the method use by most workshop
leveraging on new oil to push out old oil

 

[detach8]

Re: Changing A/T fluid

To change or not - they are some discussions about it. But for $900 by PML - it's way out of this world pricing.

well, that's the whole point. they always tell u no need to change, cos their idea is, CHANGE CAR!!! :nutkick:

 

[Red_Bean_Bun]

Re: Changing A/T fluid

well, that's the whole point. they always tell u no need to change, cos their idea is, CHANGE CAR!!! :nutkick:

Not with today's COE ............