Killing a gearbox

Iceman007

Active member
If you change the oil regularly then keep doing it. But if your car has over a 100 000km and the oil was never changed then dont do it. The New oil in an auto box that did not have an oil change before 100k causes all the impurities and that little bit of sludge to come loose and go where it is not suppose to go. This in turn can cause clutches to slip and mechatronics to fail.

if you do your research on google you will find the above I'm sure.

just my 2c
 

samman325

///Member
The age old "lifetime oil" dilemma!!

With all of the above about not changing oil on vehicles over 100k kms being the general consensus, i've also read that BMW's "lifetime"is 100,000miles i.e. about 160k km's so there should be an oil change taking place at some point.

It gets rather confusing and annoying because you left with a "doomed if you do and doomed if you dont" scenario.

As far as i know, oil in manual boxes can be changed at any time and there are no filters.

Its the auto boxes that are the delinquint children
 
Iceman007 said:
If you change the oil regularly then keep doing it. But if your car has over a 100 000km and the oil was never changed then dont do it. The New oil in an auto box that did not have an oil change before 100k causes all the impurities and that little bit of sludge to come loose and go where it is not suppose to go. This in turn can cause clutches to slip and mechatronics to fail.

if you do your research on google you will find the above I'm sure.

just my 2c

No oil change over 100k and the box will fail anyway. Ask me how I know
 

Budleigh

Active member
Change it every 50k, and your box will live longer. I think that the idea that new oil will make your box fail isn't really true - if it fails shortly afterwards, it's because there was something that was on its way out and the new oil just exacerbated that problem.

I changed the oil on my box at Triangle Transmissions - it definitely made a noticeable improvement to shift quality.
 

Philip Foglar

///Member
I remember many years ago speaking to a mech friend of ours that has been in the trade for many many years, and he also advised against changing oil in an automatic gearbox, especially if old and with high mileage. The problem as he explained is that there are lots of areas in the gearbox where metallic particles and general grit collects but mostly remains, that is until upset by changing the oil. What then supposedly happens is that all of this liberated abrasive grit is mixed into the fresh oil and sets about eating away at the gearbox (wearing it out). I reckon there must be truth in this, and ideally a new gearbox that has had oil changed more frequently from day one will be fine.

As far as I know, this does not apply to manual gearboxes. But to play safe I would probably change the oil, drive it for a few days gently, then change the oil once more. Then continue with a more frequent oil change regime thereafter.
 

sash

///Member
would a proper way of changing the oil not include flushing it. A friend of mine with a 320i E46 had some issues with his gearbox, but mainly related to hitting the oil cooler and the water and fluid mixed. While he was recommended to get a new gearbox as it would select gears once warmed up he chose to go with a cheaper option of flushing gearbox and if that fails then replace.

The flushing process used over 3 times the amount of gearbox oil, but they saved the proper oil for the final fill. The oil cooler was replaced and the car is still running fine and its been about 8-9 months. No gaurantee the box will last another 100k but my point is that maybe flushing is more important than just changing the oil.
 

ChefDJ

///Member
They say flushing is what upsets the particles stuck in those nooks and crannies of the gearbox.

Also, if you do the gearbox service, consider changing the magnet that attracts all these particles instead of just cleaning it.
 

sash

///Member
I dont know anything about the inner workings of the 6spd auto.

My logic: To an extent can understand the particles causing a problem, but the fact that the particles remain in the gearbox means that the risk is always there, in fact the a higher risk if more particles are in the gearbox versus risk of having less particles.

I would assume the lubricating properties of new clean oil is better than that of 100k oil and would better protect the particles from causing damage, especially if the viscosity has changed over time.

NB: it is just my logic and assumption. I dont know enough about this to say it is correct, merely thinking out loud and hoping the well informed can clarify further scientifically.:fencelook:
 
ChefDJ said:
They say flushing is what upsets the particles stuck in those nooks and crannies of the gearbox.

Also, if you do the gearbox service, consider changing the magnet that attracts all these particles instead of just cleaning it.

99% of the time when people decide to do a fluid change and flush it's because they're already experiencing gearbox issues (slip or shudder). At that point it's already too late.
 

Pho3niX90

///Member
The guys at ZF also gave me this story, this is what they told me -> because the inner are worn changing the oil changes the viscosity of the oil and thus causing slippage of the torque converter.

Always thought it was a BS story until I read this thread.
 

samman325

///Member
Pho3niX90 said:
The guys at ZF also gave me this story, this is what they told me -> because the inner are worn changing the oil changes the viscosity of the oil and thus causing slippage of the torque converter.

Always thought it was a BS story until I read this thread.

+1

Was told the same thing by ZF as well.

Am considering doing an gearbox oil change on my 07 e90 330d with 160k km's but now i'm confused as hell :argh:

Not having any issues with it and was thinking of doing it as preventative maintenance. I firmly believe the notion of a "lifetime oil" is BS!!

Should i or shouldn't i?
 

DieselFan

Honorary ///Member
It's a catch 22. Don't do it and have the box fail or so it and box might fail...

Sent from Samsung S5
 

Schalk94

Well-known member
samman325 said:
Pho3niX90 said:
The guys at ZF also gave me this story, this is what they told me -> because the inner are worn changing the oil changes the viscosity of the oil and thus causing slippage of the torque converter.

Always thought it was a BS story until I read this thread.

+1

Was told the same thing by ZF as well.

Am considering doing an gearbox oil change on my 07 e90 330d with 160k km's but now i'm confused as hell :argh:

Not having any issues with it and was thinking of doing it as preventative maintenance. I firmly believe the notion of a "lifetime oil" is BS!!

Should i or shouldn't i?

Well my dad has the 2007 3.0d X3 auto and it is currently on 230000km and the gearbox honestly feels as smooth as ever. So far so good i guess,so it seems like my 320d auto and his X3 are still far from the oil change,especially after reading tgis thread. I believe at 160000 you're still in the green
 

anton-sa

Active member
ok, listen up ;) :idea:
heres a theory...

dump auto gearbox oil... drive 10km or so...run thru all gears..
all auto gears..
dump oil again...
put new oil.

s o r t e d.

imho, i dont see how the above method would not work, yeah its a bit
crazy and probably extravegant.. but those 1st two fill drain cycles will
surely flush out rinse out all the crap.
 

Waseem 333i

Active member
On the e46 330d auto box I found this out.

There is a pressure regulator and a solenoid valve. Those things apparently have something to do with locking the clutch inside the torque convertor. If these things fail the clutch fails then gearbox breaks. So gearbox flush, solenoid valve and pressure regulator and filter. They say its not a big job to replace. And if slipping clutch also needs replacement. Another thing with e46 the radiator should be cleaned also to aid the gearbox oil cooler to do its job efficiently.

For manual gearbox oil change should also be done. I dont think it needs a flush though because no oil cooler or other places where oil could hide.
 

DieselFan

Honorary ///Member
Are you referring to the TCC solenoid? If so I posted a DIY link in the DIY section for this. For no reverse or little reverse

Sent from Samsung S5
 
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