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View Full Version : Oil filter same as ATF filter??



RugbyPete
26-08-2007, 10:07 AM
i just got a part from my local jap store, i wanted the engine oil filter.


i get it out the box which i thought was low profile for an engine filter, and its the same as the ATF one.

Is the filter just a small version of the same? my current oil filter fitted to the care is about twice the height

RugbyPete
26-08-2007, 02:01 PM
hmm well it's on, and fits ok, so i guess it must be

old filter was a halfrauds one, so maybe just a different design then


anywya, havoline in, ready to go

Kieran
27-08-2007, 01:10 AM
Hmmm..... I'll have a closer look next time I change the ATF, which probably won't be too far in the future - but from memory the ATF filter uses the same fitting, but the body is a different size. Without access to the data on its filtration capabilities, it's difficult to say, but I imagine there must be some reason why the gearbox filter is marked "A/T Only".

bradc
27-08-2007, 01:34 AM
K - in an engine the oil is pressurised, and the oil filter has a diaphram that opens up at a certain pressure. There is more discussion about this sort of thing in that oil filter thread that was floating about recently where someone was talking about different filters fixing or causing the lash adjuster problem.

The trans is unpressurised, hence it needs a filter without the diaghram.

Kieran
27-08-2007, 01:55 AM
That's not quite the case Brad - The transmission *IS* pressurised - In fact, when in 'D', the line pressure at the torque convertor alone should be around 72psi or above, according to the service manuals I have here. If there was no pressure in the system, the ATF would never get to where it needs to be!

The 'Diagphram' valve you mention in oil filters is simply a 'bypass' valve that opens if the filtration media blocks up - allowing oil to carry on circulating, but the oil will be mucky. The valve that opens at a certain PSI (in your average engine at least) is a pressure relief valve built into the oil pump that opens if the oil pressure gets too high - this is to prevent your oil seals and such from blowing out.

That said, you are right in that if the gearbox line pressure at the filter is enough to overcome the 'bypass' diagphram, then it's not actually going to filter the ATF much.

bradc
27-08-2007, 02:23 AM
ahh well, I had some of the theory right!