Which Way Does transmission Fluid Flow...Stock Filter / Cooler

[j.hardstyle]

I am going to be changing the external transmission filter with a Magnefine filter. But I want to know first how the transmission fluid flows on the stock filter/cooler setup so I know where to place the inlet and outlet hoses for the new filter.

There are two hoses on my stock filter....one is an inlet and the other is an outlet, obviously. One hose comes from the transmission to the filter....the other goes from the filter to the radiator, and then a third hose goes from the radiator back to the transmission.

Is the INLET from the transmission straight to the filter? OR is the inlet actually reversed....and go from transmission to the radiator, then radiator to filter, then filter back to transmission?

I would think it goes straight from the transmission to the filter, from the filter to the radiator, from the radiator back to the transmission....can anyone confirm?

[cientortas]

It flows to the filter first then the radiator. Magnifine sounds like a good option. I added a screw in filter mount, so I can use regular oil filters and replace them whenever.

[Q451990]

To verify, you can always start the car with the hoses disconnected, just to see which one sprays fluid. Messy but foolproof. The A/T definitely pushes fluid... there's no suction on the return line. I found this out during a failed experiment to create a DIY fluid exchange with 5 gallon buckets.

Heath

[j.hardstyle]

Thanks for the replies....unfortunately, the whole top end of my car is disassembled at the moment, so no starting for me!

[Towncivilian]

See NTB00-056b - 1988 AND LATER NISSAN VEHICLES AUTOMATIC TRANSMISSION OIL COOLER CLEANING to find out which cooler line is which.

[j.hardstyle]

Thanks but that PDF didnt help....the cooler on this car is on the drivers side...theres a top and bottom inlet/outlet.

It is a bit confusing because the filter itself has an arrow, indicating the flow direction.....but the way it is set up is backwards. Because the way it indicates, the transmission fluid would first enter the radiator and THEN go through the filter....rather than first going through the filter THEN the radiator.

Soooo....does it go through the radiator or the filter first??

[OwnerCS]

Here's a picture of an OEM filter bottom. The filter out line marking is in the picture. It appears the fluid flow is from around the outer edge then it exits the filter from the center tube. For a 94 model, the fluid from the dual output is routed through the radiator coolers.

[j.hardstyle]

Ended up cleaning up the bottom of the filter very well and I see where it says IN/OUT.

Ran the left side transmission line to the inlet of the new filter--->outlet from filter to lower nipple on radiator--->upper nipple on radiator to right side pipe that leads to transmission

The stock filter is set up this way, so I guess I cant go wrong...

[cientortas]

I didn't think the 92 Q came with a filter...I thought it was 94+ only. Maybe this was added later? Either way, filter first then radiator is the correct flow. The idea is to filter particles before the radiator, so they don't accumulate in the radiator and block flow.

[j.hardstyle]

Wrong....all came with the external filter. It was the 94+ that got the DUAL OUT filter, 90-93 used SINGLE OUT. 94+ also got dual coolers in the radiator.

[qship96]

Wrong....all came with the external filter. It was the 94+ that got the DUAL OUT filter, 90-93 used SINGLE OUT. 94+ also got dual coolers in the radiator.

90-93 did NOT come with ANY external filter from the factory. The transmissions were so problematic that many {most?} were replaced under warranty, and AS PART OF THAT PROCEDURE, dealers were instructed to ADD the external filter {and at some point,even a small finned cooler near the trans pan} in an attempt to extend life of the second transmission.......entire system re-configured and improved from the factory for the 94-96Q models.

[cientortas]

Qship is right. The previous owner must of gotten a factory replacement transmission along the line somewhere hardstyle. There is a TSB out there somewhere that explains this.

[j.hardstyle]

So if theres an external cooler, then the transmission has been replaced? Strange....

[OwnerCS]

My 91 has been converted to a 94 model radiator, ATF filter, transmission, drive shaft, TCU, fuel injectors, and upgraded horns..

[j.hardstyle]

Funny you should mention the horns because first thing I did when I got my Q was install my Hella Supertones