Y33 ATF flow direction

[KingKarl]

Please help...just installed a B&M ATF cooler on my 1998 Q45t. I have read/serched numerous threads about how to hook the cooler up. Bypass the OEM radiator intercooler or splice the B&M cooler into the circuit after the fluid exits the radiator and heads back to the transmission.

Question of the day...Does my ATF rteturn to the transmission from the passenger side of the radiator or the driver's side of the radiator? I have yet to get a definitive answer. It may not matter if Wes is right.

He advises a bypass of the OEM intercooler alltogether. I am reluctant to do this as I trust the Infiniti design engineers and worry about some unforseen consequence. Please discuss amongst yourselves.

[RobertsnewQ]

People argue about this all the time for all cars. Check the Subaru SVX boards for examples. It doesn't really matter how you do it (Oh!, the Blasphemy!). The OEM heat exchanger helps to stabilize fluid temps (in theory) and warm up the fluid faster. A stable fluid temp makes the trans shift more consistently at all times.

The cooler mfgs. always reccommend putting the external cooler in series for this reason - the theory being that the cooler will prevent trans fluid temps from ever being greater than water temp.

Me? I'm putting mine in parallel since I have the kind with two coolers in the radiator.

[elwesso]

I like bypassing all together.. heres' why...

In theory, I agree with you Robert and I respect your opinion. However, its a KNOWN fact, of all Qs that the heat exchangers are known for clogging. Thats why they added the filter.

The Y33 transmission exchanger is much smaller than the one on the other Qs... Not capable of handling things...

My idea of putting the cooler in between the radiator and condensor makes it better for me since i live in a cold area and wont freeze the transmission when it gets cold...

If I knew nad had faith that the OEM setup was golden, id have no problem putting it in parallel. however its a KNOWN fact that this is the problem...

[elwesso]

I also wanted to point something out

There should be 4 ports, yes? 2 on each side.

The "cooler" only works on the end tanks, it does NOT go through the radiator.

[maxnix]

FY33 is a little different. Actually, retarded would be a better description. The ATF just passes through what amount to a coke can in the bottom tank.

[DAEDALUS]

I think anyone who's proactive enough to add a cooler to the G50 transmission isn't likely to suffer from a line clog. The metal lines are roughly the same diameter as the rubber ones, which are used regardless.I believe, but am not certain, that an aftermarket exchanger will keep the ATF cooler than the stock exchanger. The stock exchanger has far less area, but obviously liquid/liquid exchangers do more with their surface areas than air/liquid exchangers. What I am certain of is that an aftermarket exchanger, in series with the stock exchanger, will be cooler than stock alone. Unlike plastic chain guides, cooling tubes to and from the radiator are still implemented on the newest models. The risk of clogging can't be that great.

[3Q Jay]

to your original question.....I don't remember. When I did the fy33 fluid change, i pulled the hose just for a sec, while cranking, to 'flush' out the exchanger. at the time, i guessed wrong, and then re-did it. I do remember that the flow was good as i made a bit of a mess.....

hey, please see my post here:

zerothread?id=121519and let me know how your transmission shifts.did you go M1?

[KingKarl]

Jay, I did go to M1 and after much to-ing and fro-ing, I bypassed the intercooler all together. I live in North-Central Florida where the mean temperature is only a few degrees cooler than the surface of the sun. I'm not certain that the OEM cooler serves any purpose in these conditions and may even function to heat the ATF in some circumstances.

Before installing the cooler and doing the transmission service drill as outlined by the astute NICO members, my Q would occasionally shift out of 2 and the engine would rev for 1 to 2 seconds (as if it were shifting into neutral) then drop into 3. This only occured an very low throttle/rpm (1000 to 1500). "Warmed up" or "cold "made no difference as it happened in both conditions. The transmission seemed to be searching for 3. I have been out of town for the last week and have not driven the Q very much since I did the cooler and AT service, but the transmission seems to be shifting smoothly with no notice of the 2-3 problem to this point. Great help, all. I am shifting large and leak-free!!

[FarFetched]

Glad to hear it !

[RobertsnewQ]

I think anyone who's proactive enough to add a cooler to the G50 transmission isn't likely to suffer from a line clog. The metal lines are roughly the same diameter as the rubber ones, which are used regardless.

Unlike plastic chain guides, cooling tubes to and from the radiator are still implemented on the newest models. The risk of clogging can't be that great.

Not to mention the same as 99% of the cars on the road !

Lots of cars share the clogging problem as well - it's a common cause of dead transmissions. I personally would probably not set them up in series because of the potential for the factory exchanger to clog, but as long as you do frequent flushes it's unlikely to happen.