XJ Transmission Oil Coolers

[carvesdodo]

Originally Posted by carvesdodo

Havent made any changes to mine since Feb .....

With 50*c - 80*c being the FSM operating range ... Im happy at this stage with a fairly stable 66*c under normal town & highway driving conditions ... altho a fan would be handy to keep it below the 80* - 90* oil temps with high ambients and working the gearbox with a load.

Still .. 80*-90* is a damn sight better than the 120*s I was getting with the factory setup or just the two factory coolers I had mounted in series with just normal driving.

Will mess around with it after winter if need be .. probably relocate it to in front of the aux fan side and closer to the radiator and finally give the fan over-ride switch something to do.

Coolant temps are still a coupla degrees higher at a stable 93*-94* because of the oil cooler size/location.

Anybody else done the simple fix of bypassing the factory fitted farce and jamming a big PWR cooler or similiar behind the grille ......

Got any long term, before and/or after temps ..... to compare with what Ive been getting ????

[ChrisXJ]

Hey Carves,
I have this setup and so far I am queit happy with the results. See post 384.
I am now going to upgrade the clutch fan to the ZJ to get more air flow at low RPM to see if it helps the Air-con issues ( Extra Noise doesn't bother me as this is not daily driven).
The other advantage is that due to the air-con not going to temp, I found the Aux fan was running constant at times to try and cool the cabin down which was assisting with the the cooling system of the PWR Cooler.
To me it was sweet, for an XJ.

[carvesdodo]

Thanks for another followup Chris.

Also .... Considering that the RHD fanclutch is ... IMHO ... on the wrong end of the radiator ... its not a bad idea having the aux fan on .... as it helps drop the coolant temp a bit ... Before the coolant gets to the last half of the radiator.

[fabio]

Originally Posted by carvesdodo

Anybody else done the simple fix of bypassing the factory fitted farce and jamming a big PWR cooler or similiar behind the grille ......

Got any long term, before and/or after temps ..... to compare with what Ive been getting ????

After my last 20000km service on the trans, the fluid was still red and smelt like new. Before the cooler was fitted, I was lucky to get 3000km before the fluid would begin to go brown and smell burnt. I see temps between 50°C and 70°C, and only when pushing hard for hours on end in the softest sand you can find will the temp reach 90°C, but new get any hotter (All temps are taken in the pan). I run a B&M 70264 cooler, and have bypassed the radiator cooler. I'm very happy with this setup, with no problems what so ever, including a recent trip along Goog's track (300 odd sand hills).

[Goneagain]

[QUOTE=Rodgebone;1179075]so in keeping with my theory of "more & bigger is better" i added a second tranny cooler a few days ago along with a 10" 1000cfm electric fan in place of the stock auxiliary a/c fan (rated @ 485cfm from memory). used a B&M SuperCooler Alloy Stacked Plate 29,200 BTU unit (11"x11"x1.5") with a ProForm fan pulling from behind all mounted behind the rad. the fan is wired directly to the pcm and switches on at the stock setting (105* from memory). this is now the primary cooling unit with the Flexalite triple fan threat as the secondary.

Hey Rodgebone, I have been following your transmission experiments, can I clarify two things please 1. that you have both the 3 by 6" fans and cooler in Place as well as the B&M supercooler? and 2. I thought that the aux electric fan was 1000 cfm. I think the the position of the super cooler is a great Idea good work.

[Rodgebone]

Goneagain

can I clarify two things please 1. that you have both the 3 by 6" fans and cooler in Place as well as the B&M supercooler? and 2. I thought that the aux electric fan was 1000 cfm.

correct - i have two coolers; 3 fans on one and a large single fan on the other. as for cfm specs i have found everything from 485 to 1150 in my research and i see 530cfm pop up a lot but this info is very hard to find and probably should not be taken as gospel. aftermarket direct replacement fan specs also vary widely so take that with a grain of salt also. i do know there were differences throughout the XJ model run (cfms, blade design etc) but to be honest i cant remember where i found the spec for my '96.

[darksidecustoms]

So I've been spending some time doing further research during my commute and I have come to a few conclusions to update my system design. The main change has been to add in an oil thermostat, as briefly mentioned early on in this thread by rainman.

Derale make an oil thermostat which is pretty affordable, link is here:
http://www.summitracing.com/parts/DER-13011/
It provides a bypass at 180'F (82'C), so this will allow a nice warmup via the heat exchanger in winter, and a 95% bypass at full open thermostat - straight to the external oil cooler. The best of both worlds, especially taking into account the arguments of line out temp vs sump temp.

There is also a bracket and hardware kit available here:
http://www.summitracing.com/parts/DER-25793/

Revised diagram attached for feedback below: