Changing the silicone oil in an LS400 fan clutch to reduce fan speed.

kemicalx

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Hi all,

I know there is a bit of info out there on using an LS400 fan clutch and 7M fan when doing a 1/2JZ swap into an A70. I know Driftmotion sell a modified LS400 clutch with thinner oil. I have a new LS400 clutch on my 2JZ and decided to try a thinner oil to reduce the off idle jet engine noise coming from the thing. Has anyone done this modification themselves? Last night I tried replacing the oil with some 3000CST and found that it didn't improve anything, if anything it made the problem worse. I am struggling to find any information on oil volumes/weight when replacing the oil in these clutches. My understanding of the operation of these things is that should almost free spin when cold, and only lock up when hot mine is tight to spin by hand, and sounds like it's locking up when cold.

Any help or past experiences would be great.

Thanks everyone.
 

hvyman

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You wont get it to spin how its supposed to, the ls400 fan clutch spins the oposite way on a jz. Get a 2jzge fan and clutch off a sc300 and trim the blades so they dont hit the water neck. gives much more room and wont hit a aftermarket radiator.
 

kemicalx

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Thanks for the heads up, I wasn't aware. Seems like a lot of people are using them regardless.
 

3p141592654

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For the 7MGTE fan clutch, after I rebuilt it it was locked on just as you described.

During the rebuild, I filled the clutch with the recommended 50mL of silicone oil, but because it is so thick I had a lot of trouble fully draining the old oil and measuring the correct amount of new oil. In the end, I had too much oil in the housing and it was fully locked hot and cold. I proceeded to drain out ~10mL at a time and after removing 10 or 20 mL I had a fully working clutch again.

So my recommendation is to drain out 10mL, then retry, and repeat until works as it should. HAving an impact screwdriver makes getting it apart fairly quick, but its still tedious to do.

I don't know about the reverse rotation issue. Not sure it would matter based on the construction of the clutch, but I could easily be wrong on that.