I wanna do a transmission fluid change, and from looking at other posts, I wanna know for sure if I have to use Matic j or s. Or is it possible there is another alternative trans fluid I can use like Idemitsu matic j fluid, which I heard could be a good alternative? Idk please lmk what’s the better option.

 

When the car was brand new there was only matic j, then they later developed the synthetic matic S. Matic S can be used in any transmission that was OEM matic j recommended. For your 5-speed jatco you can use either.

 

So to be clear, I can probably use Idemitsu matic j fluid on my 5-speed 05 g35 ?

 

No guarantee that the friction modifiers are the same (those are the only real differences between transmission hydraulic fluids) and these Jatco trannies are pretty notorious for misbehaving with anything other than actual Nissan OEM Matic fluid.

 

So should I just use Nissan Matic-J fluid ? What about matic-s ? And what is it the cost per quart at the dealership ?

 

Stop being so confused. Just get the Matic-S and youre good. I dunno the price at your dealership, but u can probably find it cheaper if u search around online.

 

I started rebuilding RE4 and RE5 Jatco transmissions over 6 years ago. I have always used Valvoline and Supertech (cheap off the shelf ATF) fluids after rebuilding and for valve body kit installs. I've never had any problems even on the boosted cars and have put over 100k combined miles on all of them. I tried this a long time ago because we were pushing the transmissions over 100% of the stock rating and knew that we would be rebuilding several times before we figured out all of the weak points of the RE4's. We didn't want to spend $60-$80 in fluid every time we dropped the transmission. We have already swapped 3x RE5 Jatcos to ATF and haven't had any problems so far. Honestly the thing I see overlooked on these transmissions that is the biggest problem is the brake band not being adjusted. They are supposed to be serviced and adjusted as they wear. If they don't get adjusted they will not grip the brake drum and burn it up over time. The funny thing is that the adjustment is on the outside of the case and not a real big deal to check.

 

How do you check/adjust the band?

 

I've used Castro Transmax Import and seems to be fine