Pentosin Trans Fluid Swap | Motul 300 Diff Swap | Impressions
 

I started a new thread for it because I want to be annoying.
This will describe my fun swap of said fluids.

Based on the discussion in this thread:
http://www.ft86club.com/forums/showthread.php?t=16604
Thanks gmhooker for being such a loser and posting quality information.

Liquids Used:

Pentosin 75w 80 Manual Trans Fluid
2.30 Quarts Needed
Drain/Fill Plugs: 27lbs TQ

Motul 300 75w 90 Gear Lube
1.27 Quarts Needed
10mm Hex Hexagon Wrench
Drain/Fill Plugs 36lbs TQ


I used a lift so clearly it was easy. And using the Motul Bottle with supplied nipple was easy for the diff, no pump needed. However for the trans I used a pump. Nothing ground breaking so please do ask me out on a date over it.

I called your mom over to help too, she warmed up the fluids for me.
Anyway, drained the fluid with the car hot and let it drip like a nasty STD for 15 minutes while I swapped my HID bulbs from rice 6000k blue to less rice 5000k white.

The trans plug had some metal on it, the diff plug per the pictures had a lot in my opinion. I never launched this car hard once, in 2500 miles. So it must be break in shrapnel. Advice, change yours.

The swap is stupid simple. Its just the fluids will cost you around $100 to swap. Hopefully they hold up 30k.

Its about 34 degrees out, and my RS3 tires have zero grip so I was not about to pull some Johnny Tran drifts or Nico Rosberg late braking and crash out. What I did was drive carefully for the first 20 minutes letting all those fluids slather all over the gears.

The Result

The trans shifts smother once the fluid reaches temperature. Better than the OEM fill. 3rd gear was much better. Second was also much smoother.
When cold, there is some notchiness but no resistence yet from 2nd gear. The key is cold weather performance. Because I will be driving in sub zero weather like a man. The diff, I can't tell any difference with how loud the tires are. However, given the repuatation of the fluid hard launches won't be as shocking with proper lube.

This car in so many ways is a shit box, but when you actually get down to it everything is designed to be so easily swapped out and worked on it's amazing. It's so not intimidating, like vehicles from the 90s.

Like the steering rack for example, on my old Lotus it was a 10 hour job.
This car you can swap in 10 minutes. So many areas just like that it's a great car for toying with.


Here are pics. Thank you and good day.

nice mags

Canadian porn....

Isn't the Motul 300 75w-90 and not 75w-85?

Thanks, apparently I cannot type numbers properly.

What does Sophia want to do now that she is 18? :eyebulge:

Vote for her favorite state representitive.

Are you actually concerned about the oil lasting 30k miles?

I thought that the pentosin was good in BMWs for 100k miles? not sure on that, but I think I remember reading it somewhere, probably gmhooker's giant thread.

I'll note that I saw the same build up on my plug. Draining that fluid should be a priority for everyone once they are past the break in.

Well, it really depends on the mechanical build of the transmission.
Was/is the original problem with the notchiness due to the OEM fluid or is it an actual mechanical problem with the snycros/gear design?

The S2000 was an Aisin transmission which SAE engineers from Honda said that that specific trans was built for great shift feel at the expense of potential longevity. Using specific trans fluids would smooth out shift feel and eliminate grinds completely BUT after 10k usually the shift feel and grinds would return.

Same with The Accord V6, Civic Si TL, all with 6SP Manuals. All had issues from the factory with problematic 3rd gear sets, not engaging. Using GM Syncromesh in all of those transmissions would eliminate the problem completely for a certain amount of time.

Point being is if the issue is mechanical in the FR-S/BRZ trans, the Pentosin will only keep things smooth for so long before notchiness returns.

I had the same experience on a Subaru 5-speed. MT starts off smooth shifting and typically between 10-15K miles it would get considerably notchier. I'm sure it could be run 30K+ and probably easily up to 100K but it probably wouldn't feel very good to shift.

It would be interesting to see why it happens, but I assume due to mechanical shearing, that the oil becomes too thin and shift feel suffers.

So for both the rear diff and the trans do you just fill until oil starts coming out of the fill hole? Cause on my WRX there was actually a trans oil dipstick and it would read full well before coming out of the fill opening. I didn't notice any sort of trans dipstick on this car.

Yes.

you're welcome!