goldberg

If you find the noise inside the cabin is a bit loud.
Like faint grinding noises, more so at low speed (i guess at higher speeds, they are drowned out by other noises) then change your diff oil.

I did mine recently, 2016 GT3RS.

OMG- MASSIVE DIFFERENCE!!! Car drives the same, but its soooooo much quieter inside.

Easy job. Drain Plug & Fill is at the top, on a banjo bolt.

jb997

What is the mileage on the car? The interval for the gear oil seems to be 10 years. The oil spec is 75w90 right?

JCGT3rs

same car .. same sound/issue .. I'll add the diff to my list

thanks for posting

GrantG

Goes without saying for most folks, but this recommendation is for the PDK. Manual has gear oil shared by gearbox and diff and is supposedly good for 96,000 miles (even with track use). YMMV...

3-Pedals

Are there any instructions? What oil do you use?

M3the01

I did mine after a yr and it was a huge difference in the gt2rs... especially the initiial change as the subsequent, even though more miles, had little to no impact.

goldberg

Im at about 85k Miles.
6 years old. 1 owner.

There is no "service interval" for this according to Porsche (That i could find)
but we all know oil doesnt last forever.
On a side note, there is also no "service interval" for coolant either. But i also did coolant flush.

I keep on top of all maintenance in general. Oil & filter every 5k miles etc.

But in the cabin, slowly slowly it had been getting louder. Like a "ballbearings in a cup rattling" / "metal-icky kinda sound"

I changed the diff fluid. The fluid that came out wasnt terrible either. Sure it was dirty, but i have seen worse in the past.
No glitter or metal filings which was good.

But the WORLD of difference in the car. no more noise.
Car doesnt appear to drive any better. But its good to know that its done. It was obviously in need.

I will keep more on top of this in the future, maybe coincide it with the PDK flush which i do every 40k miles.
PDK Flush is also very easy, but need AUTEL or similar to rear PDK temps for filling.

yes LiquiMoly 75w90 (or whatever brand you like i guess) fluid is what i used.

JCGT3rs

anything to note on the PDK flush? I have to replace the transmission pan, as its leaking.

goldberg

pan with integrated filter needs to be replaced each flush.
well I guess doesn’t NEED to be. But recommended. They aren’t expensive anyway.
the pan bolts (13 from memory) also need to be changed as they are single use

DONT over torque them. Tq spec is 2nm. (Please double check but from memory it’s 2nm)

the specs can be found in this forum, as that’s where I got my instructions from when I initially did it.

Other than that as mentioned will need computer to monitor PDK temp to get the level correct.

but if you’re handy with tools etc, I’d say this is quite an easy job. Like 4/10 difficulty.

need a lift though. Or at least quick jacks.

goldberg

Oh also with the pan bolts there is a tightening sequence.

that can also be found on this forum in one of the PDK flush threads

JCGT3rs

thank you!!!

I took delivery of my car a little over a month ago and the maintenance records aren't clear or seemingly current so looking to reset all of this

jb997

Here is the sequence, this is from 997.2 but it is exactly the same pan so. Helps if you get marker pen to mark each one once torqued

ParadiseGT3

I've asked my indy a couple of times if we should change the manual gearbox fluid. They've never done it, explains why.

JCGT3rs

jb ... so awesome.. thank you ....

ok so 75w90 for rear diff and

I think I saw some PDK fluid sold at Suncoast...

regarding the Autel - MaxySys - does it also clear the service codes?

goldberg

Yes the AUTEL will reset service maintenance reminder

PDK Fluid is Pentosin FFL-3
need 6 bottles