4th Gear Grind in an 04 w/ amsoil Severe Gear Oil

[bluej20]

Looks like i have developed the infamous 4th gear grind. I have been running "Amsoil Severe Gear Oil" for the past 16,000 miles without any problems now that the car has a total of about 30,000 miles.

The gears usually grind when i upshift from 3rd to 4th after 4000 Rpms. It is not a grind that can be heard inside the car...but i can definatley feel it on the shifter. The problem is not there when i double clutch it into 4th or if i wait a tad bit longer in neutral before going into fourth.

My Current plan is to drain out the AMSOIL Severe Gear Oil and switch it back to regular dino Valvoline 75W-90 with a quart of Penzoil Syncromesh....

Another alternative could be to take it to the dealer and get it warrantied....now my search on CLUB WRX has shown mostly positive results from the dealer about the 4th gear grind but my search on NASIOC mostly came up with abuse excuses to deny the warranty claim for the 4th gear grind.

[bluej20]

OK so no responses..i decided to changes lubes b4 taking it in..

i went ahead and purchased 2Qts Penzoil Syncromesh and 2Qts Valvoline 75W-90.

Jacked the Car up only to find the Lucky SOB *****ing ***hole POS TORX T-70 Drain Plug on my 2004...man am i pissed.

Nobody not even sears craftsman manufactures a TORX t-70 bit to open the drain Plug

I had to buy a whole set on E-bay for the TORX T-70 bit.

This better be worth it (i want my grind fixed)

All aside how does the Idea of 1.7Qts Syncromesh mixed with 2Qts Dino Valvoline Sound?

[Z3RO]

I have the EXACT same problem. All I do is not use 4th gear ...Or wait a bit before engagin it..try reving your engine in neutral too before you shift. I barely have 23k im my 02 and have the same problem . I heard mobil 1 tranny fluid works wonders.

[VOLFAN]

Maybe I am misinformed or missing something here but I thought the drain plug on the transmission pan was a 21mm?

I am curious b/c I was about to cheange mine out in the next week (As soon as I can find that damn Valvoline 75W90...that stuff is nearly impossible to locate!)

[bluej20]

Under any circumstances do not use MOBIL 1 75W90. It is too slippery for the syncros to engage properly...youll become a permanent resident of grind city.

as for the Bolt 02,03 and early 04's have the old 21mm drain plug only the later 04's and 05's got the lucky torx t-70 drain plug.

As far as Valvoline 75W-90 i picked it up at autozone and they only had 2 Qts so i decided to run the rest Syncromesh.

I will report back once i get my Torx T-70 and swap the AMSOIL out

[VOLFAN]

Oh, good. I bought my '04 in August of '03 so I think I will be OK on the bolt. I havent looked yet, b/c all I have changed is the oil to this point.

Thanks for the info though!

I also heard that the Mobil 1 pretty much stinks for the same reasons. There are poeple who liked it but if you realy, really do a thread search there seems to be more people complaining about it then liked it. Many people said it was good at first but after a few thousand miles it grinded worse than ever. Now, I have heard that it is good for the rear differential. Nevertheless, I am sticking with Valvoline OEM stuff just to be safe, since I havent had any problems.

[testes1010]

I heard mobil 1 tranny fluid works wonders.

^ on other cars maybe, but on the WRX you are sadly misinformed....all other Mobil1 products I give a thumbs up...

Redline Shockproof...or Penzoil Syncromesh are the only ones that I would recommend....I am, btw, completely satisfied w/ the Redline Shockproof....

[xdriven2004]

I HAD the same problem on my 04.Every time I would get on it above 4000rpm it would scartch 4th. I got some pennzoil synchromesh from autozone and mixed it with some regular gear oil.The problem totally went away......t.I mean totally went away.

[bluej20]

I HAD the same problem on my 04.Every time I would get on it above 4000rpm it would scartch 4th. I got some pennzoil synchromesh from autozone and mixed it with some regular gear oil.The problem totally went away......t.I mean totally went away.

What gear oil did you use???

[Trainrex]

I tried multiple different synthetic gear oils on my rex. So far, the good ol dino has been best

[nvmywrx]

ive having this problem, i thought it was my syncro were bad? so maybe i will try this.

[CCFabrications]

Pesonally I use the Motul 75/90 synthetic. I have an 02 with the STi RA gear set and this oil has been the best I've ever felt! I have heard that Solberg uses it too in the WRC tranny. My friends 05 WRX was having similar problems as your facing... we swaped his oil with the Motul... so far, flawless shifts!

[Trainrex]

Pesonally I use the Motul 75/90 synthetic. I have an 02 with the STi RA gear set and this oil has been the best I've ever felt! I have heard that Solberg uses it too in the WRC tranny. My friends 05 WRX was having similar problems as your facing... we swaped his oil with the Motul... so far, flawless shifts!

Isn't the WRC tranny a dogbox?

[CCFabrications]

Yes, in truth the WRC transmission is the "dogbox" or "crashbox" as some would say. That style of tranny does with out the synchros as gear matching and rev matching are done through driver without aid. And although it is a cheep comparison from a factory trans to a full blown WRC "dogbox", I was just merely using it as reference that the company Motul that is made in France is well respected and has a great reputation for its oils. Top choice in my book!

[Trainrex]

Yes, in truth the WRC transmission is the "dogbox" or "crashbox" as some would say. That style of tranny does with out the synchros as gear matching and rev matching are done through driver without aid. And although it is a cheep comparison from a factory trans to a full blown WRC "dogbox", I was just merely using it as reference that the company Motul that is made in France is well respected and has a great reputation for its oils. Top choice in my book!

I'm definately not downing Motul fluids, but so far I've had better experience with dino oil in the rex. We do run synthetic in our racecars, but they have dogboxes.