i lost my owners manual and just finished the tranny swap in my hatch. what is the correct wieght and amount of tranny oil for a ea81 4sp 4wd? thanks

Jon

The first hatch I owned I drained out the old stuff and then put in mobil 1 synthetic 75w90.Comes in those little gray bottles with the pointed tip.It seemed to help shifting quite a bit.I plan on doing the same thing to mine this weekend.Some may argue that sythetic is not the best choice but I love the mobil 1 stuff and use it in everything that I drive.

thanks Jerry, i`ll give that a try if i can afford it lol:lol:

shadow after testing many said that redline gear oil was the best to use, said it gave him way better shifting. better feel etc.

Or do as I do and just use Valvoline 80W-90. Its cheap, and works fine.

I too like the Redline, but there is really no fix for the crappy 4 speed. Only fix for that thing is to get yourself a 5 speed - smoother shifting, and no issues with syncros.

 

GD

Ya I too like redline better than Mobil 1.Just a little more expensive and harder to come by for me.

I use the 75W90NS from Redline. The NS is an additive to promote friction on the synchros and is to be used specifically for older gearboxes. I used it on my '91 Legacy when I first got it--93K miles and a distinct crunch going into 2nd. The crunch went away around 100K and I have 172K on the gearbox now. I don't know if the better shifting is due to the Redline NS or that I compensate for the crunch by shifting slower. Either way I can't argue with success.

By the way, for us Seattle people, Chris at Bow-Wow Auto Parts in Lynnwood sells Redline 75W90 (and the NS version on special order) by the case for $9.75/quart plus tax. Considering I use 4 quarts or so in the Legacy every 100K miles, that's really pretty cheap.

Correction: I looked up the bill for the last case of 75W90NS I got and it was $8.95 per quart plus tax. You can call Chris at Bow-Wow at 425-771-6411.

i use amz 75-90ns before i put that in it used to grind all the time in second and not down shift worth a crap so about $8 a quart its worth it

I used the same Redline that Ed uses in my 4 speed, and while it did *help* it did not completely eliminate the 3rd gear and 2nd gear downshift grinding. It's not a cure all, and in the case of the 4 speed, the grinding is largely due to bad syncro design. Note that it's "bad" only in the context of subaru's in general - they routinely last 200k or more - but they shift crappy, the linkage sucks, and they almost always die somewhere between 250k and 300k (less it abused). The 5 speeds are quite the opposite - very nice shift, hardly any syncro problems till they get WAY up in the mileage (with proper maintenance), and there are a TON of them left. It's intesting to note that Subaru STILL uses the same 5 speed design with only minor changes in 20 years. The 6 speed in the STi is the first really new subaru transmission.

 

GD

The first hatch I owned I drained out the old stuff and then put in mobil 1 synthetic 75w90.Comes in those little gray bottles with the pointed tip.It seemed to help shifting quite a bit.I plan on doing the same thing to mine this weekend.Some may argue that sythetic is not the best choice but I love the mobil 1 stuff and use it in everything that I drive.

 

 

They make alot of noise at first-- the viscosity is greatly different than regular. My old dl was changed after 15 years, and it was quite loud for 2 months , and suddenly all was quiet. I thought/felt it would go to 1 million miles with the synthetic, noticable in hot weather once viscosity synchs(sinks) in. I should do this to my loyale, but its still young at 13.

ya it took about 2 months to see notice that im not grinding gears anymore. though i could tell right away overall.

Interesting comments, GD. You'll be surprised that I have no more 4 speed gearboxes. My Brat has a 5 speed, but the synchros there are pretty shot so the Redline did not help much. Other than that, the Redline NS is only in my daily driver and the Impreza that I use mainly for rallycross and backup use. I will be installing it in my wife's Impreza as soon as I get around to it.

Yeah, I probably should do something like that on my hatch. I lost first gear for a while, missed the 2-3 shift due to the sloppy linkage, jammed it into a gear, and found myself in first. Ever since then, first has been the easiest gear to go in and out of.

Although, on mine, since it is RWD now, I might try a motor oil, maybe 15w40 diesel oil.