will conventional 80w90 be ok in a subaru forester

[ryland]

My bother has a 2001 forester and he has never changed the gear oil!! Its a manual that takes 80w90 gl-5 in the trans which shares with the front diff. and 80w90 gl-5 in the rear diff. I see on some of the subaru forums all the guys use synthetic redline 75w90 in the rear and a mix of 75-90 and some sort of lightweight shock proof something or other from redline in the trans. Do you guys think it will be ok to just use pennzoil 80w90 gearplus conventional in the trans and the rear?

 

[Tremo]

I have a Subie with the 5MT. Don't screw up or the thing will shift like [censored].

In the rear dift, you can use any good quality GL5 gear oil. I prefer synthetics.

The transaxle is another beast entirely. You must use a GL5 oil to keep the hypoid happy. However, you absolutely do NOT want any limited slip friction modifiers in there because it interferes with the transmission synchros, and they will make the thing shift like [censored] and grind on shifting. Let me cut to the chase. Use either Motul Gear 300 75W90 or NEO 75W90HD. If you want, you can add some Redline Lightweight Shockproof, maybe up to 50%. NEO makes a shockproof oil as well, you can use that in lieu of the redline.

Do NOT use the Pennzoil Gearplus.

 

[unDummy]

Don't mix anything.

Use any GL5 90wt in the rear end.

Use any GL5 90wt without LSD-additive in the the manual/front-end.

It would definitely be OK to use the Pennzoil. But, it might not be optimal. Valvoline is another choice.

 

[ryland]

why do you say not to use gearplus? It looks like I could use it in the rear but use some other 80w90 in the transaxle because gearplus has friction modifier in it. Do you have to use one with lsd in the rear or is it just a open diff.? Maybe I'll just use delo 80w90 gl5 for the front and rear if the rear dosent need lsd. I dont want to use a syn because I'm not paying for the oil and he's poor.

 

[ryland]

I already have some Napa 80w85w90 gl3-gl4-gl5 gear oil do you guys think that would work well in the subaru transaxle?

 

[friendly_jacek]

Originally Posted By: ryland
I already have some Napa 80w85w90 gl3-gl4-gl5 gear oil do you guys think that would work well in the subaru transaxle?


Don't know about transaxle, but I used 75W90 in rear diff in my 2000 Subaru and and it developed a whine in 20,000 miles. Stay with Sae 90 (if you can find one), or dino 80W90 Gl5.

New thin oil in old diff is a recipe for a noisy diff.

 

[Tremo]

Man, if you are SMART, you will go to subaruoutback.org or to subaruforester.org and get advice there from real subaru owners and guys who race the durn things who have already been down this road many times.

If you want the 5MT to shift nice, not grind, etc, you will use NEO or Motul. ELSE, go to the Subaru dealer and get a load of factory Subaru Extra-S gear oil.

You can listen to the guys with direct experience or not. You can lead a horse to water, etc.... You pay your money and you take your chances.

 

[unDummy]

Smart? Don't kid yourself.
No one here mentioned racing. But, budget was mentioned.

Any GL5 gear oil will work. It is for you to find out if it will work 'well'.

 

[Tremo]

Originally Posted By: unDummy
Smart? Don't kid yourself.
No one here mentioned racing. But, budget was mentioned.

Any GL5 gear oil will work. It is for you to find out if it will work 'well'.




Yeah, UD, "any GL5 gear oil will work", yes. But the 5MT will grind like a mofo on shifting and be notchy as heck. Now tell me, how many Subarus do you own, or have owned, with the 5MT?