I handle most of my fluid maintenance but am bringing my 2002 Impreza Outback Sport (MT) into my local mechanic and want to buy the proper manual transmission oil .  My owners manual chart indicates I will need 3.7 qts of GL-5 85W for the manual transmission.     For the rear differential a Haynes book for Legacy and Forester (2000-2006) suggests GL-5 75W-90 and .8 qts 

 

Questions:

1. I understand I can use the same fluid for the MT and Rear Differential.
2. Any brand recommendations for the oils?
3. GL-5 85W for both? (If I can't find - just use GL-5 75W-90???  

Thanks in Advance -  Guys/Gals

Pete

Edited April 26, 20178 yr by stackman1

Same oil doesn't surprise me. I use Amsoil synthetic in everything. Go by the Subaru owners book. Amsoil has reference application guides also.

Oh, change one, change both. Same miles, same time.

Same oil doesn't surprise me. I use Amsoil synthetic in everything. Go by the Subaru owners book. Amsoil has reference application guides also.

I was planning on using conventional oil.  I have 145,000 miles on it and from what I read the synthetic might be so good it could cause slipping?

I'm not specifically familiar with that model. What could slip in a manual?

 There may be some full synthetics that don't work well in the MT, I have read of many people that have 'clashing' because of the difference in synchronizer speed over the use of conventional GL-5 in the MT.

 

some manuals have a different weight listed for the rear diff than the MT, but many folks use the same fluid so, I guess it's what you're comfortable with.

 

Synthetic is fine for the rear diff BTW.

 

Subaru trans oil would be fine, many choices of course. There's a very affordable synthetic-blend at Walmart that some folks use - , I've used Redline Lightweight Shockproof and really like it in my WRX, at present it has Amsoil Severe gear which seems OK - no clashing this winter that I noticed,( but feels more 'notchy/scrape-y' than the shockproof did),  all the way up through Motul ...., lot's of fluids/prices.

Edited April 26, 20178 yr by 1 Lucky Texan

I'm not specifically familiar with that model. What could slip in a manual?

Good Point Dave.  I must have been reading about automatic transmissions with regard to slipping.

In my 2002 Forester MT, I use Walmart's own brand of 80W90 gear oil.

- MT takes 3.5 L

- Rear Diff takes 0.8 L

I change the oils more frequently than recommended by Subaru.

Car is now at 252,000 km, with original gearboxes, and running just fine.