Last year this time I changed gear oil and added Mobil 1 synthetic. It was an improvement in many ways - decel noise was lessened and shifting was indeed smoother. Nevertheless, the dreaded second to first gear downshift remained a problem for me. I believe the downshift issue is car specific, but I also believe everyone has problems of some sort with the downshift.

Last week a gallon of Neo Synthetic HD gear oil arrived at my office. I purchased this oil after having read about it in "Turbo & High Performance" Magazine. The oil languished for a few days in my garage until today. Having ordered a new gear drain washer from the dealer, today I drained and filled with the Neo Synthetic.

Having just returned from a drive with the new gear oil, I can report a hege improvement in shifting down to first gear. In fact, the downshift is grind free. Not entirely gone - I mean you can't downshift from 35 MPH without at least blipping the throttle - but you can get into the lower gear without a grind with moderate effort. I consider the improvement to be huge. New, beefier synchros might cure the problem entirely, but for gear oil to aid a major design flaw to this extent is almost a miracle.

Others have reported the Neo Synthetic gear oil to be corrosive to synchros because they are made of brass and GL oil contains sulfur. Subaru requires a GL 5 gear oil. Its a requirement for all GL gear oils to contain sulfur.

If you want to downshift to first without grinding, this is the way to go.

X

 

Dude, dont downshift into first. It's Bad.

 

Dude, use NeoSynthetic. It's Good.

 

be sure to keep us updated as to whether or not the problem worsens in the future. we've all heard the stories of people going to redline and loving how it feels at first only to report the original grinding coming back even worse after two weeks.

 

I LOVE this gear oil. One week later and the grinding is a thing of the past. It's nice to shift into first gear without worry.

X

 

NEO Synthetic has a web site that links you to the reatiler.

http://www.neosyntheticoil.com/

 

The problem with gear oils is that the gearbox is a little bit contradictive. Really slick oils (like Redline) are good for the bearings but bad for the synchros. Stickier oils (like the Neo you're using seems to be) helps out the synchros but are harder on bearings. If you plan to keep your car for 100,000 miles+ go with the stock fluid. If you plan to upgrade your gearbox anyway, use the synchro-helping oil since you won't have your bearings long enough to worry about them wearing out.