gale
09-11-2004, 07:07 PM
I changed the trans fluid a few days ago to Swepco 201 petroleum base 80W90 GL-5 gear oil, based on its high regards from the boys with 911's with the 915 trans. Now that I have 100 miles or so on it for the fluid to work in, I must say it shifts noticeably smoother. It was a very quiet trans before but is completely silent now. My only complaint before was that with the short throw shifter, the shifts were notchy at times, particularly going into 2nd & that is now much improved.
I started out with synthetic ATF in the winter, then switched to synthetic GL-4 80W90 for the spring & summer. The latter had about a 5 mile warm-up period on colder mornings but my gut feel is synthetics are too slippery for the syncro's to do their job properly, and now with the Swepco, there is hardly any feel of the syncro's engaging and the notchiness that remains feels like the detent balls in the shift shafts. Normally one should not use a GL-5 spec fluid in a manual trans that has bronze syncro's for corrosion reasons (GL-4 is formulated for them) but the Swepco is formulated with anti-corrosive additives & is not a problem.
I'll update in the winter when it starts getting cold if I notice any warm-up issues. So far it's not cold enough to notice. The Swepco 201 80W90 is much thinner than any hypoid 80W90 I've used in the past in differentials. It has the consistancy of perhaps a 10W30 motor oil at room temp. I tied off a funnel under the hood & poured it in thru a 1/2" tube from above, much easier than pumping it in from underneath.
The Swepco retails for $39/gal, the lowest price I found was at Einmalig's for $34 & fast shipping.
I started out with synthetic ATF in the winter, then switched to synthetic GL-4 80W90 for the spring & summer. The latter had about a 5 mile warm-up period on colder mornings but my gut feel is synthetics are too slippery for the syncro's to do their job properly, and now with the Swepco, there is hardly any feel of the syncro's engaging and the notchiness that remains feels like the detent balls in the shift shafts. Normally one should not use a GL-5 spec fluid in a manual trans that has bronze syncro's for corrosion reasons (GL-4 is formulated for them) but the Swepco is formulated with anti-corrosive additives & is not a problem.
I'll update in the winter when it starts getting cold if I notice any warm-up issues. So far it's not cold enough to notice. The Swepco 201 80W90 is much thinner than any hypoid 80W90 I've used in the past in differentials. It has the consistancy of perhaps a 10W30 motor oil at room temp. I tied off a funnel under the hood & poured it in thru a 1/2" tube from above, much easier than pumping it in from underneath.
The Swepco retails for $39/gal, the lowest price I found was at Einmalig's for $34 & fast shipping.