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5mt oil cooler
Posted: Wed Apr 07, 2004 2:03 pm
by mTk
Are there any option availible to cool the fluid in the 5mt? I think i read somewhere that the 5mt has no fluid pump (a feature only in the 6mt)
MK
Posted: Wed Apr 07, 2004 4:27 pm
by vrg3
Yeah, the 5MT's fluid isn't pumped anywhere; the gears all just turn through it. I suppose you could add a pump to carry the fluid out of and back into the differential; I haven't seen the inside so I don't know if there's a good spot to add a pickup or not.
Are you worried about your gear oil overheating? I don't think I've ever heard of that happening on a Subaru 5MT.
Posted: Wed Apr 07, 2004 4:59 pm
by mTk
I'm currently running 40w dino oil, not sure if it would run hotter or not, i suppose there is less friction since it is thinner, so less heat?
MK
Posted: Wed Apr 07, 2004 5:09 pm
by vrg3
40W gear oil? Or 40W motor oil?
Why wouldn't you just use 75W90?
Posted: Wed Apr 07, 2004 10:16 pm
by mTk
http://bbs.legacycentral.org/viewtopic.php?t=15752
Motor oil. I have soem 75w90 royal purple gear oil.. but so far the 40w has been excellent.
MK
Posted: Wed Apr 07, 2004 10:47 pm
by vrg3
Hmm... I'd be wary of running motor oil for extended periods of time in a gearbox; gear oils have additives to help them avoid shearing between gear teeth and stuff like that.
40-weight motor oil is actually similar in viscosity, I think, to 75W90 gear oil. Maybe a little thicker, actually. Gear oils and motor oils are measured on different viscosity scales:
http://www.irvingoilco.com/images/viscosity.gif
Posted: Wed Apr 07, 2004 11:09 pm
by mTk
Ah, it does seem pretty close to the 75w90. I'll probably be trying out the royal purple next week when i do my shift linkage and exhaust.
MK
