64mgb

iTrader: (1)

I bought some Red Line MT-90 for the transmission and some Red Line 75W-90 gear oil for the diff. How important is it to get the old oil completely out before refilling? Any hints on how to do this? Is just draining until it drains no more sufficient?

Also, I've seen it mentioned a couple of times that you can buy a pump for refilling. Can someone point me at a source for this pump?

Thanks,
Rich

speckamp

When I changed the gear oil in my 85 SE, I simply let all the old oild drain out before refilling. It's not like those $200 automatic tranny flush and fills where there's all kinds of passages and hoses in the transmission that you need to get fluid and debris out of -- it's just a case to keep the gears from sailing in the wind

Also, both the tranny and diff's drain plugs are magnetic to catch metal flakes in the oil, wipe them down good before reinstalling them

I got the hand pump from a boating supply store, it's a little pump that drops into the bottle and has a hose on the end -- it's for use in lubricating outboard motors IIRC. It cost me like 3$

Unsupa

iTrader: (2)

i just used an old peice of water hose and a funnel.. had a friend pour it in as i held it in the hole..

7aull

iTrader: (2)

head's up that the drain plugs are a TAPERED fit, so you don't want to ream them in super tight, since this just widens the hole in the diff or tranny-
Stu Aull
80GS
Alaska

64mgb

iTrader: (1)

My real concern is cross-contamination of the old fluid, which I assume is not synthetic, and the new synthetic stuff. Is that a real concern?

mazdaverx713b

iTrader: (91)

i wouldnt worry about cross contamination. most of the old fluid will come out without a problem and as mentioned above, the magnetic drain plug will catch most of the shavings. if you very concerned about the cross contamination, i would fill it with the redline or whatever fluid you decide to use and drive it for a few thousand miles and drain and refill with fresh fluid just to make sure. i have never had a problem in the trans or the diff. just make sure to wipe the plug clean. i wouldnt imagine that youd have a limited slip in your 79, so i woulnt worry about the limited slip additive. for note though, most gl-5 fluids have the additve already inside.

1984se

https://www.rx7club.com/1st-generation-specific-1979-1985-18/rear-differential-oil-360642/