MAGK944

This is for an na, no lsd.
Porsche says to use a Hypoid gear oil SAE80 GL-4. I used Redline last time and it shifts really well, but cannot remember which one. They have three on their site and all say not to be used on hypoid gears, so which should I use?

75W90 NS GL-5
MTL 70W80 GL-4
MT-90 75W90 GL-4

TIA Mike

Dmitry S.

I would use the 75W90 or the MT-90. From what I have read, the MTL lubricant doesn't work as well with transaxle units.

I run 75W90 in my 83 with LSD. Even with 130k miles, it shifts well and the diff still locks up.

Justin S2

Porsche says use only GL-4 oils...

I use MT90 in my 944S2 LSD transmission and it works very well.

944CS

GL-4 oils don't have the EP additive in them for the hypoid gear - possible result, blown r&p

If you use MT-90 mix in a quart of lightweight or heavyweight shockproof

NYFlapjack2

Running the MTL ...1983 N/A 125+K miles, and non LSD here. It cured my cold back out of the drive way and start out 1st to 2nd almost grind snap shift issue.....but keep in mind that I seldom shift above 3500, never seen 5500 yet to my knowledge... and it won't ever see the track....this is an attempt to be a more or less expensive, (compared to an econo OBDII 4 cyl crap box) self maintained DD economy commuter for me...

bgiere

MT-90 is what you want to use...it is the proper fluid for the 944 transaxle.

Arominus

I used the 75w90NS redline when i changed my transaxle fluid. It works great so far, i picked it over the others as my tranny is not an LSD and the NS is supposed to be better when its cold. Do a search there were a few good threads covering this in the older posts of this forum.

bgiere

call Dave at Redline Oil and see what he recommends.

MAGK944

Thanks for all the replies.

Redline recommends MT-90 straight with no additives. Their Shockproof additives help with r&p wear but are too slippery for most synchro boxes and can also block coolers for those who have them fitted.

Kevsporsche944

I run Royal Purple. I use it in my Porsche and BMW. I like it much better than Redline. check out their website.

bgiere

With all due respect...The trans n the 944 requires a GL 4 lube. there really shouldn't be too much debate about that. You can use either Redline MT 90 or Amsoil MTL, both are GL 4 and will give the synchros the proper speed when changing gears. GL 5 lubes can harm the yellow metals in the 944 transaxle and are also too slippery for proper synchro engagement. That does not mean the other lubes mentioned are bad, it just means they are bad for this particular application.

zoxx2004

bgiere is correct!!!

BlackOp

I used Swepco 201....was what others recommended here.

944CS

GL-5 oils since the late 90's are ok for yellow metals

75w-90NS is a GL-5 oil that is not too slippery for proper synchro engagement