Keithr726

I know, this topic has been covered too much. My car grids going into second gear every so often when its cold or I shift fast. I heard redline is good at stopping this so I picked up some at Napa(AAA members get 50% off!). I bought the MTL which is 70w/80 but after searching rennlist a bit more it seems MT-90 75W90 is more popular. Should I exchange or not? Would 75w90NS be a better option. This thread opened my eyes https://rennlist.com/forums/showthre...hlight=redline

120k miles on non LSD tranny with noisy second gear

Lets see how long it take me to choose a coolant

Thanks again guys

LFA951

I have Amsoil MTG 75W90, in mine and it runs great, but most here use the Redline MT-90 to answer your question...

Keithr726

It seems through all of the threads on this site, people cannot agree on which redline product to use. They say MTL and MT-90 which have friction stuff for LSD are not good for non LSD cars and that 75w/90 is a better option however it is Gl5 rated when the factory recommends gl4 and it is a oil, not fluid.

Wow, I never knew a liquid besides beer could be argued over this much.

Keithr726

Again my 951 is a non LSD car with 120k miles with a grind into 2nd and reverse sometimes. I also get the whining sound when off of the throttle while in gear, I was told most 944s do this due to a bad transaxle design. I remeber my car making the sound along with a friends car.

rshanholtz

I just called Redline to ask these very questions. I have an 86 951 but I just aquired a rebuilr 89 951 tranny with LSD and Oil Cooler. Dave, the tech at Redline recommended the 75w90NS which has no friction modifiers. He also likes the MT90 and said either would work perfectly. He went on to say that if I were to here LSD chatter during slow tight turns, to add a half of an ounce of their friction modifier which they sell seperately. He cautiioned me not use 75w90 as it has 55 by volume friction modifier which would could hurt my synchros. He said to avoid what porsches uses as it was never designed for the older trannies. I went with 2.1 Qts of Redline 75w90NS and also added a short shifter. 100 miles later and it feels like butter. As an FYI- IAN at 944Online is awesome to work with if you are looking for a new rebuilt trranny.

rshanholtz

Correction: 55 = 5% by volume of friction modiefier. Dave at Redline recommends no more than 1% by volume of friction modifier but only if chatter is heard, otherwise stick with straight MT90 or 75w90NS.

lleroyb

The coolant question is easy, Pentosin. BTW I use MT 90 with no additives or issues.

Lou

Keithr726

I ended up returning the MTL and went with 75w90NS from paragon, still haven't put it in yet.

Zero10

I have MTL in mine.
It's a very thin fluid so you probably don't want to run it down in California...
Even here in the okanagan it's a bit on the thin side. When I have been in traffic for a while it feels like there is no fluid at all in the transmission, but it is absolutely wonderful at all other times. Since I hardly ever sit in traffic, and even in the heat the airflow on the highway is enough to keep the transmission cool, I don't think I will change it.

FWIW my transmission has a Guard limited slip unit in it, and I have no issues at all with it and MTL.

xsboost90

i have redline but next change im going w/ some mobile 75-90- this redline seems kinda thin and didnt improve anything noticably.

944CS

you should put in 1 quart of heavy shockproof and 1 quart of MT-90. This will ensure smooth shifting and long life.

Keithr726

I just put my 75w90ns in today. I couldn't get the plugs out but after I tapped on them, added lube, and heated with a work light they came out easily. I didn't get to drive the car but the shifter does feel a bit nicer.

Keithr726

Oh yeah, a 17mm hex wrench can be found at Napa for $10.

KuHL 951

I always thought that Redline MTL (manual transmission lubricant) was strictly a standalone additive to be used with the recommended lubricant. I've never heard of running it straight in anything; it's very thin and is supposed to improve balky shifting in cold weather. I can't imagine it has real greatshear properties alone seeing it's low viscosity.

Chris Prack

I used to use MTL in BMW's that used ATF in the trans. Like E36 series cars. I would not use it in a Porsche gear box!! It is way too thin and you will have problems. Stick with MT-90 and you will be fine. Either that or Swepco.