danglerb

Pretty sure my 83 5 spd is not a LSD, checking that soon, and Red Line is my prefered brand, but I am not sure which I should be using, 75W90 NS? So far none of the local places stock the NS, just the 75W90.

Is this a good time to pull off the back plate and replace the seal if it seems oily/dirty around it?

bronto

After I got my car back from the post-purchase inspection and service, my 5spd shifted harder than it did before. My current mechanic thinks that they put in a heavier wieght than was in it before. 928 trannies are known to be hard shifters, and he says that the spec fluid is actually too thick and it's common to go with a much lighter weight.

What's the consensus here on the best weight to use in an OB manual transmission?

Scott Turnbull

Got mine from Hoerr racing. (yes, sounds just like it is spelled) They had the best price I could find and fast shipping.

http://www.hrpworld.com/index.cfm?fo...action=product

Shark Attack

i asked the same thing a few weeks ago everybody told me Royal Purple... I for get teh weight though. Just search for "royal puple" in this forum.. you'll find it

danglerb

I just got off the phone with Redline tech support, 83 928 5 spd w/o LSD takes 4 qts of 75W90 NS. The NS means its doesn't have a friction modifier that increases the slipperyness so a LSD doesn't chatter going around corners. The viscosity needs to be just right to get the syncros to match speed quickly.

Porsche specs a GL5 so I plan to stick with that unless I hear otherwise from a booming voice proceeded by thunder. Synthetics work really great, and that makes some people very brave in how they use it.

The local VW dunebuggy shop carries it, only ouch $9 something a qt., but beats paying for shipping even with tax. Gotta support those local guys too.

danglerb

I know some like Royal Purple, etc. but I have had very good results in other cars with Red Line, and they do answer the phone when I have questions.

jpitman2

bananas give the least noise....

Jim bailey - 928 International

It takes 3.8 liters... and the synthetic helps the trans shift better when cold ...

SharkSkin

I used a quart of RL 75-90 NS, the rest plain RL 75-90. Shifts fine once I've gone a few blocks, YMMV. I don't mind doing a 1-3 shift one time in the morning.

danglerb

McKenzies Performance in Anaheim, a VW buggy shop, carries all the Red Line stuff, looks like $8.11/qt which isn't bad for anybody around Orange County. Also Lucas oil and kendall, but nothing Purple that I noticed.

Plain 75W90 has friction modifier, which you don't need if you don't have a LSD.

1-3 shifting is what may keep me from getting a ticket.

SharkSkin

The reason for the extra quart of NS is to help the syncros grab a little and do their job.

danglerb

Tech guy said NS still has some friction modifier, something like 10% of the amount in the non NS. People can make a cocktail mixture that exactly suits them, including just adding some friction modifier. He said some racers use the NS to make the LSD less limited, or if the clutches are worn.

I put MTL in my Mustang's T5 at around 1000 miles I think and 75W90 in the rear end (which is LSD) and it was an amazing change. All traces of notchy shifting disappeared, and a slight whine in the rear end did too.

D_Schultz

Guess I should knock on some wood, but my previous '87 S4 shifted quite smoothly when I bought it & shifted like butter once I put in the redline 75-90NS.

My current '83 euro shifts quite smoothly (OK - the 1-2 shift was slightly stiff on the first shift in the low 30 degree range yesterday) - am sure it will be even better when I put in the redline in the spring.

Do most people really have "notchy" shifts? Am I just twice lucky? I find my '93 Carrera 4 has a notchier shifter than either of my 928s ever had (and it is more than acceptable).

danglerb

Miles 12 through 1000 or so with my brand new T5, notchy, as in very, as in no way on earth to power shift, post Redline and I could powershift (go pedal stays on the floor while you shift, so you have to shift "briskly" unless you like the sound of the rev limiter).

My 83 shifts like my old 914, it isn't notchy, its more like a pause to consider of maybe half a second, and when its cold its positively balky. To be fair it may also have some clutch engagement issue, so I am working at patience to see how it is after Greg fixes whatever is going on with that (subject for a thread of its own in a minute).

Somehow of all the different flavors of Porsche I have driven, all have been a bit on the slow side for shifting compared to other cars, so I guess Porsche likes it that way.

BarryW

I ran Amsoil for a couple of years and it shifted really well. (I have the LSD) Recently I changed to Redline. Cold shifting is not a smooth as the Amsoil, about the same when really warmed up. I'll probably change back to Amsoil. I might try the 1 Qt of NS first just because I can go buy it off the shelf at the speed shop.