bigred1001

Search is not a good friend lately. What is the concensus pick for tranny fluid for a 5 speed, no LSD? I used Redline 75W90 in my 951 and was wondering if that will be fine or if there is something better.



Thanks

Brad W

Swepco is what I use.

heinrich

I bought my S4 with Swepco Blue and it would literally not go to 2nd gear. I drained and went to Mobil One and it was wonderful.However, Mobil have recently changed their formula and I no longer recommend that either, as I am having issues with it. You should consider Redline. Especially with LSD.

Stromius

+1 for Redline 75w90 NS. Check their site.www.redlineoil.com. GL-5 spec.

hacker-pschorr

I've been using Royal Purple in both of my 928's for about five years. I have no reason to switch, my 81 with over 100k on the original syncros is 100% smooth.

cfc928gt

Mobil 1 leaked out the front input. Switched to Royal Purple and no more leak.

SharkSkin

"Best"? I don't know. I do know that Redline, 1 part 75/90 NS to 3 parts 75/90, cleared up synchro issues I was having with my original non-LSD tranny enough that I could live with it for ~30K miles. YMMV.

heinrich

Honestly, leaking is no measure for the quality of oil. If you have a leak you have a leak. Better oil will leak more easily from a bad seal. What you want is better oil. If you like your gears, that is.

cfc928gt

Heinrich, are you saying the Royal Purple gear oil isn't as good as Mobil 1? Why would better oil leak more easily from a bad seal? Synthetics have always tended to leak more than dyno because of the smaller molecules but both the Mobil 1 and the Royal Purple are synthetic. Unless there's something wrong with Royal Purple I'll go with no leaks any day over drips, assuming all else is equal.

IcemanG17

I honestly don't know what is in the widow right now......all I know is I asked the shop to check it and they said it was "fine".......for whats its worth they rebuilds dozens of transmissions a year and they really like Valvoline synthetic.....cheap and seems to work well...or at least good enough to win the 25 hours of Thunderhill?

redpathtribe

Another vote for Redline. Right after I got my car (9 years ago this month!), I was being a good new owner and changing out all the fluids. Replaced the trannie/gear oil with Mobil 1. Great for the motor, gotta be great for the trannie right? WRONG! Didn't notice so much at first, but gradually shifting became more difficult with more grinding as well. Switched to Redline and it was noticeably smoother without grinding. It seems like Mobil 1 is almost too slick, if that's possible... and yes, it was gear oil in the trannie, not motor oil...

IndyMatt

I have used Amsoil in my Nissan and it was lightyears ahead of what was in there. Admittedly it was probably non synthetic oil that was at the end of its life. I have heard good things about redline as well.

Mike Frye

I use a mixture of Redline NS and regular 75w90 and I like it. I've only got about 11k miles in 2 years on it, but with over 214k total, it's still nice and smooth (recently replaced both the reverse lockout spring and the internal 1/R Spring inside and the synchros look great).

VT928

I went with Redline and am very pleased with its performance

Paul Mammorella 1980 Euro S Red/Blk Lea

Doug_B_928

I'm getting my ducks lined up for this spring's jobs, and one is to change the trans fluid (79 5 speed). First time doing it. Why do some mix Redline 75/90NS with other 75/90? Is it okay to just use all Redline 75/90NS?

Also, for the process on a 5 speed (I've read through various threads and seen a lot on AT but not on 5speed), is it just drive enough to get the tans oil warmed up, drain from the drains on the diff and trans, fill up to fill add hole and that's it? After driving a bit to work the oil around, does one need to top up?