GuardsRedHammerhead

I have had a few sunny, but damned cold December days here in the ghettos of Akron, Ohio. For some reason, I am having a bigger itch than normal to drive my 928 lately. It is probably the coldest the car has ever been driven in. After a 10 minute warmup in the garage, I took the car out Saturday at about 9:00 a.m. while the frost was still on the ground and the air was REAL brislk. Probably sub-40 degrees for the first two hours of the day.

Anyhow the first 20 minutes of the drive were MIGHTY stiff shifting. All gears, but maybe a bit worse going into third. After a warmup, the car returned to the normal, smooth, flawless shifting that I am used to and maintained that level throughout the day as the temps increased.

I know that every manual car is stiff in the cold weather, but this seems a bit worse than most.

Think it is time for a fluid change. Any recommendations? Cold weather driving is not normal for this car. I am just taking advantage of the sunny days that I have left.

Rob Edwards

Redline 75-W90NS, Royal Purple 75W90, or Mobil 1 SHC 75-90, lots of religion on this but any of these should be fine. Fresh clean 75W90 anything is better than old n' busted.

heinrich

I got mine with Swepco Blue and could hardly get into 2nd gear on cold mornings. Drained and put in Mobil One synth (btw that was the OLD M1, it has significantly changed since then) and never had a proiblem after that. For 11 and a half years. Changed gear oil 2x with the same stuff.

GuardsRedHammerhead

Red Line and Royal Purple would be AWESOME, if approved by the powers-that-be for the 928 gearbox.

I buy Royal Purple and RedLine at cost, here at Summit. Obviously, I would like to save some money, but don't need to save money at the cost of killing my trans. We also stock, Cam2, Lucas and Moroso Gear Oils.

I generally buy RedLine for my Volvos.

I am a little superstitious about my 928 Manual. I want to put the right stuff in it.

dprantl

Then put in Mobil 1 or Redline... that's the right stuff.

Dan
'91 928GT S/C 475hp/460lb.ft

Mike Frye

I mix the Redline NS with the regular stuff 50/50 and it's usually only notchy on the first couple of shifts.

Bear in mind that 'warming up the car' in the garage is doing nothing for your trans. It needs to be moving to warm up.

The dual exhaust goes back on both sides of the trans and may take a chill off of it, but probably nothing noticeable and not at idle.

GuardsRedHammerhead

My warmup is simply a ritual to make sure that all is good "up top". I know it won't help the trans much.

I really need to flush it. It is the only "unknown" on my car. I will try the RedLine.

I am sure there is a thread about it somewhere, but do you know if they drain completely, and if they refill easily. One of my other cars was a PITA. Drain plug halfway down the side of the box. Had to vac fluid out of it. Refill was through the inspection hole or some oddball thing. This was 15 years ago, on another make of car.

Also, I have LSD to contend with.

GregBBRD

Mobil 1 75/90. Autozone. Pep Boys. Has the correct friction stuff for our syncros and has the proper limited slip additive. Won't make your seals leak....like others will.

I've put this in literally hundreds of these cars. Literally hundreds. I tie tags onto my rebuilt gearboxes telling people to use this stuff. I tell them that they can use other oils, but don't call me when the seals leak or the syncros are ruined.

Porsche has a technical bulletin telling everyone why they shouldn't use GL-6 gear oils, BTW.

Mike Frye

I think the procedure is the same with the S4 as it is for my S3 (and does drain about 100% except whatever is left laying in the bottom of the case):

1. loosen fill plug
2. remove drain plug
3. wipe metal burrs off of drain plug and clean thoroughly
4. replace drain plug
5. using your favorite method of getting the fill mechanism above the filll plug (I have a funnel with a lock to hold it, just fits up next to the battery box).
6. replace fill plug

WallyP

1) Drive the car for twenty miles or more.
2) Remove the UPPER plug on the differential cover.
3) If the upper plug comes out OK and looks good, pull the lower plug on the differential cover and the bottom plug on the transmission and drain the hot oil.
4) Clean the drain plugs and replace them.
5) Fill with magic liquid of your choice, replace fill plug. Remember that if the car is nose-down, you will be over-filling the unit...

Mike LaBranche

I've used redline for years with good results. +1 on always remove fill plug first. Beware of cold tires at those temps, they can bite you if you're trying to put some warmth in the beast.

GuardsRedHammerhead

Oh yeah! I am very careful of the cold tires. I don't want to end up looking like a Corvette guy.

Mike Frye

Damn. I always forget that bottom drain plug when I describe this procedure. Thanks Wally.

GuardsRedHammerhead

Thank you all, for the advice.

SanDiego928

Interesting reading. When it is real cold, I need to go from 1st to 3rd until the car warms up a bit and then 2nd is fine.