johnf95111

I've got a Q for the 5 speed crowd. When my 5-sp tranny is cool it seems to shift better than when warm.

I've gone on some spirited runs and when warm, find down-shifting to be a pain. I have to wiggle and push with a lot of force to get the gear change; a real negative when preparing to come out of a corner. I've got the clutch pushed in and am off the throttle. Up-shifting and a throttle mash works well.

Cheers,

John Fagerlund
'89 GT (gotta love it)

FlyingDog

That is definitely the reverse of normal (not just 928s, but any manual tranny). When was the last time the tranny had an oil change? Many have had success with switching to Redline 75W90NS (or a mixture of NS and non-NS for LSD) in 928 trannies with shifting problems.

redpathtribe

FWIW, not long after I got my GT, I replaced the transaxle fluid with Mobil 1 gear oil (assuming that was the right thing to do). Seemed to work fine for a while, but eventually started having grinding issues, mainly on downshifts. I thought the synchros were going.

Finally changed the gear oil again, but this time with Redline and it was a NOTICEABLE difference!! Very smooth shifts, both up and down.

WallyP

Don't disregard the possibility of the clutch hanging slightly when it get warm...

johnf95111

Gear oil was changed when I pulled the tranny to replace the seals. That was about 20k miles ago. I'll try the Redline approach, and since I have the belly pans off and am going under this weekend, I'll bleed the clutch again. I'll even try burping the master cylinder this time.

When warm, I tried pumping the clutch pedal to see if the shifting was smoother, but no joy. With that, I assumed the clutch was ok; but with these beasts, you never know.

Thanks,

John Fagerlund
'89GT (running like a top and shifting like an old truck)

cfc928gt

Redpathtribe, I have Mobil 1 in my GTs rear end and I've noticed the same grinding problem during DE events toward the end of my 20 minute run. At first I thought it was me getting careless but I realized it was the tranny fluid getting too hot. Need to change...

Scott M.

I had similar problems wit my 89 GT, especially after the short shifter swap. I used to be a M1 believer but switched to royal purple which made a discernable difference.

hinchcliffe

Somebody have a link to 5-spd tranny fluid change? I did the rear diff with Amsoil last year but never did the tranny. What's the procedure?

Kevin Michael

I think both of them fill but not positive

AO

It's pretty easy. First make sure you can get the fill (top) plug out - you don't want to drain unless you can refill. Then take the car out for a 10min drive to warm up the tranny fluid. Drain. Fill. Done.

johnf95111

"Drain. Fill. Done."

Yeah, what he said!

I used the royal purple stuff too. And added a short shifter at the same time. I may try going back to the original GT short shifter.

I don't have any grinding, just hard to get into gear.

Cheers,
-j

hinchcliffe

OK, so I guess when I changed my diff fluid it also cahnged the tranny fluid. I was think they may be separate. Guess I'm the dumbass.

a4sfed928

Has anyone compared Redline to Royal Purple to see if one is clearly better for our trans?

Vilhuer

To get absolutely all out what is possible with drain plugs it's needed to open both front and rear plug. When opening only rear most oil will come out. Maybe 0.5 liter will remain low down at gearbox side.

Peter F

Agree with Andrew, it drains better if the box is warmed up with a spirited drive before.

/Peter