otter

iTrader: (14)

I think it's something like after 40,000 miles. I did it at 1,000 as I wanted to switch over to synthetic.

MitsuSkot

iTrader: (2)

i'm at about 8000 miles, is it still ok to switch to synthetic?

Scooby24

Welp, time for me to chime in again.


Don't use full synthetic. I don't know why so many people still think this is good for the tranny......it's not.

Synthetic is great for a few hundred miles until you start to realize it's too slick for the synchros and you will grind gears when you shift fast.

70-30 mix Synthetic 75w90 GL-4 fluid and GM or penzoil synchromesh.

If you don't believe me put in fully synthetic and you will find out soon enough that you made a mistake.

otter

iTrader: (14)

I'm at near 4000 miles now, and the shifting is just as smooth as the first day I put synthetic in there. Perhaps there's some crap-*** synthetics out there that break down, but in my experience with both this car and others, putting out some extra money for the good stuff is well worth it and lasts a long time.

Also, I don't see how a transmission lubricant can be "too slick". The lubricant's only job is to reduce heat and friction. It can be too thick or thin, but too slippery? Maybe I'm missing something.

Scooby24

synchros need friction to work properly. Synthetic is good for bearings and gears but the synchros are spinning too fast and don't seat the gears properly. It shifts smooth when you aren't shifting fast but they will grind when you start to shift hard.

Myszkewicz

iTrader: (2)

^^^^^^^ What he said. I'm kinda biased against synthetic anyway, since the tranny in my Talon ground itself to death shortly after filling it with Mobil1 75w90 synthetic. Of course, it had 214k on it when it died.

Anyone want a large paperweight? 5th and reverse still work.

mirspeed

so whats the bolt right next to it?

otter

iTrader: (14)

I believe it has to do with synchro adjustment. You don't want to mess with that bolt unless you want a nice repair bill from your dealership.