Today, I drained the oil out of the transaxle in my 90 and replenshied it
with Redline 75w-90 synthetic gear oil. I was skeptical at first, but
Redline does make shifting much smoother...very smooth indeed. It's well
worth the $9/quart and the hassle of of draining/filling the transaxle.
Here's a little tip for those who are planning on a transaxle drain/fill
that makes filling the transmission with oil simple. Take a large
funnel and attach about 2 feet of large diameter rubber tubing to it.
You can then snake the free end of the tube into the transmission fill
hole and position the funnel end in the engine compartment. Then all
you have to do is pour the gear oil into the funnel to fill the
transmission. Works great! No need for squirt bottles, etc. Maybe some of
you have already done this...