I've been getting some whinning & squealing from my H23 tranny recently (not sure the mileage) mainly when I down shift and going in and out of 1st gear. When I've been driving for a while and tranny gets very hot, I can hear a slight rattle or grind when I'm at idle. I'm going to try putting in new trans fluid and see if it helps. I've heard GM syncromesh was good and also Penzoil synthetic? I'm looking to do this small change myself so if someone could give me instuctions on how to drain & fill, or even pics would be great. Thanks.

 

I wouldn't suggest that you use synthetic oil for a transmission. The syncro rings are like little bronze cone clutches and they require a little bit of friction to do their job. I have been told that synthetic oil is too slippery and can slow the the syncro process down.

If you have a habit of resting your hand on the gear shift ****...stop it because that will put unnecessary wear on the shifting forks. Sorry "expert" drivers, this is a BAD habit.