Huh. That's strange, because mine looks as if it is almost further out than the 1.6. While it is a 1.8, one would think they would be similar. I'll have to just wait and see what they say at school when they strip it down. I'll probably take a little off of the driveshaft spline, and a little off the transmission male spline as well before putting it together/buying another junkyard tranny.

 

Oops, I mis spoke. That's a '99 driveshaft with a '93 1.6 5spd. I've upgraded to a complete '99 rear end.

 

Well, I brought the transmission and driveshaft to school, and it appears that the tranny was bone dry... except metallic sludge. The VIN trips were the first legal trips, and never thought to check the transmission oil. I'm wondering if this was part of the reason that Miata was in the junkyard...

They are going to strip it down tomorrow to make sure what it was, but I am starting to think perhaps the driveshaft is ok--there are no signs of stress on the splines...

Perhaps it was just something that was rattling around inside the tranny...

Still, it seems wierd that it would have a grinding sound when in neutral. That's what made me think it was the driveshaft pressing too hard, as if a gear was just touching something else and rubbing the teeth whenever I let the clutch go in neutral.

 

If it's grinding while in neutral and rolling, it's the driveshaft turning the primary (half of 4th gear) shaft. It's still turning internal bits that'll grind if dry.

 

I'm starting to hope it may be a minor issue. They've torn it down, and none of the gears look abused or beaten. No broken syncros except 5th, which is missing two teeth in different areas (the one gear that was actually working--go figure). There was nothing other than some sludge by the magnet, so I am going to try to cough up a few bucks to replace the fifth gear syncro and have them put it back together and try again. The clutch pressure plate does not look bad, the clutch looks relatively new, and the flywheel is pretty clean.

Dear God, please let it just be heat and lack of fluid. I really can't afford more than this.

 

Well, it's back up and running again. Apparently it was simply dry and hot.

So, I put it back together, bolted everything down, and got to start it sunday night before calling it a day. Today, I went over everything, and then drove it.

Wow. One thing I changed while it was down and out of the car, was the wastegate actuator. It was not correctly configured, so the wastegate was open a little the entire time, making it harder to gain boost. It would start gaining around 5000rpm, and finally reaching 7.7psi at 6750-ish. What a difference. I closed it correctly, and it pulls hard in 2nd on up. It pulls some in first, but I did not notice as much. Probably a good thing, considering the transmission. I have yet to load up my datalogging from the Megasquirt to figure how much it is pushing, and where in the rpm band. Sidenote: I can hear the BOV working now, rather than sitting there doing nothing.