LS conversion driveshaft lenght and connection
 

I just noticed that my driveshaft is flinging fluid at the tranny connection. I'm wondering if I should have NOT used the rubber pad in the rear to connect the driveshaft to the diff. Seems like the input shaft is bottoming out in the tranny? How much input spline should I see? Does this look right? Should I do a direct connect to the diff?

https://www.v8miata.net/attachment.p...ine=1439664607

http://i447.photobucket.com/albums/q...pskaur14nq.jpg

I believe I've seen people post that they don't use the flex disc aka guibo. I can also tell you that you've got it installed incorrectly. It should bolt to the drive shaft then bolt it to the rear end. As you've got it installed it's only purpose is a spacer, it's original intent is to lessen the drivetrain shock load with a rubber cushion.
See in this picture how it's installed? Also, note the location of the thinner portion how the driveshaft is bolted into the left hole and the rear end flange in the right side.

http://www.mye28.com/tech/rods_pages...ting_guibo.jpg

Honestly after looking at your picture again if that's the drive shaft that came in your car you shouldn't use the flex disc, the shaft is too long.

I'm thinking I don't need the spacer. The only way it will attach is the way it is now, and it seems pointless. How much engagement do I need from the input spline? I'm gonna remove spacer and measure how much driveshaft spline goes in with no spacer.

After closer investigation, I could see that the transmission output seal was damaged. Here is the old and new one:
https://www.v8miata.net/attachment.p...ine=1439853612

I removed the rubber spacer, and reinstalled the driveshaft. Looks much better now:
https://www.v8miata.net/attachment.p...ine=1439853612

I think mine splits the difference between your before and after but it should never move right?

slight movement with the motor, transmission, and rear rend mounts.

That is why I went in to correct everything. As it was, there was no room for flex. The shaft still has over 3in of engagement and with the new seal should prevent anymore slinging of fluid.

so whats the length ?