NA8 Torsen Diff Damper

[Cal]

I've never really paid much attention to this thing until it broke. I noticed a rattle from the back end and on closer inspection it is completely broken like this one: http://www.codrus.com/miata/diff/companion-broken.jpg

I have read you can simply remove it & throw it away by either cutting it off or removing the pinion gear nut. The later seems like the correct way to do it, but I understand the torque on it might effect pinion depth. Does anyone have any experience with this?

[Cal]

I think I may have found the answer. This is from one of the Spec Miata guys: http://mazdaracers.com/topic/4030-is-my ... epairable/

"Since it was my letter that got the removal of this allowed, I will expand.

They only seem to break at hi speed tracks that use 5th gear. I have experienced a rash of 5th gear failures following the damper breaking. My theory is that the drive shaft starts to whip and actually flexes the output shaft of the trans. Since 5th gear is the rear most gear, it takes all the abuse and eventually says F-you and breaks.

You do not need to replace the crush sleeve or reset back lash. Before removing the big nut, make a mark showing where the pinion tip, nut and flange line up. I like to use a chisel to make a line going accross all 3 items. Remove the nut, remove the driveshaft flange. The majority of the damper ring will fall off. To get the inner portion off, a press and bearing race remover work perfect. I usually put in a new pinion seal while it is apart.

To reassemble, install the flange on the pinion while lining up the marks you made above. Tighten the nut slowly until the 3 marks all line-up. You will now have the same bearing preload as before disassembly. I usually go an extra 1/8" tighter on the nut. Please remember the 3 marks will line up on every turn of the nut. One turn too loose is just as bad as one turn too tight.

I have used this method thousands of times in my 30+ years of fixing cars.. It works just fine for emergency trackside repairs or for in the shop permanent fixes.

We have made it a practice to remove the damper any time we have the driveshaft removed from the car. I carry flanges with the damper removed in my trailer as spares.

The auto trans flange does not have the damper. It is the exact same piece, just without the damper. The auto trans part is not available from Mazda. Plus why spend $100 when you can remove the damper for nothing."