So I'm going to swap a 2002 3.9 Torsen into my 1.6. I have a 1.8 driveshaft and 1.8 (1 piece) axles.

1) Can I reuse my 1.6 driveshaft -> diff BOLTS w/ the new 1.8 driveshaft?

2) Can I reuse my 1.6 PPF bolts?

3) Is the 1.6 nut on the axle (hub) compatible w/ the new axles?

4) Is there ANYTHING (and I mean anything) else minor I'm overlooking? Or can all the 1.6 bolts be reused w/ this swap?

Sanks.

 

1) Im told the driveshaft bolts from the 1.6 are smaller in diameter and dont actually fit. However I didnt get this memo and ive been running the 1.6 bolts for a few months now without any issue.

2) PPF bolts are the same, no need to change them.

3) Nope, the axle nut on 1.8 is bigger, get a pair from rock auto.

4) minor info, the nut on the 1.6 hub is a 29mm IIRC and is a pain to get off. get something bigger than 1/2" drive or you WILL break the tool(s).

Keep in mind this is info I gathered when I did a '99 open diff to my 1.6.

 

I had a tough time finding the axle nuts for the 1.8 axles, mazda couldn't get them for some reason. Fortunately, most Hondas use the same size nut and the Honda dealership had them in stock.

 

why is it that im using my old 1.6 axle nuts on my 1.8 axles guys.... there the same dont worry about it.

 

The size changed somewhere on the NB axles, I am not sure of the year, but I have run into the size change. The spline into the hub did not change.

 

Ohh ok, gottcha

 

since we're on the subject of torsen swaps does anyone know if they only made torsens in 96??

 

http://www.miata.net/faq/Miata90-97A3.pdf

 

I am using 1.6 driveshaft bolts on my 1.8 torsen. The bolts are technically too small in diameter, but properly tightened they are fine. As y8s said when we did the swap, the bolts are there for clamping force and under proper torque should not see any shear force. I have put a ton of shear torque through mine since and they are holding up fine.