R200 diff Mod

[Zed2k]

Hi all, I am thinking of uprating my diff from the standard R180 to a R200, apart from the diff unit itself and 260z rear diff mounting are there any other parts I will need to fit this unit to my 73 240z do the driveshafts and prop bolt straight on?
Any advice would be great. Any diff ratio suggestions

Nick

 

[Mr.F]

If the R200 comes from a 260Z, everything will just bolt into place with the 260Z rear "moustache" bar. If the diff comes from a 280ZX you will need a 260Z rear diff cover and, if from a late 280ZX, you will also need a pair of output shaft stubs. The 260Z ones or the early 280ZX manual ones will pop straight in.

Late 280ZX manual will give 3.9:1 to maintain same gearing and not upset the speedo reading.
Early 280ZX manual will give 3.7:1
260Z will give 3.7:1 or 3.5:1 depending on year. Check as there may have been changes during the life of the car anyway.....
I think the Silvia S12 diff can be used also. These are 3.7 for manual, 3.9 for auto (odd?) and, if you can find an FJ20 engined (i.e. 2.0 dohc) version, then 4.11:1 is yours! Same deal as late 280ZX re. back plate and shafts.

 

[zedhead260]

If you do change ratio from 3.9 to something else, you can keep the speedo' reading correct by changing the colour coded cog that fits into the gearbox.

If your not sure what ratio the R200 is, open the back cover. On the big cog inside, you will find a couple of numbers stamped into it separted by a colon " : ". Divide those numbers and you will have the ratio.