i've heard that you can put in a rear end from a later model z into a 71 240z.is this true and what year rear end should i look for?



1376-my 240Z.JPG

 

Hi 71

Yes you can swap in later diffs. They take more power but are heavier and you need the mustache bar and the front diff
mount.
BUT
Some of the other R180 diffs (that bolt right in) from the front of Nissan 4 by 4's will work and have CV joints. The diffs will swap OK if you can change the ears on the pumpkin. Just take out the center bolt on the ear and the ear with a splint will come off and put the one from your diff (3.36) in the new one. Most of the 4 by4 ones are 4.11. But I just got three! from 4by4 made Jan 83 to Jue 83 only and these are 3.90. These are supposed to work well with the 5 speed trans. The early one from the 77 and 78 and 79 are lower in 5th and the 81-83 ZX are higher (lower rpm on cruise). These were originally hooked to 3.54 and 3.90 respectively I think - check this - and so if you want more low end torque then the early one should work ( some say the first is too short but I thought the whole idea was to get going fast- hmm?) Also change the oil fill plug to the one on your old diff as it is a male so that you can get the plug off with the diff in the car. The one in the 4 by 4 is a female and you will not be able to remove it once it is in. You do not need to change the halfshafts I understand but the ears on your diff are different lengths and so if you swap them then beware of the difference and get them in the same sides that they came out of.
The big ring geat will have 39:10 on it for the 3.90 and 37:9 for the 4.11 and beware there are some others such as 35:8 which are too tall 4.375 unless you want 'em. There is even a 4.675!
We found an R180 that did not have the center bolt and It has circlips to hold in the ears and they will not swap to your present diff.
Best of luck.
Mark