Differential question

[Reverend]

Im planning to change the diffy in my 72 and as being a total rookie in this kind of business i ask thou help. If i happen to get R200 (lets say 3.9) is it plug-and-play change or do i need to change other parts as well? My current (R180) is quite loud and it might need rebuilding. R200 just popped in my mind, as some say its the best option if looking to improve the car.

[Reverend]

Using THIS(http://webspace.webring.com/people/cz/z_design_studio/) calculator it seems that the R180 differential gives the maximum speed with normal 4 speed tranny...

Edited January 3, 2012 by Reverend

[jmortensen]

The diff should match the transmission. I think in Europe you got 5 speeds, so it's probably a good match, but check to be sure. That link provided has the close ratio and wide ratio comp transmissions. I think those were the ones that you should have, and I want to say that you have the close ratio, but I'm not 100% on that.

As to parts, here's my list from my big diff post over at Hybrid Z (http://forums.hybridz.org/index.php/topic/49194-differential-cv-lsd-hp-torque-r160-r180-r200-r230-diff-mount/)

The parts list needed to bolt in a longnose R200 into a 240Z is as follows:

1. mustache bar from 280Z with R200

2. yoke (companion flange) from 280Z with R200

3. rear cover from 280Z or ZX with R200

4. side stub shafts from 280Z or ZX with R200 to bolt up to stock halfshafts

FOR EARLY 70-71 Z's only, you need 5 -7.

5. Longer 72-78 driveshaft

6. Curved transverse link that sits right behind the diff from 72-78 Z

7. Flip front diff mount around on crossmember

5-7 are necessary because the early Z's had the diff mounted forward, and swapping to the R200 moves the diff rearward. Obviously if you buy a diff from a 280Z with an R200, it has everything you need except the mustache bar. If you buy the 300ZX diff, then you need the above pieces.

Here are some more resources for the R200 swap: http://zhome.com/ZCMnL/tech/R200.htm. www.zbarn.com sells a kit containing all the parts necessary to do the swap. It's part number is DT1299.

[tlorber]

The stock diff was a 3.36. If you put a 3.9 in without changing the tranny you will have very short gears-maybe good for autocross but not great on the highway. There are plenty of 3.36's here ( I have one) and maybe you could have one shipped over. If you do put in a 5 speed, it would be simpler to put in an R180 with 3.9 or 3.7 gearing (I have the latter in my car with an '82 tranny and I really like the combination).

[jmortensen]

He is in Europe guys. Assuming his car wasn't imported from the US, they had 5 speeds to start and they had correct diff ratios to go with the 5 speeds. I don't know what they had, whether they were 3.7's 3.9's or 4.11's but they weren't running around with 5 speeds and 3.36's.

[Walter Moore]

He says in his second post that he has a 4 speed. The FSM shows that only in the U.S. and Canada. It also shows the 5 speed with a 3.9 differential.

I assume that he must have a car from North America. But there I go...

[jmortensen]

I thought that second post was not by the OP. Reading comprehension fail.

[Reverend]

Thanks for quick reply guys. My Z is imported from CA in 2009. So 3.36 is the best option for factory 4 speed? I dont want to autocross, im more cruising kinda guy. Maybe occasionally i race against some BMW guys in traffic lights but thats it As said before, my current one is noisy and im good if i only get it silenced. BUT also if possible, im looking to get little more out of this nice car.

[Reverend]

Is there any way i can rebuild that R180 i currently have?

[jmortensen]

You should be able to replace the bearings. Gears are NLA. A 3.36 R180 should be easy to find in the states and so you could have another one shipped over. Might also look for a 3.54, which would make the car a bit faster off the line.

[Reverend]

I found some parts in Rockauto.com but i dont know about the diameters. Can anyone give me a list of the parts needed and diameters..?

[jmortensen]

Diameters of what? Bearings? I'd suggest you look at the factory service manual for part numbers, or check www.timken.com.