Hello everyone,

I have a 1982 280zx 5speed non-turbo that probably started its life as an automatic since I found out when I blew my diff that I had a 3.54 R180. so I decided to upgrade a bit and put a 3.9 R200 and CV-shafts from a turbo 280zx. To do the conversion I bought a 3.9 R200 and a set of used axles still bolted to the suspension tables so that I had the matching stub axles. I had the CV-shafts rebuilt, ordered new bearings, bushings....etc and bring the car to a mechanic to put all the stuff together.

The car is at the garage and everything is bolted and went fine but now my mechanic called me and he just cant put the axles in the car : he says they’re too long ! Actually he managed to put the shortest one on the passenger side but he had to unbolt the suspension table to squeeze it in. With the table hanging at the end of the suspension travel there is probably less than1/2’’ of play left in it. The other axle is about ¼’’ longer. I also had bought the snap rings that were supposed to clip the axles in the diff (from a nissan dealer) but my mechanic says that they don’t fit and he didn’t find any that can fit there.

I just don’t get it ! I thought everything should fit since turbo 280zx have the same body than mine and came from the factory with a R200 diff and CV-axles. I’m sure the stub axles, spindles and shafts I bought came from a 280zx turbo since they were bolted to identical tables than my car and the shafts were bolted with 6 bolts to the stub axles. And I had the right and left side from the same car. R200 diffs are supposed to be all the same except for the driveshaft flange and mine fits perfect.

The only thing I can see is maybe the shop that rebuilt my shafts put a different head on them or modified them inside or something. I know that they didn’t have a lot of experience with this type of axles and they couldn’t find new boots anywhere close and had to order them from the states (I live in Canada). I will call them tomorrow morning.

Has anybody here done this conversion on a 280zx ? Or went through a similar problem and know what can be going on? Any info or suggestions that can help solve this problem are greatly appreciated !!

 

R180 & R200 are different sizes and require different half/cv shafts.

R200 ON THE LEFT, R180 ON THE RIGHT


You need adapters to do the swap correctly. There are tons of websites on the internet that talk about the swap. Here's one (swapping an R200 into a 240z... but same idea).

http://alteredz.com/240ZCVHalfshaftConversion.htm

 

your speedo is going to be off and you need output shaft form the tranny for the speedo gear in to match the rear gears, thats the problem i ran into when i swapped to 3.90's but the acceleration will be really noticible. its nice for gettin off the line. unless you have the power for it 3rd gear unless u redline 2nd is going to be a bit slow because its got so much of a rpm drop. but its nice. i beat mustang gt's out of the hole line nothing. its insane. its soo fast of the line.. if you can hook that is. but when i tried to put the speedo gear in to the output shaft on my tranny the gears from the 3.54 and the 3.90 were totally different in teeth. and it didnt even turn it. so. just to let you know, unless out speedos are adjustable. which i dont know thats what you gata do. but i think you like 3.90's and i still get 27mpg on the freeway. but as soon as you get on it i can watch my fuel guage drop

 

The speedo gear (cog) should match the rear end gears in order for the speedometer to read the proper speed.

The shafts that the speedo gear attach too are slightly different between the various transmissions used on the 70-83 Z cars. If you have a speedo gear assembly from a different tranny, you may have to swap the cog onto your assembly for it to work properly.

Some of the assemblies are slightly offset from the centerline of the gear.

 

thanks for your help but I already knew all that stuff......and I dont need adaptors since my car is a 280ZX and not a 240Z. I just had to bolt the stub axles and companion flange from a 280ZX turbo (whitch came from the factory with a R200 and CV-axles) and it should fit since it's the same body and control arms and I installed a R200. My car should have come with this from the factory(except for the CV-axles) if it was built originally with a manual tranny.

 

Then why is it again that they don't fit?

 

i hate to say it. But you don't need adapters to do this swap. I took my R200 3.54 to a R180 3.90. The swap went fine. You need the lil hubs that connect the CV's to the wheels also. Other wise they Will Not Work. they will be to long. and will not even bolt up. The long cricket dick lookin bolt that the rear end bolts too needs to be pulled out. and turned 180 degree's, then droped back in. With that said. that rear end will just go right in. and your mech needs to pay attention to these things.