Can a CV half shaft be modified?

[ezzzzzzz]

I don't have access to a CV half shaft so I can't decern this myself. I've done some searching just to look at a CV half shaft but figure someone out here can look at a shaft assembly in hand. Maybe someone else has thought of this? What I'm asking is can a CV half shaft be disassembled then reassembled using extra parts such that you end up with a bolt-on assembly at both ends? I was thinking that someone like Moser Engineering could fab the splined shaft to build a custom assembly, if necessary. If this were possible then R180 diff flanges (bolt-on) could be made similar to the MM modified stub axle flanges. This would allow CV's to be run on early R180, longer and equal length shafts, etc.

[zcarnut]

I have thought about this already....

 

Yes, the CV axles dis-assemble and be re-assembled so that you have you have a “bolt-on assembly†at both ends. Of course, this requires getting four CV axles in order to make two.

 

This is how the CV axles used by the Nissan 4x4 720 truck (1979-85) were made.

 

To join these axles to the diff all you need is the diff flange piece used by the 4x4 720 truck This piece slides into the R180 diff and is secured by a single bolt. You usually get these pieces when you obtain a junkyard diff from a 4x4 720 truck.

 

I looked into this as a possible way of using the earlier R180 LSD diff with the CV axles.

 

However, if you don’t have to use the earlier R180 diff, then I think it is far easier to just to swap out the earlier R180 diff with the later CV type R180 (like used on the first generation Maxima). Why? Lots o’ reasons: You can get a better (3.70) ratio; you will probably be getting a diff with less mileage on it than yours; and since you need some R180 CV axles anyway (as well as the companion flanges) you might as well get everything you need from a single donor vehicle.

[frank280zx]

I have thought about this already....

 

Yes' date=' the CV axles dis-assemble and be re-assembled so that you have you have a “bolt-on assembly†at both ends. Of course, this requires getting four CV axles in order to make two.

 

This is how the CV axles used by the Nissan 4x4 720 truck (1979-85) were made.

 

To join these axles to the diff all you need is the diff flange piece used by the 4x4 720 truck This piece slides into the R180 diff and is secured by a single bolt. You usually get these pieces when you obtain a junkyard diff from a 4x4 720 truck.

 

I looked into this as a possible way of using the earlier R180 LSD diff with the CV axles.

 

However, if you don’t have to use the earlier R180 diff, then I think it is far easier to just to swap out the earlier R180 diff with the later CV type R180 (like used on the first generation Maxima). Why? Lots o’ reasons: You can get a better (3.70) ratio; you will probably be getting a diff with less mileage on it than yours; and since you need some R180 CV axles anyway (as well as the companion flanges) you might as well get everything you need from a single donor vehicle.[/quote']

 

Hmm this makes my 150 for an r180 including shipping ( 70 USD ... wish i was UPS now!!) look cheap

[ezzzzzzz]

I'm looking into the 720 4x4 diff flanges and hope they still exist out there (and for a reasonable price). A local driveline shop is willing to build custom CV's for me ($$$?). Alternately, I could machine and weld up companion flanges like those that MM sells. I'd do it for both ends to match so a shaft could be installed in any position. I know that Porsche 928/944 used a bolt-in CV axle too. They just might be the perfect match. All of this because my diff is fine and unique. I wouldn't sell it off so buying another LSD diff/ axles would probably cost about the same as creating CV axles/ flanges. There would have to be interest from other early Z owners for such an adaption if I can make it happen..

[zcarnut]

Let me clean up the application info: The Nissan part number for the 4x4 720 diff flange you want is 38220-50W00. It was used on the 4x4 trucks from Jan 1983 to Aug 1985. The earlier 720 diff flange (Jun 1979 to Dec 1983) is the snap-in type.

 

However, a phone call to my Nissan parts man revealed that the 38220-50W00 is no longer available new. So, unless you luck out in the junkyards I think that making an adapter would be your best bet. A flat plate drilled for both the CV axle bolt pattern and the early four-bolt R180 diff flange should work. I don’t think any welding is necessary.

 

You can easily rebuild the CV axles yourself so I wouldn’t pay someone to do it. If you need CV axles and axle parts I suggest getting a hold of Roger at the Z Barn. (I’m very fortunate to live only twenty some miles from the Z Barn.)

 

Some more info for you. If you find you need a different length CV axle shaft after you make your adapter, there are several different center shafts you can use:

 

280ZX Turbo (L side) ______ 14 3/16 inches

280ZX Turbo (R side) ______ 14 11/16 inches

Z31 non-turbo (L side) _____ 15 5/16 inches

280ZX/Maxima (R180) ______ 15 7/16 inches

Z31 non-turbo (R side) _____ 15 11/16 inches

 

All the above center shafts will accept the same tripod bearings and all the CV axles that use the tripod bearings used the same six-bolt end housing piece.

[ezzzzzzz]

I have access to two late 85 production date 720's. One is 11/85 and the other unknown because the tag was missing. The diffs look identical to my R180 except for the CV flanges. The CV's look just like the 6 bolt 280ZX or 300ZX CV's too (three series of two closely spaced bolts). I can pick both up for $100 each with the inner CV assemblies (shafts cut) so I get the proper CV ends still attached. With all four pieces I can fabricate my shafts with the info you have provided. As for gearing, I have the close ratio early 5 speed box which seems married to my 4.11 rear end. It is a blast to drive and pulls strong throughout all gears. Dropping in a 3.70 would improve mileage but cost performance I believe. As for road miles, my diff is solid, quiet and performs very well. I don't see mileage as an issue unless poor maintenance, worn bearings or mechanical failure have created a problem. The only disappointment is my understanding that the 720 diffs are non-LSD(?). I suppose there could be a market for one of these to recoup some money, if only for the low ratio r&p set?

[zcarnut]

...I suppose there could be a market for one of these to recoup some money, if only for the low ratio r&p set?

 

I'm sure you can sell them. The ITS racers like the 4x4 720 diffs for the ratio (4.11) and the later ones were four pinion for added strength.