For CV axle conversion, who makes the best kit?

[B^2]

I know there are a few companies out there making cv axle conversion kits for the 510 and I'm wondering if their is a hierarchy of who is making the best kit.  I was reading that one person had an issue with the Ermish kit but it's hard to tell if that's a design issue or something else.  I know the datsunrestomods kit is popular but I don't know how it compares to futofab or zcargarage.

[iceman510]

.The biggest issues I have heard from users is constant loosening of the adapter fasteners.  Now Futofab and Ermish have made a second generation  without at least one set of the adapters in the construction.  I have looked at the Z car garage kit but not studied it in detail.

 

Datsun restomods took two different approaches to the axles depending on R160 or R180.  I bought a set of the R180 CV axles which directly incorporated the stub shafts to go into a Subaru R180, bolting to the flange at wheel side in the stock manner.  I will be trying this combo in my 69.

 

I also got a set of the Subaru-sized stub shafts only (diff side) for an R160 that will bolt directly to either the stock half shafts or their own CV shafts that directly replace the stock halfshafts.  I will be putting these in a Suby R160 with stock halfshafts in my 73 to try first.

 

There is also Driveshaft shop.  All kits have some similarities and also some slight design differences. 

[Icehouse]

I've had 2 styles.  The aluminum adapter with the VW CV's which were pure junk.  The adapters came loose in about a month or two.  I always had to keep my eye on them and they had ton's of backlash which made your car make bad noises when turning.  I also have a set of Restomod shafts.  They were okay except they bottomed out on the body on my low car and the boots ripped open on both sides.  They are sitting on my shop floor in need of 3 of the 4 boots......   

[iceman510]

Good to know about clearance on very low cars.

 

Parallel conversation going on for this same question on the Realm:

 

https://the510realm.com/viewtopic.php?f=30&t=34581

 

 

[Tedman]

Year old thread, but Dave, I'm wondering how you fared with the Datsun Restomods axles? I removed one of my rear springs and installed one of the RestoMods-style CV axles (from ZCarDepot). I found that I only had ~1 3/4" of bump travel (measured fender arch to wheel center) before CV interference with the arch in the underbody above the axle. Solid contact while driving would likely rip off the boot clamp and rip the boot. Sounds like that is what happened to Icehouse. Now, my rear springs are Datsun Comp with 1/4" urethane coil spring insulators.  My ride height may have been considered very low back in the day (lower than Mulholland Springs), but by today's standards, I'd consider it moderate. Anyway, Since the CV hit the body before the bumpstop engaged, I raised the bumpstop with a 1" spacer underneath. These are the progressive rate conical Foamex ones from Top End Performance. At 1.75" they are too short even with stock axles! Stock rear bumpstops are ~3 1/4" tall. That's plenty tall to protect this CV kit, but they eat into suspension travel quite a bit, and are not very progressive. Were I to run them I would cut off ~1/2" like they show in the How To Modify book. I also replaced my 1/4" spring insulators with the 1/2" version (also from TEP). That added ~1" of ride height. Now I can jack up a rear corner under the semi-trailing arm until the body lifts (no spring, all bumpstop), and still have ~/1/2" of CV clearance. Between the taller bumpstops and additional ride height, I'm fairly confident I won't make hash of the CV boot, or worse. 

 

The problem:

 

Bumpstop comparison:

 

Bumpstop with 1" spacer, compressed enough to begin lifting body:

 

Clearance at CV with taller bumpstop (ignore temporary flange hardware):

 

Urethane coil spring insulators:

 

"Before" ride height:

 

"After" ride height. I can live with that. 👍

 

 

Edited December 11, 2022 by Tedman

[paradime]

If it's not too late...

I have a WRX R180 dif on my 510 and used to run a set of Troy's VW CV axles. I agree with Icehouse, they were complete garbage.About 3 years ago we swapped them out with the driveshaftshop setup. They weld the 27 spline stub ends no the inner flange so no adaptor. The CVs are super stout and have Porsche style shields rather than exposed boots. My ride hight is a bit taller than yours, but we're pushing 400hp through them without a hiccup. It may take a while to get your order because they build them in batches, but well worth the wait IMO. https://driveshaftshop.com/product/datsun-510-240z-with-r180-differential-108mm-cv-conversion-kit/

 

 

[iceman510]

Hey Ted, as always I am learning from those who blaze the trail.  I have not installed the Restomod axles in my 69 yet.  That car is still in waiting mode while I work on the 73.  I am very slow, LoL.  Are the CV axles from Z car Depot actually the same (exactly or dimensionally) as the Restomod version or are they their own? T3 has some shown now too that look nearly identical to the Z Car depot parts, and maybe they are. Did ZCD say they fit a 510?  They don't list them for it but I know they are the same.

 

Did they provide installation instructions specifying which end towards the diff?  Maybe it makes no difference or could be even worse the other way.

 

This seems to be a significant concern and interesting it has not been reported by anyone on the Realm other than Icehouse (a few of the early sets of those axles went on a couple cars there).

 

Second topic- are you saying you installed a single CIN-220 and it raised your ride height 1"?  That is twice what they are saying it should do.  I'm asking because I may need to utilize something like this on my 73 to get the ride height back up a bit.  I don't know what springs are in there, but when it was a track car that spaced it up with aluminum plates which will be too noisy for the street.  Springs look really short and not sure what rate they are.  Any extra good street rear springs sitting around your garage?

[Tedman]

I don't know if the dimensions are identical to Datsun Restomods, but they sure look the same, as do the T3 ones. It would be interesting to compare all three side by side. ZCD does not say they fit a 510, and they don't market them as fitting a 510, probably because of the interference issue. There were no instructions included. I had to find pics of them installed to verify which end is which. Also, their description of the optional bolt kit says it facilitates installation at the outboard flange. The conical end is the one in which you cannot install a stock bolt from the CV side of the flange, nor can you install the stock bolt from the wheel side of the 510 companion flange, so that end must be the outboard end, at least that was my reasoning. That and the pics I found show the straight "tripod" end attached at the diff flanges. 

 

Regarding the spring insulators, yes, I removed the single CIN-219 I had on each side, and replaced with a CIN-220 on each side. The claim that the CIN-220 will raise the ride height by 1/2" on the package is bogus. First of all, relative to what? Old OE rubber, new OE rubber, or CIN-219? I figured that adding 1/4" above the spring x the motion ratio of 3.8 would raise the ride height by about 1" and that's about how it turned out.  

 

As for springs, funny you should ask. I have some front springs I removed from my '05 Xterra that will fit the 510 rear spring cup. By my calculations, cut 3 coils will give a drop of ~1.5" vs. a stock 510, and a rate of ~880 lbs/in. I posted to the Bluebird list about these a while back. You can go to the Bluebird510 Google Groups page and search "Another possible 510 rear spring option?". In my post there's also a link to my writeup in MS Word .doc format with the gory details.  You could be the trail blazer!