VLSD R180 hybrid coming up!

Today I picked up a Pulsar GtIR AWD R180 rear viscous limited slip diff complete for $275 Australian, approximately $210 US. Now I know the centre is not clutch pack type LSD, but its better than an open one. You can't use the complete diff in our cars, but a certain person who is famous for having an under 10 second FJ20T, has told me that he uses one of these centres in our style R180 long type diff, in his 510 datsun 1600 FJ20T.
These later R180's use slightly bigger bolts to hold the centre to the crown wheel. To fit this centre to our diff I have to get the centre holes shimmed slightly so I can use the smaller bolts, then she's a bolt up to my the crown wheel in my open R180 and I'll be away,(actually haven't tried my CV's in it, but I'm pretty sure they'll fit okay) and I'll have an R180 VLSD, with a 4.11 ratio for my sr20det Gazelle.
The importer had a heap of these diffs sitting on a pallet. The diffs come in:
RNN14 Pulsar/Sunny GtiR sr20det AWD (rear diff), U13 bluebird sr20det AWD (rear diff), U12 bluebird sr20det AWD (rear diff), and there is a few others also.

Very nice work!!! Good to see we got another option for diffs!!

Too bad its useless for drift :cry:

Yeah I know, but I'm to old a bastard for drift, so it will have to do me. At least it will be a big improvement in a straight line. Another reason I got it is coz I was nostalgic for the GtiR's I had in Japan. Those things handle like they are on rails, nothing like passing five cars at full throttle on a skinny Japanese road just before a pretty tight corner, with confidence, hehe. I thought at least I can have a little piece of GtiR in my Gaz!

I tried my s12 CV's in the GtiR diff centre and they fit fine. Now just have to get the shims and bolt the centre into the s12 diff. Hopefully get the shims for less than $70.

Awesome, now to find some up here...:|

how much for the center alone? or do i gotta buy the whole diff??

as my car is being set up for street/windy roads, the viscous will do fine for me.

please email me once finished or if you need any help, i am SUPER keen!

catch ya

Nah they wouldn't sell just the centre, or if they do they won't sell it to you for any less than a complete diff, (I checked), so you may as well get the whole diff anyway as at least it has newer bearings etc than your old R180, I read somewhere that the bearings are the same but have to inspect them to be sure. They actually wanted $350 for the complete rear ends, (disk to disk) in the cradle, but I found this one that had had the cv's cut in half with an oxy, (no use to me anyway) and been removed from the rear suspension crossmember, (which I definitely didn't want anyway as I would have had to go home and get my trailer, and then just have had even more scrap metal lying around my shed!!
My mate rang up an importer aquaintance and asked him if he had any of these diffs in stock and how much he sold them for and he said $275. I told the guy and said I wanted to get it off him to save me the trip to the other place , (which was true), so he gave it to me for $275, (reluctantly, but the fact the other place was a direct competitor helped!!).
Be careful though when I was researching doing this I rang a few places. For example one very well known importer in Adelaide quoted me $500 just for a friggen centre out of the same diff, (a friggen VLSD centre!!!!). You have to shop around, and pays to quote the price another mob gave you, (a real one as they will check if its a fair bit cheaper).
Honestly I'd say you'd be real lucky to do any better than $275.

The drivers side inner shaft of the GtiR CV that goes into the diff has an extra smaller spline on it to operate the VLSD. So our s12 drivers side CV is no good for this diff.
The inner diff side GtiR CV cover comes off the CV joint, so you can separate
this shaft and the CV cover from the CV. I'm going to have to go and get an s13 Vlsd drivers side CV, and see if I can remove its inner cover and see if this GtiR one will fit.
Sorry for getting your hopes up folks. I'll let you know how it pans out.

Okay I have fixed the CV problem. What I am doing is getting the inner drivers side CV shaft resplined and then the inner GtiR spider (CV) bearing will fit....

I was lucky that the Gaz spline was big enough so they could machine it done and respline it for the smaller GtiR bearing, so its all good. When I get it back I'll put the GtiR rubber boot on, (I'll have to stick the end of it in boiling water or something and use that silicon spray stuff to get it to slide over the shaft). Then put the spider bearing on the new spline, regrease the bearing cup and fit it, then its done.

The GtiR CV cup/cover has the shaft (necessary to operate the viscous centre in the diff) that goes into the diff attached to it. On the other passenger side the Gaz CV assembly seems to fit the diff fine.

I reckon we need to stick this!!!

Gerry, when you finish you reckon you could do a writeup?! When i get another gaz, this would be an excellent option!!

Wd mate http://www.club-s12.org/board/images/smilie/pimpflash.gif

You'll have to get some pics, did your solution end up having anything to do with what we chatted about on the phone?

Yeah it did help, it kept me going at it, (the old lateral thinking). I'll get pics after I get dowels made up for the crown wheel bolts, (probably not till after I get back from Japan, bit over a month or so). I'll lay the parts out before I do the assembly and take pics, so its clear exactly what's to be done.
You can drift with these diffs, its just that after about 20 minutes, the viscous fluid heats up to much and you are running on an 'open' from then.
You have to go and park up somewhere and let it cool down.
From what I have determined the VLSD is good in a temp range. Not warmed up enough = not locking enough. To hot - no lock!
PL swears by these things as a good compromise for daily driving.
To be honest I got it just because I'm a cheapass, and it was cheap!

Only 2 possible issues I can see that may come into effect some time in the future:

1. Because I had to machine down the CV shaft slightly to fit the smaller inside diameter GtiR spider, this could be a slight weak point on very hipo applications over time.

2. Its an R180 not an R200, so won't be as strong again on very hipo applications, keeping in mind also that these diffs are from AWD cars, where the power is distributed, (40% to front, 60% to the rear), so they wouldn't get as much punishment.

BUT in saying all that, here at least, the diffs seem to be relatively cheap here,(I did get some bullshit prices from w%#ka import places, (like $500 just for a centre, as opposed to the $275 I paid for a complete diff and inside CV's), when ringing around initially to other areas of Australia, what a joke!) and I think you'd have to be getting pretty up there in power IF these issues were to come into play. And hey I might just go and get another centre later and chuck it in the shed somewhere as a spare.

It sounds like it'll be sufficient for almost all aplications, very few road going cars can handle being flogged on a drift track or circuit for long enough that the VLSD will break down i think, your engine cooling (esp in an oz summer) will probably limit your track time more than the diff.

so this is useless or ok for drift? (obviously not as good as a clutch type or weld but still can be used right?)

Alot of S13 drivers drift on a viscous but many of them change later and never go back, i'd say yes it's possible no it's not the best yes it's better than a open diff. Tsuchiya Keiichi reckons a viscous is shite and should be replaced with a clutch pack ASAP tho. Demonstrates by doing doughnuts in a clutch pack then attempting in a viscous. Mutch open wheeling to be had by the viscous when it's pushed hard.

yeah the viscous is good for a daily driven, non competition drifted car, and its certainly better than an open wheeler.

keep it up Gerry, i am keen for a hybrid for my daily driven S12......might have a spare locker for drift days!

Thats me done