Its about darn time some one made a Subaru viscous lsd work!

KamodoDragon · Post by **KamodoDragon** » 17 Dec 2005 07:06

Well its 6:27 Saturday morning and Ive been up for and hour and a half working on a new project. Im still proceeding with the control arms and tc rods but lack of a welder is making progress difficult. Anyway, I couldnt sleep at all so I decided to see once and for all if a late model Subaru lsd with plug in axles could be made to work in a 510 without custom cv axles. So I took one part busted up datsun r160 and one part very good condition wrx r160 viscous lsd and got to work. on the outside there is very little difference other that the stub axles and some dirt/oil. I started by removing the stubs from the 510 r160 and checking fit in the wrx one. Turns out the the slide in and engage the splines just as they should, ant the dust seals/covers are exactly the same. So next I measured the distance in to the c-clip and made sure it would come up far enough to hold the stubs in. At first It looked a little questionable but after researching factory Subaru axles, it looked ok. I then took the stub over to my handy 10" south bend lathe an made myself some nice c-clip groves. This was not as easy as it would have seemed as they super hardened rolled splines. I also have to use the bolt that holds the 510 stub in with a nut on the back side to keep oil from exiting out the holes they occupy. Once that was done I test fit the stub in the wrx diff and presto, it worked. It took a good pry with a bar to get them out just like they are supposed to. The last step is to switch the input shaft flange as the bolt pattern is wrong. The only down side to this is my wrx diff is from a manual trans and the ratio is 3.55:1. Not terrible, but a step in the wrong direction for an L20/5speed. The good news though is that automatic wrx came with a 4.11:1 for thoughts interested. Some people my question the amount of material between the c-clip grove and the end of the shaft, but after cutting the grove and having to re-sharpen the tool 4 times because it was wearing down almost as fast as the axle was being cut, I think that the c-clip would brake long before the end of the shaft. As always let me know what you guys think.

KamodoDragon · Post by **KamodoDragon** » 17 Dec 2005 07:08

more pics

KamodoDragon · Post by **KamodoDragon** » 17 Dec 2005 08:24

Here are pictures of the completed stub axles ready for installation.

Post by **Byron510** » 17 Dec 2005 09:50

Good job!
Having never once removed the front flange off of any diff, was it difficult? And does this effect the shimming and preload setting on the pinion gear, there for affecting the gear set up and wear on the pinion? If you have photos of this, let us know. Thanks for sharing this with us. I guess no auto subi diff is safe now!!
Byron

KamodoDragon · Post by **KamodoDragon** » 17 Dec 2005 10:48

The front flange off of the old 510 dif was a PITA, but nothing a gear puller and a hammer could not fix. The suby diff came right off. I didnt get pics of the two off but I have another Datsun r160 I could pull apart to get a side by side comparison. The only difference I could find was the flange bolt patern. Once it was bolted up everything was snug and as it should be. I just got back from a test drive with the new set up and was pleasantly surprised with the taller gearing. With a dogleg 5 speed it makes the gearing more usable and not so short. The car dosent feel any slower but it drives much better with a bit lower revs in 4th and 5th. The lsd is no clutch pack though, and it takes some warming up to get it to work properly in the dry. I suspect that this wouldnt be a problem in the wet however, and it is still loads better than an open diff. Overall it was much easier that I had anticipated and wil work nicely until I can source a good clutch lsd.

Post by **510rob** » 17 Dec 2005 12:45

nice job.

it's funny that a differential out of a brand-new hot-rod car can (more or less) drop into an old Datsun from the late 1960's!!!

vgwagon · Post by **vgwagon** » 17 Dec 2005 16:21

or vice-versa

ajen68510 · Post by **ajen68510** » 18 Dec 2005 09:33

510rob wrote:nice job.

it's funny that a differential out of a brand-new hot-rod car can (more or less) drop into an old Datsun from the late 1960's!!!

ahh, but are they not made by the same company ? The procedure above was pretty much the same as swapping a Suby 3.70 to a 510. amazing that the design had not changed.

BanzaiDime · Post by **BanzaiDime** » 18 Dec 2005 09:55

why change a good design? 30 years later and it still works, it amazes me sometimes how these 510s perform

KamodoDragon · Post by **KamodoDragon** » 31 Dec 2005 19:15

Well Im back after a nice Christmas vacation down in AZ. I have a few interested people up I know im vlsd stub axles, so I put together a more user friendly package. I made a tapered nut to hold the center bolt in and make installing them easier. With out it it is a PITA to get the c-clip to expand and let the axle slid in place. I also polish the seal surfaces nice a smooth just like new. I will be selling these at $60 a set if any one is interested. The benefits over a vlsd are two fold. First they are cheaper, legacy one can be had for as little as $100. Second it opens up the door to using a really nice lsd like a cusco or kazz without custom half shafts. E-mail me if you are interested.
Brad

Five10packs · Post by **Five10packs** » 17 Jan 2006 12:24

I don't know if you fitted the 510 front flange on yet, but you need to grind off the dust shield to make it fit, or else it pushes on the front oil seal and you get a nice leak. Something I ran into for my vlsd

datsunfreak · Post by **datsunfreak** » 17 Jan 2006 20:29

One more myth busted I guess...

Would you say you've driven it hard enough to test your theory? No slippage of the shafts yet?

Green_Bastard · Post by **Green_Bastard** » 17 Jan 2006 21:04

Awesome Idea Kamodo.

Now if I would have known this when I had my drive shaft shortened, I could have just used a Subbie flange on the rear of the drive shaft. Wait, that might have been pre USDM WRX..

Questions, for 60 bucks would we have to supply cores to you? And have you beat the hell out if them yet?

Also,I like your past rides, I have 2 GVR4's.

Fast510 · Post by **Fast510** » 19 Jan 2006 12:52

very cool that you are checking into this, but are you sure the LSD is working? When I looked at using a Subaru SVX differential one of the CV flanges that wen't into the differential was much longer than the other to engauge the LSD carrier. Without that special flange the LSD wouldn't work, it would only work as an open differential. Easy to put the 510 flanges on it, but then you only have an expensive open differential not a LSD. Did I miss something? I would really like to be able to use a Subaru SVX differential as they are R180's with the 3.54 gearing for my VG. The 3.7 Subaru clutch pack I have now is nice but it makes 1st gear too short, most times I just start out in 2nd unless I want to light'em up

Five10packs · Post by **Five10packs** » 21 Jan 2006 13:02

That is cool, but for the normal guy , that is a lot to modify for a VLSD.