1973 Rebuild

[Patcon]

Good! They got there. I hope they work great for you... make small welds and let them cool completely or they will warp

[Matthew Abate]

Just bought my first choice 5-speed! Got one from a 1980 720 with the 3.592, 2.246, 1.415, 1, 0.882 ratios for $401 shipped to my house. Hopefully it won't be a pile of crap. Had to buy it on faith because it's in Idaho.

Very possibly an irresponsible gamble, but I felt lucky and brave at the same time at that moment.

[Matthew Abate]

Okay, now that I presumably have the trans question settled I have a differential question: why do people swap in the WRX STI differential and mess with the half shafts and axles rather than installing WRX STI internals into the r180 already in their car? I would assume the guts from one r180 would fit into another. Is it that the Nissan axles won't mate to the Subaru internals? Is it that doing that costs way more? I would think the guts from a Subaru dealer would be sub-$1,000, which is about what a used WRX STI dif + the custom parts costs. Plus, wouldn't doing it this way mean we could put any ring on to give us any ratio we can imagine?

[Patcon]

I am not sure, but just guessing, the ring gear may be drilled in a different pattern or it is easier to bolt in a complete rear end then move the parts to a new case and get the mess and gear lash setup properly. It is evidently somewhat difficult to get the preload right. Plus with used parts the mesh would have to be very close to the way the previous case was or you can have gear whine...

I would love to learn moving the ring and gear and chunk over from the STi case is possible as for me that seems easier. Another possibility is the output shafts from LSD chunk are splined differently than the factory outputs...

Edited March 28, 2016 by Patcon

[Matthew Abate]

I would love to learn moving the ring and gear and chunk over from the STi case is possible as for me that seems easier

I know! Please please let it be true that this is just a massive oversight and no one thought to look into it. I know there's little chance of that, but it would be a total game changer.

Who on this forum (or HybridZ) might have dug into both of these enough to know? I'm not seeing any threads that discuss this specifically.

/M

[Zed Head]

You can't even swap ring and pinion within the Nissan family, from old to newer -

" In addition to the bolt in axle issues, there is another difference between early and late R180s. Early R180's measure 110mm inside the ring gear. 77 and later model year R180s measure 115mm inside the ring gear. This minor change means that the ring and pinions won't swap between the early and later models. If you have an early diff you must use an early carrier, and if you have the later diff you must use a later carrier. It is possible to use a early carrier on a later ring gear with a spacer, but that is outside the scope of this thread. "

http://forums.hybridz.org/topic/49194-differential-cv-lsd-hp-torque-r160-r180-r200-r230-diff-mount/

Here's John C's first prototype shaft thread.  It has comments specific to the different spline count  - http://forums.hybridz.org/topic/78123-subaru-wrx-sti-r180-side-axles/

Here's one of the early Subaru diff swaps - http://forums.hybridz.org/topic/73182-subaru-sti-r180-differential-and-axle-conversion-revised/

[Zed Head]

Just to followup - almost everybody has looked for an easy, inexpensive way to get limited slip in their Z, R200's included.  Nothing has been found yet.  Numerous Franken-axles, adapters, and flange swap shave been devised and tried.  Even what looks like the most straight-forward and easy swap of an R200 from a 300ZX turbo has axle length problems.  Nobody has come up with the sub-$1000 LSD setup yet.

There is a guy on Hybridz though, who's helping a company develop an R200 LSD that should swap directly in to an R200 case and use R200 axles.  Unclear what they'll cost in the long run, but the first batch is going for $700.  Worth keeping track of.  Maybe you can talk him in to doing the same for the R180.  At least the invisible hand is doing its thing.

http://forums.hybridz.org/topic/121007-mfactory-r200-lsd/

[rossiz]

mr. smith would indeed smile upon the fruits of many attempts to solve this issue - sooner or later there has to arise a solution as long as the need persists. the question is how long must we wait, or do we join in the fray? the hellfire system and headlight cover rings come to mind...

[Matthew Abate]

A little piece every day.

And a little practice. Went too slow and warped the sh!t out of it, but penetration was good. Just need to work on my swirls and making bigger dimes.

[Patcon]

When you butt weld like that, or pretty much anytime for that matter, you have to do just little spot welds 1/4" or so long at a time. Space them out 6-8". You have to let it cool a lot between welds. If you can touch it, and it feel relatively cool, it's too hot. Sometimes I used compressed air to help it cool, but that may do more harm then good. If you weld too much at a time the panel will warp, especially on our thin Japanese tin

[CHL240Z]

Really enjoying the build thread.  Keep it going and please keep us all updated.

Clay

[Matthew Abate]

When you butt weld like that, or pretty much anytime for that matter, you have to do just little spot welds 1/4" or so long at a time. Space them out 6-8". You have to let it cool a lot between welds. If you can touch it, and it feel relatively cool, it's too hot. Sometimes I used compressed air to help it cool, but that may do more harm then good. If you weld too much at a time the panel will warp, especially on our thin Japanese tin

Yes. I spaced some of the advice I got from the guy who taught me how to use the welder, which included everything you said above. The other mistake I made was beveling the whole edge instead of leaving some material to actually create a butt joint, which explains why I burnt through it so much.

Gonna make a check list for next time.