A Differential Situation (Kinda long, but has Pics!)

[TanDaMan99]

Ok, well, the situation begins when I recieve a Z32 N/A (VLSD) Diff as a gift. Great, I've read the posts, dimensions are same; just slap on some 240sx VLSD outputs and its funtime. The thing is, outputs are expensive, So...I look around on ebay, and see a J30 (VLSD) Diff for cheap (kinda; little over $200) and it's got the 6 bolt outputs. I know the diff is also pretty much plug and play except with an extra inch that doesnt cause any issues. So I figure they're the same outputs as the 240sx VLSD outputs (which i found out i was wrong, maybe) so i'll just throw them on the Z32 Diff. Seller says he autocrosses with it so it may be tired, thats ok, i only really need the outputsI get the J30 diff. Pop out the outputs, tap them into the Z32 and i get this:The longer output wont fit/go in all the way. After wailing on it for too long, I know something is up. I think maybe it's too long. I'm pretty sure now that the J30 output is different than the 240sx VLSD output that would make this plug and play. The shaft is slightly longer than the 5-bolt that was on it:I decide to open it up, see if there's maybe something else stupid going on. I also open of the J30 diff for comparison. First thing i notice, it may be nothing, but the J30 Diff doesnt have the washer that bounces around in the center of the VLSD, whatever. I open them up, blow through a few cans of brake cleaner get everything shiny in the Z32 diff. Nothing weird was in ther so i reassemble. While reassembling I had the side bearing spacer and both side bearing adjuster washers in place in the diff. When i was about to drop in the diff the spacers and washers fell off the seat and they got all mixed up.Now I know it was stupid BUT this was a critical step to my findings. It sucked but i have the J30 diff for reference so no big deal. I put it back the way it was on the J30 Diff, popped in BOTH 6 bolt outputs and BINGO! PERFECT fit. BUT, now the lash to and from the drive pinion to the ring gear is INSANE. This cant be from just switching the adjustment washers around. I'm talking 10mm of play, i'm hearing metal hitting metal when i turn it back and forth.I take it all apart again, and move the Side Bearing Spacer to the OTHER side of the VLSD unit; OPPOSITE to that of the J30 Diff. I put it all together and almost ZERO lash, good. I tap in the outputs and the long one STILL sticks out. I make the connection:The shaft sticks out almost as far as the thickness of the spacer. When the spacer was on the "wrong" side, the J30 6 bolt outputs fit perfectly.I confirm from the service manuals.

The Z32 NA Diff has the spacer behind the ring gear (circled in yellow):

The J30 Diff has the spacer in front (circled in yellow):

I also notice that the J30's ring gear is alot thicker, to compensat for the spacer being on the ring gear side:

NOW, What I'm wondering is; what are my options?

Possible options:

Opt 1.I shim the J30 VLSD slap it in the J30 diff in the car and just have the Z32's VLSD as a backup. Thing is, i really dont want to do this. The Z32's i know is in great condition that spent most of its life sitting around looking pretty.

Opt 2.Swapp the ring gear and pinion gear from the J30 into the Z32 diff. Thing is, the pinion gear looks like a b*tch to get off and properly install. My impact can barely get the ring gear off. Would it be possible to just swap over the ring gear only? The difference in final drive size says no but maybe they DO use the same pinion gear.

Opt 3.Cutting the longer output shaft, just a bit. Is that even an option? Can bad things happen from that? Will that even work?

If you've read the whole thing, way to go. Any input or suggestions would be appreciated. Thanks.

[thrasherx89]

that looks like a lot of trouble...

shim the j30 and slap it in

[1KleenS13]

The only thing I can tell you is Option 2 is not an option. Ring and pinions start to wear together and its not advised to swap a ring without the pinion. I would try to get the spacers back in the right order so the backlash is correct.

[OutToWinPAHC]

Hmm I dunno, seems off. I have a hybrid rear myself, dont go too nuts on it, you buy a clutch type for not much.

[TanDaMan99]

Ok, Well, Thank you for all your input; appreciated. I ended up taking the vlsd unit from the z32 diff and putting that into the j30 diff and shimming it. I'm not sure what I'm not seeing and how other's with the Z32 diff and 240SX outputs are doing it but I guess I'll just keep an eye out for some missing information.I just finished stalling the diff last night. Its fun and feels great but has augmented my slipping clutch problem. And has also lead to the following post:

zer...-much