diff help:::J30 vlsd internals inside S13 open diff pumpkin (yes searched, make sure)

[iRONDONkey]

I've read that people have done it successfully, but it clicks because the the gear needed to be swapped out.

So just to make sure....

the J30 VLSD internals WILL fit into the S13 pumpkin.

I have to-



use the same SPACERS that are in the open diff



I have to swap the j30 PINION GEAR into the S13 pumpkin

(((since the J30 already has the J30 ring gear on it, I just have to have the matching pinion for it)))




I have to swap over the 5 bolt output shafts on both side



I have to use the 5 bolt axles

Is this correct?




I don't want to end up like this guy-

http://zilvia.net/f/engine-tech/400212-300zx-diff-w-j30-half-shafts-does-not-fit.html


Also, has anyone had problems with their rear main seal using the j30 diff?



I have found that it puts extra force on it, wearing it down faster that it should.



Am I able to use the S13 open diff ring gear and install it onto the J30 VLSD itself? Then use the S13 open diff pinion gear, so I don't have the extra length?



I'd like to cruise at a higher speed-- roughly 60-80MPH-- at a lower RPM, which gearing should I go with?

[ghoti]

use the same SPACERS that are in the open diff



I have to swap the j30 PINION GEAR into the S13 pumpkin

(((since the J30 already has the J30 ring gear on it, I just have to have the matching pinion for it)))


YES



I have to swap over the 5 bolt output shafts on both side



I have to use the 5 bolt axles

Is this correct?


You have to use J30 output shafts because they have a different internal spline pattern compared to S13. You can keep 6bolt half shaft if you get a +95 j30


I don't want to end up like this guy-

http://zilvia.net/f/engine-tech/400212-300zx-diff-w-j30-half-shafts-does-not-fit.html



Just don't use half shafts from a Z32 or S13/S14 and you should be fine


Also, has anyone had problems with their rear main seal using the j30 diff?

I have found that it puts extra force on it, wearing it down faster that it should.


It puts extra stress on the rear main seal when you don't use an ABS driveshaft which is 3/4 of an inch shorter. That being said I ran mine with a non-abs driveshaft for 4 month and had no problem



Am I able to use the S13 open diff ring gear and install it onto the J30 VLSD itself? Then use the S13 open diff pinion gear, so I don't have the extra length?


don't know


I'd like to cruise at a higher speed-- roughly 60-80MPH-- at a lower RPM, which gearing should I go with?

The J30 final gear ratio will raise your RPM about 100-150 RPM higher crusing at 65 not much of a difference

[iRONDONkey]

i thought the j30 had a higher gear?

according to the calculator, at 2500rpm, i travel at 80mph with the J30 final drive.

with the stock s13 open diff final drive, at 2500rpm, it's roughly 75. 2800 rpm gets to 80mph.

[iRONDONkey]

im doing this to save myself 35-40 bucks from having to buy diff bushings on the J30. the stock ones broke off.

[iRONDONkey]

im doing this to save myself 35-40 bucks from having to buy diff bushings on the J30. the stock ones broke off.

[racepar1]

The ring gear on the J30 3.9 gears is much thicker than the S13 4.1 ring gear. You would have to use the shims from the J30 diff. Why don't you just use the whole J30 pumpkin and not swap anything but the cover? The J30 pumpkin bolts right in and if you get the right one it even has 6-bolt shafts. You can use the non-ABS driveshaft on an ABS diff. You just have to knock the metal dust shield off the back of the transmission. What you're describing doesn't make any sense. If you were going to try to use the J30 VLSD with the 240 ring and pinion then maybe it would make a little tiny bit of sense. But really for the amount of work to swap everything over, you're still wasting a lot of time for nothing.

[iRONDONkey]

to save myself 40 bucks, and i suppose i can shim it. I was using my current J30 pumpkin with the S13 cover, but the bushings are done for, and i dont feel like buying new ones. I have both diffs in my garage, i might as well spend the time to swap it over.

when you say i have to use the J30 shims, what part are you referring to?

what year S13's had abs?

[racepar1]

to save myself 40 bucks, and i suppose i can shim it. I was using my current J30 pumpkin with the S13 cover, but the bushings are done for, and i dont feel like buying new ones. I have both diffs in my garage, i might as well spend the time to swap it over.

when you say i have to use the J30 shims, what part are you referring to?

what year S13's had abs?

I am referring to the shims that go between the differential and the case, where the stub shafts pass through.

IF you're going to waste your time with this use the S13 ring/pinion and shims. At least then you'll have the correct gearing.

As for the bushings, just use some washers/spacers and jimmy-rig something up. You're going to spend hundreds of dollars worth of time just to save yourself a VERY miniscule amount of money. It does not make sense...

[racepar1]

what year S13's had abs?

ALL of them...


:picardfp:

[iRONDONkey]

I am referring to the shims that go between the differential and the case, where the stub shafts pass through.

IF you're going to waste your time with this use the S13 ring/pinion and shims. At least then you'll have the correct gearing.

As for the bushings, just use some washers/spacers and jimmy-rig something up. You're going to spend hundreds of dollars worth of time just to save yourself a VERY miniscule amount of money. It does not make sense...

so i have to use the J30 spacers inside the s13 pumpkin..?

are you sure?? the second poster stated that I will have to use my S13 diff spacers, not my J30. I'm trying to make sure, thus this thread. I was hoping someone had actual experience with this.

i'll be using the J30 ring and pinion.

I would use washers, but the rubber on the j30 diff pumpkin are completely destroyed. I would need for it to at least be in one piece where it doesn't move around and using washers would be effective.

it wont take me long to do the swap, i have power tools. i would rather spend a couple hours than to spend money on something i dont necessarily need.

ALL of them...


:picardfp:

mine didn't have abs.... ? I have the long driveshaft.

[KiLLeR2001]

so i have to use the J30 spacers inside the s13 pumpkin..?

are you sure?? the second poster stated that I will have to use my S13 diff spacers, not my J30. I'm trying to make sure, thus this thread. I was hoping someone had actual experience with this.

i'll be using the J30 ring and pinion.

I would use washers, but the rubber on the j30 diff pumpkin are completely destroyed. I would need for it to at least be in one piece where it doesn't move around and using washers would be effective.

it wont take me long to do the swap, i have power tools. i would rather spend a couple hours than to spend money on something i dont necessarily need.



mine didn't have abs.... ? I have the long driveshaft.

If you are going to use the J30 ring and pinion you will need to use the J30 spacers.

I swapped the 4.08 ring gear onto my J30 diff and kept the pinion gear in the s13 pumpkin in tact.

You can further view my build thread to see what I did entirely...

http://zilvia.net/f/builds-builds-only/378665-s13-5-daily-driver-build-thread.html#post4062641

[racepar1]

so i have to use the J30 spacers inside the s13 pumpkin..?

are you sure?? the second poster stated that I will have to use my S13 diff spacers, not my J30. I'm trying to make sure, thus this thread. I was hoping someone had actual experience with this.

i'll be using the J30 ring and pinion.

I would use washers, but the rubber on the j30 diff pumpkin are completely destroyed. I would need for it to at least be in one piece where it doesn't move around and using washers would be effective.

it wont take me long to do the swap, i have power tools. i would rather spend a couple hours than to spend money on something i dont necessarily need.

If you are using the J30 ring and pinion, use the J30 spacers

If you are using the S13 ring and pinion, use the S13 spacers.

The diffs ALL have the same dimensions, the spacers set the backlash/gear pattern on the ring and pinion. Since the S13 4.1 and the J30 3.9 ring gears have different dimensions you have to use the corresponding spacers.

If you have to ask all these questions I doubt that it won't take you long, no matter what tools you have.

mine didn't have abs.... ? I have the long driveshaft.

ABS was an OPTION on ALL years of S13. Yours doesn't have that OPTION.

This is like talking to a god damned wall...

[iRONDONkey]

If you are going to use the J30 ring and pinion you will need to use the J30 spacers.

I swapped the 4.08 ring gear onto my J30 diff and kept the pinion gear in the s13 pumpkin in tact.

You can further view my build thread to see what I did entirely...

http://zilvia.net/f/builds-builds-only/378665-s13-5-daily-driver-build-thread.html#post4062641

thanks.

i would like to keep the ring off the J30, but if the pinion itself wears my rear main seal faster... i would rather switch. higher MPH at a lower RPM to save me some gas is nice.

as for the output shafts, only the j30 6 bolt is longer?
i'll have to use my 5 bolts then. those are a direct clean fit, correct?

If you are using the J30 ring and pinion, use the J30 spacers

If you are using the S13 ring and pinion, use the S13 spacers.

The diffs ALL have the same dimensions, the spacers set the backlash/gear pattern on the ring and pinion. Since the S13 4.1 and the J30 3.9 ring gears have different dimensions you have to use the corresponding spacers.

If you have to ask all these questions I doubt that it won't take you long, no matter what tools you have.



ABS was an OPTION on ALL years of S13. Yours doesn't have that OPTION.

This is like talking to a god damned wall...

okay big guy.

good luck with you S chassis goals of 2010.

Lololol

[racepar1]

thanks.

i would like to keep the ring off the J30, but if the pinion itself wears my rear main seal faster... i would rather switch. higher MPH at a lower RPM to save me some gas is nice.

as for the output shafts, only the j30 6 bolt is longer?
i'll have to use my 5 bolts then. those are a direct clean fit, correct?

You CANNOT mix ring and pinion gears of different ratios. The gears will not mesh properly and your diff will be noisy and eventually destroy the ring and pinion. Use the J30 output shafts with the J30 diff and ring/pinion. The J30 shafts are different lengths because the centering of the differential is different due to the thicker 3.9 ring gear. I've done all this before, I'm the guy you want to talk to here.

okay big guy.

good luck with you S chassis goals of 2010.

Lololol

I'm in here spoonfeeding you all the information you request. You ought to show some respect to the people who are helping you. If you listen to me and check your little attitude it'll all be okay. Without me in this thread you would still be completely lost. I've handed you everything you asked for on a silver platter. Excuse me if you made me say the same exact thing multiple times and I got a bit exasperated.

[iRONDONkey]

yeah.. i'm going by what that poster did.

install his open diff ring onto his VLSD, and used his stock pinion, because he's using a s13 pumpkin.

[racepar1]

yeah.. i'm going by what that poster did.

install his open diff ring onto his VLSD, and used his stock pinion, because he's using a s13 pumpkin.

Good luck...

:hide:

[ShadowDrifter]

just put the full set up in j30 diff with axels and be done with it.

[ghoti]

i thought the j30 had a higher gear?

according to the calculator, at 2500rpm, i travel at 80mph with the J30 final drive

It does at 2750 I'm doing 80

[jubee]

I don't understand why not just get a six bolt j30 diff switch covers and be done. Just seems like your making this harder then what it is.