LSD identification

Started by street_ruler · Oct 5, 2005 · 32postsSMF 2010–26

street_rulerOct 5, 2005, 3:48 am · #1

so the z31 rear lsd fits to my knowledge right?

how does one identify one of these diffs from the outside? or what does it look like when looking at the gears? i know with FWD hondas its a bar that runs across the opening for the axels.

street_rulerOct 7, 2005, 4:55 pm · #2

not a single person knows....geeze

ravenS13.5Oct 7, 2005, 8:20 pm · #3

I`m not familiar with z31 lsd`s, but usually just jack the back end of the car up and give the driveshaft a twist. both wheels may spin the same dirrection but stop one and see if the other stops too. Then hold one wheel and try to spin the other , if lsd, then the wheel in your hand will try to break free, if not the wheel will either try to go backwards or not spin at all. That is just one way to see.

street_rulerOct 7, 2005, 8:46 pm · #4

i was hoping for soemthing more concise...like...take off the rear diff cover and look for \"this\" or something...some times tehy dont take care of these things like they should at a bone yard.

Cavi MikeOct 7, 2005, 8:48 pm · #5

Well if you can\'t tell from taking the dif cover off you are one blind mo-fo!

These are ways to tell withOUT disassembling anything.

street_rulerOct 7, 2005, 9:35 pm · #6

this is the first rwd car i have dealt with...so not a \"blind mo-fo\" just never seen one...hows that strike you

bartc_jOct 7, 2005, 9:43 pm · #7

the rear cover should have heat sinks built into the cover whereas open diffs dont..plus there usually is suppoosed to be a lsd tag on the diff itself

VEGIEOct 9, 2005, 8:52 am · #8

i dont know where the finned cover and id tag thing keeps coming from, but i am yet to see a lsd that does!

there is no real easy way to identify an lsd externally from what ive found, and even the internals of the diffheads vary quite a bit too, both lsd\'s and non lsd\'s.

youre best bet is to remove the rear cover...

Nicholas S12Oct 10, 2005, 5:54 am · #9

I`m not familiar with z31 lsd`s, but usually just jack the back end of the car up and give the driveshaft a twist. both wheels may spin the same dirrection but stop one and see if the other stops too. Then hold one wheel and try to spin the other , if lsd, then the wheel in your hand will try to break free, if not the wheel will either try to go backwards or not spin at all. That is just one way to see.

What will be the selection into the gearbox: neutral or 1st gear?

street_rulerOct 10, 2005, 6:42 am · #10

from my personal expierence with FWD...in gear or out of gear.

Cavi MikeOct 10, 2005, 7:52 am · #11

If you even have the slightest idea of how a LSD works, you will be able to tell by taking the cover off.

street_rulerOct 11, 2005, 6:45 am · #12

see thats just it...i ahve never seen a RWD LSD before in my entire life.

hey CAVI, you ahve yet to contribute anything posotive to this thread, so why bother?

bartc_jOct 11, 2005, 7:02 am · #13

ok guys lets cool it.. no need for this bickering.....first and last warning

VEGIEOct 11, 2005, 7:57 am · #14

it should look something like this....
posted image

IndecisiveOct 11, 2005, 4:36 pm · #15

sorry, this is a bit OT. why would a FWD lsd differ from a RWD lsd? aren\'t diffs of the same design(generally speaking of course) just mounted differently?

I\'ve yet to see the fins on an LSD as well, but some cars do have them. There was a video of the history of skylines in the UK and they went under the car and showed the LSD and it had distinct heatsink fins on the rear diff cover.

bartc_jOct 11, 2005, 4:42 pm · #16

I\'ve yet to see the fins on an LSD as well, but some cars do have them. There was a video of the history of skylines in the UK and they went under the car and showed the LSD and it had distinct heatsink fins on the rear diff cover.

i guess then the z31 dont have them but i know all vlsd on s13\'s have them

IndecisiveOct 11, 2005, 8:31 pm · #17

I never said they didn\'t heh. I just never seen them before in real life. I haven\'t looked at many diffs before though.

street_rulerOct 12, 2005, 12:43 am · #18

well, im a honda guy...and on honda\'s the way to identify a LSD is to take out the axels and look through the hole. if its got nothing in there just a clear line of sight form one end to the otehr, its open diff. if its got a bar running tthrough the middle of it, then its and LSD. i thought RWD diff\'s were alot different being as how they are driven...(driveshaft is different and you can see it alot better) thats why the confusion.

sorry, this is a bit OT. why would a FWD lsd differ from a RWD lsd? aren\'t diffs of the same design(generally speaking of course) just mounted differently?

I\'ve yet to see the fins on an LSD as well, but some cars do have them. There was a video of the history of skylines in the UK and they went under the car and showed the LSD and it had distinct heatsink fins on the rear diff cover.

Nicholas S12Oct 12, 2005, 4:57 am · #19

My both Silvia got fins on differentials but only one has LSD according to previous owner. I tried and spin the rear wheels with gear in and both wheels spin the same direction. On the other side when I spin the wheels of my 1st Silvia only one wheel spin.

NebuchernezzerOct 12, 2005, 5:48 am · #20

My long nose R200 LSD has no external signs it\'s an LSD, normal rear cover and no tag. Oringally all mech LSDs will have a tag saying so on the outside so you use the right oil but 90% of them are no longer present. Viscous LSDs use normal diff oil so it won\'t have a tag. Jack the car up and spin the wheels, it\'s a good test. Do it in neutral cos if you do it in 1st and it\'s a LSD nothing will spin unless you can crank the engine over with your hands hehe.

weedeOct 16, 2005, 12:19 pm · #21

any one knows were i can find a explode drawing on a 88´ ca18et differential?

SilverBoxOct 17, 2005, 12:43 pm · #22

well ... decided to pull my finger out

should have it in about 6 weeks. considering it requires a custom bell housing and other such items to suit my VH45DE-T S12

2 speed powerglide
full manualised valve body
trans brake
custom convertor (looking like it will be a 3500 rpm stall)
and as above custom bell housing adapter

of course all other bits like big tranny cooler and pro ratchet shifter

Umai NaaOct 17, 2005, 12:52 pm · #23

you\'re really going all out on this aren\'t you??

well done. i look forward to seeing it finished.

SilverBoxOct 17, 2005, 12:56 pm · #24

yes well ...

i get silly ideas in my head and my wallet goes running after these silly ideas ... especially after i attend races and see gtr\'s winning ... i mean seriously ... a gtr winning ... its just not right! :-P

Umai NaaOct 17, 2005, 1:01 pm · #25

just coz our cars dont have a nickname like Godzilla!!

SilverBoxOct 17, 2005, 1:04 pm · #26

i thought the s12 nickname was zillakilla?

Cavi MikeOct 17, 2005, 1:16 pm · #27

2 speed? Never heard of that before.

Umai NaaOct 17, 2005, 2:53 pm · #28

silverbox, i\'ve heard that one before, but never in reference to the s12. but hey, why not??

Cavi, they\'re pretty common in the dragracing scene. very popular in aust. too.

vg30e_x2_200sxOct 17, 2005, 8:56 pm · #29

The powerglide transmission was the predicessor to the GM turbohydramatic 350. The powerglide was all GM had for an automatic trans back in the day. It was either that, a 3 speed manual, or a 4 speed manual.

The powerglide is well liked and used in drag racing fro a couple of reasons. It is just about the lightest auto you can get your hands on. It can be built to hande GOBBS of HP. And it has a very low enharent parasitic loss.

NemisisOct 17, 2005, 9:22 pm · #30

The powerglide transmission was the predicessor to the GM turbohydramatic 350. The powerglide was all GM had for an automatic trans back in the day. It was either that, a 3 speed manual, or a 4 speed manual.

The powerglide is well liked and used in drag racing fro a couple of reasons. It is just about the lightest auto you can get your hands on. It can be built to hande GOBBS of HP. And it has a very low enharent parasitic loss.

Actually there is also the Turbo 200 trans. (Its turbo 200, 350 and 400 The difference is the gearset, the 400 has beeafy gears and can handle loads of power and the 200 has wimpy gears) I know, I have a 200 trans. I\'ve also had a powerglide in my old daily driver. At 75mph the revs were just screamin (about 3500rpm from a 283ci small block) and is sucked gas like nobody\'s business...

SilverBoxOct 17, 2005, 11:38 pm · #31

The powerglide transmission was the predicessor to the GM turbohydramatic 350. The powerglide was all GM had for an automatic trans back in the day. It was either that, a 3 speed manual, or a 4 speed manual.

The powerglide is well liked and used in drag racing fro a couple of reasons. It is just about the lightest auto you can get your hands on. It can be built to hande GOBBS of HP. And it has a very low enharent parasitic loss.

yes i\'m still deciding whether to opt for the $300 extra 1600 hp waranty (beefier input shaft) ... or just go with the 1000 hp setup ... i think 1000 will be plenty

C4 will break. Turbo 350 will break.

The only real option was 2 speed power glide or turbo hydramatic 400 ...

The up side of the TH400 was the 3 speed ... but at a greater cost ...

Top gear is 1:1 so its just a matter of finding the correct diff gears ... probably 3.7\'s

Cavi MikeOct 17, 2005, 11:43 pm · #32

Ahhh, so this is old-school american-muscle parts we\'re talking about. Gotcha.