Do I have LSD?

Another thread got me to thinking...

When I do a burnout and leave some rubber layin down...I leave two lines of it...isn't it usually just one line with FWD? Is it possible I have LSD? or am I just confusing LSD with something else?

I responded in the other thread but if you are laying down two strips then you most likely have either a LSD or a LSD type insert.

hmm so that means I get better launches and possibly a faster ET than an SL w/o it then?

Well a better 60' will equal better 1/4 mile sop yes its possible if you can drive right.

Is it possible I have LSD?

if you do, could you hook a brotha up?

Is one line longer than the other? I doubt you would have an LSD without knowing it.

In another thread he did say he bought the tranny off ebay and ever since he swapped from ATX to MTX he hasnt had torque steer.

Yeah I saw that last night, and was going to edit my post, but then this forum stopped working and I couldnt.

you know... now that I think a/b it... I've gotta get my tranny rebuilt... I'm gonna get a LSD thrown in while they're rebuilding it...

dont make fun but whats ATM MTX trannies or tanny fluid ?

check out the fluids page on 3sxperformance.com ... they offer suggestions, and have many other things to offer than just the fluids... NC's finally got something to offer to me...

dont make fun but whats ATM MTX trannies or tanny fluid ?

ATX, automatic transmission, MTX manual transmission, and transmission fluid... some people shorten transmission by saying tranny...

my car does the same, two long strips of rubber and a heck of alot of smoke and i know i have the LSD cause i have the original sticker from when it was new

I get two strips... one much longer than the other... and if I spin going around a corner... the car jerks and sometimes wants to die... I know I don't have one...

My car lays equal strips from both tires as well hmmmmmm i always thought the SL had a lsd

hmmm so do I have it or not? lol

It never occured to me that I didn't have any torque steer anymore until that other guy's question came up yesterday.

And whats this about SL's having LSD? was it a factory option?

most likely you don't have an LSD. if you did, then the previous owner would have most likely mentioned it. you're probably just used to the torque steer by now...OR you drive/launch your car in a way that doesn't produce/keeps to a minimum the torque steer.

i should have my tranny+LSD back together and up and running in a few days. i'll let you know what kind of difference i feel from the stock diff.

Oh i didn't mention in this thread, I had bought a tranny off Ebay when i did the swap..and I think it might have had it in it.

interesting! there's definitely that possibility. surprised that IF there is a LSD in the tranny, the e-bay seller didn't notify you. but also, perhaps it was from a car in which he had no information about.

i'm trying to think if there's a definitive way of telling whether or not you have a LSD..... After looking at pictures, figuring the orientation of the LSD, think you'd just have to take apart the tranny to find out. even if you removed one of the half-shafts, you still couldn't see anything definitive b/c the LSD sits perpendicular to the half shafts. BUT you might be able to see a small edge of the LSD through the half-shaft opening. i'll take a look.

ok...i did some looking, and i can actually see part of my LSD insert inside the differential in the tranny. basically, both half-shafts go into the differential and the teeth (splines) on the half-shafts slide snuggly into the teeth (splines) of the differential. between the splines of the diff. is the LSD insert and a large differential roll pin slides through the middle of it all, holding the LSD insert in.

i would actually have to take a picture for you of the view i had, but since i don't have a digital camera right now, i'll try my best to explain what you're looking for with pics from other websites.

here's what the MTX looks like with the case remove. you can see the differential.
http://files.automotiveforums.com/gallery/watermark.php?file=/500/1238941_mtx-diff.JPG

here's is the LSD insert. it is taken apart. but picture a large roll pin (in blue) going through the center. the other half of the LSD insert would be on top of the red springs.
http://files.automotiveforums.com/gallery/watermark.php?file=/503/1238942_diff_pin.JPG

here is the stock differential removed from the tranny case. you have to remove the huge ring gear on the right to get the roll pin out.
http://files.automotiveforums.com/gallery/watermark.php?file=/503/1238943_diff_removed.JPG

here is a side view of the differential with the ring gear removed. see the roll pin that must be removed first. once removed, the LSD insert can be put in, adn the roll pin back through the diff+LSD insert. in this picture, the LSD insert has already been put in, adn roll pin back in.
http://files.automotiveforums.com/gallery/watermark.php?file=/503/1238944_diff_removed_upclose-med.JPG

and finally here is a better view of the LSD insert inside the stock differential. the springs inside the differential (very powerful, rated at 1200# i think) push the metal LSD insert against the worm gears. this pushing against the worm gears causes equal output transfered to both half-shaft...thus equal traction to both wheels (both tires spin at same rates).
http://files.automotiveforums.com/gallery/watermark.php?file=/503/1238945_diff_up_close_2.JPG


---------------SO, when you remove one of the half-shafts, you'll see a ring of splines in the differential, and then you'll see a bit of metal surrounding the differential roll pin. this metal surrounding the diff. pin between the ringed splines is the LSD insert. IF YOU HAVE A LSD INSERT, then you will see the metal around the diff pin. otherwise, you'll just see the ringed splines and a diff. pin.

you asked about a LSD. there are two categories, 3 or so options for the 3/S tranny.

1. true LSD (replaces entire stock diff.)

a. Kormex,Quaife LSD
b. helical LSD

2. LSD insert (simply goes in the middle of the stock differential, creating the same effect as a true LSD)

i purchased the LSD insert from speedfreakracing.net for $199 in a group buy (regular price is $229). This was less costly than a $800+ true LSD!!!

Can't ask for a better explanation than that one, geez thanks! But I don't think i'll be removing half-shafts anytime soon. I've dropped that tranny 4 times in the past year and a half...i'm tired of doing anything to it, so I won't if I don't have to lol.

where'd you find those pics?... I would like to see the internals of the f5m33 a bit more... I'm interested in what a complete rebuild would involve...

having taken mine apart, its actually quite simple. i got most of the pics from here: http://bmtranny.escic.com/ . i found that to be the most helpful description. but this site (http://www.vfaq.com/index-main.html) is where i located all the write-ups on transmission rebuilds, and such. just click on Drivetrain, scroll down to Manual Transmission.

could you tell me the difference between Helical LSD, and Quaife...?
just name brands, or different in function?

having taken mine apart, its actually quite simple. i got most of the pics from here: http://bmtranny.escic.com/ . i found that to be the most helpful description. but this site (http://www.vfaq.com/index-main.html) is where i located all the write-ups on transmission rebuilds, and such. just click on Drivetrain, scroll down to Manual Transmission.

Do you mean that a rebuild was easy, or that taking it apart/putting in the LSD was easy?

could you tell me the difference between Helical LSD, and Quaife...?
just name brands, or different in function?

here's a description of the the helical LSD (http://www.speedfreakracing.net/catalog/product_info.php?cPath=43_44_24&products_id=439). not entirely sure about the difference from a regular LSD, but it seems that the latter is a clutch-type operation, whereas the former has some kind of ingenious torque-sensing design. practically put, the helical is claimed to operate more smoothly, and i believe is a new design.

Do you mean that a rebuild was easy, or that taking it apart/putting in the LSD was easy?

taking it apart/putting in LSD was easy. however, as i examined the entire system, it appears much less complicated than people make them out to be. now ATX are quite complicated with the planetary gear set, park, reverse, etc.... whereas an MTX simply has a few forward gears and one reverse gear.

now you say your tranny needs a REBUILD?? why not just take it apart and see what parts (gears, shift forks, etc, etc) are damaged and replace those parts? granted, its nice to be on the safe side and replace everything, but basically the MTX is a much simpler design than the ATX. that's why i claim it would be rather easy to rebuild yourself. ask around 3si.org...i think several guys have taught themselves to rebuild their own trannies. Alan92rttt comes to mind.

yeah, I've looked around those websites posted earlier... I'm actually gonna attempt to do it myself next week... I may even fix my Toyota Corolla... I'm pretty sure it has a couple of bad sychros and a broken shift fork (stuck in 3rd gear, but an excellent car)... Thanks...

read this to find out about different types of limited slip differentials: http://auto.howstuffworks.com/differential1.htm

I'm pretty sure it has a couple of bad sychros and a broken shift fork (stuck in 3rd gear, but an excellent car)... Thanks...

stuck in 3rd gear? is it a manual or auto? (assuming manual by your description).

yes, it is a manual... I don't know if you know anything a/b the Corollas... but it's got the toyota 4AFE engine with the C50 (I think, can't member, haven't driven since Jan... it broke)... 5 speed transmission, I was told that a bearing on the end of one of the shafts wore down and made it kick out of fifth... then on the way to work one day, the transmission seized in third... the car still drives.. but the clutch will burn up, and even with the car off, it will not come out of third... looking at it the other day, the master cylinder is leaking... and the slave cylinder boot was cracked and leaking as well... oh well, I could still pull it apart...

Well I did a little testing for LSD today. Now I don't think I have it.

First I took off from a stop w/o spinning wheels and w/o touching the steering wheel but flooring it, and it went perfectly straight.

So I tried a 45 mph 2nd gear launch w/o touching the wheel, and it still went straight...so that made me happy.

But then I tried a 15 mph 1st gear launch w/o holding the wheel and the steering wheel jerked right a little bit....so I think that determines I don't have it....I just wonder why I have so little torque steer now as compared to ATX?

Don't confuse the 2 concepts... Torque steer is present in almost all FWD cars... It's because the driveshafts to each wheel is not the same length and therefore the engine is more efficent to driving one of the sides then the other (the driveshaft torque builds faster on the short side then the long side).

So almost all FWD cars will jerk to one side when torque is abruptly applied.

The LSD is there to make sure that some torque will be applied to both wheels even if one is free spinning. This means that the the car can still jerk to one side because one wheel can still have more torque then the other wheel but some power will still be transfered to the non-spinning wheel.

I you don't trust me... Take an old RWD truck with an open diff and see if you can get torque steer on it. You will see one wheel spin if it looses traction but the truck will not jerk to one side.

you guys are making this waaaaay to complicated... all you have to do is jack up the front end and kick one of the wheels to see if it moves... if both wheels move than you have some form of an LSD... if only one moves, than you don't... simple as that.

well on every car if you move one wheel the other will move...i thought it depended on the direction the other wheel moves.

But i dont know what means what...i vaguely remember learning about it but i cant remember if when you have lsd the other wheel goes the same direction or the opposite.

well whats a test I can do to be absolutely sure then?

the test i described where you pull one of the half-shafts out...that's a fool-proof test. but unless you're dropping the transmission, its not very practical.

well try moving the wheels both ways I guess, but I mean, if you can move one wheel and the other doesn't move that means you don't have an LSD, but if both do move than you do;

on my z, I was working on the brakes, and I took some sand paper to the rotor to get some of the rust off, and when I moved the one wheel, the other one didn't move; I have an open rear end/no LSD, so I think the result might be the same for you if you don't have an LSD... just my two cents tho, maybe I'm wrong...

with an open, I b/l the way that differential is... (car jacked up) you can spin one wheel a little and nothing should happen, but if something is to happen, then the other wheel should spin opposite...

not to ressurect a dead thread... but I got tires on my car the other day... while it was on the lift... I kicked the left wheel (I have an open diff).... the right wheel began spinning backwards... I tried it from both sides...

when i got the transmission in and both half-shafts in, i spun one side forward, and the other side spun the same direction!

looks like we're on to something here!

Awesome... so the solution is, open differential- the wheels spin opposite... LSD- the wheels spin the same...

Awesome... so the solution is, open differential- the wheels spin opposite... LSD- the wheels spin the same...

i THINK so. i would do a bit more research before i put my life on it.

well, I wouldn't swear to it... but it kinda makes sense... and I was told that if the car had an LSD it was safe to tow it drive wheels down

well, I wouldn't swear to it... but it kinda makes sense... and I was told that if the car had an LSD it was safe to tow it drive wheels down

true, it does make sense.

can't you tow ANY car drive wheels down, provided the car is in neutral?

I was told not to... b/c that messes up the tranny (I b/l it has something to do with the differential, that's why I said that)

but if the transmission is in neutral, then nothing adverse should happen. for example, say you're cruising down the highway and suddenly you randomly (for the purpose of testing your differential) decide just to slip it into neutral? i've done this many times on autos and manuals. NOTHING happens. the car continues to roll forward. despite what people 'hear' or what they are 'told', most of the time it doesn't have much to back it up in principle or theory.

i'm almost 100% positive that towing a car that's in neutral on its drive wheels is perfectly fine.

I just heard that on the open differential, the way one wheel spins one way, the other opposite will damage something... I don't recall exactly how it works... but when the worm gears connected to the engine spin... it causes both wheels to spin one way... but power applied to one side of the differential (i.e. spinning one wheel) causes it to spin opposites... IDK ... just a speculation

but if the transmission is in neutral, then nothing adverse should happen. for example, say you're cruising down the highway and suddenly you randomly (for the purpose of testing your differential) decide just to slip it into neutral? i've done this many times on autos and manuals. NOTHING happens. the car continues to roll forward. despite what people 'hear' or what they are 'told', most of the time it doesn't have much to back it up in principle or theory.

i'm almost 100% positive that towing a car that's in neutral on its drive wheels is perfectly fine.

towing a car in nuetral is fine for MXT cars, it is bad for ATX cars. It heats up the fluid, but the engine isnt spinning so there is no way for the fluid to be cooled down. 4X4 vehicles with a selectable transfercase get away with it by putting the tcase in N.

Awesome... so the solution is, open differential- the wheels spin opposite... LSD- the wheels spin the same...

correct

ok, yeah... now that I think a/b it... the guys I was talkign to were talking about ATX cars... as well as full-time AWD vehicles...