used supra lsd... what to do before install?
12-09-05, 07:26 PM
#16
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Originally Posted by rominl
umm i don't have a pic myself
install? 2 hrs should be enough, if they know what to do
install? 2 hrs should be enough, if they know what to do
https://www.clublexus.com/forums/sho...ight=supra+lsd
is this the worm gear you are referring to?
12-09-05, 07:31 PM
#18
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were there different casings over the years? as i was searching for info i found this pic of a new supra tt lsd:
and this is BA_GS400's unit, who bought from synco357 also:
this was taken from one of TLW's old threads:
gs diff on the left, supra lsd on the right.
they all look different... what am i missing here?
and this is BA_GS400's unit, who bought from synco357 also:
this was taken from one of TLW's old threads:
gs diff on the left, supra lsd on the right.
they all look different... what am i missing here?
Last edited by Benjamin T; 12-09-05 at 07:51 PM.
12-09-05, 08:15 PM
#19
The only way to tell if it's a supra lsd is to open up the unit and look inside. Take it to a professional if you don't know what you are doing.
One of the signs that it is a stock supra lsd unit is if it has the cooling fins on the pumpkin as in TLW's picture. Unfortunately, this isn't always reliable because some previous owner could have removed the lsd like in my case. On the other hand, it gave me a great reason to buy the TRD LSD.
One of the signs that it is a stock supra lsd unit is if it has the cooling fins on the pumpkin as in TLW's picture. Unfortunately, this isn't always reliable because some previous owner could have removed the lsd like in my case. On the other hand, it gave me a great reason to buy the TRD LSD.
12-09-05, 09:11 PM
#20
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as you can see from the pics, the one i have has no cooling fins whatsover. it looks identical to the GS diff on the left in TLW's picture.
i'm now worried
.. i've pm'd synco357 about this and i'm waiting for a response back.
the mechanic i was hoping to go to is gone on holidays for the next 2 weeks. i think i better bring it in to the dealer tomorrow and ask for help.
i'm now worried
.. i've pm'd synco357 about this and i'm waiting for a response back.the mechanic i was hoping to go to is gone on holidays for the next 2 weeks. i think i better bring it in to the dealer tomorrow and ask for help.
12-09-05, 10:31 PM
#21
wait that's NOT a lsd unit as far as i know!!!!!!!
the lsd unit has fins on the housing coz' it's a lot hotter than the normal rear end. all the supra auto rear end i have seen so far with lsd have those fins. the unit you have there doesn't....
i would be very skeptical about what you got there (unless they mysteriously changed the housing for whatever reason)
btw, yes, the gear in the pic (right one) is the worm gear
the lsd unit has fins on the housing coz' it's a lot hotter than the normal rear end. all the supra auto rear end i have seen so far with lsd have those fins. the unit you have there doesn't....
i would be very skeptical about what you got there (unless they mysteriously changed the housing for whatever reason)
btw, yes, the gear in the pic (right one) is the worm gear
12-09-05, 10:38 PM
#22
I got your PM Benj.
I am NOT a Supra parts expert, but, as I look at your pictures here are my thoughts.
1. your rear end CASE looks a hell of a lot like TLW's stock casing in his picture.
2. I DO think you should replace that bushing......that picture on the 2nd page of this thread is better than the first one. And as you know, you if you do one bushing, you may as well do both!
3. It's POSSIBLE that you could have a supra 'posi' (yeah, i own a chevy) inside of that case. So, don't get too worried yet. (I'm thinking of how Chevy and Ford rearends are built where the actual posi unit is interchangeable inside of the casing)
4. You should figure out what gear ratio is in there. If it were 3.23, it would have more odds of being a non-posi,....if it's 3.76 then there's a better chance it's a posi.
You can do this by counting how many "drive-shaft" rotations it takes to make one axle side turn 1 revolution.
5. I don't see the leak you're concerned about. It's not that little bit on the fins of the rear cover is it? I dont' think that's a leak,..just vapors. Perhaps it was over-filled?
6. Regarding which side is up, the rear end cover's breather should point up.
I'd like ROMINI's input on this one, but, on OTHER rearends, when you rotate one axle side, if the other end turns the opposite direction and cannot be held in position, then you've confirmed a 'posi' type of unit without removing covers or tracing numbers down. (on second thought, the verifying of a non-LSD was done with unit installed, and one wheel on the ground, hence, a lot more resistance than I can do with my hand if the unit is out of the car. Am I the only one here that old-school?)
Speaking of numbers, would there be some numbers on the outside case or inner carrier of the unit that can be tracked down in a Toyota / Lexus parts book? (or online)
I am NOT a Supra parts expert, but, as I look at your pictures here are my thoughts.
1. your rear end CASE looks a hell of a lot like TLW's stock casing in his picture.
2. I DO think you should replace that bushing......that picture on the 2nd page of this thread is better than the first one. And as you know, you if you do one bushing, you may as well do both!
3. It's POSSIBLE that you could have a supra 'posi' (yeah, i own a chevy) inside of that case. So, don't get too worried yet. (I'm thinking of how Chevy and Ford rearends are built where the actual posi unit is interchangeable inside of the casing)
4. You should figure out what gear ratio is in there. If it were 3.23, it would have more odds of being a non-posi,....if it's 3.76 then there's a better chance it's a posi.
You can do this by counting how many "drive-shaft" rotations it takes to make one axle side turn 1 revolution.
5. I don't see the leak you're concerned about. It's not that little bit on the fins of the rear cover is it? I dont' think that's a leak,..just vapors. Perhaps it was over-filled?
6. Regarding which side is up, the rear end cover's breather should point up.
I'd like ROMINI's input on this one, but, on OTHER rearends, when you rotate one axle side, if the other end turns the opposite direction and cannot be held in position, then you've confirmed a 'posi' type of unit without removing covers or tracing numbers down. (on second thought, the verifying of a non-LSD was done with unit installed, and one wheel on the ground, hence, a lot more resistance than I can do with my hand if the unit is out of the car. Am I the only one here that old-school?)
Speaking of numbers, would there be some numbers on the outside case or inner carrier of the unit that can be tracked down in a Toyota / Lexus parts book? (or online)
Last edited by BA_GS400; 12-09-05 at 11:02 PM.
12-10-05, 07:03 AM
#23
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i did what you instructed me to try. i held one side down, and the other side turns freely. if i am interpreting what you said correctly, this would mean it's NOT an lsd
i am going first thing this morning to my lexus dealership. they have short saturday hours for the garage to be open today.
i still have not heard back from synco357...
i am going first thing this morning to my lexus dealership. they have short saturday hours for the garage to be open today.
i still have not heard back from synco357...
12-10-05, 07:51 AM
#24
Sounds like a one-wheel-peel to me. I was not able to hold the other side with my left hand, while turning the other with my right hand.
Synco357 had mentioned that he's sold several of these, so, it's all very odd. You'd think he'd have recognized the difference easily.
EDIT!!! For some reason, today, I got a different result! Maybe it was "stuck" or something, I just don't know. TODAY when I tried the test, I was easily able to hold the left side while turning either the driveshaft end or the other axle end!
Synco357 had mentioned that he's sold several of these, so, it's all very odd. You'd think he'd have recognized the difference easily.
EDIT!!! For some reason, today, I got a different result! Maybe it was "stuck" or something, I just don't know. TODAY when I tried the test, I was easily able to hold the left side while turning either the driveshaft end or the other axle end!
Last edited by BA_GS400; 12-10-05 at 05:33 PM. Reason: CHANGE OF TEST RESULTS!!!
12-10-05, 08:37 AM
#25
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synco357 is a longtime member and he has a clean history as far as i could search on this board. i just need to get a mechanic to look at it. i don't want to jump to conclusions. like everyone says, the only way to confirm is to open it up and see the gears.
12-10-05, 11:27 AM
#26
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Originally Posted by Benjamin T
"mini axles"?
Based on the pics, they are already installed. What threw me was the bolts. However, I did take a look at my oem diff (keeping it for when I sell) and yours looks just like the stock oem diff. My rmm unit looks like the pic you posted showing the new supra tt lsd. Good luck and hpoe it works out for you 
12-10-05, 03:15 PM
#27
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okay i understand what the min-axles are now.
today was unsucessful. the lexus dealer could not look at it without an appointment. i also tried my nearest toyota dealer and they said to leave it with them and come back at the end of the day, but the same thing happened... too many scheduled appointments and no one had time to look at it before closing... so back it sits in the basement
i'm debating whether i should try and crack it open. i've never done this before, and i've never seen it done off a car. i know the second i pull the cover it will puke it's guts out , but that's about it... 2 quarts worth?
today was unsucessful. the lexus dealer could not look at it without an appointment. i also tried my nearest toyota dealer and they said to leave it with them and come back at the end of the day, but the same thing happened... too many scheduled appointments and no one had time to look at it before closing... so back it sits in the basement
i'm debating whether i should try and crack it open. i've never done this before, and i've never seen it done off a car. i know the second i pull the cover it will puke it's guts out , but that's about it... 2 quarts worth?
12-10-05, 03:18 PM
#28
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Originally Posted by BA_GS400
I'd like ROMINI's input on this one, but, on OTHER rearends, when you rotate one axle side, if the other end turns the opposite direction and cannot be held in position, then you've confirmed a 'posi' type of unit without removing covers or tracing numbers down. (on second thought, the verifying of a non-LSD was done with unit installed, and one wheel on the ground, hence, a lot more resistance than I can do with my hand if the unit is out of the car. Am I the only one here that old-school?)
Speaking of numbers, would there be some numbers on the outside case or inner carrier of the unit that can be tracked down in a Toyota / Lexus parts book? (or online)
can someone tell me again how to do this manual check again? if i lock the input driveshaft side and keep it from turning, the 2 outputs to the axles are locked together and will not turn.
but, if i let the input turn freely, both outputs counterotate against each other. but if i hold one of the outputs and keep it from turning, the other output will still turn freely.
am i doing it right?
12-10-05, 05:47 PM
#29
Hold My Horses!!!!
Short story here:
I went out into my garage, which happens to be a balmy 32 degrees, and jacked up the rear of the car. I put the car in nuetral. The stock rear-end is in the car.
With one wheel on the ground, I could still spin the other wheel by hand.
With both wheels off the ground, I COULD easily hold one in with my hands and spin the other with my foot.
So, I then wanted to give my feedback to ya but I think, "hey, BA, let's go double-check the Supra rearend again"
FOR SOME REASON, I can now hold one side with the left hand and turn eithe the driveshaft side OR the other axle side with the other hand. Different than yesterday. Maybe it's all the flipping around, turning this and that,....maybe this rearend had sat for a long time?
Whichever,........I edited my post on Page 1.
You can still check the gear ratio to gain further evidence of it's origin. (as noted earlier)
Drain that oil out and you can look for that worm gear as someone else mentioned and it sound like you're ready to do anyway. Nothing will fall out but that 1.75-2 qts of oil.
Sorry bout that slip up in my previous test.
I went out into my garage, which happens to be a balmy 32 degrees, and jacked up the rear of the car. I put the car in nuetral. The stock rear-end is in the car.
With one wheel on the ground, I could still spin the other wheel by hand.
With both wheels off the ground, I COULD easily hold one in with my hands and spin the other with my foot.
So, I then wanted to give my feedback to ya but I think, "hey, BA, let's go double-check the Supra rearend again"
FOR SOME REASON, I can now hold one side with the left hand and turn eithe the driveshaft side OR the other axle side with the other hand. Different than yesterday. Maybe it's all the flipping around, turning this and that,....maybe this rearend had sat for a long time?
Whichever,........I edited my post on Page 1.
You can still check the gear ratio to gain further evidence of it's origin. (as noted earlier)
Drain that oil out and you can look for that worm gear as someone else mentioned and it sound like you're ready to do anyway. Nothing will fall out but that 1.75-2 qts of oil.
Sorry bout that slip up in my previous test.
12-10-05, 07:21 PM
#30
sorr i made my post yesterday and then i disappeared @_@
well here's what i think, and although it's been a long time, i think i still remember correctly. please correct me though if i am wrong.
first of all let's understand what lsd we are talking about. the stock one is an open differential, meaning the car will just put the power on the wheel with least traction. that is why with the stock differential, if one wheel is up in the air, it will just keep on spinning, coz' it has no traction and is the "easiest" to spin.
the lsd in the supra auto 3.76 rear end is a torsen type lsd. torsen means "torque sensing". what it means is it sense the tq on each wheel and adjust the power accordingly. in simple terms, it basically "monitors" both wheels, if one wheel start to loose traction, the unit will "multiply" the power on the wheel with less traction and put it on the other wheel.
so that's why say on a hard right turn, your right side wheel start to loose traction (since the car roll to the left), and the unit sense the difference in traction (the right side being less) and it multiplies the tq and put it on the left wheel, helping you push through the corner.
however, what *IF* the right wheel is off the gnd? you have ZERO traction on the right. what does that mean? anything multiply by ZERO is ZERO, so you will get ZERO power on the left wheel as well. so on a car with the torsen lsd, what if one wheel is in the air? the car will NOT move. the wheel in the air will just keep on spinning and spinning and the other wheel won't even go.
so how do you deal with this situation? well simple, look at the old school big boy hummer. they have torsen type rear end and they go through some of the toughest gnd. when one of the wheel is off the gnd, they simply apply a bit of BRAKE. you start to put some "grip" on the wheel that's up in the air, and that will create some "traction" to the system, and it will multiply it and apply it to the other wheel, pushing you forward.
so with all the above "lesson", what do we know now? both the stock open differential and the supra tt auto rear end (3.76 torsen lsd), when one wheel is up in the air, you still can't tell which one is the lsd. coz' that will will spin freely. and i believe if you jack both wheels up and spin one of them, the other one will spin in the other direction (for similar reason). and in both cases, if you spin the drive shaft, the two side axle will spin in different directions too
so that's why in the previous post i said in this case, it's pretty much too hard to tell if you have an lsd unit without opening it up. another type of lsd (clutch type), i believe you can tell. the trd lsd is a clutch type. but i forgot how you tell from that already, i pay more attention on torsen coz' that's what i have.
back to your case. i am still very much in doubt to be honest. i talked to someone, he said the supra tt 3.76 lsd unit gets much hotter than the normal one, that's why it's quite a bit bigger AND heavier, and it has the fins to help dissipating heat.
good luck to you, definitely try to open it up and confirm. like i said, i am not 100% on the outside appearance, i am just talking from what i know
well here's what i think, and although it's been a long time, i think i still remember correctly. please correct me though if i am wrong.
first of all let's understand what lsd we are talking about. the stock one is an open differential, meaning the car will just put the power on the wheel with least traction. that is why with the stock differential, if one wheel is up in the air, it will just keep on spinning, coz' it has no traction and is the "easiest" to spin.
the lsd in the supra auto 3.76 rear end is a torsen type lsd. torsen means "torque sensing". what it means is it sense the tq on each wheel and adjust the power accordingly. in simple terms, it basically "monitors" both wheels, if one wheel start to loose traction, the unit will "multiply" the power on the wheel with less traction and put it on the other wheel.
so that's why say on a hard right turn, your right side wheel start to loose traction (since the car roll to the left), and the unit sense the difference in traction (the right side being less) and it multiplies the tq and put it on the left wheel, helping you push through the corner.
however, what *IF* the right wheel is off the gnd? you have ZERO traction on the right. what does that mean? anything multiply by ZERO is ZERO, so you will get ZERO power on the left wheel as well. so on a car with the torsen lsd, what if one wheel is in the air? the car will NOT move. the wheel in the air will just keep on spinning and spinning and the other wheel won't even go.
so how do you deal with this situation? well simple, look at the old school big boy hummer. they have torsen type rear end and they go through some of the toughest gnd. when one of the wheel is off the gnd, they simply apply a bit of BRAKE. you start to put some "grip" on the wheel that's up in the air, and that will create some "traction" to the system, and it will multiply it and apply it to the other wheel, pushing you forward.
so with all the above "lesson", what do we know now? both the stock open differential and the supra tt auto rear end (3.76 torsen lsd), when one wheel is up in the air, you still can't tell which one is the lsd. coz' that will will spin freely. and i believe if you jack both wheels up and spin one of them, the other one will spin in the other direction (for similar reason). and in both cases, if you spin the drive shaft, the two side axle will spin in different directions too
so that's why in the previous post i said in this case, it's pretty much too hard to tell if you have an lsd unit without opening it up. another type of lsd (clutch type), i believe you can tell. the trd lsd is a clutch type. but i forgot how you tell from that already, i pay more attention on torsen coz' that's what i have.
back to your case. i am still very much in doubt to be honest. i talked to someone, he said the supra tt 3.76 lsd unit gets much hotter than the normal one, that's why it's quite a bit bigger AND heavier, and it has the fins to help dissipating heat.
good luck to you, definitely try to open it up and confirm. like i said, i am not 100% on the outside appearance, i am just talking from what i know