s4 or s5 Limited Slip Differential
09-08-09, 07:55 PM
#1
s4 or s5 Limited Slip Differential
So I bought a Limited Slip Differential yesterday. The guy claimed it was a series 5 Naturally Aspirated Limited Slip Differential. Does mean its a GTU's LSD? Is it possible to tell by the casting number on it? It says M055. Let me know thanks
09-08-09, 09:54 PM
#4
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look at the bottom of it if it has a raised "circle" in the middle then it could be a s4 if if does not more than likely it is a s5
a s5 gtu is a open diff "spin one side the other side goes the other way"
a s4 gtu is a vlsd "which what i have seen acts the same way untill the fuild locks up"
hope this helps
a s5 gtu is a open diff "spin one side the other side goes the other way"
a s4 gtu is a vlsd "which what i have seen acts the same way untill the fuild locks up"
hope this helps
09-09-09, 07:12 AM
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The differential that you have is definitely S5. I have never seen or possibly never notice the casting on the side of the differential. Your one lucky bastard if it is GTU's. One way you can find out is by driving at 60 MPH on 5th gear. The RPM should be slightly higher due to the changed gear ratio.
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09-09-09, 07:22 AM
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Another way you can find out, since it is sitting out in the open all pretty like... turn the input shaft and count the number of rotations the input shaft does, per revolution of the output shaft.
09-09-09, 08:20 AM
#9
Useless ******* post.
He bought something and the seller said what it came from. He come to the list to make sure, since the seller could be wrong or ******* with him. We don't have pictures of the different Diffs in the archives and stickies last time I checked.
He bought something and the seller said what it came from. He come to the list to make sure, since the seller could be wrong or ******* with him. We don't have pictures of the different Diffs in the archives and stickies last time I checked.
09-09-09, 09:33 PM
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Not always indicative of an LSD.
An open diff will do this if no load is on either output shaft or the driveshaft.
Also, someone could have put an LSD of any type in an S5 open diff 4.10:1 ring and pinion.
Only way to know is to look inside.
I usually turn the two output shafts to the same position and mark them with chalk or tape... Then I turn the input shaft and count the revolutions of the output shafts, making COMPLETELY sure that they stay in the same relative positions...
If it's from a "GTUs" model, it'll have the coveted 4.30:1 gear ratio... That'll give you a little better launch torque, but take you down a bit on top speed.
.10 is 1/10th of a rotation... Like from 12 o'clock to a little past 1 o'clock.
.30 is almost 1/3rd of a rotation... Like from 12 o'clock to a little before 4 o'clock.
So the difference is easy to tell.
One good way to find out if it's a tight LSD is to block ONE of the output shafts and let the input shaft turn... Take a torque wrench to the lugs (Works well if this is on the car.) of the unblocked shaft and turn. It should turn, but it should take a LOT of torque to do it...
Viscous LSDs will not react this way... (They need to already be slipping to heat up the fluid.) Worn out clutch type LSDs (better than an open diff... Clutch packs are cheap.) won't react either because the clutches won't grip.
Like I said before...Only 100% sure way to know is to crack it open or look inside.
An open diff will do this if no load is on either output shaft or the driveshaft.
Also, someone could have put an LSD of any type in an S5 open diff 4.10:1 ring and pinion.
Only way to know is to look inside.
I usually turn the two output shafts to the same position and mark them with chalk or tape... Then I turn the input shaft and count the revolutions of the output shafts, making COMPLETELY sure that they stay in the same relative positions...
If it's from a "GTUs" model, it'll have the coveted 4.30:1 gear ratio... That'll give you a little better launch torque, but take you down a bit on top speed.
.10 is 1/10th of a rotation... Like from 12 o'clock to a little past 1 o'clock.
.30 is almost 1/3rd of a rotation... Like from 12 o'clock to a little before 4 o'clock.
So the difference is easy to tell.
One good way to find out if it's a tight LSD is to block ONE of the output shafts and let the input shaft turn... Take a torque wrench to the lugs (Works well if this is on the car.) of the unblocked shaft and turn. It should turn, but it should take a LOT of torque to do it...
Viscous LSDs will not react this way... (They need to already be slipping to heat up the fluid.) Worn out clutch type LSDs (better than an open diff... Clutch packs are cheap.) won't react either because the clutches won't grip.
Like I said before...Only 100% sure way to know is to crack it open or look inside.
09-09-09, 10:44 PM
#22
Not always indicative of an LSD.
If it's from a "GTUs" model, it'll have the coveted 4.30:1 gear ratio... That'll give you a little better launch torque, but take you down a bit on top speed.
.10 is 1/10th of a rotation... Like from 12 o'clock to a little past 1 o'clock.
.30 is almost 1/3rd of a rotation... Like from 12 o'clock to a little before 4 o'clock.
So the difference is easy to tell.
V
If it's from a "GTUs" model, it'll have the coveted 4.30:1 gear ratio... That'll give you a little better launch torque, but take you down a bit on top speed.
.10 is 1/10th of a rotation... Like from 12 o'clock to a little past 1 o'clock.
.30 is almost 1/3rd of a rotation... Like from 12 o'clock to a little before 4 o'clock.
So the difference is easy to tell.
V
turn the input shaft, make sure the output shaft are aligned
then what
turn the input shaft 4 times and see what rotation the output shaft is at?
09-10-09, 08:16 AM
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You mark both the output shafts AND the input shaft.
Turn the input shaft until the output shafts come back to the same position (ONE full rotation)
Count where you come out at with the input shaft.