3.76 Supra LSD Differential DIY -- SC430--
11-20-11, 08:41 PM
#16
Driver School Candidate
So I have been looking for ways to make my SC a little bit quicker and I came across a really good deal. I found a differential off of a 1995 Toyota Supra (auto, worm gear type torsen 3.76) with really low miles (35 K), the bad part was that it had been sitting in a junkyard for a good 8-10 years. As soon as I picked it up I began ordering new parts, I changed every seal, bearing, shim, dust shield, breather plug, and all bolts and misc hardware. After all was said and done I pretty much had a brand new diff, granted it took a little longer and cost more than I expected I am very happy with the outcome.
The car feels so much more responsive off the line, and that lag all the SC owners complain about is now non existent. Once you punch it the car breaks loose for only a second then takes off like a bat outta hell, through the gears the car feels livelier as it revs up effortlessly and shifts without hitting the rev limiter. Cruising at freeway speeds (80mph) puts the rpm’s at 3K, which is tolerable and I really haven’t had a chance to document my gas mileage. According to the fellow members you can expect a 1-3 mile per gallon decrease in MPG.
Installation wasn’t too hard.
For the average mechanic I would rate this a 6 out of 10. Took me about 3-4 hours.
Remove rear exhaust (mufflers) 14mm
Remove mid pipe (silencers) 14mm there is a brace that also needs to be removed to access the front bolts.
Remove metal heat shield (above the mufflers) 4 bolts 10mm
Remove chassis bracing 2 metal pieces one on each side of the car 12MM
Remove 2 smaller metal braces 14MM
Remove drive shaft shield, a thin piece of metal covering the drive shaft. 4 10mm bolts
Loosen but do not completely remove the 6 bolts that connect each axle shaft to diff.
There are a total of 12 bolts, 6 on each side and they use a 10mm Allen key
Remove drive shaft bolts, only remove the 3 bolts that are holding the differential in, do not remove the other 3 bolts. You will need a 17mm wrench and socket, or just two wrenches.
So now you have all the bolts that connect the diff to your drive line disconnected, next you have to remove the 5 bolts that are holding the actual diff in place.
Loosen but do not remove the 3 rear hex bolts; you will need a T-60 hex type socket.
Loosen the 2 (19mm) bolts on the wings/arms/ears that are holding the diff up.
Once you have broken the bolts loose then slide a jack under the diff and make sure the jack is able to safely and evenly lower the diff.
Once the jack is in place and you have raised it enough to take support the weight of the diff you can proceed to remove all 3 rear hex bolts, along with the 2 main 19mm bolts.
Now that all the bolts are removed you can carefully begin to lower the diff out from underneath the car.
Carefully and slowly let the diff drop, making sure it does not snag any of the lines/wires or other pieces present in the area.
Once the old diff is out make sure the new diff is filled with fluid, tighten all the bolts, check all the mounting points on the new diff to make sure none are plugged/broken/or damaged.
Once everything looks good bolt that sucker back up. Everything should be a direct easy swap, there are no modifications, alterations needed just reverse exactly what you did while removing the diff.
Last step take her for a drive and ENJOY!!!!!!!!!!!!!
The car feels so much more responsive off the line, and that lag all the SC owners complain about is now non existent. Once you punch it the car breaks loose for only a second then takes off like a bat outta hell, through the gears the car feels livelier as it revs up effortlessly and shifts without hitting the rev limiter. Cruising at freeway speeds (80mph) puts the rpm’s at 3K, which is tolerable and I really haven’t had a chance to document my gas mileage. According to the fellow members you can expect a 1-3 mile per gallon decrease in MPG.
Installation wasn’t too hard.
For the average mechanic I would rate this a 6 out of 10. Took me about 3-4 hours.
Remove rear exhaust (mufflers) 14mm
Remove mid pipe (silencers) 14mm there is a brace that also needs to be removed to access the front bolts.
Remove metal heat shield (above the mufflers) 4 bolts 10mm
Remove chassis bracing 2 metal pieces one on each side of the car 12MM
Remove 2 smaller metal braces 14MM
Remove drive shaft shield, a thin piece of metal covering the drive shaft. 4 10mm bolts
Loosen but do not completely remove the 6 bolts that connect each axle shaft to diff.
There are a total of 12 bolts, 6 on each side and they use a 10mm Allen key
Remove drive shaft bolts, only remove the 3 bolts that are holding the differential in, do not remove the other 3 bolts. You will need a 17mm wrench and socket, or just two wrenches.
So now you have all the bolts that connect the diff to your drive line disconnected, next you have to remove the 5 bolts that are holding the actual diff in place.
Loosen but do not remove the 3 rear hex bolts; you will need a T-60 hex type socket.
Loosen the 2 (19mm) bolts on the wings/arms/ears that are holding the diff up.
Once you have broken the bolts loose then slide a jack under the diff and make sure the jack is able to safely and evenly lower the diff.
Once the jack is in place and you have raised it enough to take support the weight of the diff you can proceed to remove all 3 rear hex bolts, along with the 2 main 19mm bolts.
Now that all the bolts are removed you can carefully begin to lower the diff out from underneath the car.
Carefully and slowly let the diff drop, making sure it does not snag any of the lines/wires or other pieces present in the area.
Once the old diff is out make sure the new diff is filled with fluid, tighten all the bolts, check all the mounting points on the new diff to make sure none are plugged/broken/or damaged.
Once everything looks good bolt that sucker back up. Everything should be a direct easy swap, there are no modifications, alterations needed just reverse exactly what you did while removing the diff.
Last step take her for a drive and ENJOY!!!!!!!!!!!!!
This is Randy, 07 SC430 owner from Taiwan,
I am just wondering if my SC is 6spd Auto with Diff. GR is 3.769,
is that possible to straight up bolt on with 1995 Supra with 4.272 LSD's Diff?
are they the same holes to bolt on or do i need to do any thing to bolt it on?
thanks you for answering.
11-21-11, 07:29 PM
#17
From what I know the automatic supra pumpkin is interchangeable with our cars, the 6 spd is not.
In the auto supra the only LSD was offered with the 3.76 gearing
I would suggest you either purchase a LSD carrier or get one off a supra and swap it out with your current setup, while keeping your stock gearing. The issue is that if you choose too high of a gear ratio you will hit the rev limiter prematurely and it will not allow the car to perform as it should with the taller gears.
On our models (02-05 / 5 speed) I know that a few guys tried to mess with taller gearing and they would hit the rev limiter. So it was shown that the tallest gears we could use was 3.76, I even remember one or two guys having that issue with the 3.76 gears, where they would hit the rev limiter prematurely.
In the auto supra the only LSD was offered with the 3.76 gearing
I would suggest you either purchase a LSD carrier or get one off a supra and swap it out with your current setup, while keeping your stock gearing. The issue is that if you choose too high of a gear ratio you will hit the rev limiter prematurely and it will not allow the car to perform as it should with the taller gears.
On our models (02-05 / 5 speed) I know that a few guys tried to mess with taller gearing and they would hit the rev limiter. So it was shown that the tallest gears we could use was 3.76, I even remember one or two guys having that issue with the 3.76 gears, where they would hit the rev limiter prematurely.
11-22-11, 06:10 PM
#18
Driver School Candidate
From what I know the automatic supra pumpkin is interchangeable with our cars, the 6 spd is not.
In the auto supra the only LSD was offered with the 3.76 gearing
I would suggest you either purchase a LSD carrier or get one off a supra and swap it out with your current setup, while keeping your stock gearing. The issue is that if you choose too high of a gear ratio you will hit the rev limiter prematurely and it will not allow the car to perform as it should with the taller gears.
On our models (02-05 / 5 speed) I know that a few guys tried to mess with taller gearing and they would hit the rev limiter. So it was shown that the tallest gears we could use was 3.76, I even remember one or two guys having that issue with the 3.76 gears, where they would hit the rev limiter prematurely.
In the auto supra the only LSD was offered with the 3.76 gearing
I would suggest you either purchase a LSD carrier or get one off a supra and swap it out with your current setup, while keeping your stock gearing. The issue is that if you choose too high of a gear ratio you will hit the rev limiter prematurely and it will not allow the car to perform as it should with the taller gears.
On our models (02-05 / 5 speed) I know that a few guys tried to mess with taller gearing and they would hit the rev limiter. So it was shown that the tallest gears we could use was 3.76, I even remember one or two guys having that issue with the 3.76 gears, where they would hit the rev limiter prematurely.
my ride is 07 with 6spd, therefore, my differential GR is 3.76, just about last week, i went for Dyno for my ride, and used 4th gear to do it, and the spd hit up to 268km/hr(166.5 mph) with out hitting up the rev limit.....this is the actual case caused me to finding some information to swap my diff. and i found you, so i supposed maybe 4.272 might suitable for my ride.....somehow i am just so worried abt if comes up with CANNOT bolt-on......since there are only FEW supra in Taiwan, if i really wanna do so, i must order totally new part......so far i have not find out any information that the 1995 NA Auto supra with diff GR 4.272 can straight up bolt on to my 07 SC, therefore i left a message to you if there is anyway that i can ask for your help.....
02-26-12, 12:32 AM
#19
Driver School Candidate
Okay so I have been looking for a Supra LSD Assembly (the whole pumkin) for my SC 430. No one wants to ship it , unless I buy it new. Is there a way I can use the gear set from MK IV Supra on my SC430 LSD if so where can I get the 3.76 or gear and pinion from???
Last edited by XristosP; 02-26-12 at 01:02 AM.
10-21-14, 07:03 AM
#21
Lexus Test Driver
03-15-15, 04:58 PM
#28
HELP please
I am working on the 3.77 GR / LSD differential swap and got stuck. I have all the bolts off from the axles but when I lower the differential the axles don't come loose from the differential. I might be missing something in the procedure or I have to whack it lot harder with the mallet than I tried.
If anyone knows the missing step or a mechanics' trick please advise.
If anyone knows the missing step or a mechanics' trick please advise.
Last edited by SlvBullet; 03-15-15 at 05:07 PM.
03-15-15, 08:34 PM
#30
Ok I saw on YouTube the differential removal on a SC300 and the axles just pop out when the diff is lowered. I completely dropped the differential and it kept hanging on the axles. So after 11 years mine are pretty tight so I'm going to going to apply WD40 overnight and see if that helps ...