ATS Carbon LSD
03-12-15, 11:56 AM
#46
Tech Info Resource
iTrader: (2)
If you really want to make it easy, just drop the spool in a liquid nitrogen bath. Ring gear falls on, bearings fall on, everything is pretty simple at LN temperatures.
03-12-15, 11:57 AM
#47
The ring gear is moved from side to side with the snap rings. The pinion gear is moved fore and aft with shims. When you install the spool, you put prussian blue (I use conventional artist's oil paint) on the ring gear and rotate the assembly to see where the teeth engage and adjust either the spool or the pinion to get the engagement in the center of the teeth. It's not rocket science, but it does take good visualization skills, much like doing cylinder head work and placing the contact line on the middle of the valve's face. It is critical to get it right or the gears will chew themselves to death in short order, or if the contact is too high on the tooth, the gear teeth on the ring gear will break off.
03-12-15, 12:17 PM
#48
Tech Info Resource
iTrader: (2)
Thanks for the response - additional question, will checking the gear-mesh with paint usually get the backlash within specification? Or on the contrary is the backlash spec written so that you can reasonably expect that the gear mesh is correct if within spec? Regardless I like the extra check you described with the paint.
03-16-15, 02:00 PM
#49
Well the news you all have been waiting for, Its in the car and I have been driving it since mid day Saturday. Initial impressions are great! this is a huge increase over factory! as far as noise, I still have not "broken" it in yet by doing the figure 8's nor put the 500 miles on it so im still doing that but I have not heard a peep from the diff. not so much as a clunk or anything. When turning sharply with throttle you can feel the diff lockup and it feels great on turns.
I will say from comparison to the OS Giken unit to this, the OS unit states that after the initial oil change you can use factory service intervals which means around 30k miles an oil change. OS also states you should use their oil only which can get expensive.
the ATS Diff, they recommend it be replaced every 2-3k miles due to the carbon disks since the magnetic pickup wont be able to grab the particles. The diff oil they state you can use many different oils as they have tested quite a few. I will re update the thread once I get the break in miles complete.
I will say from comparison to the OS Giken unit to this, the OS unit states that after the initial oil change you can use factory service intervals which means around 30k miles an oil change. OS also states you should use their oil only which can get expensive.
the ATS Diff, they recommend it be replaced every 2-3k miles due to the carbon disks since the magnetic pickup wont be able to grab the particles. The diff oil they state you can use many different oils as they have tested quite a few. I will re update the thread once I get the break in miles complete.
03-19-15, 04:52 AM
#50
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03-19-15, 04:13 PM
#51
That's what I was wondering. That's a diff change at every oil change, plus once in between! 
At that rate, the cost of diff oil will bring this unit up to the same price as the OS in no time, not to mention all the extra hours spent changing it.
At that rate, the cost of diff oil will bring this unit up to the same price as the OS in no time, not to mention all the extra hours spent changing it.
03-20-15, 08:24 AM
#52
Correct it is the life of the unit.
To be honest it is soon but to me, that's what every diff ive ever had calls for.
On top of that when you track your car, you are supposed to do it before and after every event regardless of what diff you have that way you have new oil.
To me having to change every 3k miles is a mute point because oil is cheap when bought in bulk and I don't mind getting down and doing it however I have a lift in my garage so its quick and easy to do.
I would assume if you are not tracking your car you could probably go a lot longer on the oil change but I need to confirm with ATS on that. certainly wont be 30K like the OSG unit though. I personally would not feel easy going 30K on a clutch type unit between oil changes.
To be honest it is soon but to me, that's what every diff ive ever had calls for.
On top of that when you track your car, you are supposed to do it before and after every event regardless of what diff you have that way you have new oil.
To me having to change every 3k miles is a mute point because oil is cheap when bought in bulk and I don't mind getting down and doing it however I have a lift in my garage so its quick and easy to do.
I would assume if you are not tracking your car you could probably go a lot longer on the oil change but I need to confirm with ATS on that. certainly wont be 30K like the OSG unit though. I personally would not feel easy going 30K on a clutch type unit between oil changes.
03-20-15, 09:58 AM
#53
Correct it is the life of the unit.
To be honest it is soon but to me, that's what every diff ive ever had calls for.
On top of that when you track your car, you are supposed to do it before and after every event regardless of what diff you have that way you have new oil.
To me having to change every 3k miles is a mute point because oil is cheap when bought in bulk and I don't mind getting down and doing it however I have a lift in my garage so its quick and easy to do.
I would assume if you are not tracking your car you could probably go a lot longer on the oil change but I need to confirm with ATS on that. certainly wont be 30K like the OSG unit though. I personally would not feel easy going 30K on a clutch type unit between oil changes.
To be honest it is soon but to me, that's what every diff ive ever had calls for.
On top of that when you track your car, you are supposed to do it before and after every event regardless of what diff you have that way you have new oil.
To me having to change every 3k miles is a mute point because oil is cheap when bought in bulk and I don't mind getting down and doing it however I have a lift in my garage so its quick and easy to do.
I would assume if you are not tracking your car you could probably go a lot longer on the oil change but I need to confirm with ATS on that. certainly wont be 30K like the OSG unit though. I personally would not feel easy going 30K on a clutch type unit between oil changes.
).And if I had a lift it definitely wouldn't be as bad. Been on my wish list for a while, still can't get the wifey to sign off on it. She says since I've been able to do everything short of a transmission swap without lift up until now, then I don't need one.
Last edited by jleonard71; 03-20-15 at 10:01 AM.
06-03-15, 03:27 PM
#55
to be completely honest, I haven't gotten to drive the car much.
I did however take a road trim from Ohio to Georgia for Formula D and did tail of the dragon on the way. Compared to what I remember of the car last year it was amazing to drive. The diff makes a HUGE difference in the car.
Not that you can see much but here is a video from TOD, its boring but if you get bored something to watch.
https://youtu.be/IFue2kqgExE
I did however take a road trim from Ohio to Georgia for Formula D and did tail of the dragon on the way. Compared to what I remember of the car last year it was amazing to drive. The diff makes a HUGE difference in the car.
Not that you can see much but here is a video from TOD, its boring but if you get bored something to watch.
https://youtu.be/IFue2kqgExE
03-12-16, 11:39 AM
#56
Bringing this thread up
Is there a document somewhere to get backlash and shims specs for this LSD swap?
I bought ATS silent metal and I want info for installing properly
Thanks
Is there a document somewhere to get backlash and shims specs for this LSD swap?
I bought ATS silent metal and I want info for installing properly
Thanks
12-07-17, 08:08 AM
#57
No pictures of the tooth profile as my phone died before I got to that point however it was spot on which it should have been since we didn't mess with the pinion spacing.
I used the same snap rings that came off my diff as putting it back in as it was still within factory specification. factory is spec for backlash is 0.000 to 0.005 IIRC, Mine spec'd out factory at 0.001 and with the new ATS LSD I was at 0.003 which I am happy with. I was under the impression however that the snap rings should match on both sides of the case but in my case the left side was 4.15mm and my right side was 3.95MM.
I would think that for most installs, you will be able to use the snap rings that came off and still be in specification. I know mike at FIGs used the same snap rings that came out and his was at 0.005. I however cannot say what his backlash was from factory though.
the install itself was not bad except for shaving the side of the case down to fit the whole unit in. I was at it for quite a while and I finally got it where I though it should go in got frustrated and walked away for a little bit. when I came back I barely touched the thing and it just plopped right into the carrier.
I used the same snap rings that came off my diff as putting it back in as it was still within factory specification. factory is spec for backlash is 0.000 to 0.005 IIRC, Mine spec'd out factory at 0.001 and with the new ATS LSD I was at 0.003 which I am happy with. I was under the impression however that the snap rings should match on both sides of the case but in my case the left side was 4.15mm and my right side was 3.95MM.
I would think that for most installs, you will be able to use the snap rings that came off and still be in specification. I know mike at FIGs used the same snap rings that came out and his was at 0.005. I however cannot say what his backlash was from factory though.
the install itself was not bad except for shaving the side of the case down to fit the whole unit in. I was at it for quite a while and I finally got it where I though it should go in got frustrated and walked away for a little bit. when I came back I barely touched the thing and it just plopped right into the carrier.
Something everyone should consider when doing diff carrier swaps is bearing preload or lack there of. It is one thing to get the proper pattern and backlash. But when swapping the center sections like this, if the distance between the bearings of old to new carrier are different and/or the surface where the ring gear mounts is shifted at all, you may not be able to simply reuse the old snap rings (shim stack).
Most of us have no means to measure the flange to flange bearing spacing and bearing flange to ring gear mount thus we are relying on the manufacturer to build the unit meeting Toyota specs. Even this is no guarantee.
In short a quick test is this. Grab an inch pound beam style torque wrench. Before you tear down OEM setup, measure the torque required to spin the pinion keeping it in motion. You may also want to take note of the max break away torque to get it in motion.
Optional: Once the carrier is out, measure pinion and seal torque.
Install carrier and get proper pattern and backlash. Oil the gears to mimic as found conditions. Measure the pinion torque again. If all is well you get the same torque value.
Just something to think about. If anyone has the Yoda method to verify carrier bearing preload, that would be great. That said it can't be much or they A) run hot B) you can't get the snap rings in without brute force....
EDIT: Note, new bearings will require more torque. What you don't want is too little preload or the pinion will shove the ring out of the way and destroy it.
Last edited by 2013FSport; 12-07-17 at 09:18 AM.
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