I researched this not long ago, and I am 90% sure that the limited slip that is available for the rear of the 80 series is a wear item that is not rebuildable.
Anyone out there running front & rear LSDs?
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Ryan that is correct. At one time, Auburn had a "trade-in" program for failures within a certain time period after install. My current unit is 6-7 years old and functioning properly.
A contact person at Auburn informed me the original Auburn Pro-Series for 80 series was made in Japan
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- #24
Yeah, it's my understanding that it's a non-rebuildable unit. I can't imagine that it would wear out super fast though. I guess my plan would be to hang onto it as long as I liked it and it was working, and when it wears out make the decision to either replace it with a new one or perhaps "upgrade" to a selectable locker if I felt that was the better choice. However, my guess is that it would outlive some critical part of the LC and I'd be in a position to upgrade my whole rig to something newer at that point...
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- #25
LXDOC, is that a good thing, a bad thing, or just a statement of fact?
I have run an Auburn rear/Tru Trac front on an AWD Cherokee. The dual limited slips with AWD is a good system, but the Auburn is quite a bit more unpredictable in low traction conditions than putting a full automatic locker in the rear. It is a lot less effective offroad and in especially in winter conditions where the slip/engagement process will cause the rear to kick out under throttle.
I had also wanted a fully passive "no road impact" system, and the front Tru Trac is just awesome with AWD. But a full Detroit on the other hand was completely civilized, for the simple reason that in a straight line under torque it isn't 'locking' whereas a LSD has to engage. So outside of some clicking in parking lots in tight radius turns, the Tru Trac front/AWD/Detroit rear was vastly superior to that combo with Auburn rear.
It was so good in winter conditions that with Trxus MT's I could hammer the throttle turning out of a parking lot and it just wouldn't break free. I was a little bit concerned moving to the 80 having a selectable system. I still think the auto rear locker with any decent wheelbase and AWD is better than the selectable, because it is there all the time.
So don't fear the rear locker. It is superior in every way and the parking lot clicking will reassure you that it's there. It's been probably 13 years since I was doing my research and testing, but Detroit had an article as to why rear auto locker/AWD/front gear driven LSD is such an effective combo. It doesn't hold a candle to being fully locked offroad in hardcore terrain, but as a passive system pretty awesome in my experience.
I had also wanted a fully passive "no road impact" system, and the front Tru Trac is just awesome with AWD. But a full Detroit on the other hand was completely civilized, for the simple reason that in a straight line under torque it isn't 'locking' whereas a LSD has to engage. So outside of some clicking in parking lots in tight radius turns, the Tru Trac front/AWD/Detroit rear was vastly superior to that combo with Auburn rear.
It was so good in winter conditions that with Trxus MT's I could hammer the throttle turning out of a parking lot and it just wouldn't break free. I was a little bit concerned moving to the 80 having a selectable system. I still think the auto rear locker with any decent wheelbase and AWD is better than the selectable, because it is there all the time.
So don't fear the rear locker. It is superior in every way and the parking lot clicking will reassure you that it's there. It's been probably 13 years since I was doing my research and testing, but Detroit had an article as to why rear auto locker/AWD/front gear driven LSD is such an effective combo. It doesn't hold a candle to being fully locked offroad in hardcore terrain, but as a passive system pretty awesome in my experience.
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- #27
Thanks for the feedback, Nay. That's another option I considered but had started to rule out due to road manners. I'm surprosed that the autolocker was more civilized than the Auburn, considering they do basically the same thing but the autolocker stated from locked and is either fully locked or fully slipping and the LSD started from the middle and varies in both directions (to and from locked, but never fully)
Perhaps my best option is to start with an Aussie and see how I like it. If it feels good as a DD, I can add the TrueTrac in the front. If I don't like it I can replace it with the Auburn or just go back to open. Hmmm....
The issue with the Auburn, at least in my experience, is that it's a clutch based system so you have "engagement" that is different than a gear driven system. It's also much stronger - not sure there is any gear driven LSD you want behind the t-case in low range - and hence the reason to run one in the rear diff. So, yes, the LSD is more "silent", but I view "civility" within it's relationship to "predictable". And the Auburn was not predictable at all (granted, again, this was like 15 years ago).
The other standard I use is whether I would be comfortable with my wife driving it in bad conditions, meaning it isn't just me knowing how to not engage the dark side. At least at the time, I far preferred the predictability of the rear locker in winter than the unpredictability of the clutch driven LSD as a passive safety system. Of course now the passive system is electronic traction control that rules us all.
I think auto lockers suffer from carryover bias of people using them in 90" wheelbase CJ7s and there's a fear of messing up daily drivability. I finally just said screw it and never regretted the locker for a second - it was 100% upside. But as a wise man sayeth, "know thyself".
If it were me, I'd Aussie the rear diff and then see what you think you need. I'd only add a front trutrac for winter reasons as it won't make all that much difference in offroad situations that have overwhelmed a locked center and rear diff in low range. In that case, a front locker is everything and LSDs just don't cut it.
I ran Auburns front and rear in my Dodge ramcharger for many years. 4" lift, 35", and granny 4 speed and it would tear up the rubicon. Other people thought it had lockers. Are they good? Damn right! Are they locker good? No but with some learning of the necessary driving style they will impress. They also have a "Pro" line of LSD's. Not sure if they sell one for the 80.
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- #30
I think with the AWD system in the cruiser, having the TrueTrac up front would make it easier to drive since there's less torque bias. But to your point.. I keep seeing this over and over - people who run front and rear LSDs seem to universally like the setup, even with everyone around them shouting "lockers or it's not good enough!!"
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- #31
I think this is what I've decided to do. I found a Spartan on Amazon for $257 with free shipping. I'm gonna throw that guy in the back and see how I like it. If it's not my style, I'll replace it with the Auburn. If I like it, I'll put a TrueTrac up front when I have the front end rebuilt.
I decided on the Spartan for two reasons:
- It comes with a new crosspin, which after watching several install videos on youtube, seems to often be significantly worn on old diffs.
- It doesn't use thrust washers, meaning two less parts for me to mess-up or forget.
I probably won't get around to installing it until after the Overland Expo East next month, but maybe I'll do a write up of the install and my initial impressions.
Kind of an older thread but figured i'd chime in. I have a 1990 jdm 80, and it has rear LSD which I assume is factory. So far it has been good, haven't had an instance yet where I thought, damn i wish I had a locker...mind you I have no idea how worn it is
I have TrueTrac's in front and rear of my 96 Bronco. Night and day difference over open diffs. While they aren't as good as lockers they are gentler on the drivetrain as I haven't broken anything yet. In bad situations where I need to transfer more torque I simply tap the brakes and away I go. The nice thing is they are always working and don't need to be engaged. Also I don't have any steering issues like I get when my LX has the front locked.
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- #34
Is it a torsen or clutch type?
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- #35
Thanks for the feedback. That's the kinda info I was looking for. I was able to find a FF rear end to swap into my 80, so the new plan is a TrueTrac up front and a Harrop in the back - once funds allow.
I'm not 100% sure, but I think it's a clutch type, I did the research 4 or so yrs ago and thats the answer that's ringing in my brain...now that i'm thinking about it 350k kms and 27 yrs later i'm betting the clutches probably aren't grabbing like they should anymore..
I have a factory LSD as well I am at just under 200000 miles but the vehicle has lived in some rough areas of the world I have no idea of knowing if anything is wearing out or past its life span. The one thing that worries me is that the previous owner messed alot of things up on the vehicle and I am curious if he used the correct fluid. I never hear any clicking in the back but who knows.
I was seriously considering the front & rear LSD set-up because where I live we have snow on the roads 4-6 months of the year. I think F&R LSD would be great for this application. The reason I backed off was in the summer, the trails I run have what I call "rollers". These are large dips and rises in the trail. If you have a rise on driver front and passenger rear wheels you really only have traction at those two wheels. Even if the passenger front and driver rear are on the ground they don't have much weight on them and therefore very little traction. You might be able to run these with F&R LSDs with practiced use of riding the brakes to transfer power. But, that may not be enough. So, long story short, for me the best set-up would be Front-LSD, Center-LSD/Selectable (like an 80 series), Rear-Selectable. Run Center-LSD, Rear-Open all winter. Run Center-Locked, Rear-Locked on the trails. With the Front-LSD helping out giving me some power to both Front wheels year round.
I think the bases have been covered here. LSD is great in sand, gravel and snow. Front and rear LSD's are no problem (I have driven a number of subarus with this setup and the traction is impressive, and spent a lot of time in FWD LSD cars in the snow). Once a wheel goes in the air, they're about as useless as open diffs. So if that type of wheeling is not in your repertoire, I see no reason not to try it. 
