Aussie locker + center diff lock
- Thread starter kerry
- Start date
cruiseroutfit
Supporting Sponsor: Cruiser Outfitters
No problems doing it. How different is it than front and rear lockers? Well the same but without the front locker 
The center diff does not repace locking differentials in either axle, its a completely seperate function. Do you have the center diff lock setup? If not Slee has the button ready to go. You didn't mention what year your LC is but we can assume and FT4WD 80 Series chassis.
The center diff does not repace locking differentials in either axle, its a completely seperate function. Do you have the center diff lock setup? If not Slee has the button ready to go. You didn't mention what year your LC is but we can assume and FT4WD 80 Series chassis.
I'm in the process of purchasing a 94 FJZ with a center differential lock but no front or rear lockers. I understand front and rear lockers but I'm not entirely clear on what the center differential lock accomplishes. I assume that if the front and rear were locked the center lock would lock all 4 together but with front and rear unlocked I'm not sure what's it's advantage is. Is it that it always provides power to either front or rear axle even if one has lost traction, whereas without it, loss of traction on one axle can result in loss of traction on both?
cruiseroutfit
Supporting Sponsor: Cruiser Outfitters
Mmmkay.
Think of a single axle. When turning, the outside tire has to turn faster the inside tire right? Hence why we have a differential instead of a live axle.
Now the 80 is full-time 4wheel drive, so the front axle is always engaged and power is sent to both axles from the t-case. Well, again in turning situations, you now have 4 different tires turning 4 different speeds. The axle differential can balance the two parts of tires but what balances in the middle... the center differential does. Lock all three and you truly have equal distribution to all 4 wheels.
Clear as mud?
Last edited:
Yep, I can conceptualize the advantage when both axles are locked. I don't know why but I don't have a clear understanding of the advantage of locking the center differential when both axles are unlocked. Is that with the axles and differential unlocked losing traction on one wheel will cause all traction to be lost whereas with the center differential locked, and the axles unlocked, you would have to lose traction on one front and back wheel together to lose all traction?
cruiseroutfit
Supporting Sponsor: Cruiser Outfitters
Yes, theoretically with an open center differential and two open axles, one tire could break lose while the other 3 are stagnant. Lock the center diff and each axle will have one moving.
Why not leave it locked? Slight differences in the speed of the front axle and rear axle would cause wind up in the t-case and adverse handling to boot.
Ruffin' It
Explorer
I think it largely depends on how you plan on using it. I have a triple locked 80 and love it. I also haven't been in a situation where I felt the front locker was really necessary though. I do most of my wheeling in high desert mountains, so mud is rarely an issue. Generally I am on sand in some form with rocks added for flavor and texture.
Not too long ago I ran a one of the harder trails in Southern California called Cleghorn (rated an 8 out of 10, some pretty steep sections with some good sized rocks and sections of loose surface) and, while I switched the front locker on a couple of times to try it out, I would have been fine without it. I also have quite a bit of flex, so that is going to help.
Ultimately, I think the set up you are talking about would get you almost anywhere - especially if you put a good lift under it that lets you flex and a good set of tires. If you are doing hardcore stuff in the Rockies or spend a lot of time waist deep in Alaskan mud, a front locker is needed. But for 97%* of the trails in the world, a flexy center/rear locked 80 won't have a problem.
*83% of all statistics are made up
Just my thoughts though, I could be wrong.
Not too long ago I ran a one of the harder trails in Southern California called Cleghorn (rated an 8 out of 10, some pretty steep sections with some good sized rocks and sections of loose surface) and, while I switched the front locker on a couple of times to try it out, I would have been fine without it. I also have quite a bit of flex, so that is going to help.
Ultimately, I think the set up you are talking about would get you almost anywhere - especially if you put a good lift under it that lets you flex and a good set of tires. If you are doing hardcore stuff in the Rockies or spend a lot of time waist deep in Alaskan mud, a front locker is needed. But for 97%* of the trails in the world, a flexy center/rear locked 80 won't have a problem.
*83% of all statistics are made up
Just my thoughts though, I could be wrong.
MoGas
Central Scrutinizer
Not in a 93+. The viscous coupler will provide power differentiation to the front and rear regardless. In the 91-92 there is no viscous coupler, so all the power will go to the slipping tire unless the CDL is engaged.
To answer your question, in a 93+ with an Aussie or other similar, full time, locker, you will have positive, 3 wheel drive with the CDL locked, and the front and rear can differentiate via the viscous coupler with it unlocked. You should barely notice the locker during day to day running around. You will notice it off road.
Dave
Box Rocket
Well-known member
Bottom line is it works good if you have an 80 series that came without lockers. My '93 is one of the oddball 80s without the viscous coupler so it's similar to the earlier '91-'92s. I added an Aussie locker a couple years ago and it's been great so far. Hardly noticeable on the road but does it's job offroad. Not quite as good and locker front and rear but 3/4 of the way there.
cruiseroutfit
Supporting Sponsor: Cruiser Outfitters
True, I was leaving it simplistic for the sake of my explanations, I didn't have the wind in me
. The viscous coupler is not a 50/50 bias though and in fact can slip to some degree, just not enough to matter in this situation. I had a customer drive home from Moab with no front drive shaft (no CDL switch) I was completely amazed that he did not destroy his VC. When he first brought it over and we were diagnosing the problem we took it for a spin around the block the VC had an amazing amount of slip. He took the recommendation of a small service station in Moab to pull the shaft and drive home... amazingly several years later the VC is still working fine. On the flip side you hear about VC issues with mis-matched tires.
MoGas
Central Scrutinizer
Too bad they didn't tell him the rest of the "fix" for driving a 93+ without a dash switch for CDL when you pull a drive shaft. Put it in 4LO, after the ABS and CDL lights come on, pull the CDL fuse and put the shifter back in 4HI. You won't have ABS, but you can drive a very long time on one shaft that way..........
Dave
That's a very good trick to know.
cruiseroutfit
Supporting Sponsor: Cruiser Outfitters
They didn't even realize it was full-time so CDL tricks were not going to happen
He did promptly buy a CDL switch after we fixed the axle.
rusty_tlc
Explorer
Back OT.
Here is a question.
When the Detroit on my FJ60 locks on ice I lose traction on the rear axle, very exciting during my daily commute. (It has a Detroit in front too, I learned not to use 4WD on ice the first snow day after I got it.:Wow1
I assume with the 80 the center diff would transfer drive to the front axle in this situation, thereby unloading the rear axle and allowing the locker to disengage?
Here is a question.
When the Detroit on my FJ60 locks on ice I lose traction on the rear axle, very exciting during my daily commute. (It has a Detroit in front too, I learned not to use 4WD on ice the first snow day after I got it.:Wow1
I assume with the 80 the center diff would transfer drive to the front axle in this situation, thereby unloading the rear axle and allowing the locker to disengage?