Preparations for a Spartan Locker in rear diff (1 Viewer)

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DKW

Joined
Dec 7, 2018
Threads
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Location
Fl, USA
Have decided to fit a rear auto locker, and the Spartan is easily available on Amazon and it looks simpler as no washers are needed - already have a factory locker on the front. I had a couple of questions for those that have done it.

Replacement Oil. I have been using 80W-90 Valvoline gear oil in my diffs, but I read you may need to go heavier if using an auto locker. Is it needed?

Carrier Gasket. There is a gasket available, but I saw people also use FIPG often. Is there a reason why OEM gasket is not used?

Not intending to change any of the oil seals, as I I think this is best done with correct SST tools, which I do not have, but if there is a strong reason to do it please let me know. There are no leaks right now.

I hope the spartan instructions are clear, and this is my first time so 🤞.
Thanks
 
You said you have a factory locker in the front, is it the rear differential an open carrier? Or is it a locked carrier that you are planning on putting the mechanical locker in? Asking bc I don’t think they fit in a locked carrier.

I just used grey silicone to seal up my diffs when I regeared, no problems.
 
You said you have a factory locker in the front, is it the rear differential an open carrier? Or is it a locked carrier that you are planning on putting the mechanical locker in? Asking bc I don’t think they fit in a locked carrier.

I just used grey silicone to seal up my diffs when I regeared, no problems.
Rear is not locked, so a regular diff
 
Auto Lockers do not 'require' a heavier gear lube, but some folks use them to supposedly 'quiet' them down (ratcheting sound on occasion in turns). Since you are in a Warm Climate....you could go with something heavier if you like.
 
Nothing special needed, oil-wise. If it's noticeably clunky, then heavier oil can dampen that a bit. My bet is you won't notice too much either way. Gasket vs. FIPG is up you you. I dislike paper gaskets personally.
 
Personally I would not install an auto locker in an '80. The strength of the '80 is it's general purpose abilities. An Autolocker will contribute negative handling driving quirks that I would not want in something that drives as nice as an '80.

And I would not install a Spartan locker in anything. You comment that it is simpler because it does not use (thrust) washers. Which means that there is no way to adjust for varying clearances due to manufacturing variance in the carrier. And these clearances do occasionally vary. You can toss it in and hope. I have seen more than a few autolockers that were too tight or too loose until the right combination of thrust washers were installed. Too tight will not unlock correctly. Too loose will unlock too easily and wear of extremely quick (Saw one last about 150 road miles and 50 or so trail miles before it was toast from being too loose.

Why they chose to design it to not use thrust washers is beyond me. I figure that is the cheapest unit out there and they maybe decided to play the odds and accept the warranty returns that they actually got hit with?


Mark...
 
I dont really have a preference on which auto locker, the spartan seemed simplest but i haven't seen anything yet that shows any brand is better than the other. Also i have not seen, until now any negative comments on them, apart from the some people say they may need getting used in snow. I will continue to research.
 
Personally I would not install an auto locker in an '80. The strength of the '80 is it's general purpose abilities. An Autolocker will contribute negative handling driving quirks that I would not want in something that drives as nice as an '80.

I disagree strongly. An autolocker is the best $300 you can spend on an off road truck IMO. The quirks are minor to the point you don't even notice anything once you've gotten used to it. A very small price to pay for a major improvement in traction. I've used them in a couple different rigs and would definitely do it again.
 
I disagree strongly. An autolocker is the best $300 you can spend on an off road truck IMO. The quirks are minor to the point you don't even notice anything once you've gotten used to it. A very small price to pay for a major improvement in traction. I've used them in a couple different rigs and would definitely do it again.

I've used them in a lot of rigs. I will continue to. Just not in a full-time four-wheel-drive 80s series . I will not use or install a Spartan again either.

Mark...
 
Personally I would not install an auto locker in an '80. The strength of the '80 is it's general purpose abilities. An Autolocker will contribute negative handling driving quirks that I would not want in something that drives as nice as an '80.

And I would not install a Spartan locker in anything. You comment that it is simpler because it does not use (thrust) washers. Which means that there is no way to adjust for varying clearances due to manufacturing variance in the carrier. And these clearances do occasionally vary. You can toss it in and hope. I have seen more than a few autolockers that were too tight or too loose until the right combination of thrust washers were installed. Too tight will not unlock correctly. Too loose will unlock too easily and wear of extremely quick (Saw one last about 150 road miles and 50 or so trail miles before it was toast from being too loose.

Why they chose to design it to not use thrust washers is beyond me. I figure that is the cheapest unit out there and they maybe decided to play the odds and accept the warranty returns that they actually got hit with?


Mark...
I've used them in a lot of rigs. I will continue to. Just not in a full-time four-wheel-drive 80s series . I will not use or install a Spartan again either.

Mark...

The ones we’ve installed in 80s aren’t noticeable. The all-wheel drive system makes them pretty transparent.

The most recent one we did, the kid drove it around the building and came back saying “I don’t think we did it right, it’s not doing anything”
 
Yeah I installed a spartan in the rear a few months ago and I haven't had any "negative handling quirks" or anything. Its a long wheel base and heavy AF.. its worth it for off-road so just do it and don't look back (until its time for ARB Air Lockers lol)
 
Thanks for the further feedback. Carried out some more research and for our trucks, hard to tell which is best auto locker company, they all seem to be good. I suppose i could always keep the old locker parts in the truck just in case
 
Have decided to fit a rear auto locker, and the Spartan is easily available on Amazon and it looks simpler as no washers are needed - already have a factory locker on the front. I had a couple of questions for those that have done it.

Replacement Oil. I have been using 80W-90 Valvoline gear oil in my diffs, but I read you may need to go heavier if using an auto locker. Is it needed?

Carrier Gasket. There is a gasket available, but I saw people also use FIPG often. Is there a reason why OEM gasket is not used?

Not intending to change any of the oil seals, as I I think this is best done with correct SST tools, which I do not have, but if there is a strong reason to do it please let me know. There are no leaks right now.

I hope the spartan instructions are clear, and this is my first time so 🤞.
Thanks


1. I have an auto locker and I just use regular 80-90 gear oil, you can go heavier if you want that would just be more of a personal preference.

2. I personally prefer the paper gasket, that's what was designed to go there and my original lasted well over 20 years with no leaks so its got to be doing something correctly. if you do decide to go with fipg I would recommend at least going with Toyota red as it is designed to work with trans fluid and gear oil. you will also need the hub gaskets as they are paper as well and you will need to pull the axles out enough to get the third out

3. opinions vary on this, some do it because they can others just wait for a leak so that choise is up to you. there really isn't any special sst to replace the seals other than a screwdriver or small pry bay to remove the seal and a hammer and brass punch to install the new seal. it would also be advisable to service the rear wheel bearings at this time as well and do a bearing repack.

4. you will definably need the thrust washers for install as that is how you adjust the side clearnaces on the locker. as mentioned above if the clearances are either too tight or too loose it will be locked all the time or not lock at all. you can play around with the clearances to allow the locker to lock quicker or unlock quicker


some more of my thoughts and observations on install of my locker Lokka locker install instructions
 
1. I have an auto locker and I just use regular 80-90 gear oil, you can go heavier if you want that would just be more of a personal preference.

2. I personally prefer the paper gasket, that's what was designed to go there and my original lasted well over 20 years with no leaks so its got to be doing something correctly. if you do decide to go with fipg I would recommend at least going with Toyota red as it is designed to work with trans fluid and gear oil. you will also need the hub gaskets as they are paper as well and you will need to pull the axles out enough to get the third out

3. opinions vary on this, some do it because they can others just wait for a leak so that choise is up to you. there really isn't any special sst to replace the seals other than a screwdriver or small pry bay to remove the seal and a hammer and brass punch to install the new seal. it would also be advisable to service the rear wheel bearings at this time as well and do a bearing repack.

4. you will definably need the thrust washers for install as that is how you adjust the side clearnaces on the locker. as mentioned above if the clearances are either too tight or too loose it will be locked all the time or not lock at all. you can play around with the clearances to allow the locker to lock quicker or unlock quicker


some more of my thoughts and observations on install of my locker Lokka locker install instructions

Thanks for the link. The Lokka you fitted is slightly different to the Spartan. No thrust washers needed on the Spartan. I still may chose the aussie locker over the Spartan so this is helpful
 
You could get a full carrier auto locker like the grizzly locker, kind of best of both. Strength and smoothness.
 
All “auto lockers” (Spartan, Lokka, Aussie, Lockrite, Detroit, etc) based on tooth/gear type drivers and couplers are based on a 1955 Detroit Gear patent and they work the same way with very little difference in characteristics. The work very differently than open differentials and true lockers that actually fasten both drive shafts together (ARB) that act like a selectable spool. The big difference is that autolockers lock and unlock each side independently depending on wheel speed and whether you are accelerating or decelerating.

You will notice the different driving characteristics right away especially when executing turns. Around turns one side is driving and the other side ratcheting. When you switch from coast to accelerate in the turn, they change drive sides which can cause banging, tire chirping and other objectionable characteristics. If you adjust your driving style to accommodate the characteristics, then you won’t have as many problems. Different people have different opinions as to what is tolerable. It would be a good idea if you could test drive the same vehicle with an autolocker so you can decide for yourself what is objectionable.
 
Personally I would not install an auto locker in an '80. The strength of the '80 is it's general purpose abilities. An Autolocker will contribute negative handling driving quirks that I would not want in something that drives as nice as an '80.

And I would not install a Spartan locker in anything. You comment that it is simpler because it does not use (thrust) washers. Which means that there is no way to adjust for varying clearances due to manufacturing variance in the carrier. And these clearances do occasionally vary. You can toss it in and hope. I have seen more than a few autolockers that were too tight or too loose until the right combination of thrust washers were installed. Too tight will not unlock correctly. Too loose will unlock too easily and wear of extremely quick (Saw one last about 150 road miles and 50 or so trail miles before it was toast from being too loose.

Why they chose to design it to not use thrust washers is beyond me. I figure that is the cheapest unit out there and they maybe decided to play the odds and accept the warranty returns that they actually got hit with?


Mark...

Just curious Mark:
have you put on a spartan locker on an 80? Have you driven an 80 with one on?

I daily drive an fzj80 with a spartan rear locker all year through winter. Yes, has some quirks that are mostly unnoticeable.

I don't regret my investment- You will need gaskets: for the axles and the diff, and I'd get some new hardware- conewashers etc just in case you loose some or youneed htme.
 
Just curious Mark:
have you put on a spartan locker on an 80? Have you driven an 80 with one on?

I daily drive an fzj80 with a spartan rear locker all year through winter. Yes, has some quirks that are mostly unnoticeable.

I don't regret my investment- You will need gaskets: for the axles and the diff, and I'd get some new hardware- conewashers etc just in case you loose some or youneed htme.


I have driven all of the auto lockers out there in a number of different rigs, most of which I have owned and driven routinely, including 40s, 45s, 55s, 60/62s and yes, 80s too. Even Mini-trucks and Tacomas. ;) I have for years and I continue to. I have not had a Spartan in a rig I personally own. For the reasons I have already mentioned. But I have installed and driven them too. I don't think I have put a spartan in any of my rigs... maybe I did put on in the front end of one of the trail rigs once. Not sure right now. Anyway...

I have nothing against auto lockers in general. I am actually a big fan. They are tougher than many think when used in a Cruiser diff, and do a great job in most applications. Back when Detroit first brought out their "EZ Locker" version they did have some problems (I sent a batch of five back to the factory once they acknowledged the problems) but they solved that.

I am not an overly picky wannabe that is concerned about the quirks of an autolocker in most rigs.

BTW, I (and others) have found that Toyota full floating axles with autolocker installed tend to suffer loosened hub nuts much more often than axles with any other (or no) locker. We have attributed it to the constant shock (small but constant) of the locking/unlocking action. Like tapping on everything with a ball peen hammer. Eventually the vibrations have an effect. I apply a small amount of medium strength locktight to the studs and nuts if I put an autolocker in an FF rear axle. And make sure to torque the studs to spec before putting the nuts on. You do not want those working loose. Once one does the others follow quickly and broken studs come fast.

For me, the autolocker characteristic that I will not accept specifically in an '80 series, is the loss of constant equal differentiation and equal torque loading to the wheels. For me, as well as for most people driving '80 series they are not dedicated trail rigs. The primary use of my '80s are as road rigs. Yep, mine see more trail miles than most, but I still see a lot more road miles with them than trail miles. All year long, all conditions road miles.

If you actually use the rig in higher speed, low traction conditions where the "all wheel drive" aspect matters (Running down snowy highways like the ones I have to deal with right now after about 18 inches of wet snow yesterday or the bare ice that often covers the outlying highways all winter around here) then you really really really want all four wheels to be able to deliver equal power to the pavement without any of them being forced to scrub or skid going through a curve or having only one tire on the rear pushing as the other freewheels around the outside path.

That gives you a much larger envelope of safe operating parameters and keeps you on the road and on your way where you might very well have been in the ditch and on your lid without that ability to maintain full available traction. It has made a difference for me a more than few times over the years .

Does an autolocker make an '80 unsafe? Absolutely not. Does it reduce it's performance capabilities? Yes it does. I chose not to accept that reduction. :)

Mark...
 
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