USA Standard Gear Spartan Locker for Dana 30 diff, 27 Spline, Includes Heavy-Duty Cross pin Shaft

This is a very nice locker. it works very well and installs easily with hand tools and no special tools, knowledge or equipment. (you just need a torque wrench, sockets a punch for the roll pin) Offroad this thing is amazing and will pull your jeep over things that were impossible before. However on-road this is VERY sensitive to tire pressure. Make sure you rotate your tires often and monitor tire pressure frequently. even 1-2 PSI is enough for it to act squirrely. This is especially noticeable for the first 1000 miles. During break in even in 2wd with the locker in in a front differential, It can lock up and make the jeep hard to handle. After it gets worn in - it works like a dream but if you put it in right before winter you will struggle. During break in the unlocks are LOUD -almost like a bang. You will get looks in parking lots where people think you broke something. The steering is much tighter in 4wd then before you put this locker in and it will not turn as tightly in 4wd. Offroad in 4lo with this in the front dana 30 you will have to make more multi point turns (or get a terra 2w low kit for your np231 so you can shift in and out of 2w/4w low on the fly to get the front to unlock) The TJ i put this in didn't work right until i ran it through a couple tanks of gas and flat towed it at 65 for about 650 miles - then it was good to go. In the YJ i put this in it wasn't "right" with the world until just after 1000 miles This does have some negative driving characteristics in 4wd as well. If it's icy you need to be very careful - if you have this in the front axle it will understeer and the locker will not always differentiate because it needs that friction with the road to do so. you will find yourself putting more and more wheel into a turn and then when it finally unlocks it will get squirrely. It will also understeer and is much more likely to loose lateral control in the ice. If you put one of these In the rear it will torque steer (pushing you in a straight line) for as long as you are on the gas. If you don't watch it closely you WILL do unintentional lane changes or donuts when its icy out on the road. Do not just toss the keys to your buddy who doesn't know how to drive an auto locker in in a light vehicle when its shitty out. It will take some time to learn to drive it, you drive allot with your foot - you learn to let off around curves, lane changes etc. Make sure to give yourself some time to adjust to how to drive one of these on the road. Spend some parking lot and back road time with it when its crappy out until you get used to it. When shifting out of 4wd the jeep will have a tendency to not unlock the front axle. If you let it roll with the trans in neutral and turn the wheel back and forth a bit it helps. This gets much much better after you break it it (that first 1000 or so) Finally if you didn't pay attention to the tire size limits - you are much more likely to break axle shafts with larger tires with one of these. Make sure you know out to pound out a u-joint or pull and inner CV . I didn't start breaking things until i went over 33s then it was quite often until i went to 4340 chromoly shafts. The inners are what tend to break on stock shafts and the CV cups blow up on the ZJ shafts. basically take your time, learn to drive it, keep in mind of the limitations and dont judge it until you have that first 1000 or so on it and enjoy the massive off-road advantages

Overall it's a cheap locker, it works when in 4wd and you can't tell that it's there. In my short time running this locker I like it and this review will change based on my experiences with it. My reason for buying this is my U Joints in the Dana 30 High Pinion on my 1998 Jeep Cherokee decided to sheer off some teeth from binding and this was roughly the same price as a new set of spider gears so I gave this a shot instead of getting a front selectable locker. After I installed this I noticed my jeep now tracks a lot straighter and doesn't have as much wander on the highway. When driving at low speeds, lock to lock, there is no audible ratcheting noise or popping, if you are familiar with Cherokees or any vehicle that has U-Joints in the front with a 50-50 power split as in the NP231 in a Cherokee when in 4wd and turning on pavement the vehicle wants to hop due to the U-Joints binding, this is natural of 4WD; however, when this locker is in 2wd there is no hoping or rubbing but in 4wd there is noticeable rubbing but no hopping due to both tires spinning at the same rate while turning on the pavement. When climbing over obstacles in either 4H or 4L you can tell the front axle locks up due to the reduced throttle needed when climbing rocks or barriers, in off-camber situations when one tire is either at full droop or on lose material and the other tire has full traction both tires spinning at the same rate as a locker should and unlocks as soon as I engage 2WD. Overall it works off-road and I can't tell it's there in my daily driving. I'd recommend this. Installation - went easy cant have any complaints, in my Cherokee I had to pull the diff cover off, 4 bolts to get the carrier out, took the ring gear off by removing the retaining bolts and smacking the ring gear off with a hammer, you use a small punch to remove the retainer pin of your main cross pin to removed your spider gears, make sure all 4 of your thrust washers are removed, you put the spring into the locky key way thing and push it into the locker and insert a little metal pin that they include, you do that 4 times then you put your splined locker gears teethy things into the carrier then insert the two locker bits that have the metal pins, you pull one metal pin out and allow the locker to engage, once engaged you pull the other three out, then roll the center of the carrier to allow the new cross pin to slide through and put a new retainer pin in that is also included. After you punch the pin in you're done installing the locker just reinstall your ring gear with a soft hammer and put the bolts in torque em to spec reinstall into the pumpkin, bolt up your 4 carrier bolts that go in the pumpkin to retain the carrier then throw some gasket maker on the diff cover bolt that down and fill it with fluid and your done, I'd recommend you jack both tires up and or put em on jack stands so no tires are on the ground, when you turn one tire they both should turn in the same direction indicating the locker is indeed locked, to verify proper clearance and that you wont blow up your locker have a buddy bear hug one of your tires and spin the other if she make clicky ratchet esk noises you're good she'll unlock when you turn in 2wd and when you are in 4wd sending power to the front diff she'll lock up. To be noted I am running 8in lift, 35's, long arms, 1 - ton steering, and during the installation of this locker, I replaced my U-Joints, hub bearing, brake pads, and the spider gears due to installing of the locker so my experience may be influenced by the new surrounding parts.

Easy install, functions as it should. Great way to lock up your Toyota's front end.

I installed it into a Dana 30 HP for my 99 XJ. Really easy to install, it took a couple of hours. Perfect fit, follow the instructions to the dot and you will be pleased. For my application, it is really quite, I can barely hear it while turning. BE AWARE, it might lock and unlock (in 2WD) the first 10 miles. I drove my Jeep to a parking lot and drove in circles forward and backward for a few minutes to help lubrication and to brake-in the locker. Then I drive around town for 20 min. Finally, I took it to a fire road to see how the locker works, I put it in 4 low works like a dream. It is a day and night difference. Ever since I have driven the jeep on the freeway for over 200 miles (commuting) and that has helped with lubrication. Now the locker is even quieter. I am planning on replacing the diff fluid in a few more hundred miles to remove any potential debrief from the brake-in process.. Instructions don't say anything about it but I figure gear oil is cheaper so why not. I should be going to Moab and other off-road trails in the following months, I will give an update on how it holds. UPDATE 10/23/2019 - I have run it for about 1000 miles, I have got really quire, even when I am at full lock turning in parking lots. I run Valvoline 80w-90. I have taken it off-road (Moderate trails) and it has performed great. Something that I have noticed is that right after using it on the trails, I would go back into 2WD and it gets way noisy!!!! but after driving for 20 miles it goes back to quite mode!! Loving it! IT WOULD LOCK AND UNLOCK once in a while when backing up and turning, but you can feel it in the steering wheel, it makes a loud pop noise, but if you were the one installing it you won't freak out, you would be able to tell "bad breaking noyses" from the locker loading and unloading lol 11/21/2019 Took it to rattlesnake trail (moderate to difficult) in Utah. I performed great. I was able to struggle less than my buddies with larger tires and open differentials. I have put around 3k miles on it. The more I drive it the quieter it gets. Now I can only hear it sometimes when turning full-lock on parking lots. It stopped locking-unlocking on his own while driving in 2WD on parking lots and tight places. I will keep you all posted. 12/19/2019 I have driven it for 4k miles now. I went to Moab last weekend. Wheeling on slick rock was like driving on pavement sometimes. The Locker would bind and lock and unlock pretty hard. So I had to take my turns pretty easy and some times I would cost in neutral. (I have a 5 speed). I still love it, I got me over obstacles way smoother than my buddies with bigger tires. I was able to take the hard lines on trail w/o major issues. The locker has gone quieter after many miles. I can hardly hear it while turning in parking lots.

Works great but it is noisy in a tight radius turn. I expected the noise so for me no problems

I put a Spartan locker in my '87 F150. It's a 2wd truck and I was having traction issues in wet grass if you know what I mean. This locker costs $300 and its pretty simple to install. You don't have to take the gears out of the pumpkin. The directions weren't clear on how to get the C-clips back in but I found a video on YouTube that explained it perfectly. Now that I've done one the next one will be a breeze. With this type of locker the wheels are always locked in a straight line. When you turn and the outer wheel wants to go faster it is allowed to do so because the locker can unlock when driven by the wheel. It just will not unlock when driven by the gear. It's like a one-way thing. You here a noticeable CLICK - CLICK - CLICK when this happens. I think it sounds cool, doesn't bother me at all. The unlock function of this design is 100% dependent on traction. When I turn sharp in my gravel driveway there's not enough traction to hold the tire. So the tire cannot transmit enough force to make the locker unlock and that wheel spins in the gravel. Of course this only happens when you are turning. If I goose the throttle it will pitch the truck sideways. If I am easy on the gas, that wheel just spins and it's no big deal. It's actually a lot of fun on dirt & gravel roads and I imagine it would be fun to play in the snow when acceptable! No snow where I live, so can't say for sure on that. Once you understand the limitation of the locker it's perfectly safe. But you will want to be careful until you get it figured out. The truck will go sideways on you when you goose the throttle in a turn. This is because the outer wheel is turning faster than the inner wheel, so the outer wheel is unlocked. At this point the only wheel being driven is the inner wheel. If this wheel loses traction & spins it allows the ring gear to go faster. Once the ring gear catches up to the unlocked outside tire it will LOCK and now you are driving both tires again. Hopefully traction is regained, but if you were goosing the throttle probably not - and now both rear tires will break and the rear of the truck will go sideways. Not a problem as long as you don't play happy feet with the throttle. For me with a 2wd truck this type of locker was perfect and a lot cheaper than an Off/On style of locker. Plus there is nothing to wear out, it should last the life of the differential. Update 2/14/2014: Tire squeal on pavement depends heavily on what tires you are running. I had 30x9.50 Cooper ATV/3 off-road tires on the truck when I installed the locker. These tires slipped enough when turning on pavement that I didn't notice any tire squeal. I swapped these wheels and am now running 30x9.50 Michelin LTX M/S tires. These tires squeal much more on pavement, in turns when you give it a little throttle.

Installed November 7th 2025, everything went smooth on the install, it’s fairly simple but time consuming if it’s your first time “it was my first time”. There’s tons of videos on YouTube that show step by step how to install this exact locker. I’ve only tested it in a small field and it seems to be working. I’ll do my best to keep this updated.

Works great, installed this in longwheel base 2wd ford f150. Daily driver, difference was from night to day. Originally had open differential (one tire fire) slapped this locker in. Took about an hour. At first it sounded horrid when first installed was ready to take it out, loud bang an pops at ever turn, worse with sharp turns, caught looks from everyone when entering parking lots or drive thru, chirping tires, teeth clicking an whining noise. But after about 500-1000 miles it got better, quieted down quite a bit. Currently at almost 3,000 miles after install an I hardly hear it, super quiet now. I only hear it if windows are down, music off, on a slow turn, and that's still barely able to hear it. Install was a little tricky, wasn't able to get center pin to go back in, quick google search and other people had same issues, fix was to throw the center pin in the freezer for an hour or 2 Edit almost 1 year with it installed, after break in period I changed fluids, kinda went a little longer then I should have not changing fluid after break in period. Started locking up hard, changed gear oil to heavier weight oil. I forget it's even installed sometimes catches me off guard when it wants to lock up coming out of a turn, from me giving it gas. Took it off road once or twice to really test it, only got stuck once cause my chassis bottomed out. Preforms damn good, nice bang for your buck.