How to upgrade your diff


Active Member
When I first bought this truck I liked how it felt but found the rear lsd diff to be some what lazy, so I did some digging and found upgrades for it by calling up wier performance to see if they made a kit for our truck since our lsd is pretty much the same diff found in the mk3 supra 86 to 92.

So I paid for the kit which came to 45 bucks

I all so found another upgrade for our diffs as well form yokon

So some may ask is it worth upgrading the stock diff instead of buying a aftermarket lsd? is our lsd stroung ? Well the answer is yes our diff are very strong the casing will take 1000 plus hores power and not even wink as for the ring and pinon well thats the down fall of any 8 inch toyota diff and well ya cant really fix that.

The best part about our diff it's it's pretty much the first gen tundra diff and has joined baring caps to make the diff even more ridged to stop it front twisting under load.

OK lets get down to the tools you need to installed this kit

- Dail gauge
- basic socket set
- micrometer
- felt pen
- automatic punch or a punch and hammer
- paint pen

diff Oil

80/90 none syntactic oil preferred but I figure once I find it I will swap to 75/90
or if you want a smoother diff then just run synthetic oil like Redline 75/90

lsd addtive

yokon gear
ac delco stuff is gargbage

so drive you truck on the hoist or jack up the rear end in the drive way

clamp the soft brake line with vise grips or line pinching tool undo the brake line fitting then remove 2 bolts that hold the e-brake cable down then the 4 14 mill nuts that hold the axle in and then just pull the axle out

next un bolt your drive shaft from the diff and push it aside and then un bolt you diff and pull it out

Now the fun part keeping every thing in order

I used a white paint pen to mark the one side of the diff showing which side goes were you do not want to mix these up because you back lash will be off.

now it time to mark the case and then pinon for the spider gear so you know wich way then go it is best to use a punch for this one mark close to the top of the pin then one on the case

un due the carrier bolts and then take the diff apart and keep the plates in order and all ways keep the one clutch that has one blank side and one textured side on the case side this is what toyota used to shim the diff from the factory

once it is all apart you have the option on glass beading the stock coating off if you want a smoother diff might be an idea to leave it on but it does were out fast I chose to remove it so my spider gear back lash will not change as fast

next we start to shim the clutch pack and mic out all the shims

it best to start off with the thickest shim and go from there and then put your clutch pack in the lsd unit and pop in you spider gear assembly then setup your dail gauge and then rock one of the spider gears with you finger and see what back lash you have and add from there. I ran 20 in stead of the 005 target mostly because I ran out of shims and still way tighter then stock. ps may be good idea to ask wes to add more shim's to the kit if you plan to remove the coating. Ps you have to make sure you clean off all the oil or it will mess with your measure ment

then all ya do if repeat this on the other clutch pack

now ya just have to put it together just remmber the spring retainer plates go only one way and try to miss aline the retainer pins

pop in the new helper spring

slip on the plate and aline the pins and then place up cap on the diff to put it together then use to clamps to slowly clamp the case together wail making sure the pins are lined up

then torq the retainer bolts to 35 foot pounds

then use a dead blow to tap the shims back in

then tap on the carrie cap I useded 2 dead blows because well one just was not doing it because I was rocking it back and forth with just the one and I am sorry I forgot the bolt torq spec i will have to look that up at work

and there you have it a new better then stock diff that you will just love

ps it's best to use half the bottle of lsd additive when you first break in the new diff if you choosed to remove the coating you will not have to find a place to drive in figure 8 for about 1/2 and hour at about 30 km then after that drain the oil and then add the rest of the bottle and then enjoy

warning the diff will clunk abit for awail tell it break's in this is normal if you don't like the clunk you can just run synthetic oil this should make it clunk less

I may dump my fuild out that i have right now but my clunk is going away.

well i know there has got to be about billion spelling grammar mistakes but all fix thosu later and add to the write up cheers for now
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Active Member
It's pretty easy took me about 2 hours for a frist timer much more but it's not very hard to do. No if you had to re do your back lash or replace Pinon that take longer becase you have to make a jig up or buy one

x-runner kid

Active Member
I tempted to do the Yukon upgraded plates though. Although it says on the site it's for aftermarket eaton positraction only.


Active Member
I tempted to do the Yukon upgraded plates though. Although it says on the site it's for aftermarket eaton positraction only.

ya i saw that but kinda does not make sense I think it's best to call them and fully confirm

if not leaving the coating on will be fine

the big issue is the stock spring is fairly weak and the clearnce in the spider is way way to much and make for a fair bit of play

further more after Christmas i going to try to swap in some synthetic oil like I did in my other truck what is metal on metal plates

x-runner kid

Active Member
You think just a spring and shim kit without blasting would be ok then? I'm a noob when it comes to diffs but I'm very mechanically savy.

x-runner kid

Active Member
Oh I somehow got a faulty throwout bearing upgrade. So gadget hooked me up with a new one. The other one lasted maybe 2k. I figure when I'm in there I'll put in a new clutch release fork also just as cheap insurance.


Active Member
Im looking into doing this to my lsd. And was wondering if the stage 2 kit with the spring plates and spacer would work on our diffs and whats ur breakaway torq right now on ur truck.


Active Member
just call him ask for more shims if you plan to blast your plates mine is aggressive if ya want it abit less aggressive run the coating or blast them and run synthetic oil if you find it to much

I truly love my diff makes my truck so much fun to drive and no second guessing ever