m3technic

my 01 4runner all of a sudden started to sound like a machine gun. sounds like its coming from the rear differential. the truck has a s.s 1.2 lift w/ 315/75/16 tires just to give yall some info. checked my u-joints and greased to crap outta them. i thightened the flange nut and didn't really get much movement. i had to stop driving it and i parked it at a friends house. so i really have to get this taken care of asap. so any suggestions?? i dont know if i should just get a used rear. or regear everything. and what the easiest way would be to go about it. yadda yadda yadda also is there an easier way for me to check what gears are in it now rather than that chart floating around on here? because the code fore my truck gives me like 3 different options it coulda had. i know it has the factory e-lockers if that helps. thank you in advance for you help.
oh yea i also pulled the check/fill plug just to look at the fluid and level. the diff fluid appeared to be kinda of metallic, i did not pull the drain plug though to see if there were any chunks.

brian2sun

All elocked 3rd gen 4runners came with 4.30s. I would pull the plug and look for chunks. Also, spin the rear by hand in neutral, you should be able to hear the carnage. A new complete axle would be more expensive and hard to find with an elocker. An elocked 3rd would be easier to find and easier to install than a whole axle. Or, you could repair yor diffs depending on the severity of the grenade that went off in there.

BornChaos

I'd say at least pull the third member (after you've isolated the source of the noise to be from your rear diffs and confirmed the presence of debris in the oil by draining the rear diff) and see how much damage was done. If I remember correctly, its was around 400-500+ parts here in Ventura, CA to have a shop bench install some new gears and an E-locker assuming everything fit properly and no modifications were necessary, i.e. the use of a toyota E-locker. See whats damaged and what needs to be replaced, and you can save money by removing/installing the axles and third member yourself, just don't disassemble anything so a that the shop that does your rebuild can know how things go back together.

m3technic

so i can just buy a 3rd to slip into the axles? any suggestions on where to find an e-locked 3rd? and do you think i should just put the 4.30 back in? or should i re-gear to prevent a reoccurance? thanks again for the help.

UKMyers

Sounds like your Ring and Pinion is done.. I've heard that sound a few times now with mine on 37's. You won't be able to hear it spinning it by hand unless it's really bad. Throw it on jackstands and stick it in 2nd gear and let it spin. I had to actually load mine by acclerating to hear it this last time around. On the coast side it would not make a sound. Be prepared to pay a pretty penny for that E-locked 3rd. They are pretty highly sought after. Might be a good time to just regear. A Ring and Pinion and a rebuild kit is way cheaper than an entire third. If your running 315's you'd be way better off with 4.88's anyways. Just don't forget to do the front too if you go that route

Here's what mine sounded like

http://www.youtube.com/watch?v=Jrj3kc49Paw

Elton

im thinking mines getting there too its got some play to it

Bajallama

Pull your driveshaft and manually check the rotation of the u joints, I bought a whole new third member as I thought It was my differntial also, turned out my u-joint on the shaft was seizing up causing the vibration, I'm on my third driveshaft now! However I do have a 2wd 4cylinder with non-greasable u-joints.

Your ring and pinion is allowed some play, usually from .006 to .013

Mauzer

Did you put the elocker axle in yourself? the rear elocker was not an option on the 01' runner, they have a center diff lock

J2F42C

+1 on the ring and pinion. But to start, drain the fluid and see what it looks like. Then you will have a better idea on how to proceed.

For gear ratio ID on a 4x4, look on the driver's door jamb for either A03A/ (4:10) or A04A/ (4:30) to identify gearing.

The electric locker for the 3rd gen did come in a 4:10 ratio, but it is not as common as the 4:30. I am looking at mine 4:10 axle right now.

brian2sun

Good point Mauzer, that elocker would have either been retro-fitted because they were discontinued after 2000 (or he's referring to his center diff locker which is totally different) and that means he could have any gear ratio. I've never heard of a factory 4.10 elocked 4runner ever, just tacos. Are you sure yours wasn't retrofitted from a taco, J2F42C?

J2F42C

It took me quite a while Brian to find one but I did (1999 axle and all) from a yard in Deleware. I made the guy pull out the diff just to count the teeth. I'd going to do the axle swap rather than replace my axle bearings thanks to the inner seal leak. My stock is 4:10 so I wanted to keep in line with what was there. I know you hit the salvage yards out in your neck of the woods quite often; I guess the 4:30 is much more common in CA, and maybe in the rest of the US.

BTW, the Part # is: 41110-3D030, possibly the same as for a Taco.

ChildrenOfBodom

Just my opinion... if you're going to go through all the trouble to change your gears out, might as well regear to 4.88s like someone suggested above.

I only have 32" tires but I even have 4.56's over my old 3.91's. I had a similar noise, in my case, the shop I had replace the axle housing seal (i really just did not want to do it at all) tightened the carrier to the point where the bearings broke. I made them pay for an all new 4.56 3rd with detroit posi.

I understand that with two diffs, it's expensive as hell, but no better time than now.

I used Jaw's Gear and you can order the turbo/v6 3rd with an ARB air locker, powertrax, e locker, posi, or whatever type you want...

edit: forgot to mention I replaced the u-joints too because they went bad. I had a bad vibration on the road during acceleration, too. Grease couldn't have saved them... in my case.

brian2sun

CoB, how are you liking the new gears and posi? Cangrats!

m3technic

ok so apparently i am wrong about the e-locker thing it is the center diff lock. sorry for the wrong information. does this in any way change what gears i have and what gears i should get? and i am pretty sure i am goin to go with 4.88's and just take them to a performance driveline shop to get them put in. does anybody have any suggestions on where i should get them and what exactly i should get. there are too many confusing options for me to just be like "i want that one". should i buy as a third member, as a gear rebuild kit? or what. never re-geared so please bare with my stupid questions. thank you for all of the much needed quidance! now just to make sure 4.88's are the right way to go. i have 35's and i drive it everyday and i pull a pop-up camper on the highway a few times a year. so i still need it to be very much road worthy.

m3technic

UKmyers, thanks to the video. that is exactly what it sounds like. basically a wwII turrett machine gun.

brian2sun

Since you don't have an elocker, you could have anything between 3.91s and 4.56s, but most likely 4.10s. I would not attempt setting up your own gears unless you are an experienced mechanic or have done it before becaue you must be very precise when you set the backlash. If you take out the 3rds and send them off, it'll probably be cheaper than taking to a shop, however the front diff is a beast to R&R IMO. Check out eastcoastgearsupply.com, they send you rebuilt 3rds with the ratio of your choice and optional lockers installed (which now would be the best time if you want to ever get a diff locker). When you get them, you install them and then send your old 3rds back to them in the same boxes for a core. They do fine setups too.

BTW, the center diff locker confuses just about everyone who is new or doesn't wheel much. It gives no off road performance gain. It's for icy/snowy/wet on road conditions. Center diff locked is 4x4, plain and simple. Center diff unlocked functions as an in-between 2hi and 4hi, very similar to AWD and gives you more traction while still allowing the front and rear axles to spin at different speeds and not bind up.

4.88s, 33s, 3.4, and auto tranny = perfect. Since you have 35s, 5.29s - for sure. Your freeway rpms will still be fine.

m3technic

so you think i should go with 5.29s? you think it would be dumb to go 4.88s? and if i get lockers put in does this mean i would be using like an arb air locker? and i am going to check on pricing but is that alot more expensive?

m3technic

and what size like 7.5,8.0? sorry first time im regearing

m3technic

what is the difference in say a lockrite and a spool? are these no go to go with? what is good to get but wont kill my wallet. arb are like 775 extra where as the lockrite is 260 and spool is cheaper yet

brian2sun

Mine used to be my DD and 4.88s are totally fine - 3K RPMs @ 80 miles per hour. The O/D gear is so tall in the autos that 5.29s and 33s would even be acceptable on a DD, but with 35s it would be a no brainer IMO. I would only consider 4.88s and 35s if it was a stick.

You have a 7.5" hi-pinion front diff with reverse cut gears. Your rear is called the 8" V6/Turbo diff.

You could do an automatic "ratcheting" style locker, an LSD, or a selectable locker (i.e. ARB or factory elocker). Selectables are the best for DDs, but are the most $$. Ratcheting lockers are cheaper, but will make noise and occasionally bind up on a DD. LSDs are very smooth for a DD, about the same price as a ratcheting locker, but do not provide quite as good traction because they will still allow some slippage.

Of the ratcheting type, there are ones that do not come with carriers like Aussies, and ones that have their own carriers like Detriots. The ones that come with carriers are a little harder to install and a little more $$, but are stronger. I went with an ARB because at the time it was my DD and nothing beats being fully open on road and fully locked off road - at the flick of a switch. Still, many people love their Aussies and Lockrights on their DDs so they're not that bad on road.