84runner

I have a lifted 85 4 runner 4 by 4. The engine is rebuilt, but other than that, the drivetrain/diffs are stock.

ok guys. I already made two posts about my transfer case and rear diff. At first i was told the transfer case was bad, but now a mechanic looked at it and told me for sure that it is the rear diff.

Can someone simply explain how a rear diff works to me, and the parts that could go bad and can be replaced. I am still unsure what a "third member" is, and how much/ where i can get a "locker." i'm assuming a locker is just a posi, right?

My truck felt like the driveshaft u joint was bad. A thumping feel and sound was coming from underneeth. However, the driveshaft is good, and the rear diff is bad.

What exact part is going bad/grinding to make that noise/feeling? Can i replace it with an aftermarket/better part? The mechanic said it is not the two main gears in the pumkin, but the part that transfers the power from the driveshaft TO those gears. Please give me some info on the terminology, prices, and where to buy these parts needed to replace/upgrade my stock/busted rearend.

I can't justify paying 200 dollars to replace the rearend with another STOCK and USED rearend.

thanks!

Sorry for my newb stupidity!

fiveofeen

sorry i dont know what it is, you do have a haynes manual for this vehicle that you have read through right?

toy283

This is a third member (a high-pinion in this case but standard low-pinion ones look similar):

It is the style of differential used by Toyota. It has certain benefits over the Dana style in that the differential gears, etc. can be swapped out much easier since you don't need to work on the whole axle. In all likelyhood, you have broken gear teeth, probably ring & pinion gear teeth. If you are reasonably mechanically inclined (and I believe you are from previous posts), you can swap out the third member yourself and save a bundle of money. Check the various bulletin board For Sale sections as stock third members with 4.10 gear (which is what you need) come up for sale quite frequently and are often dirt cheap ($50 or so). If you want to put new gears in, they will cost quite a bit more; $200 or so for the gears, another $100 for an install kit (bearings, shims, etc.) and another $100-400 for installation labor. Installing gears is not something for the average or even above average shadetree mechanic. As far as lockers go, a "locker" is a step up from a "posi" or limited-slip differential. In the case of a locker, the two axleshafts are locked together under most circumstances whereas a limited-slip will allow slippage more easily. Expect to pay anywhere from $150-450 for a locker depending on the type/brand you want.

In the end, paying someone $200 to swap in a used third member may be your best bet at this time until you decide what you really want. Continued driving on a bad diff will break it more until the point it leaves you stranded altogether. Get it fixed ASAP.

84runner

It's already so bad that i got "stranded". My truck(work and fun) has been sitting for the past week now. I would LOVE to upgrade and repair at the same time.

THANK YOU SOOOOOOO much for your kindness, and for not having a "your a dumb noob" attitude with me!

i have just a couple more questions to clear up with you!

Ok.
1. The ring and pinion are the "GEARS" that I would get to re-gear. Right?

2. The third member is different from the ring and pinion? Is that the gear that transfers the power from the driveshaft to the ring and pinion? or is it the entire set-up of the gears and pumpkin?

3. Is a locker something that you add to an existing diff, or do you have to change the gears etc. to use the locker?

4. So in order to rebuild the "entire" diff, i need the kit(100bucks) the gears(about 200) and what else to have a NEW diff?

thanks again. I can't stand not knowing what everything is and how it works! I also try to get the most outa my money, so nows the time to upgrade!
thanks again. and sorry for my lack of knowledge!

waskillywabbit

iTrader: (-1)

If you are a DIYer, then get a Factory Servie Manual on Ebay for sure!

jvmin

you can get used stock thirds all day long even v6 thirds for that matter for less than a hundred but having it installed is the costly part. and yes the locker types are very variable for your application. there are air lockers electric lockers limited slip lockers and lunch box type lockers. a drop in application will cost you anywhere from 200 for the locker and the extra cost of install all the way up to 1500 dollars depending on what route you take. selectable air or electric lockers are the best choice but also the most exspensive. the luch box type being the least exspensive type of drop in locker. then there is the spool option very trail worthy but not too street freindly. and of course you could always weld the rear into a spool if you wanted.

some prices for you
ARB air locker 650 - 1250 or so plus the cost of compressor and installation needs to be done by a professional. your best bet would be to buy one installed in a housing already. the cost will be higher for the preinstallation (selectable type locker)

e lockers vary in price from 500 to 1000 depending on who you buy them from and what type they are. (selectable type locker)

detroit locker (full time ratchet locker) needs to be professionally installed
cost in the range of 450 to 750 plus the cost of install and gears

lunch box tyes are cheaper but they too are also full time ratchet lockers
aussie locker
lock right
both are around 200 or so.
can be installed in the driveway with some limited mechanical skills

weld the rear spider gears together for a spool
the cost will vary by who does it and how much they charge you to weld it. unless you can weld then the cost goes down significantly.

then there is the spool they are cheap but are a real full time making the rear axle solid with no diferentiation between the rear axles at all. same with the welded rear end. both the last two mentioned are the least road freindly on tire wear and the spool need gears to be set up

it may be to your benfit to just buy a complete wider rear axle housing from hub to hub with all lines attached brake lines and e brakes. but the cheapest route will to be to buy a third from someone near you with the right ratio gears the installation isn't real complicated but does require some mechanical skills. there are 4 bolts on each end of the axle that hold the axles in the housing. the brake lines need to be unhooked from the rear brake calipers. the ebrakes need to be unconnected from the axles. the third member bolts need to be removed. the tire need to be removed. and you have to be real careful with the rear axle seals. you may have a rear axle bearings bad as well. if so they will have to be pressed off and repressed back on with the new ones.

so here are a few more questions to answer

is the truck 4cyl or 4cyl turbo?
is it carburated or fuel injected?
is it automatic or straight drive?
what size tires are you running?
how much money are you willing to spend?
how do you plan to drive it?
how do you plan to wheel it?
how much mechanical ability do you have?
or do you have some good mechanic friends?
do you plan to do the work your self or pay a mechanic?

here are a few things that might help you out.

do a google search for toyota forums and sign up for as many as you can
just read and search as much as you can with out posting questions
the search button is your friend.

do a search for toyota forums in your state

the rear end you have is most likely a four cylinder 4:10 ratio for a straight drive or a 4 cyl 4:30 ratio for a automatic. it is probably a two pinion open carrier that comes factory in almost every stock four cylinder truck built from 79-95 or so.

you could spend the extra and get a full rear axle from an 86 newer v6 truck for a little wider rear axle with a beefier carrier than the four cylinder. that will bolt right up in most cases. the rear axle is the same in the four runner with rear leaf springs and truck with leaf springs. unless yours has coil springs in the rear. if it has leaf springs you can swap in any axle from an 79-85 for the same width you have now or 86- up which will be a wider by 3 inches rear axle bolt in application. the flange may have to be redrilled for the drive shaft. but in most case any third member from an 79-92 will fit your housing. the v6 version will bolt right in for a more beefy stock third member.
you can even modify your rear housing a little and drop in an elocker from a trd. the ring and pinion are 8 inch

the forums mentioned will have parts for sale sections avilable to find the rear third you need. you probably have someone real close by who has one sitting there in his back yard waiting to go in your truck and they may even be able to help you install it if you ask.

www.pirate4x4.com is a great place to learn but be advised they don't take thier wheeling lightly and most are hard core rock crawlers drivers. so their remedy may not be what you need. and only post in the newbie section

www.4x4wire.com is another place to get great information

http://dreamwater.com/zuk/projects.html
http://www.off-road.com/toyota/cheaptricks/swaybar2/
http://www.toyotalinks.com/
http://www.off-road.com/toyota/tech/...ugs/index.html
http://www.wildyoats.com/about_wild_yoats.htm

www.marlincrawlers.com

I know this probably helped you because they sure helped me.
www.nc4x4.com is also a good place to get excellent information

jvmin

jvmin

and to give you some idea I got three complete rear axles for an 84- 85 for 125 and one had a locker in it. it turned out to be a detroit locker. the other two third were good with stock gears sold them both for a hundred dollars sold both housings for 50 bucks and the rear axles one set are my spares and the other two sets went with the housings. I had the third rebuilt with the locker in it for 350 with new gears and bearings. I also bought a rear axle from an 89 for 50 buck put the new rear in it sold my spares and the the stock rear from my truck with the new third from the 89 in it for 50 bucks.

so do some looking and you'll find what you need. and you may even get real lucky.

84runner

jvmin. You are my hero.

To answer a couple questions, and ask a lot more!


i have an 85 4runner
rear leaf,
4*4, Fuel injected
33 inch tires on stock gears
I am fairly mechanically inclined. Rebuilt a chevy 350 just fine, but know nothing about gears or these trucks (yet!)


I am using this mainly as my work truck, but enjoy some mild weekend crawling/off roading.

The 200 dollar lockers you mentioned sounded in my price range. So what exactly does the locker REPLACE? For example, pretend everything in my diff is fine, and i buy a 200 dollar locker. Will that be "added" to my diff, or will it replace something?
The ring and pinion gears stay the same, right?

ALso, the third member is the unit with ALL the working gears of the rearend, right?

You mentioned getting a v-6 third member. Will the gearing be the same? Will the third member fit into my existing diff o.k? You said that the 4 runner rearend is the same as something..... Is it the same as the v-6 TRUCK diffs?

If i had 4 hundred bucks to fix my problem and upgrade a little, what would you recomend?

thanks again! i'm catching on slowly, and i know I prob. sound retarded, but bear with me.

Thanks again!

4Crawler

iTrader: (3)

http://www.4crawler.com/4x4/4R_TechInfo.shtml#DiffInfo

Unless the rear axle is totally siezed, you can just remove the rear driveshaft, lock the front hubs and use 4H in the transfer case to drive around (in front wheel drive).

Nathan Buchanan

The "luncbox" style lockers replace the spider gears in the carrier, but keep the stock carrier. I've got an Aussie locker in mine; it was easy to install, and I love it. I think I got it for like 160 shipped from http://www.offroadlockers.com . I've got an open 4.10 third member for sale, but I'm in Oklahoma. You can probably find one that's in your part of the country pretty easy. That would probably be the way to go. The 4.10 4 cylinder thirds usually go for something like 40 bucks. If you got a few spares, you could blow up several used ones before you spent the money it would cost to get new gears set up. They aren't too hard to swap out, it just takes a little time.

Nathan Buchanan

Oh yeah, here's a link to the differential section of the FSM I have for my '93: http://personal.utulsa.edu/~nathan-b...35differen.pdf . You can see the pictures and check out how everything goes together.

84runner

How is that aussie for daily driving?

Ok. So i could get the locker for 160, the gears for 40, and a rebuild kit for 100 and have a completly rebuilt diff for 3oo?

thanks for any info. BTW- how much money would you want for those gears shipped to san diego 91902?

And will they match my stock gears, or are they lower, and also, are the 85 4runner and pickup diffs the same?

thanks!

Fahrenheit 451

I didn't read in-depth on all posts so forgive me if I missed it, but let's not overlook that you cannot regear only the rear axle if you ever want to go four wheeling again. The front has to match the rear and is significantly more difficult to R&R. Figure on more than doubling the costs of purchase and installation if you want to regear both axles.

Nathan Buchanan

If you buy a complete third member you don't need a rebuild kit. The third member is a housing that holds the ring and pinion gears. All you have to do is swap to swap in a different one is pull out the axle shafts, unbolt the third member, pull it out, and put the new one in. As long as you stick with 4.10 gears, if indeed those are the gears you have, you won't need to regear the front. You won't have a rebuilt diff, but it will be cheaper than one. the 85 4runner and pickup have the same differentials. The Aussie locker is pretty easy to drive around with. If you like to hot rod around corners, you may have to adjust your driving style slightly.

84runner

cool. Thanks a whole lot man.

The cleared a lot of questions up for me, and now i can at least make wise decision. Guess i'll be looking for a used third member, and if i can't find one i'll just buy some gears and a cheap locker!

thanks again.

Nathan Buchanan

Oh yeah, I would sell you the third member I have pretty cheap, but they weigh like 60 or 70 pounds. It would be more than it was worth to ship.

84runner

oh ok.

One last question. Doesn't my 85 4 runner have a wider axle than a pickup?

thanks!

Nathan Buchanan

nope, the 85 4runner and pickups had the same axle width. The 86 and up pickups and 4runners do have a slightly wider rear axle, though I can't remember exactly how much wider.

Biff

Try this


http://www.safari4x4.com.au/80scool/...ffs/diffs.html

84runner

ok guys. I just went to the junkyard and found a BUNCH of toyota pick ups.


I found many all ranging from a 1979 to 1991. They are ALL 2 wd, 5 lug rear ends. So will ALL those third members bolt into my 1985 4 by 4, 4 runner rear end, even though they are all from a 2wd? If they all fit, i'll just buy the one with the lowest mileage.

also, they should all have the same gearing as my stock one....Right?

thanks again. I can't tell you guys how much i apprititate it!