New to Mud... Need some advice on replacing 3rd members and gearing down

[Minneyota86]

Hey guys. I've got an 86 pickup, manual transmission. I bought it a bit over a year ago and have been working on it and slowly learning through it ever since. The latest project is the bearings in my front diff are going bad, and I am going to replace the whole 3rd member rather than screw with the bearings. I figured if I need to replace the front diff I may as well gear down while I'm at it and replace the rear diff, too. I've got 31s on, now, and I don't plan on going bigger, so I'm thinking 4.56 would be the way to go.

This is where I'm not sure what to do next. My options seem to be 1)find someone getting rid of a front and rear diff with 4.56 gearing and hope they are in good shape or 2)find a good shop and have them build me new front and rear 3rd members. From the looking that I've done so far, it doesn't seem like 4.56 came stock on too many (if any) models, so my powerful deductive reasoning is pointing me to find a shop to build me new third members, ideally at a shockingly reasonable price.

Any tips, advice, thoughts on the subject? Are there better options I am missing completely? If a shop is the way to go, does anyone know of a good shop, online or local to Tucson, AZ (I live about an hour south of there), that would fit the bill? Any thoughts on a decent, realistic price range I should be expecting?

Any other details I've missed that I should be paying attention to?

Thanks in advance for the help! Much appreciated. I have a lot to learn.

Here's a picture of my pickup if you're interested...

 

[pappy]

As you have said, there are two options, more or less.

1. Regear the third member you have.
2. Get a third member already with the gearing you want.

The easiest thing to do would be to get the diffs from a pickup or 4Runner with factory 4.56 already in them. They were found in trucks that came with manual trannies and 31" tires from the factory. The VIN plate on the firewall has an axle code. Learn to read it. Sorry, too much in a hurry to look up the codes right now. This would be the way to go if you don't plan on installing any sort or traction device (locker, LSD, etc). You should be able to get them from you local boneyard or u-pull.

If you are going to lock the diff at the same time then you will need to evaluate the cost of gears, locker of your choice, and install kit ... vs ... getting the boneyard 4.56 and having the locker installed.

Also, if you go the boneyard route, the rear V6 diffs are a bolt-in and a stronger option to consider. Front is no different.

 

[dusty husky]

Front axle?

Finding a 4.56 front end shouldn't be to hard.They seem fairly common, my dd 94 x-cab has them, and turns 31s pulling a drift boat no problem There is one for sale on craigslist in Bend, Oregon & the local LKQ u-pull-it has a truck sitting there w/ 4.56s. These are third gens. 89-95. Look on the drivers side door jam tag, lower right corner should have a gear code( g254) would be 4.56.If the diff is out of the truck theres a paint code on the pinion nut, yellow is what your looking for, Toyota 4Runner Technical Information learned all this from the faq. sticky @ the top of this forum, happy hunting. I'm looking for factory 4.88 thirds for my 1980.

 

[fjfodee]

Or...since you're in AZ, check out gearinstalls.com. Zuk does nice work.

 

[jynx]

Check craigslist and eBay. I am always so jealous of all the Toyota parts that are always on CL in the southwest. Agreed that a set of stock diffs should be fairly easy to find. I found several, but could never land a pair so I ended up with a 4.30 front and rear.

Both from the net and I swapped the front in direct, no changes, the rear I replaced the pinion seal and put in a solid spacer before I installed it. So far no problems.

The 4.56 is perfect for 31s the 4.30 suited my 235s great.

As far as price, to buy a pair and direct swap them, probably $200-$300 for a pair. To regear you are gonna be in the gears and install kits for $300-$400 plus install and setup on both diffs, so depending on shop time and if you bring them in or they have to pull them, probably somewhere north of $700 total, and that is if you get a really good deal on setup. I've seen prices for installs go anywhere from $150-$300+ per axle.

Good luck and Welcome..

 

[Yotaonly]

You should definitely be able to find a set of stock third members to meet ur needs. Just look for a setup out of a '90 and up v6, 5speed 4Runner, they should all be 4.56's. And so you can double check, there's a code inside the driver's door jam, i can't remember off hand which code is for which ratio, and but a quick search should find you that answer.

 

[Minneyota86]

Thanks for the info! I'm gonna look for some stock 4.56s. Installing the lockers will be sweet, but I'm putting that off for another day.

Again, thanks. I owe you all a beer.

 

[2ndGenToyotaFan]

Look in the FAQ under differential info, there are a few links to the diff code information.

 

[raevenzero]

If it you can hold off a little longer, it would probably be better to do gears and lockers at the same time.

If you can't wait (because of bearing issue), run your good diff in the rear and keep it in 2x4 until you area ready to do it all at once. Depending on the locker type, you may have to remove the carrier, or at least a ring gear to install a locker. Best to do everything at once, and never have to open it up again.

 

[WarDamnEagle]

If it you can hold off a little longer, it would probably be better to do gears and lockers at the same time.

If you can't wait (because of bearing issue), run your good diff in the rear and keep it in 2x4 until you area ready to do it all at once. Depending on the locker type, you may have to remove the carrier, or at least a ring gear to install a locker. Best to do everything at once, and never have to open it up again.

x2 but only if you ultimately want lockers. Of course if that's the case then just buy two TRD elockers. They are available from the factory in 4.56.

 

[Minneyota86]

A quick update for those interested.

After looking a bit, I found a pair of 4.56s out of Oregon off a 95 4runner v6 manual. I opted out of installing lockers. Very tempting, but I can't afford them at the moment. If I would've done it, I wanted to put an e-locker in the front only.

Thanks for all the input! I'll let ya know how the install goes!

Brad

 

[Minneyota86]

I got the 4.56s installed! They went in great. We swapped over the non-add axle tube from the old diff. Things went pretty smooth.

After the install I got onto some gravel and tested the 4 wheel drive out. Awesome, except it still makes the sound in the left hub that got me started on this project in the first place. Since I kept the old side axle and bearing from the old, non-add diff, it could be that bearing is bad (the one right next to the flange connecting to the CV axle) and I just transferred the problem over. But we checked it out before we put it back in and it felt good. I put the truck up on blocks to run it and isolate the sound, and it really seems like the sound is coming from the left hub/wheel. It only makes the sound when the hubs are locked in. Is there a bearing in that hub/wheel configuration that is turning only when the hubs are locked? I haven't found one in the FSM, but maybe I'm just not seeing it.

Any thoughts/ideas on what that sound could be? I may need to take the diff back out and replace that bearing on the left side, but I'd like to rule out all other possibilities before I do it.

Thanks for your help in advance.

Brad