Figuring out gear ratio <stupidly common, I know>

Hey all, it's nice to see so many people are into Yotas versus the other garbage out there. Every vehicle has is quirks, but I tell ya what, I've never had another truck go as long and as cheaply as mine.
I've had an '96 SR5 5spd 4X4 for about five years now and I got it when it had 323K on the dial. I know, it's a lot, but I know a guy that was a master tech for Toyota that told me it didn't matter, a few things and she'd be good. Well, there's 374K on it now, and it's been totaled by my insurance. I t-boned a Ford F-150 back in February when he blew a stop sign in front of me. I folded him in half and all I did was bend in the bumper, various sheet metal and the front clip a bit on my truck. I used a chain fall to pull it all out and she runs fine. Now she's my parts truck for my '98, which brings me to the point.
I just got a '98 SR5 5spd TRD Tacoma with the rear e-locker in it. Only 222K on this one and she runs AWESOME! Problem I'm having is craploads of chatter coming from the rear end. I've already made all the fluids current, and there's no slap in the u-joints. I don't think it's the transmission (I opened up the rear slider window and listen when I'm accelerating and decelerating) because when engaging the clutch you can still hear the faint "noise" that just get's louder when under load (uphill or down). So...I believe my third member is in need of rebuilding or replacement. I've talked with my resident tech and looked all over the interwebs to figure out what gear ratio I have in that puppy so I can get parts and no one seems to be able to nail it. I've got the code from the inside of the door, as does everyone with this question but maybe this'll be the powerball winner.It's C/TR 3K4/FC40 (then) A/TM B03A/R150F. VIN#: 4TAWN72N8WZ138611. From what I've read the "B" represents the 8" ring gear, the "03" stands for 4.10 gears and the "A" stands for the two pinion design. Then there's differences of opinion on whether or not its "open" or not. Keep in mind I have NO FLIPPIN' CLUE on what to do here. Also, I guess the front's a different ratio? AND they have to match? HUH? I've done a lot of wrenchin' in my life, but never any drivetrain work. I really don't care for regearing this thing, I just want to stay bone stock. It's got 33's on it which dogs me a little, but you'd be amazed man, there's really no loss of power compared to my '96 with the 31's and I took the Elephant Hill course up past treeline outside of Empire, CO in 4 low with absolutely no problems when a caravan of Jeeps ended up with quite a bit of damage on the same trail. SO, I don't want a kit to tone it down, thanks in advance on that. Anyway, as you can see, I love to rant and can go on for days, so get back to me with some advice please and I would greatly appreciate it. Have a good one guys.

 

How did you know what code to look for?
You should have 4.10s I don't know what is wrong with your differential, but I would drain the oil (make sure you can remove the fill cap first) and see if there are metal shavings in it first.

 

Thanks man, preciate it. I knew where to look cause my tech friend told me, but I still read the numbers like they're russian. Either way, after I got the truck I drained and refilled the rear diff, the tranny, t-case, front diff and the engine and logged it so I know I'm current on that. When I drained the rear diff the magnet plug had a TON of fine sediment on it (looked like globs of silver anti-sieze). No chunks or anything though, so that's okay I guess. As far as driveability, there's no slipage and there's no broken teeth, but the chatter is driving me CRAZY! My '96 has a ton more miles on it with no issues like what I'm gettin.

 

I WOULD be willing ta go ahead and just BUY a complete third member with the e-locker for that truck just so I don't have to go through the hassel of paying someone to rebuild mine. I would rebuild it but I don't have the shop press or the time to mess with it.....

 

It could just be a bearing, but I don't know.

Hopefully someone else could fill you in.

 

Fer sures tterror. Tech friend said the same thing. Like I said, I ain't familiar with the drivetrain at all except maybe installing a clutch/flywheel/etc. Gears aren't my fortei. Yessir, it could just be a bearing, but I think we can both agree that if yer gonna split the third member open you should plan on rebuilding the thing so it's all current on everything (bearings, sleeves, shims, pinion, etc). That's why I'm thinking I might try and find a complete one with lower miles than what's on my truck. I got a couple lines on yards here in the Denver area. I like Yota Jims more than anyone, but there's also Yota Yard and a few "all make and model" yards around. Anyway, I'm stuck with having someone do the work if I decide to rebuild it as it stands right now. I'm on the fence man.

 

If your '96 has the same 4.10 ratio, you could swap over the entire rear axle housing with its diff. Of course, you'd lose the e-locker.

The third members are totally different, so they aren't swappable.

 

Yea, it looks like the one with the locker is a different shape alltogether. Prolly would just go ahead and swap the entire axle with the third member attached like you said. Gonna talk to Yoda Jim and see if he'll consider a truck trade + cash for a third member w/locker tomorrow. That thing's road legal and it's got a lot of usable parts, I dunno.
On another note, I crawled under the truck (new little guy) today to see why I was shifting real hard from first to second and found out that one of the boots on the tranny mount (the one that crosses behind the t-case) was completely blown out. I swapped the one from my '96 to band-aid it till NAPA gets me a new one from Utah, but even it's got a lot of miles on it and ready to blow out on BOTH sides, lmfaowf ("wf": with frustration) Thanks for the heads up on that third member though, saved me a couple crouches under the s.o.b.

 

When I drained the rear diff the magnet plug had a TON of fine sediment on it (looked like globs of silver anti-sieze).

^^^^^^^^^^^^^^^^^^^^^^^^

not good at all, even if a bearing, the gears are already starting to degrade because of the large amount of suspended particulates (silver globs)

 

Mos def "bald eagle," my thoughts as well. Plus, with all the chatter I might as well pop in a new one (if I can). I will definitely drain and refill the fluid a couple times over a week or so to make sure that all the "metal glitter" is out of that axle housing before calling it good with a new third member though.

 

Can I swap the rear diff from a 4Runner w/locker and same ratio to the Taco?

 

Addition to above: I'm a budding welder and am using a Millermatic 212 with all the other tools to make a welder worth while so I'm willing to do the mods to chop off the coil mounts and weld on leaf perches.

 

There is a place located here in NC that sells complete refurbished 3rd members.

East Coast Gear Supply

Just so you know, your differential is smaller than ones without the E-locker.

 

Thanks brother, you took my attention back to that company. MAN I've spent a long time online in the last couple days looking for a reliable and cost effective third dude, and ECGS looks like the best for the price. I've seen 'em for over a grande elsewhere. Tell ya what, if I can't get my trade or find a decent swap over I'll go with these guys. Thanks again.

 

I don't know if this is true or not. Or if it just applies to 4x4s but my code is B03A...seriously doubt I have 4.56s.

 

B04A*

 

False alarm. I got the 3 and 4 mixed up from the code above the axle code...carry on.

 

I hope and pray that whoever had this '98 before me didn't do any gear changes in it, because if so then if I go with what Yota calls for (4:10) in the rear and the rest of the train is different I'll end up with the same problems. Best way to figure this out would be to peel apart the front and count teeth to be sure. Have ta say, I really didn't want to plan on wrenchin' on this puppy after only four days of owning it, but that's the way she goes sometimes, lol.

EDIT: And the only way to figure out if the tranny was regeared is....well, a bit of a project as well.

 

The ratio (or teeth counts) are usually stamped on the outside of the ring gear. Of course, you'll have to remove the diff to see it.

 

You know how many times I prayed to wake up the next day with x-ray vision?....dude....