Dan_P

this may not be of anyhelp at all im sure these guys are right about the gears
but i once had the problem when i had an old chevy 4x4 and all 4 tires were not the same size the front where like 225 x 15 and the rear were like 235 x 15. swaped the front for 235's and the problem went away. you could always check the air hose and conector on the add and make sure its all hooked up maybe even pul the plug and clean the terminals? just a thought

Reedr125

I may be wrong, but I think I heard somewere that for certain situations running 2 diff gears was the way to go. Not sure if its rock crawling or what but I think it helps pull the front end up more. Is this a street truck, any mods or anything? Has it been trail ridden? Maybe your truck was modded this way for something the previous owner was doing? Never know, but I would say diffrent gear ratios. I would switch the rear diff to the front gears, would be super easy. And you could sell the diff first to cover most of the costs. Just need to find yourself one!

toyotabull

Ok, block the front tires, put the truck in neutral and jack up 1 rear tire. mark your driveshaft and your tire. Now turn the tire 1 complete rotation and watch your driveshaft and see how many turns you get. Then do the front the same way, jack up 1 tire and lock the hub, mark it and the driveshaft, what you want to see id if the driveshafts make the same amount of rotation. might make 4.5 rounds or 4.1 rounds, and that will tell you which one is different from factory. Hope it makes sence.

retrospect

Okay so I went under the truck and looked one more time at the diffs. No markings... except the front seemed to have some white and yellow chalk markings that were somewhat gone due to driving around. This make me think that its the front that has the incorrect gears but let me continue....

I jacked up one rear wheel, marked it and counted driveshaft rotations; I come up with what looks like 4.56 gears in the rear end.

I did the same to the front; I come up with what looks like 4.10 gears in the front diff.

When I decode my VIN using this website
http://http://www.brian894x4.com/Gearratiosanddiffs.html
It says I should have 4.88 gears.

So where does that leave me....Can the VIN decoder be wrong? I believe by looking at the truck and being under it, it has 4.56 gears and it came with 31" tires (the door plate confirms this). The rear end seems untampered with.... but the front, as mentioned above, has chalk markings so I think it may have been at a yard or something and the chalk was used to ID the front diff. But then why does my VIN say 4.88's?

Now assuming it does have 4.56's and it did from the factory, I would want to fix my problem and get a new front diff to match the rear. Is it hard to replace the front diff? (I CAN get the part locally)

I know I could alternatively go 4.10's in the back and it would be way easier but seeing as how my truck is an auto and I plan on maybe going to a 32" tire in the future, I want to have the 4.56's.

Shed some light yotatechers!!!

PS: Stuwy123 I see your a member of CT4WD, I plan on going for my intro course soon, but judging by my current problem, I may need to go for CT2WD hahahah.

Stuwy123

iTrader: (1)

I'd trust my door jam over the internet. And I'd trust physical results over my door jam.
My door jam says G292 (4.10's) and I stuck in 4.56's (G254).
If you want some 4.88's so you can run bigger tires, I've got a set for sale if you want to make the trip to calgary.

As for replacing the front diff, it's almost a two person job. You can do it by yourself and a floor jack (with ratchet straps). If you've never removed one before, it's an all day event. Be sure to eat your wheaties that morning, that sucker is heavy.
Easiest way to get it out is to knock the axle studs out. I used a long jack extension and a hammer. Worked great. Dropped it right out.
Don't listen to the guys on here and DO NOT grind the ridges off the axle studs. It's not hard to line them back up. You'll understand when you knock the first one out.

toyotabull

Well I wouldn't have said don't listen to the guys on here. I would listen to everyone's opinion and make up your own mind
Easy way out... change the rear 3rd to 4.10
Best way for offroad and bigger tires.. change the front out, but I would make sure of the rear gears before I bought a set for the front just to be accurate.

Stuwy123

iTrader: (1)

I was only referring to grinding the splines off the axle bolts. Everyone on here says to grind down the little splines on the bolts. If you do this, there's a good chance the bolt will work it's way loose. They were designed to be there by Toyota. It's like taking out a lock washer.

toyotabull

Ok i read it wrong, and you are right, you shouldn't grind them down, just spend the extra time to do it right

retrospect

Alright well thanks guys, thanks stuwy but i think im gunna go with 4.56's cause I should be running 31's for probly the next 2 or 3 years. So the only real way to check the rear end before I go and buy a new front diff, is to pull out the rear third and count some teeth?

Windsor

raise a tire, mark the driveshaft and tire and count rotations until you get an even ratio.

Since you are only spinning one tire, the tire rotation numbers are doubled.

4.56 gears is 9:82 (nine driveshaft rotations to 82 tire rotations) for example. (The 4.56 gear set has 9 teeth on the pinion gear and 41 teeth on the ring gear.)

note: This method can be difficult to do as you'll get spots where both marks are close to the original position.

toyotabull

it would be 4.5 driveshaft rotations to 1 tire rotation for a 4.54 gears

Also not understanding how the rotations are doubled for only spinning one tire
count the ring and count the pinion, then divide the ring and pinion #'s 41 / 9=4.55556

And yes the best way is going to be pull the 3rd unless someone else knows if you can look into the oilfill plug to do it

Windsor

whups, you're correct, more driveshaft rotations than tire rotations.

No way you can see the pinion through the oil plugs. It might be doable with a flex bore-scope, but even then I doubt it.

retrospect

So, a very small amount of progress on my problem.... The weather was decent here in Southern Alberta and I was able to pull the driveshaft to confirm this problem before I go drop the coin on the diff. I pulled the driveshaft, put the truck in 4wd and found the truck drives perfect in 4wd with the driveshaft removed (or i guess i should say Front wheel drive??) So i think that confirms any doubt about it being a 4x4 engagement problem of any kind.
4x4 with rear driveshaft installed/connected = binding 4x4
4x4 with rear driveshaft removed = no binding in Front wheel drive

I need to do a front diff swap. Stuwy, your 4.88s are calling me... haha ill be in touch. thanks guys!!

mlrtime99

This is quick and easy, the "chalk" marks you're seeing on the front 3rd member are put on by every junk yard or part source since they have to mark reused parts. Your front diff does not match the VIN decode and probably not the gear ratio if you're losing tires up front.

JollyGreen

My front diff was easy to swap. I used air tools.
I air hammered out the studs and reversed them so I can change my CV's on the trail if I have to.