Tech - Ring and Pinion Upgrade

[3stagevtec]

A nice way to regain some power when running over sized tyres (18% taller to be exact!) is by upgrading your ring and pinion ratios. Since I am planning to keep the original Suzuki power plant (J20A) and automatic transmission with a pretty tall overdrive (van has to remain wife friendly), some upgraded gearing was definitely in order for me.

I really didn't take any pics of the tear down process, so forgive me for that. Taking apart a 3rd member is pretty easy. At minimum you would need a socket set and a hammer.. Ideally, a shop press and appropriate gear pullers for removing bearings would be best..

Now for reassembly. I changed out all of the main pinion bearings for new ones. A 20T press and a bearing splitter made easy work of this.



Toyota 3rds.. use shims between the pinion head and the pinion bearing for adjusting the pinion depth. Pinion depth is responsible for the mesh between the pinion gear and the ring gear. A poor mesh between those gears will result in gear whine (loud humming while driving), and an overall weak install. Here you can see me adding the shims to the pinion BEFORE pressing on the pinion bearing.



Who here knows how to use one of these? A Vernier Caliper comes in quite handy at very small measurements. This one can measure down to 1/1000th of an inch and is certified too! Thanks Khameel for the nice toy!

[3stagevtec]

With the new bearing pressed on, It is time to reinstall it into the empty 3rd. Note the shims in place.



The press makes it pretty easy to push in the upper pinion bearing, via pressing against the pinion flange. You can also use an impact gun to pull against the pinion nut to force in the upper bearing, but this could damage the nut over time.



I did not install any crush sleeve at this point since I needed to check if the pinion depth was guessed correctly. A crush sleeve is used for setting the pinion bearing preload and is a one time use object.. I tightened the pinion nut until the required bearing preload was achieved. (I forgot to take pics of that part, but bearing preload was measured via a beam type torque wrench.. and it is rated in inch - pounds of torque.)



Time for the ring gear installation. During disassemble, I made sure to mark the carrier bearing caps to ensure I don't mix them up. I and II..







New ring gear was bolted to the differential case. Loctite was used on the 10 ring bolts.



Everything reinstalled making sure I line up the proper bearing caps.

[3stagevtec]

To properly torque down the carrier bearings, I made this special tool out of a piece of flat steel with two bolts and a wheel nut.



To achieve proper carrier bearing preload, they recommended I use approx 80 - 100lb-ft of torque on them! A power bar was required to do that job eventually..



Next was setting the backlash between the gears. Gear backlash is the free play normally felt between gears. This free play is there to allow for proper lubrication of the gears. Proper lubrication prevents wear on the gears and helps keep them cool when running hard. The manufacturer recommended 0.008" of backlash, measured using a dial gauge with a magnetic base.





At this point, we now begin to check to see if the pinion depth (set via the shims mentioned earlier) was chosen correctly. There is no correct spec for this, you need to start with an average spec, assemble the 3rd member, then check if the gears are meshing properly. Depending on the mesh pattern (see below pics), you will have to either add or minus shims to get the correct depth.. and everytime you get it wrong, you need to disassemble EVERYTHING just to change those shims..

A section of the gears was painted and the ring gear was turned back and forth a few times (to intersect with the pinion gear) to get an idea on how they mesh. (See the problem with buying used stuff, this 3rd had went through hell by the previous owner, somehow his pinion tried to eat the differential housing!! )



This is the drive side of the gears. Notice how the markings are centered on the tooth.. a Perfect mesh pattern!



This is the coast side, similar story with the mesh pattern.. ideal..



Of course it took me a few tries to get them to that point, initially the drive side was marked way off to the inside of the ring. (The coast side was to the outside of the ring). By adding more shims, I was able to bring both of them to the center.. Once the required mesh pattern is achieved, a crush collar can then be installed for the pinion bearings. You ONLY crush that collar until you get the required bearing preload, then stop right there. I used Loctite to lock the pinion nut in place.

I have been driving on these gears for approx 2 weeks now and they run dead silent! and the power regained is superb! I previously ran 30" MTs on my Vit (up from the stock 27"s) and the power loss was significant. Now I am running 31"s and it feels like the stock 27"s, even with my dead engine..

Special thanks goes out to Imtiaz for the technical assistance during this build. Thanks also goes out to Khameel for the use of his tools + the technical assistance. Finally would like to thank my brother (Runul) and Brian for the parts they played during my build..

Hope others will benefit from this..

[rottedv]

Very nice write up. Information is well shared and very informative. Will go a long way to helping those who are DIY kinda peeps.

BTW.....Nice Press......

[200sx]

X2! I'll be needing to do that upgrade very soon! Changed from 33's to 35's BFG's MT! Lol!

[3stagevtec]

X2! I'll be needing to do that upgrade very soon! Changed from 33's to 35's BFG's MT! Lol!

You gonna feel the power loss with those. They generally recommend 4.88 gears for around 33" - 34" tyres and 5.29 gears for 35"+..

You also need to match the gearing to your engine's power band and transmission gearing. Too low a gearing and you will be crawling everywhere, too high and the engine's response will be lagging plenty.

[200sx]

Goin the 5.29 ratio when I'm locking up one time! Went up maracas Friday! 1kz pull good! But I'm feelin the power draw/loss! Installed the tyres Thursday! So that was the road test! Lol!

[droppa]

Nice write up and install dey Rene, things like these take months of research, when your DIY, btw what gearing did u go up to?

[medalist]

nice build

[3stagevtec]

Nice write up and install dey Rene, things like these take months of research, when your DIY, btw what gearing did u go up to?

I went right up to 5.71s, but remember those are not recommended for hardcore off road use. In my case, since I am running small power / torque, I'm taking the chance and I suspect I shouldn't have any issues.. *fingers crossed*

[sliderz1]

research to back up...nice

[Ted_v2]

saw the van taking gas yesterday in Unipet

O__O
Highly lifted

[bigdady]

I have a question . . . I'm a "newbee" . . My bt50 has a backlash in the rear diff . . Can this be fixed? If so what's the cost and time?

[rottedv]

Backlash is usually a tightening of carrier bearings.... Easy fix once the spec is known

[droppa]

you dont necessarily need to know the spec, where it is the proper method,

a good experienced mechanic will use a feel and tighten method, and you can still paint the crown wheel and test the results so u see what the outcome is.

[rottedv]

you dont necessarily need to know the spec, where it is the proper method,

a good experienced mechanic will use a feel and tighten method, and you can still paint the crown wheel and test the results so u see what the outcome is.

The spec is to have a base to start from. Good mechs with feel and tighten method? Well I for one would rather a dial guage indicator and some concrete numbers rather than that method you mentioned. These are gears. They must be precise

[droppa]

true eh boi...

[bigdady]

Ok . . . HELP . . . Can any of u assist?

[droppa]

na boi bigdady, real pace these days.....

[bigdady]

Any idea how much it would cost and how long it would take? . . I really need some help here guys . . This is my only means of income and I can't afford for it to get damaged

[rottedv]

Its not difficult to do really. Just a little time consuming. And depending on how your diff set up, it may require shims if the carrier has accomodation for it. Then cost could go up depending on if bearings bad, seals to replace etc.... Where you located?

[bigdady]

Diego Martin

[3stagevtec]

I have a question . . . I'm a "newbee" . . My bt50 has a backlash in the rear diff . . Can this be fixed? If so what's the cost and time?

Hypoid gears, like those used in your differential, must have a backlash. Backlash is the free play measured between the gear teeth. You must have some backlash, to help lubricate the gears while in operation and to help with cooling. Too little backlash will cause over heating and damage to the gears. Too high a backlash will reduce strength and reliability.

That said, what exactly are you experiencing with your differential? Any odd noises while driving? Clunking? Rattles? Chances are, your van will have an LSD in it as well. Describe what issues you are having first..

[bigdady]

The entire drive shaft has a play of about an inch

[3stagevtec]

you dont necessarily need to know the spec, where it is the proper method,

a good experienced mechanic will use a feel and tighten method, and you can still paint the crown wheel and test the results so u see what the outcome is.

[3stagevtec]

The entire drive shaft has a play of about an inch

Call me 330-6630

Need to speak to you to assist..

[bigdady]

Ok gimme a few mins

[bigdady]

Called a couple times . . . Let me know when to call back

[3stagevtec]

Called a couple times . . . Let me know when to call back

Was working on another van at the time you called..

[bigdady]

We spoke