i feel stupid knowing almost nothing about locking differentials

[bradze]

well I know I want them at least. but how would I know which gear ratio id be happiest with? and do I buy one for the front and one for the rear? im confused.

 

[wcjeep]

gears front to rear must match. Are you changing gears to accommodate a tire change? Towing?

Front and rear MUST be changed at the same time.

 

[bradze]

ok thanks. I am a Subaru guru but I don't know anything about real 4wds. however this is my 3rd Toyota truck. so I might not need to change gears, only differentials for offroading. I don't tow often and I should never be above 2000 lbs. my 4runner came with 285 tires.

 

[4Runner fun]

ok thanks. I am a Subaru guru but I don't know anything about real 4wds. however this is my 3rd Toyota truck. so I might not need to change gears, only differentials for offroading. I don't tow often and I should never be above 2000 lbs. my 4runner came with 285 tires.

Locking diffs, 2 one for the front one for the rear if you want you don't have to do both. if your doing any do the rear first.
gear changes, you must do both, so tires turn the same speed.
picking gears? figure what tire you want to run, search the internet for a gear calculator and enter your numbers, try and match your stock ratio as close as possible.
if you have a choice try and pick a ratio that give you a couple 100 more RPM. it won't hurt your fuel mileage or freeway driving, and will help the truck be more peppy.
if you can't find the exact ratio, which you won't. pick one that gives you more RPM's
just my thoughts.

 

[bradze]

so what do I have to do to change gearing? so is that in the transmission I need gears? who makes options for that? I know im impressed with ARB stuff so the locking differentials, twin compressor, and diff breathers will come from.

 

[4Runner fun]

you may not any upgrades

 

[techno]

so what do I have to do to change gearing? so is that in the transmission I need gears? ...

No. Changing the gearing typically refers to changing the differential gear ratios. Your 4runner probably has 3.727 gears. This means that the drive shafts going into the differential will need to do 3.727 revolutions to make the axles (and wheels) complete one revolution. There are two parts to the differential gears, the ring gear and the pinion gear. These need to be replaced as a set. Therefore, to change diff gears you will have to remove both front and rear differentials and then replace the ring and pinion gears in each. You're probably looking at about $500+ for parts and then maybe $1000 in labor. Not cheap, and not something you could do at home without proper tools and experience.
The main reason to change gear ratios is if your engine is struggling to turn bigger tires. It's not common to regear for small increases and I doubt you need to do this.
Upgrade to locking diffs only if your offroading needs them. If the terrain you drive on is getting you stuck or bogged all the time, then that's the indicator you need an upgrade, otherwise the toyota atrac system is pretty good and probably all you need.

 

[Bumbo]

Don’t feel bad, its been reported that Toyota sales people thought diff lock was an anti-theft device… you can only go up from there.