bennyt4130

Hi everyone! My pinion gear shattered yesterday and I am going to have to replace it. I have been pouring over threads for hours and just need some patient soul who knows what is up to help me out. I'm sure if I had more experience, I could eventually find the answers I need myself but this is a bit of an emergency so I hope you guys will understand and drop some gearing science on me.

FYI- I have an '88 4runner with a 3VZE and an auto tranny. It has a small rear lift with Downey springs. I think its about 3". I also have 32" Radial TA's.

The broken rear gears are not stock and were not installed properly as far as I can tell. They were installed by a shop a few years ago and I cannot confirm what they are but a #47 is clearly imprinted on the ring gear. I have been getting ˟˟˟˟ty throttle response and bad gas mileage ever since the tires, lift and gears were installed. I need to order new gears in the morning and what I want to know is what gear ratio/brand would be ideal for 32" tires for daily driving on road. I very rarely go offroad. I am assuming I need to order a ring and pinion gearset and an install kit? If I need anything else, please chime in!

Any information you guys can give would help. I have been to the gear calculation site and it does not help because I don't have all the base info it asks for. I'm hoping someone will know what a good ratio for daily driving on-road might be. I am a newb to working on this truck but have been wrenching for years.

Thanks, dudes!

Edionne13

Honestly if you want kick 4.88 I run with 4in susp and 33x12.5x15 but I'm planning to run 35's soon. Mine are factory 4.88's. honestly I'm a newb also. But my recommendation would be 4.56 being a dd and a rarely wheeler. I'd go Yukon gears

RSR

Email or give zuk a call -- one of the best w/ gears on these boards: http://gearinstalls.com/index.htm

But I'd say figure out which third member was stock. If 4.88s and keepign the 4.88 housing and installing something else in it, the shop was wrong...

The 4.88 rear third member is a special housing and cannot accept a gear swap. Any of the others can.

Here's how to find your stock gear ratio: http://www.brian894x4.com/Gearratiosanddiffs.html

If not 4.88s, then it's likely less of cluster, but I can't be of further help here...

93Xtra-Cab

I doubt they were factory 4.88s since his is an '88 4Runner. I don't think 4.88 gears came from the factory until 1992...I think...or '91. I can't remember. Early 90s, let's just say that. He could possibly have a factory 4.88 differential if he swapped it out from a newer 4Runner, which he didn't say he did.

http://www.brian894x4.com/Gearratiosanddiffs.html

That site recommends for 32s, you use either 4.56s or 4.88s. 4.56s if you have a manual transmission, 4.88s if you have an automatic. I think you should figure out what gear ratio you have now by counting the teeth on the ring and then divide by the amount of teeth on the pinion. Once you figure that out, you can go from there in deciding what ratio you want.

EDIT: *sigh* Looks like in your first post you said you have an automatic. And RSR already posted the link I posted. Sorry, I just woke up. I lack reading comprehension skills this early in the morning.

bennyt4130

Thanks to everyone for their responses! I am thinking of swapping out the entire diff rather than rebuilding the one I have. Can you guys clarify that the 4.88 gears were stock after 92? Is this just a direct swap out of stock diffs? Anyone have a spare?

Edionne13

Whoops sorry guys didnt see he was automatic was kinda late and yes I swapped it from a 91 factory to my 93 Manuel . I was just telling him what I used. Depending on his personal preferences he could do 4.88. I use the 4.88 just for the more pep my truck has.

93Xtra-Cab

I used to know what year, but for some reason I can't remember. Allow me to clarify. Not all 4Runners or pickups after 1992 (or whatever year) had factory 4.88s. Not even all automatic 4Runners with the 3.0L v6 had the factory 4.88s.

Taken from brian894x4s site:


On the door code in the pic above, look for the code G144. That tells you that the vehicle has 4.88s. That's a good tip if you ever go to a junkyard looking for gears.

It is a direct swap out. Take you're entire third member out, put the entire G144 code third member in. Don't try to put the gears from a factory 4.88 diff into your diff and vice versa. Factory 4.88s use a thinner ring gear.

If you're interested, look at the Yotatech classifieds. There's usually at least one person trying to sell a set.

Another tip: Think about the long term. Are you planning on getting larger tires at some point? If so, you might want to regear for them now.

osv

if the ring/pinion gear was replaced, and you don't have a receipt for the work, you can't be 100% sure what replacement gears were used.

the only way to be 100% sure is to count the teeth:
http://www.crawlpedia.com/gear_tooth_calculator.htm

"a #47 is clearly imprinted on the ring gear" indicates that you have already pulled the third, so why not count the teeth?

the gas mileage problem could be nothing more than miscalculation of the mileage, due to not compensating for tire size and gearing changes.

stock gearing is probably irrelevant, in a situation where you aren't running stock sized tires... call up marlin crawler and see what they have to say... could be a good opportunity to go to a rear locker of some sort, just buy the entire diff and plug it in.

bennyt4130

So, I counted my teeth and it's an 88 ring with an 18 pinion which puts me at 4.56. Can anyone shed some light on the compatibility of 4.88 gears with my current 3rd member? Is it compatible? According to ebay, it is. Not a dependable source. Thanks for any info you guys can give.

93Xtra-Cab

Copy and paste the ebay page you were looking at. And make sure you're looking at gears for the V6. The v6 and 4 cylinder have different gears.

The gears that companies sell are almost always gears for the regular carrier. I don't think I've even seen a company that sells gears for the factory 4.88 carrier. So, I'm going to say yes whatever gears you're looking at will fit

osv

since your "pinion gear shattered", you'll probably want to replace the entire third, so i don't understand the question about "compatibility... with my current 3rd member".

are you referring to the shell that holds the gearset? it could be distorted or damaged, hence the reasoning about replacing the entire 3rd member... just get the entire third from a junkyard, fully populated with the ring/pinion, and bolt it into your rear end.

here you can confirm the rear end/third that you have, by the ribs on the side of the third:
http://home.4x4wire.com/erik/diffs/

if you want to take this opportunity to upgrade to a v6 diff, which you probably don't have now, it would be something to consider... not sure that you need it, since you don't offroad.

additional from the above link:
"The FACTORY 4.88 V6 diff is unique!
- Axle code G144, white pinion paint code,
- generally came in 92-95 trucks/4runners with V6, auto tranny, 31" tires, and tow package.
- Housing offsets pinion towards ring gear, allowing ring gear to be thinner
- OEM Toyota gears are the ONLY gears that fit this diff due to the thinner ring gear. All other gear sets have thicker ring gears and do not fit.
- The carrier (case) is the same as the V6 diffs, so normal V6 lockers, LSD's, etc. will work in this diff"

coryc85

One thing that has not yet been mentioned, you probably want to check what gear ratio is in the front of the truck. Then you have a decision to make on whether or not you want to match that diff at the same time, so do you get a rear ratio to match the front, or do you need to regear both diffs to a new ratio? If they don't match, you don't want to put it in 4wheel drive. I know you said you drive on the road, so 4wd may not be important to you at this time, but it's still another piece of info to add to your decision. If you don't match them both at this time, it's something you would want to do in the near future.