Rear gear ratios

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M

Mustang_man298

10 Year 15 Year
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Jul 18, 2007
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Location
Shingletown,Ca
Howdy all, we just added an 88 xtra cab 4x4 to our collection. I need some input on gears. The previous owner said he blew up the rear gears and put a 2wd pumpkin in it since he couldn't find the right one, but the front end is supposedly original. I was unable to find any markings on the front IFS diff as to ratio, called a dealer and they said the only ways to know were to count the teeth (royal pita to get a cover off that diff) or to block a wheel, turn the other 1 turn, and count pinion turns. I got 2.75 turns on the pinion, that seems tall to me for a 4 cyl 4x4 with manual trans. Am I doing this right? Anyone know what the gear is?
-Chris

I did check the rear too, it is indeed mismatched, it only goes 2 turns to one of the tire.
 
If the front is stock then there should be a color code on the end of the pinion:

Toyota 4Runner Technical Information

By the numbers you posted the front sounds like a 5.29 or 5.71 which is not stock... and the rear is probably a 4.10 the most common ratio.
 
2ndGenToyotaFan said:
If the front is stock then there should be a color code on the end of the pinion:

Toyota 4Runner Technical Information

By the numbers you posted the front sounds like a 5.29 or 5.71 which is not stock... and the rear is probably a 4.10 the most common ratio.
Click to expand...

I did pull the front driveline & look for a color dot (a friend mentioned that) but there was no paint on this one. (Which might reinforce what you are saying about it possibly not being stock) The dealer also claimed no knowledge of such thing, go figure, lol. It's looking like I might have to dig into this a bit to see what I actually have going on here...

Edit: Interesting, the link you just gave me shows a 5.29 & 5.71 have no paint dot.....thanks for that link & the input,BTW.
 
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Yes, 5.29 and 5.71 never came from the factory, so no color code... Have you checked the rear for a color? What engine and trans are in the truck? That will shed some light one what it's supposed to have... also, what size tires are you running or are going to run?
 
tntoyota said:
2wd 4cyl's are 7.5..........



2wd V6's and Turbos are 8"



slightly :confused:

Look for the C/tr/a/TM in your door jam....
Click to expand...

No offense man but can you explain this answer to his question for me?

Thanks!
 
If he gives us C/tr/a/TM then we can look up his axle code & tell him what gear ratio it would have been originally. If the PO has been swapping differentials willy-nilly, the safest thing to do would be to look.
 
MOST of the time people mess with the front diff LAST!!! and......the way he made it sound the rear was the only thing messed with and as the story moved on we got more and better info....


He does not have a 7.5 in the rear UNLESS it is a 2WD full axle, 2MK a 7.5 will not bolt into an 8" housing.

I was going...trying to find out the front using this method.


And "look for c/tr/a/tm" was a separate answer to a separate question, I do not use the color codes.....why should I?, and why look for the color (hardest) than knowing where to look for the plate, (easier) on those body styles it is in one of two places, fire wall or door jam (kinda confuses those who dont know already)



agreed the "look for c/tr/a/tm" is now out the window...:flipoff2:
 
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it is really easy to pull the third out and check it.
the third had to have come out of a V6 truck. no way would the 7.5" fit in there.

just pull out the third and count em. the fluid needs to be changed anyway ;)
 
tntoyota said:
agreed the "look for c/tr/a/tm" is now out the window...:flipoff2:
Click to expand...

Why? Since the question is what's up front, and since the front has probably NOT been changed, then the axle code is still valid for finding the ratio on the front diff.
 
pappy said:
Why?
Click to expand...


....odds :flipoff2:



I have bought lots of trucks, and usually when a PO (:hillbilly:) does really questionable things I have learned that the rest of the truck is a krap shoot.


(bought an RET donor truck, half the bolts were standard :mad: whats a standard wrench/ socket when all you work on is metric? a.k.a I have very few std tools)

(bought a RET w/ 4" lift, :meh: fender damage, removing the lift find evidence of frame repair :frown: )


When I get to "that" point I dont trust anything more until i see it. (pull the diffs)
 
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tntoyota said:
speaking of the rear.....


can the front diff cover be easily removed?
Click to expand...

it looks simple enuff. never taken one off. only obstruction may be the end of the upper bracket where the A arm bolts. unless theres a lift on it.
 
WristPin said:
it looks simple enuff. never taken one off. only obstruction may be the end of the upper bracket where the A arm bolts. unless theres a lift on it.
Click to expand...



my rational is, and correct me if I'm wrong but, (even if you cannot see the pinion to count the teeth) how many gear ratio's have the same # of teeth on the ring gear?


so if you can pull the front cover (as to avoid pulling the entire front diff) and count the ring teeth i think you can get an accurate idea of the gear ratio.



















WristPin said:
it looks simple enuff. never taken one off. only obstruction may be the end of the upper bracket where the A arm bolts. unless theres a lift on it.
Click to expand...

x2, looks like you can pull the diff cover bolt, jack the diff up, the diff mounting bushings should flex enough to angle the diff up enough to properly remove and install the cover....?
 
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damn, i mis read the first post. i thot mustang man was tackeling the rear diff.

when you have the third out, in such case as a rear, you can see the pinion, but only a small portion. you could reach down there with a long q tip with some paint on there and mark it, so the teeth can be counted.

the front diff has a different design of case, and ive never re geared it. so i dont know how easy it is to see the pinon.

but with any stock ring gear, the ratio, or at least the number of teeth for both the pinion and ring should be stamped on the side of the ring. withthe removal of the front cover, that should be easily spotted
 
tntoyota said:
my rational is, and correct me if I'm wrong but, (even if you cannot see the pinion to count the teeth) how many gear ratio's have the same # of teeth on the ring gear?
Click to expand...

its close. only 1-4 teeth different in some cases.






















x2, looks like you can pull the diff cover bolt, jack the diff up, the diff mounting bushings should flex enough to angle the diff up enough to properly remove and install the cover....?
Click to expand...

the bushing is stout. i dont think it would give much. there are only what, four bolts maybe five up there?

if the truck is lifted, you wont have to take em out at all.
 
2ndGenToyotaFan said:
Yes, 5.29 and 5.71 never came from the factory, so no color code... Have you checked the rear for a color? What engine and trans are in the truck? That will shed some light one what it's supposed to have... also, what size tires are you running or are going to run?
Click to expand...

It is a 4 cyl 5 spd (as per the post, lol). It has 33's on it now. I didn't bother to look for a rear color code since he told me it was the one he replaced with the wrong one, I just spun it to make sure it was indeed mismatched.

Had a lot of late nights @ work this week, and the boss running into my car didn't help. Got the car put back together over a couple nights, today's my friday, so tomorrow I'm going to look for those door sill numbers and do some digging in, I need to replace one of the front driveaxles anyway it looks like so I'll probably be pulling the front diff and kill 2 birds. It has a 2" lift which makes getting to the mount bolts a little easier.

I've bought all kinds of trucks in the past in various states of condition, I am going to go thru this one carefully. I think it was still a good trade for a worn out rusty bondo laden 73 chevy 2wd I paid $500 for & drove a year,lol. I'll post some pics if I can get them resized to fit.
 
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Here's the new rig, supposedly has a recent engine, pretty clean looking and runs well. I picked up another o2 sensor the other day to replace the broken one so we can get it smogged to drive it while we fix it,lol.
IMG_1275.webp
 
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