4:10 verses 4:30
- Thread starter Singtoe
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PitbullRescuer
New member
I've had both in different Runners, never switched from one to the other in the same vehicle. Honestly, barely a difference. If you're going to go to the trouble, I'd go with a lower gear. Maybe a 4.56 given all the extra power you have. Probably not a need for a 4.88 or lower in your case.
JWaldz
Moderator
I've had both. Actually, I've had both at the same time 
The difference is so minimal you probably couldn't tell. They say if you run separate gears in front and back to keep it at or under a 5% ratio difference. The difference between 4.1 and 4.3 is pretty much 5%. A lot of people run across this when they sas from a different brand axle. While the rear would take 4.88s the front might take something very similar but not the same. As long as it's within that 5% you'd be ok. As far as the difference between the two, you probably wouldn't be able to tell other than looking at your tach. What are you trying to achieve here?
If you want to play with numbers this is a good to go by..
MPH = RPM / (( trans_ratio * rear_ratio * 5280) / (60 * PI() * tire_dia / 12 ))
RPM is the speed of the motor; revolutions per min. Be aware that the stock tach may only be a good approximation of engine speed.
trans_ratio is the gear ratio of the tranny
rear_ratio is the gear ratio of the rear end
PI is pi
tire_dia is the outside diameter of the tire you are using. You can get this from the manufacturer or calculate it from the sidewall info.
The difference is so minimal you probably couldn't tell. They say if you run separate gears in front and back to keep it at or under a 5% ratio difference. The difference between 4.1 and 4.3 is pretty much 5%. A lot of people run across this when they sas from a different brand axle. While the rear would take 4.88s the front might take something very similar but not the same. As long as it's within that 5% you'd be ok. As far as the difference between the two, you probably wouldn't be able to tell other than looking at your tach. What are you trying to achieve here?
If you want to play with numbers this is a good to go by..
MPH = RPM / (( trans_ratio * rear_ratio * 5280) / (60 * PI() * tire_dia / 12 ))
RPM is the speed of the motor; revolutions per min. Be aware that the stock tach may only be a good approximation of engine speed.
trans_ratio is the gear ratio of the tranny
rear_ratio is the gear ratio of the rear end
PI is pi
tire_dia is the outside diameter of the tire you are using. You can get this from the manufacturer or calculate it from the sidewall info.
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PhdNPrerunners
New member
So would changing to a 4.56 from a 4.30 be a waste?
brian2sun
Elite Member
The difference between 4.10s and 4.30s (as well as 4.30s and 4.56s) will only be ~100 prms at 65 mph. Basically not noticeable. With gears, it's just too much time and money to spend unless you're skipping a couple ratios (like going from 3.90s to 4.56s or 4.10s to 4.88s). My rpms at 65 mph when up ~400 when I went from 4.10s to 4.88s. Any less than that, I don't think it would have been worth the $$.
mmml4
New member
Do the 4.88s seem to get the job done or do you wish you had gone to 5.29s?
The reason I ask is I will be on 35s someday and I plan on a gear change.
I would have to agree that 4.10 to 4.30 is just not worth it.
KidVermicious
New member
I've had both. Actually, I've had both at the same time
I have too - I ran a couple trails with 4.10 in front and 4.30 in the back, and it made a huge difference in my steering - very pushy, lots of understeer.
pcleary1210
New member
I have a set for sale! Cheap! Make me an offer and they're yours! :hungry:
-PC
-PC
zgensler31
Senior Member
I'm not sure if there is a way to get the elocker without switching the diff out though. And you need the same front and rear so....not really following you here.
are you planning on taking the elocker from the new one? Or not?
are you planning on taking the elocker from the new one? Or not?
fourwd1
Moderator
If you pick up a pair of used ones for dirt cheap and do the R+R your self, it might be worth it to you. But to pay to have your diffs regeared, no way.
matthinnant
New member
singtoe I hqave recently been looking in to doing this to my 4runner as well and I talked with Chase from eastcoastgearsupply.com and he recommended me the 4.56 b/c of the supercharger and the extra power im trying to get so I would suggest giving those guys a call and seeing what they think you should do plus your a lil closer to them than me. They are located in brier creek so you could probably get your gears asap. I plan on making a trip up there after my surgery to talk to the guys about doing my tundra and 4runner
Blake H
New member
??? I TOTALLY disagree. I had my front diff go kaplooey and i swapped out.. I have 4.30's and the donor vehicle was supposed to match but had been swapped by PO to 4.56... upon switching to 4x there was NO POSSIBLE WAY to run the vehicle in 4x... It makes a huge difference ... my front end started bumping and popping the tires loose taking HARD nose dives as the rear just acted normal. So going from a 4.30 to a 4.56 is actually quite a difference. After putting in ads on CL and such asking for a 4.56 rear to match the 4.56 front or a 4.30 front to match my existing rear they want a couple hundred bucks for the 4.56 gears but are willing to trade out even my 4.56 to a 4.30.
So obviously a 4.56 is much more sought after than a4.30... about 250 bucks worth ... so needless to say i am going to trade my 4.56 front for a 4.30 front even up rather than pay 250 for the 4.56 and not able to trade. Also on my friends swap the difference from 4.30 to 4.56 was aprox 900 RPM not 100.. or did you forget a zero?
So obviously a 4.56 is much more sought after than a4.30... about 250 bucks worth ... so needless to say i am going to trade my 4.56 front for a 4.30 front even up rather than pay 250 for the 4.56 and not able to trade. Also on my friends swap the difference from 4.30 to 4.56 was aprox 900 RPM not 100.. or did you forget a zero?
Singtoe
New member
My 99 runner has 4:10 front and rear diffs. The rear diff is an elocker.
My new 97 runner has 4:30 front and rear diffs. Its rear diff is also has an elocker.
I am not following you here.
My question was, would it be worth it to go from 4:10 to 4:30?
I won't be buying gears so this option is out. Mind you that with the V8, gearing is not an issue at all.
I was trying to figure out if it was worth it to swap diffs in both trucks. I will sell the 97, so it will have to be put back together.
zgensler31
Senior Member
Sorry. Just thought you were planning on taking the elocker, but not the 4:30s. That's what I was confused about because I didn't think it was possible. But I guess you were more concerned about the gearing instead of the locker. Which like you said doesn't really,,y matter cuz you've got more power then any 4runner on here.
Blake H
New member
better mileage on the 4.10 but if you are running a locker and a v8 i dont think power is an issue at all and the differance at that small of a rate is moot.
So I agree with what HE said... with that power it wouldnt matter .. you could go 4.88 or taller and see if you could stand it on a wheelie!... stay with the 4.10, its already there and parts are readily available anywhere
IMO
So I agree with what HE said... with that power it wouldnt matter .. you could go 4.88 or taller and see if you could stand it on a wheelie!... stay with the 4.10, its already there and parts are readily available anywhere
IMO
snow junky
New member
If i had a v8 switching from 410 to 430 wouldn't be worth changing the diff oil
KidVermicious
New member
Singtoe, I don't think you'll like 4.10 in the front and 4.30 in the rear, if that's what you're considering. If you're going to go to the locker, it's worth it IMO to swap the front diff to match the 4.30 or regear the elocker third to match your existing 4.10.
