MadCityRich

I'm considering regearing my 2002 4Runner w/ an auto tranny. Right now it's got the factor 4.10s. I'm running 265/75 tires. I am considering going to 285s when the tires need replacing. Might also get 255s on a second set of wheels at some point. Occasional offroading, which is really why I'm looking at the gears and tires change.

My question is really about towing procedures. I don't tow a lot, but will be hauling wood in a trailer, plus the occasional U-haul single axle trailer. When I tow I take it out of OD. Will it be wise/necessary to take it out of OD if I have shorter gears? I'm a bit concerned about engine rpm on the highway with the shorter gears and being out of OD.

I'm also very concerned with my transition plan to 4.88s. If I do gears first, I'll be running the 265 tires. Am I going to have crazy high rpms on the highway, in or out of OD, with 265s and 4.88s? I will run the calculations, but am looking for general opinions.

I'm also considering 4.56 gears, but my local shop is pushing me to the 4.88s as their opinion is that 4.56 cost isn't really worth the incremental gain over 4.10s.

Thanks,
MadCityRich

hross14

I thought Autos ran 4:30's?

WEll--i run 4:88's/35's, 5spd and will be going back down to 4:10's/33's on the street--BUT i will also be adding a crawl box. On the highway my truck is pulling some pretty high RPMS and my MPG's are a joke (13.5) with 4:88's and 35's. Granted the MPG's are probably because of the 35's and the need to dial in more initial timing to take advantage of the cam...

It really boils down to what can you live with--run the gears and numbers in a calculator and then see what you can live with.

In my case i see it this way--if i am towing i can use the tranfer as a granny gear and because the gearing is tall 4th at 3k will give me 72 mph. Which i think would work great for hills and 5th @2750 rpms will give me 80 for the flats.

But i also have cams, high flow valves and balanced/squared bottom end--it has pep

So in reality--i dont know ??

MadCityRich

My question is really about towing in OD w/ 4.88s. With the shorter gears, would it be safe to tow in OD?

Thanks,
MadCityRich

brian2sun

Here are my #s for normal driving - no trailer: (if you're running 265s, I'd add maybe 2-300 rpms)
65 mph - 2400 rpms
70 - 2600
75 - 2800
80 - 3000
Mine does good on the flats and rolling hills while pulling a U-haul size trailer in O/D, but you'll probably need to turn it off on the longer hills (which isn't a big deal to me). I say if you go to 285s, get 4.88s. If you stay with 265s, go with 4.56s. And remember to factor in the money it's going to cost for a 2.5-3" lift if you want 285s.

troyboy162

is it ever not safe to tow in od? its just a matter of power avalible and OD is a fuel economy gear.

4.56 gives a 3rd gen (auto) stock ratios again after changing to 33" tires. 35" tires require like 5.10 gears to get stock ratios again.

gas milage will never be good enough to really factor in so if you tow alot go 4.88 to give yourself some extra power with 33". my concern is offroad ability so i wish i had gone 5.29 now but 4.88 works very very well for my 33". go 529 for towing with 35" for sure.

MadCityRich

Thanks, this is a big help. I've already got a SS 7.2 lift, so I'm good to go with 33" clearance.

I'm thinking that the concern with towing in OD may be related to the heat generated in the transmission, rather than something fundamentally wrong with the OD gear.

4.88s seem like a reasonable option given the rpms and extra HP that can be accessed.

MadCityRich

vital22re

iTrader: (2)

have you replaced your radiator? or added a tranny cooler yet?