The 4.88 mega thread!!

Agreed, looks like Cooper is the only option really.

 

I like my 235/85 16 wild peaks. Wearing like iron. 28k on that and very little wear. They are stiff though.

 

Everyone raves about Wildpeaks, as long as they balance OK. I’m still recovering from my Falken Rocky Mountain hangover… oof.

 

I had wildpeaks when they came out and had a lot of issues so I’m not a big fan of them.

 

After a 6500 mile cross country trip this past summer, I am considering gears again. Truck weighs 6k pounds on 265/75R16's that weigh 47lbs each. I found that on the highway, I had to stay under 65 to keep it in 6th (auto trans). Climbing up mosquito pass in CO, 4 low and locked into first, there just was not much there. I actually was not sure it had the power to climb some of those hills. I know the 13k altitude was in effect, but I'd like to think lower gears would have helped a little.

I'm not planning on going up in tire size, and I may be able to drop 100-200 pounds. Am I in a weight class where I should just go to 5.29? MPG is still important to me, too.

ETA-i had no trans temp issues on that trip. I can't remember exactly how hot it got, but I remember seeing 220 on a long highway ascent. Can't remember if that was the converter or the pan though, I watch both.

I'm also curious to hear if any AT trucks got an enhanced compression braking effect with the regear.

 

I just hit 1000 miles on my 4.88s this week. Im still stock except for a bed cap. What I can say for the 4.88s to this point is that if you arent looking to increase tire size any more than what you have- 4.88s are probably a good way to go. My RPMs on the highway are at 2000 doing 60mph in 6th gear (used to be 2000rpm at 80mph before gears). I havent gone over 65 yet, so I cant speak for how high the rpms will be at faster speed (just something to take into consideration if youre thinking about 5.29s). But with my set up, it drives great and mileage didnt suffer too much (like 2mpg lower on highway...2mpg better in city). With these gears- it doesnt hunt anymore and going up hills made it way better.
*didnt notice any change in deceleration. Still coasts pretty much the same, but mountains in the southeast carolinas are...not real mountains

 

80mph with 32’s is 2550rpms for me

 

If you aren’t tuned for the gears then you will likely notice some compression braking and gear changes on descents. Tuning for the gears changed everything. Pulling a trailer I’ve seen my temps hit 233 (very steep grades in 3rd gear with TC kicking on and off). If I pin the thermostat it’s about 15-20 degrees cooler on average

 

Anyone running one of the speedmaster/nitro front torsen LSDs with thick cut 4.88s?

 

Only one I've seen is this truck



have checked every retailer that lists it and have been unable to find in stock.

 

https://www.speedmaster79.com/Toyot...line-TorqueWorm-LSD-Limited-Slip-Differential

In stock, ships in 24 hours

 

Thanks. I'd hit them up first to confirm. Had before sites say that then change and not really be.

Are you gonna get it?
I'm thinking about it. Trying to decide between that and ARB air locker.
Local shop charges $375 a diff for bench regear/rebuild.
Torsen would be easier for them to install, and less work in general.
But the air up/down and onboard air supply features that come with ARB (twin) are appealing

 

I got 5.29s before I knew those torsen units were available. So I would need to regear again to 4.88 to make it work.

 

for the front torsen or rear Truetrac?
Is it only compatible with 4.88 thick cut or something?

 

The torsen front is only compatible with thick cut gears because of the carrier break, And 5.29 are not available in thick cut.

 

4.88’s here no complaints

 

I guess that narrows it down. From research, talking to people, and asking professional shops

I’ve been recommended a perfectly even mix of go 4.56, 4.88, and 5.29 lol.
That counts out 5.29. As does the beefy rear ends ECGS has coming in 4.88 not 5.29.

I’ll rerun the calculations again. Truck is 6spd manual; not sure the ratios or if they differ. And if that also means no TCM/TCU rev hunting because it’s manual.
I know 6th manual (RA60F) drops RPM lower than 5AT.
But it may be different from FJ 6spd and 3rd gen 6spd RC62F. FJ supposedly has the best 6th.

from what I recall the last time I looked at the calculations of 4.56 on 35”, it equated to the same as stock 3.73 on 31”

While I understand the rhetoric of “you want to mimic stock”, I think it’s better to gear in a bit more leverage than stock and go the next step up to 4.88.
Because the relationship of 3.73 to 31” is horrible, weak, slow, designed for emissions, and unheard of when most sedans come as 4.10 with less stress.

plus the truck itself is no longer stock (no truck regearing is)
The tires are not only bigger but heavier. The lift adds drag. There are mountain trails to wheel, passes to uphill, altitude, UHauls to tow
and always added weight in the form of armor and equipment

plus the potential option to simply drive accordingly to the gear ratio and reduce highway speed. Which hopefully can be reduced enough to drive well without impeding traffic. I already am generally not the fastest on the road and keep more toward the right.
Lifted without a sway bar, heavy and small brakes, puny engine that chugs gas when you rev up; it’s not the thing to go fast.

so yeah if anyone has any feedback on gear choice please let me know
Gonna do some more research to try and see if 4.88 is the way to go.
It may also be more “future proof” if ever going 37
Last 4.56 I saw was on 34’s I believe without a 200lb shell and at flat sea level.

 

You don't specify anywhere what gen your truck is, and the answer is different for each.

 

2nd gen

 

Ahh, yeah. What I've read is that you want 4.56 if you will only go to 33s, and 4.89 if you plan to go any higher. I've never seen 5.29s recommended for a 2nd gen, especially not a manual.