The 4.88 mega thread!!

I was going back and worth on 4.88 vs 5.29 as well (I guess I still kind of am since I found myself in this thread). I am going to be running 32's with a fair amount of armor. Nitro and Premier West pretty much told me there is no wrong answer. So I went with 5.29's as they both recommended. Just ordered at this point not installed. I think the recommendation was based on the fact that people tend to eventually add more weight or get bigger tires, I don't think I will so 4.88 might have been a little better. I will never know though, haha. Excited to get them though

 

That’s my exact feeling! 4.88 still sound better in my head for how I drive and what I’m doing but I can’t argue with those who have done it and if I ever do get the bug a couple years down the line, i would already be set.

I’m still nervous about it haha

 

I’m in the same boat, I keep going back and forth on which to get..I have a appointment to get them installed this Saturday...I’m running 33’s , Rock Sliders , Skid Plate nothing to heavy.Its my daily driver..Mobile Gears says I should do the 5.29...If I do the 5.29 am I going to hear the larger gears?

 

From everything I have leaned you are doing it right. With your setup 5.29, it’s not like it’s going to get any lighter. Let us know how you like it!

 

Hey guys,

Just came home with the truck after a 4.88 install and noticed a very faint howl when I let off the throttle going from 68 to 58. Ive read through various forums and can't seem to find a commonality after re-gearing. I know some members had the diff howl when stock but can't find too much info after a re-gear. I did not have any sort of howl prior to the gears but just wanted some info in case someone has had the same. Any info would be appreciated, thanks!

Build-
2" front 2.75" back lift with Dakars HD in the rear with a carrier bearing drop kit. ECGS bushing in the front and that's about it.

 

Do you know what oil they used?

 

I just had 4.88's installed on my 2020 OR, I only had about 200kms on it from the dealership when it went in. I'm bone stock (for now) and before I went in there was zero howl or noise of any sort. Since I got it back I notice a slight howl driving, increasing in noise the faster I go (almost nothing under 50km/h) and a noticable howl if I let off the accelerator from about 100km/h down to 70km/h.

Don't recall ever hearing this sort of noise on any of my other vehicles whenever I had them regeared. I had a really good shop here in my parts do the work, and they specialize in this sort of thing. They did say some noise is normal, and the Nitro info noted the same thing. All the same it's annoying for sure and I'm hoping it dies down a bit over time once it's all broken in. If not, then in hindsight I'm not so sure I'd want to do the regear as the noise outweighs the benefits of how it drives so far.

 

There may be a howl, but it shouldn't be loud/annoying to people. Most don't hear it at all. If there's a noticeable howl, then they either shimmed it wrong or used regular gear oil. They are supposed to use thicker oil which Nitro's recommend as well.

 

Maybe it's the oil? They did mention they used something different as it's only in the break in period, and that they would be using whatever Nitro supplies once I go back in after the initial 800km. Guess I'll wait and see if it's different at that point as I'll also be adding a lift and tires.

 

They used the supplied oil from Nitro 80w-140, I believe. I had them installed at Main Line Overland and will hopefully do enough research before my 500 mile oil change to remedy the howl.

 

Shop probably used a different oil because 80W-140 and 85W-140 synthetic (the two oils recommended by most aftermarket gear companies) are expensive. Like 2-3x more especially Nitro's 80W-140 since it's not common. However, those oils are thicker to protect and "cushion" the gears more compared to the thinner ones.

 

With that, I would expand my research outside of Tacomaworld. If it's very faint and you have to actively listen for it, then it's normal. If you can hear it without much effort and it didn't do that before, I would take it back. Maybe they didn't shim it correctly and have them do a wear test again which can be a d!ck move if nothing is wrong with it since they have to basically take it apart again. It's your truck and you paid for it though.

 

Hey guys so I got gears about a month ago and just noticed a small leak in the front differential area. I’m not too good with terminology, but can anyone identify if there’s a gasket or something that would need to be replaced if oil is leaking from the circled location below? It doesn’t look like it’s the actual differential housing itself (this is not my truck - just a stock photo for orientation):



There was oil kind of pooled at the bottom of it. It looks like the spot where the differential meets the passenger axle. You can see some of the sheen after I wiped it up (this is my actual truck):

 

Did you ever get the howl to go away? I’m at 500 miles in and I’m about to change my oil once again to see if that’s the issue. I initially used valvoline.

 

This could be one of two things.

1. During break in, the oil heated up enough where it started to travel up the breather tube and came out the breather in that area.

2. When the person who installed the diff was reassembling the ADD tube, they either didn't put enough RTV, didn’t put RTV in the right spot, or during assembly rubbed away RTV.

Clean the area well, make sure the diff is topped off with oil, but not over full, and drive in 4wd. If it continues to leak, then yes, the seal (RTV) between the diff and ADD tube needs to be re done. Very easy job if you know what you need to do.

 

Its still there, just very faint. I only have about 230 miles on it so far so. Let me know how yours works out. I hope with the oil change it will be a little quieter.

 

Would 4.88’s help with that gutless feeling we get when we pull away from traffic lights and stop signs? Just seems like there’s no power in the lower rpms from a dead stop.

 

It will continue to be there. The howl is just a symptom of these trucks. I had REM 4.88’s installed with 85w-140 with no howl for the first 2000 miles. Switched to

$29 75w-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75w-90 since it was really cold during the winter and the howl showed up after the fluid change. Going to 75w-110 in a few months to see if it changes. MANY people experience the faint howl. Just turn the radio up

 

Gears will help, but OVTune will make the biggest difference

 

Tune and for sure lower gears will help from stops.