The 4.88 mega thread!!

Need some advice, I'm in on the group buy for 4:88's ,but after reading a post in the 5:29 thread, I'm wondering if I should get those instead. In the background of my pic is a six mile descent from 5000 ft to about 1500 ft, its my wood stash road, but in first gear 2wd, my truck consistently runs away with itself, I constantly have to keep on the brakes and then the last couple of switchbacks I go to 4 lo to get off the brakes,it f---ing sucks.even without the trailer and a load of wood these kind of roads where I live, have me braking way more than I want to, I'm old school granny gear just creep down the road style of driving, this is my first taco, so I was really surprised at the gearing factor and compression performance. Right now I have my winter studded 265/75/16's on , but I will be going to 285's in the spring, not definite on that though because once I do a proper lift ,if the proportions of having the smaller tire on don't look that bad ,I may stay at 265's, I just need to do a quick calculated decision on which gears I should go with? I hate buyers remorse.Any advice from anyone who's re geared on how driving in 2wd down steep roads is, would be greatly appreciated.Thanks.

 

I chose 4.88s because I do a fair amount of highway driving on the way to my off-road excursions. If I was more of a rock crawler than an overlander (god, I hate using that term now), I probably would have gone with 5.29s. I’m glad I chose 4.88s.

 

Are your 4.88’s as quiet as stock?

 

Check out Max Powell 5.29 install
https://m.youtube.com/watch?v=3auo58-kXaQ

 

So this is what my 4.88’s sound like.

https://www.youtube.com/watch?v=XFBoPF_0geY

 

What speeds do you hear it? I have a howl only when feathering the throttle at 65. It’s a bit higher pitched than yours and under load or full deceleration nothing and it’s quiet at all other rpms.

Could be related to what many complain about with stock gears and the resonance issue Toyota has a TSB out for.

 

It’s pretty loud. Hard to tell in video, but if I’m on a call people on the other end hear it and ask what that sound is.
It was completely quiet when stock. Hopefully this next set will be better. If I thought (or someone could confirm it ) that it was normal for this gear ratio to make more sound I would learn to live with it. I suppose I will end up living with it either way. I like the truck better with 4.88.

 

i'm assuming you've looked at youtube for videos of gear whine. if a set is mis-aligned, it's apparent as soon as you start moving.

to me, your sound is similar to mine but mine occurs in a bit narrower window of speed. i think this is still a resonance issue. big gears have completely different harmonics vs. the stock gears.

point of reference that i think i already mentioned, but when i had my 18 pro MT, i had the same noise that my AT has now with 4.88's. it's quiet under all other speeds, loads, etc unless i'm feathering (where there really is no positive or negative load on the drivetrain) at about 65mph. that right there tells me it's harmonics.

if the shop is willing to reset or swap the gear set at no cost to you, let them. You only lose time, but if it still does it after break in my guess is it will always be there due to the resonance issue. Next step would be toyota and tell them about the TSB and see if that helps.

 

I saw your video. My gears had a slight whine at the same speeds/RPM as you, but most certainly not as loud as yours (especially after you noted the video didn't convey the loudness very well). I don't believe the whine is there any longer. However, this may be due to me being used to it. I will confirm this weekend.
A couple of notes: The whine did not bother me. It caught me off-guard at first, but quickly understood this may (should?) be expected. Also, I bought the gears directly from Nitro at their HQ and had them install the gears (just like Max Powell, it seems). I have no doubt they did the best job as anyone could do. Super happy with everything at this point.
Good luck!

 

I recorded this this morning. I tried to capture the howl but i don't think my phone picked it up very well. Towards the end of the video you can kind of hear it when i'm a bit over 65.

Edit - Right at the 2:00 minute mark you can hear the howl/whine. Besides that mine are quiet.

https://www.youtube.com/watch?v=fM5tGkprkF8

 

Ok. We just put 3rd set in. I documented everything and it all looked good. Pinion preload perfect, backlash perfect, and gear pattern perfect. Doing break in now. Keeping it under 40mph and only doing 10 mile intervals with 45 minute cool off ( or longer) at a time. Seems quieter than before, but it never was that bad under 50mph.

 

Thanks for all the input. I’m leaning towards your point of view. It may just be what this ratio does. However it would be nice if the manufacturer would let you know that, instead of saying they are as quiet as stock. Maybe for 8” diff, but 8.75” seem to make more sound.

 

Not even close to how loud mine were. I hope mine are that quiet with new set!

 

I went off roading this past weekend and 5.29's made a huge difference. Especially going down hill. Before switching to 5.29's I remember going down hill I was always riding the brake pedal, but now I could actually use 1st gear in 4lo and let the truck go down hill slowly. It didn't feel like truck was trying to run away either. Hope that helps.

 

agreed - but the mic didn't pick it up as well as i'd hope. keep us posted.

 

Yes. I wished I had a better method for recording mine as well. Thanks again for your input and making the recording. It helped a lot to get a comparison. I got about 50 miles in today on break in, all under 40 mph and no more than 10 miles at a time. I’m going to shoot for 100 miles before I go to 55mph. After I feel I can go to 65mph I will make another recording and update.

 

take er easy bud! Good luck! i think we are all rooting for you!

 

So hit 115 miles today all under 45mph and no more than 10miles at a time. Decided to try it on freeway and same sound, however this is the quietest set of the three. Much better than last set. Looks like there just going to make noise. I will try and post an updated video later today.

 

They may calm down a bit after some breaking in.

 

So I am going to take the truck in next month for timing cover leak and try and have T-SB-0013-18 performed at the same time. Hopefully that will make the diff whine livable. Really bummed about front cover leak, they have to pull the whole front of the truck apart and drop the front diff.