The 4.88 mega thread!!

THIS

 

For 305/70R17 10 ply tires should I go with 4.88 or 5.29? Long bed AT with about 400lb+ of weight, feels sluggish therefore I know I have to do gears. I do run OVTune which offers tunes for 4.88 or 5.29.

 

5.29

 

I really do appreciate the advice here and from personal messages. I have pulled the trigger on the gears from Revolution. They come in Tuesday and have an appointment to install on Thursday. Super stoked now.

 

Get the gears installed tomorrow!!

 

Did the bearing kits not come with shims?

 

I'm getting 4.88s and an Eaton Truetrac in the rear. Running 33s (255/80r17), probably 32s for winter tires.

She's going to be decently heavy because I've got a built out OVRLND camper in the rear, but I live out of it so I won't be wheeling too hard and I move around a lot so I want to retain good highway speeds.

Not many 3rd Gens with the Truetrac. Should be interesting.

 

I just got back from having my gears installed at ORW in Marrieta, GA. I also had to needle bearing replaced from ECGS for free while it was there too. I drove 50 miles home, driving no more than 15-20 miles at a time and then a 45-minute cool down at each stop as instructed from the shop and looking at the paperwork from Revolution. I can't honestly feel a difference right off the bat. I'm sure it's because I don't want to run the truck hard on the drive home, but that is how I felt. I will say that driving no faster than 60 mph at any given time, I was getting 20-22 MPG. Big improvement from the 15-17 mpg I was getting previously. The transmission seems like it is trying to learn the new gears the whole drive, I guess it will take a while to adjust. From the rear diff, there is no noise coming from the rear. SILENT AS A MOUSE AND NO GEAR WHINE OR NOISE!! That being said, I can not say the same about from the front... It does whine pretty noticeable in 4HI from deceleration from 30 mph. From what I've been reading on TW, it is a common thing for it to whine even on stock gears. I assume that since the new gears have more teeth, it is a lot louder and more pronounced. (Someone, please test for me) Saw that @MESO had the same issue with his gears as well. Going to test more tomorrow; just giving you guys an update. Also, how do you guys break in the front, or do you even have to? I was so focused on leaving that I forgot to ask.

 

There's a third gen on YouTube that shows off how the truetrac works in conjunction with the auto lsd

 

me. But they didn’t offer 5.29 at the time I did it.
Truck still drives great with the OV tune. But had the 5.29 been available, I would’ve done that

I’m on 35s. Empty bed = piece of cake.

when loaded with spare carrier/35, and fishing camping shirt (roughly 400 additional lbs), it’s doable. Even 11,000 elevation climbs (although at this point I really can feel the load from atmospheric differences - this is when I wish I had the 5.29). But it’ll still hold 60-65 in S4 without kicking to 3rd

 

I should add, at that 60-65mph pace in s4, rpms just at 3500 I believe. It’s been like a month since I made that trek so I hope I’m remembering correctly

and that mountain in the back was the drive lol

 

Still averaging close to 20mpg on long freeway trips, turning 2000 rpm at 65mph. 4.88s, heavy E-load 33s, empty bed, rock sliders, aluminum engine/trans/tx skids, steel gas tank skid.

 

im in norther nj and have a possible rear diff issue. anybody have a recommendation for a shop to diagnose and, if needed, replace with 4.88's? the two places ive called thus far have both said they don't like to work with Yukons or nitros because they make noise and are lower quality than oem

 

Where can I get this calculator? I'm wanting to stay stock 265/70 16" & 4.88's and want to research the RPM differences.

 

Any engine rpm calculator found from a simple google search can do this. Crawlpedia as an example

 

4.88’s Going in report back when I get rig

 

4.88's purchased today....going to be a few weeks before the installer can put them in, but that's ok.

 

I got the assembled clamshell and 3rd member from ECGS with 4.88's a few weeks ago. Still have 120 miles to complete break in but so far I'm happy. The new gears are actually quieter then the factory set that had a slight whine around 50mph.

 

if you put the 85w-140 Lucas oil they recommend, it will definitely help with reducing the noise due to its viscosity. I experienced the same.