Ok yall, with GFC and 275/70R18s (33.15") & auto trans,
I dont plan on adding anything to the truck beyond sliders and diff guard, no drawer systems because i use the truck to haul HVAC equipment occasionally.
I want to do a re-gear, Nitro gear said 4.88 others have said 5.29. I would love to hear what you think, GFCs are light and with 33s im stuck in the middle between the 2 gear options.
I did 4.88 with my 33s (285-75-16) and I have much more weight than you. It’s been fine.
Thats encouraging! Thanks for the input.
GFC, nothing in the bed, 34’s, sliders and steel skid but OTT tuned and not regeared. It’s not a rocket ship but drives much better. Unadjusted I get ~15mpg highway/city for my 9 mile commute.
Guess a question on gears is what will be your primary driving conditions. You looking for something that does well at highway speeds or crawling. I’ve heard 5.29s alone will sit your rpm’s pretty high still. Also heard that gears don’t really shine unless your tuned as well.
There’s an immediate and appreciable difference if you have bigger tires and weight, but yeah, a tune really helps because it fixes the shift points.
Ill definitely look into that! Sounds like 488 plus a tune would be pretty sweet. But I like the non intrusiveness of the tuning and looks like it can be set back to normal
My thing was, I gotta get a tune if I decide to regear so why not get a tune now and decide if I really need gears. I’m super happy with how it performs with the tune and have really decided against getting gears.
If you do the tune first make sure your tuner does free changes or something. The tune will be different for stock vs re-gear.
What’s your mpg on the highway?
Me? Like 18hwy and 15city. 18 is if im conservative. Otherwise 16hwy when im hauling ass
I did the 4.88’s and run 33’s. V1 gfc and camp gear always in the truck. No tune and no complaints.
I’ve got 5.29s but have done a lot of other things to my truck including bumpers, 35s, etc. that add weight (along with the GFC). I also did an OTT tune last year which gave a lot better throttle response. I really like how my truck is set up now and the combo works great everywhere EXCEPT cruising at anything over 74mph on the highway. Mainly because I also have a Tom Woods solid drive shaft (removes the carrier bearing) which due to the length has a lower critical rpm than a 2-piece shaft. There are plenty of forums/articles on this, but the short story is with gears, if you rotate the shaft too fast at speed, it can vibrate.
Short story, if you have a little weight, stock drive shaft, and 5.29s you won’t be sitting too high in the rev range on the highway, and you will actually be able to use the overdrive gears (5-6). What you’ll notice at low speed is ripping through gears before you hit 35-40mph. I’m often in 4th over 30mph.
Hope some of this helps…
Oh, and like others said - the tune is different for different gears AND different size tires…
What’s your MPG’s with that set up and 4.88’s?
Oh it’s not great. As long as I’m running 65 mph or so and zero wind it’ll read 17.5 to 19.5 mpg. And that is off by about 6% due to tire diameter. So actually closer to 18.5 to 20 maybe. Above 65 it drops off. 70mph into a head wind more like 15mpg. Around town matches highway and 45mph back roads I’ve seen 25 mpg. I didn’t do the gear change for mileage, it was for driving comfort. It drives more like it was meant to now.
For reference I run 2000rpm at 65mph indicated, actual 68mph
Bone stock new with an empty bed it only did about 22mpg highway and shifted in and out of 6th gear non stop. The constant shifting is gone now. And 4 low is really nice with the 4.88s. 4.88s with 33’s is a better driving truck than stock gearing with stock tires.
I don’t know what it weighs but I have full-time onboard a full prinsu rack with 100w solar panel, V1 gfc with a 100 solar panel and beef bars, 8’ awning,40L 12v cooler, Propex heater and 11gal. Propane bottle, 3 gals spare fuel, 50ah battery and charge controller. And kitchen gear. Homemade steel rear bumper, and SSO steel front bumper. So whatever that weighs.
If you ever plan to go 35’s I’d go 5.29s. I’m pretty sure 35’s would make my truck feel just like it did before the gear change with the 33’s.
Is 2000rpm at 65 in 6th gear?
Yes your speedo will read approximately 65mph at 2000 rpm in 6th gear.
Cool, its hard get get a gauge of what its actually going to be when the calculators all give actual speed and not what you speedo will read.
And yeah according to the nitro gear calculator, 488 and 33s is only 40 rpm less than 529 and 35s. People always say 488 on 33s is like stock. But its still better than stock by about 250 rpm
The biggest thing for me was when it was stock on the highway it would shift to 6th on flat ground. As soon as you hit the slightest incline or headwind it would drop to 5th. Then it would start picking up speed because of the torque increase. So you let off the pedal slightly to maintain your speed. As soon as you did that it would go back to 6th ,which it still couldn’t pull and would start to slow down again, so you give it more pedal and it drops to 5th again. Over and over and over.
That issue is gone.
The tune has “helped” with this but yes it still happens I notice at certain speeds especially on cruise.