Can anyone recommend a shop in Oregon (preferably Portland area) for gear install? I just moved from 33" tires to 34" and feel like it's now time to go with 4:88 gears.
Oregon shop for gear install?
- Thread starter ElJayBird
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I can't recommend a shop, but I can say that 4.88's on 34's are a lot of gear and while they can be fun especially with ECT PWR on they're generally overkill and will hurt highway mpg. If you want the lower crawl ratio they're good, but for highway mileage and manners you'd be better off with 4.30 gears. Note that 4.30s are good for 35's too.
Now if you're thinking about 37's down the road it's a different story.
Now if you're thinking about 37's down the road it's a different story.
4.88s here, and my previously dismal mpg on 3.90s remained dismal on 4.88s. I really like the 4.88s, but haven't driven the 4.30s. Whatever you get, it'll be a big improvement.
Maybe call Metaltech4x4 and see if they have a shop recommendation.
Another alternative is to book a short vacation in Wenatchee and have Nitro's shop do the gear install.
Maybe call Metaltech4x4 and see if they have a shop recommendation.
Another alternative is to book a short vacation in Wenatchee and have Nitro's shop do the gear install.
- Thread starter
- #5
Got it - I was thinking 4.88 because I tow a trailer pretty frequently, but the camper is only about 2200#. Mostly looking to restore power and get my MPG back over 10.
I can't see myself going to a 35, but I said the same thing about 34 when I went 33.
Sounds like 4.3 is the better option.
I'll give the guys at MetalTech a shout.
Thanks errebody!
I can't see myself going to a 35, but I said the same thing about 34 when I went 33.
Sounds like 4.3 is the better option.
I'll give the guys at MetalTech a shout.
Thanks errebody!
I just installed 4.88s, but the build is super heavy and I’m only on 33s. I will go to 34s eventually. In my early driving impressions so far I’m happy with the ability to get up and rolling again, especially in the mountains here in CO
Are they though...
I've made my opinion known on this already but I'm happy to beat the drum. I don't think you can over-gear a 200 series assuming you're running over a 33" tire. If you're going to shell out the $3k+ to have someone set you up, I'd hate to look back and think if it was enough. I rather be slightly over-geared than under. I get ~17% better MPG around town in a less aerodynamic and heavier (~350lbs) 4:88 truck than I did in my stock geared truck. Highway speeds is about even until 65ish MPH. Either way I still got under 11 MPG going across Kansas at 75 MPH with a 15 MPH cross wind.
Point being, do what you want.
- Thread starter
- #8
I feel like I've got analysis paralysis at this point. I'm heavier than stock, especially when loaded out. I tow a 2000# camper and carry at least 200# of gear when I'm on trips. I've got a bumper, winch, carry 10ga of extra fuel and will likely add drawers and possibly an LRA tank at some point. I've read so many threads on this topic that I'm tired of thinking about it.
The only clear solution is 4.56.
I went 4.88s on 34s with the only aero impacting mod being a roofrack and XL cargo box. I dont tow frequently, but I do haul consistently at GVWR.
I've seen a consistent mpg improvement (~2mpg) living in a hilly terrain. Doesn't mean mpg is good, but I'm not single digits anymore..
I'd stick with the decision on 4.88s. I found the increased highway RPMs made for easier highway cruising with much less downshifting on minor hills and headwinds.
YMMV
I've seen a consistent mpg improvement (~2mpg) living in a hilly terrain. Doesn't mean mpg is good, but I'm not single digits anymore..
I'd stick with the decision on 4.88s. I found the increased highway RPMs made for easier highway cruising with much less downshifting on minor hills and headwinds.
YMMV
- Thread starter
- #11
Oh wow - I didn't realize that Nitro was in Wenatchee. I would seriously consider that - love the area. The gears I've been looking at are Nitro, so that would make a lot of sense.
On what size rubber? I am on 3.90 stock gears with the 8 speed and 33's and I still see 17-19 hwy and 15-16 city without trying. I caught a 20+ mph tailwind on the way to the coast this past weekend and we averaged 22.3 mpg at 70 mph over 25 miles, I couldn't believe it, needless to say it was a solid 5mpg less than that on the way home haha.
- Thread starter
- #14
285/75/17 on both trucks. 6 spd trucks.
I’ve never seen a tank above 16.8 mpg in either of my 200s, a lightly built 09 and fairly built 11. The 11 regularly returns over 1.5mpg better around town than the 09 did. I don’t particularly fly around town. On the highway, the 11 doesn’t seem to really suffer compared to the 09 until you push over 70. But then again it sits higher, has a bullbar and a FR rack so it’s safe to say aero accounts for much of the inefficiency at those speeds.
For me, the fuel economy debate is a nonissue as it relates to selecting the gear ratio as I’ve not experienced anything suggesting going higher numerically makes a significant difference. And anecdotally even some folks with 8spd trucks learned this for themselves but that’s another can of sardines. If 4.30 is someone else’s Goldilocks gear, good for them. Gimme 5.29s
Is more always better?
As much as gearing can help efficiency for a heavy rig, excess gearing has the potential to bring its own efficiency losses in the form of driveline drag and windage losses.
Here's a gearing reference for the 6-speed against various spec tire sizes and gearing options. More here- Definitive 200-series Gearing Reference - https://forum.ih8mud.com/threads/definitive-200-series-gearing-reference.1043543/#post-11503139
You can see that 4.3s are going to offer better gearing than stock for anything short of a 35" tires, and practically stock gearing for said 35" tire.
4.88s are almost a full gear step in the transmission. Good to 40" tires.
An unresolved integration of gearing is transmission tuning to be able to leverage gearing outside of stock parameters. Jeeps and Tacoma's have this. We don't unfortunately. We know when undergeared, the transmission doesn't shift well. The shift map is all over the place with transitions at load points outside of a well tuned system. The same is true with overgearing.
A symptom that @linuxgod might have discovered is torque converter lock-up for 4.88s. It's not clear if left in "D", if lockup is happening for 4 and 5th gears. Only 6? Which would be a pretty large impact to efficiency. Fortunately this can be worked around driving in sport as he discovered. Whereas my setup with 4.3s on 35s, which practically results in stock-like gearing, the torque converter is locking up as expected in 4,5, and 6th. I can say it performs with a factory tuned quality.
Practically speaking when towing, my rig is arguably one of the heaviest out there at 15k lbs combined. On 35s. Efficiency and performance are both priorities, especially when towing. For my use, 4.3s are still the right gears for me.
So maybe 4.88s, or maybe not, depending on your priorities. Now if 4.56s existed to @grinchy 's point...
As much as gearing can help efficiency for a heavy rig, excess gearing has the potential to bring its own efficiency losses in the form of driveline drag and windage losses.
Here's a gearing reference for the 6-speed against various spec tire sizes and gearing options. More here- Definitive 200-series Gearing Reference - https://forum.ih8mud.com/threads/definitive-200-series-gearing-reference.1043543/#post-11503139
You can see that 4.3s are going to offer better gearing than stock for anything short of a 35" tires, and practically stock gearing for said 35" tire.
4.88s are almost a full gear step in the transmission. Good to 40" tires.
An unresolved integration of gearing is transmission tuning to be able to leverage gearing outside of stock parameters. Jeeps and Tacoma's have this. We don't unfortunately. We know when undergeared, the transmission doesn't shift well. The shift map is all over the place with transitions at load points outside of a well tuned system. The same is true with overgearing.
A symptom that @linuxgod might have discovered is torque converter lock-up for 4.88s. It's not clear if left in "D", if lockup is happening for 4 and 5th gears. Only 6? Which would be a pretty large impact to efficiency. Fortunately this can be worked around driving in sport as he discovered. Whereas my setup with 4.3s on 35s, which practically results in stock-like gearing, the torque converter is locking up as expected in 4,5, and 6th. I can say it performs with a factory tuned quality.
Practically speaking when towing, my rig is arguably one of the heaviest out there at 15k lbs combined. On 35s. Efficiency and performance are both priorities, especially when towing. For my use, 4.3s are still the right gears for me.
So maybe 4.88s, or maybe not, depending on your priorities. Now if 4.56s existed to @grinchy 's point...
I've verified lockup in 4, 5 and 6 on 4.88 via the obdii/obdfusion, but I was only going around 35mph. I need to recheck on the freeway next time I'm out. I expect no difficulties.
- Thread starter
- #18
To be clear, MPG is Not my priority here. Just looking to restore power and reduce gear hunting on the highway while towing. Also keeping transmission temperatures down. I don’t have a Scangage installed yet but the transmission has been hot enough to feel radiant heat through the console a time or two.
All I know is I look at the numbers in the above chart and think about applying it to an upfitted 200 with a couple hundred pounds tacked onto it with additional aero loss from other modifications and come to a different conclusion. That’s not a way of arguing right or wrong, it’s simply a different decision based on my experience and expectations.
Oooooo look at Mr. BigMPG over here
Interesting snide reply to a simple statement.
