Gears are in!
Extreme, I get a slight whine in the 50 to 60 mph range as well. The engine and exhaust is quiet in that range and with the radio off I hear it. Gears are sweet for sure, too bad the labor is so much. It sounds like you like to run 80 mph or so, so the 4.56 was a good choice.
Baja, if you don't do a lot of highway or are even thinking 4.88, DO IT. I would recommend the 4.88's on 35's for your situation. I went back and forth and ended up with the 4.56 b/c I do so much highway but even so I kind of wish I'd gone 4.88 sometimes, I love them but if I could do the gears myself I'd switch. I used to run 80 mph so I was scared of the 4.88's but in this truck I kind of like cruising 70 or so. Try playing around with this calculator... http://www.grimmjeeper.com/gears.html it is very flexible and good for side by side comparison.
Hear's the thing about towing. I towed a boat (~6,000-6,500lbs) with the 4.56's and tried OD at first on the highway at 65-70 mph and although it would hold OD it would not lock the torque converter and the throttle position was probably at 60 or 70% and just seemed like it was killing it, plus the rpm's were high bc of the unlocked converter. So I turned OD off and it pulled 3rd like a dream. At 65 mph it ran about 2,800 rpm which sounds high but the throttle input was very low like maybe 15% or less and you have to remember it's a gas engine and just getting into its best power range. The engine felt super strong and if I needed to pass it easily pulled up to 70 or 75 in a hurry. I just set the cruise and it didn't even blink at headwinds or overpasses. So that leads me to this. Even with 4.88's there's no way it will pull OD comfortably with a decent size boat (in this case a 24 footer) so it would be 3rd and pulling about 3,000 rpm at 65mph which is the speed I feel comfortable towing a load of this size. I look at it this way, if pulling something more than 7k or so I'd want 4.88's and run 60-65 mph in 3rd pulling 2,800-3,000 rpm. The best part was that even at 2,800 rpm I got a hand calculated average of 9.5 mph towing approximately 500 miles. That was .5 mph better than my '98 5.4 ever got with the same boat and that truck was all stock and regular cab.
As far as 37-inch tires there's no question at least 4.88's. I'd probably go 5.13 if it were me.
Baja, if you don't do a lot of highway or are even thinking 4.88, DO IT. I would recommend the 4.88's on 35's for your situation. I went back and forth and ended up with the 4.56 b/c I do so much highway but even so I kind of wish I'd gone 4.88 sometimes, I love them but if I could do the gears myself I'd switch. I used to run 80 mph so I was scared of the 4.88's but in this truck I kind of like cruising 70 or so. Try playing around with this calculator... http://www.grimmjeeper.com/gears.html it is very flexible and good for side by side comparison.
Hear's the thing about towing. I towed a boat (~6,000-6,500lbs) with the 4.56's and tried OD at first on the highway at 65-70 mph and although it would hold OD it would not lock the torque converter and the throttle position was probably at 60 or 70% and just seemed like it was killing it, plus the rpm's were high bc of the unlocked converter. So I turned OD off and it pulled 3rd like a dream. At 65 mph it ran about 2,800 rpm which sounds high but the throttle input was very low like maybe 15% or less and you have to remember it's a gas engine and just getting into its best power range. The engine felt super strong and if I needed to pass it easily pulled up to 70 or 75 in a hurry. I just set the cruise and it didn't even blink at headwinds or overpasses. So that leads me to this. Even with 4.88's there's no way it will pull OD comfortably with a decent size boat (in this case a 24 footer) so it would be 3rd and pulling about 3,000 rpm at 65mph which is the speed I feel comfortable towing a load of this size. I look at it this way, if pulling something more than 7k or so I'd want 4.88's and run 60-65 mph in 3rd pulling 2,800-3,000 rpm. The best part was that even at 2,800 rpm I got a hand calculated average of 9.5 mph towing approximately 500 miles. That was .5 mph better than my '98 5.4 ever got with the same boat and that truck was all stock and regular cab.
As far as 37-inch tires there's no question at least 4.88's. I'd probably go 5.13 if it were me.
Last edited by BlackDawg; Aug 14, 2007 at 12:00 AM.
Well for 37s, 4.56s work just fine for me. I tow my 25' Mariah with no problem. Now if i were towing it ALL the time then i would probably get 4.88s BUT i never installed 4.88s so i cannot say whether or not to get them, depends on your situation.
extremeethan, did you program your edge for your gears and tires?
extremeethan, did you program your edge for your gears and tires?
Originally Posted by BlackDawg
Baja, if you don't do a lot of highway or are even thinking 4.88, DO IT. I would recommend the 4.88's on 35's for your situation.
Originally Posted by BlackDawg
Hear's the thing about towing. I towed a boat (~6,000-6,500lbs) with the 4.56's and tried OD at first on the highway at 65-70 mph and although it would hold OD it would not lock the torque converter and the throttle position was probably at 60 or 70% and just seemed like it was killing it, plus the rpm's were high bc of the unlocked converter.
... also, how exactly do you know if the TCC is locked or unlocked? Does the EDGE provide this info?
Under normal (non towing) conditions, does the torque converter clutch lock around 35mph?
Under normal (non towing) conditions, does the torque converter clutch lock around 35mph?
Last edited by baja150; Aug 14, 2007 at 09:01 AM.
Baja, your exhaust and tac will tell you about the tc unlocking because it'll jump up a couple hundred rpm and you'll hear it especially with aftermarket exhaust. It almost seems like a shift to 3rd but it's not. If the torque converter is unlocked in OD it'll run almost the same rpm as 3rd locked except it's heating the tranny.
As far as the gears it's not really a blank decision IMO. You can't just say if you run 35's you should run 4.56 or whatever. You have to think about driving style, where you drive, and gas mileage if that's important. Plus what you tow. When I inquired about gears on here I got mostly 4.56 and some 4.88 opinions for 35's. I went a little cautious bc I'm 75% highway. It sounds like Extreme does a lot of highway too so he probably has the right gears for him. Someone told me "don't fear the gear" and I thought that was funny but it's also good advice. Good luck.
As far as the gears it's not really a blank decision IMO. You can't just say if you run 35's you should run 4.56 or whatever. You have to think about driving style, where you drive, and gas mileage if that's important. Plus what you tow. When I inquired about gears on here I got mostly 4.56 and some 4.88 opinions for 35's. I went a little cautious bc I'm 75% highway. It sounds like Extreme does a lot of highway too so he probably has the right gears for him. Someone told me "don't fear the gear" and I thought that was funny but it's also good advice. Good luck.
Originally Posted by extremeethan
Yup edge is set for the 456, I am pretty sure its gear whine, but I only hear it around 50 would Royal Purple help?
Nope they did it all for me brough the gears in and everything. I was just looking at my tires and some how they were like 8 psi over where I run them
and the rear edges were feathering so I lowered them back down and am hoping thats where my wind/whine is comming from ill know in a couple of days when they strighten out. (I filled them back when it was 80 its now of 115, that has to be the pressure increase)
and the rear edges were feathering so I lowered them back down and am hoping thats where my wind/whine is comming from ill know in a couple of days when they strighten out. (I filled them back when it was 80 its now of 115, that has to be the pressure increase)
I just called the dealership where I purchased my truck and they said $1700 and I have to provide the gears. The $1700 covers the install kits and the labor only.
Granted I would expect to pay a little more at a dealership, but it still seems a little steep.
Granted I would expect to pay a little more at a dealership, but it still seems a little steep.


