Got 4.56 gears in! The good and the bad.
#1
Senior Member
Thread Starter
Got 4.56 gears in! The good and the bad.
So finally stepped up to 4.56 from 3.73. Tires are 285/75/r18, effectively 35". The good news is I have my power back. I can get up to speed without the sluggishness and I can pass people on the highway again when I need to. At 70mph I'm at 2100-2200 RPM where as I used to be at ~1800. It's too early to tell the effect on my gas mileage, but it's not looking good
Now for the bad news. There is no additional noise when accelerating or under load. When cruising or off the gas pedal, the is hum. It's not what I would describe as a high pitched whine, but definitely a hum that wasn't there before. The guy that installed them gave a 2 year/24k mile warranty so I'm not too worried. I'll run them the 500 miles for break in then change the fluid and see what's up with the noise.
Now for the bad news. There is no additional noise when accelerating or under load. When cruising or off the gas pedal, the is hum. It's not what I would describe as a high pitched whine, but definitely a hum that wasn't there before. The guy that installed them gave a 2 year/24k mile warranty so I'm not too worried. I'll run them the 500 miles for break in then change the fluid and see what's up with the noise.
#3
Senior Member
So finally stepped up to 4.56 from 3.73. Tires are 285/75/r18, effectively 35". The good news is I have my power back. I can get up to speed without the sluggishness and I can pass people on the highway again when I need to. At 70mph I'm at 2100-2200 RPM where as I used to be at ~1800. It's too early to tell the effect on my gas mileage, but it's not looking good
Now for the bad news. There is no additional noise when accelerating or under load. When cruising or off the gas pedal, the is hum. It's not what I would describe as a high pitched whine, but definitely a hum that wasn't there before. The guy that installed them gave a 2 year/24k mile warranty so I'm not too worried. I'll run them the 500 miles for break in then change the fluid and see what's up with the noise.
Now for the bad news. There is no additional noise when accelerating or under load. When cruising or off the gas pedal, the is hum. It's not what I would describe as a high pitched whine, but definitely a hum that wasn't there before. The guy that installed them gave a 2 year/24k mile warranty so I'm not too worried. I'll run them the 500 miles for break in then change the fluid and see what's up with the noise.
#4
Boost :)
Either way it needs to be looked at before it becomes worse.
#6
Senior Member
It's not necessarily the set-up (although it's entirely possible). I went through this on my 05 a couple years ago. Assuming you have a 9.75, the only gears available are Indium or Chineseium. The machining/finish/lapping quality is mediocre at best. I tried Sierra, Yukon and Dana SVL. The Sierras were disappointing, the Yukons hideous and the Dana SVL were acceptable but they have a bit of a coast whine at 42-50 and a soft but perceptible whir at high speed. I've set up a lot of diffs and did these by the numbers.
FWIW, as a GENERAL rule, (assuming the backlash and pinion preload is correct) a coast whine comes from too much pinion depth and a drive whine means too shallow. A float whine may be too much backlash.
FWIW, as a GENERAL rule, (assuming the backlash and pinion preload is correct) a coast whine comes from too much pinion depth and a drive whine means too shallow. A float whine may be too much backlash.
Last edited by PerryB; 09-28-2017 at 08:20 PM.
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#9
Junior Member
I have roughly a 34 inch tall tire and want to change from 3.31 to 3.73. My fear is 4.10 gears would be a bad choice with the 6 speed auto trans. I'm afraid the first two gears will shift so quick it would yield them almost useless.
How is your truck from a stop? Does it shift more like it should with a factory tire?
How is your truck from a stop? Does it shift more like it should with a factory tire?