Gearing yet again

[blizz]

so I just found out I have 3.42s and a G80. I also have 285s which are roughly equivalent to 33s. I also tow about 6000lbs. It seems to do fine but would like it to do better. Also, when driving without towing, it seems sluggish after about 50mph. Everything I'm reading leads me to believe that the gear ratio is off. I'm considering going to 4.10 gears to help with towing and give me a little more power as well as get it back to stock numbers, if not a little more due to the tires as it originally came with 245s. It is also 4x4. So what all does this entail? How much should I expect to spend? Are the gears changeable or does this require new axles? What about this G80? Haven't had any problems but am curious if this is something I should address now also. Thanks.

 

[TheAutumnWind]

245 and 285 are widths for tires btw... need the second number and the wheel size to tell how tall a tire is.

 

[blizz]

285 75 16 up from 245 75 16, thus my reference to 33s. I assumed the 75 was a given. My bad.

 

[TheAutumnWind]

"75" refers to the amount of sidewall, which along with the wheel size, tells you the tire height. It varies obviously.






4.10's seems like a reasonable final drive. You have to change front and rear gears and its not going to be a cheap endeavor.

 

[Matt_]

Basically it entails you dropping your truck off at a shop and picking it up later that day. Ive done gear swaps and honestly have reached the point where I'll just pay a shop to do it lol.

You dont need new axles or anything. They'll replace the ring and pinion in both axles and likely recommend putting all new bearings/seals in as well (which I highly recommend).

A solid replacement for the G80 is the Detroit Truetrac. Although it doesn't fully lock like the G80, it's tough and never met me down in deep snow or mud.

Prices vary A LOT based on region. Expect to pay somewhere between $1500-$2000 if you're also replacing the G80 with a new carrier.

I consider 3.42s undergeared from the factory (at least with trucks with 4spd trans). Should have been 3.73 or 4.10 stock for a fully capable fullsize IMO. depending on what you're doing with it, and if you might go larger with the tires, I'd strongly consider 4.30s.

You'll also need to reprogram the computer for the new gear ratio. Most handhelds will do it, but it's a prime opportunity to get a blackbear custom tune.

 

[blizz]

I won't ever put bigger tires on this thing and it is mainly just my tow vehicle to pull my travel trailer that has a dry weight of 5300lbs. With 33s I'd think that 4.11 is good enough from what I've been reading. Thanks for the info. Can the G80 be done at a later time without much more fuss? Seems to be doing fine, however, I don't know how that comes into play while towing. Oh and I've already done a BB tune and just have to send the pcm back for a re-tune.

 

[Matt_]

Stock trucks with tow packages came with 4.10s... so you're regearing with a handicap if it's a tow rig. Honestly it's minor so you'll probably be happy with 4.10s, but if you're spending the money I don't see a benefit to 4.10s over 4.30s if you're towing.

Replacing the G80 later will cost as much as the regearing does in terms of labor. Whereas if you do it at the same time there should be no additional labor. Again, rates vary... I'd get it priced out both ways and decide from there. Where I'm from the labor costs more than the part, so it's worth doing with the gears.

 

[blizz]

It's crazy that my Tahoe came with the towing pkg but with 3.42 gears. I guess with puny 245 75 16s it would be ok. Still though. That sucks.

 

[Matt_]

Might have something to do with how they marketed SUVs vs trucks, and max tow capacity. My gmt800 silverado was 4.10s with tow package. Stock tires were only an inch taller than yours.

I wouldn't lose sleep about it either way. If I was regearing for a tow rig for 33s, I'd go 4.30s. Either will be a HUGE improvement over your current 3.42s though

 

[blizz]

Thanks. I'm going to call up the place today and see what they say. Any particular brands to look for or stay away from on the ring and pinion?