NEW GEARS - 3.08 - 3.73

[snowboardman2002us]

2012 Tahoe LT 4x4 with GU4 3.08 gears. Volant intake with magnaflow muffler 305 70 17's BB tuned.

After tons of research this is what I believe are the facts.

This truck OEM can tow 5200lbs

with the K5L cooling package and 3.42 gears can tow 8200lbs. KL5 Package I believe to be a trans and engine oil cooler.

I have installed a large trans cooler and might also be installing a engine oil cooler as well.

I have a RV that weighs 4650 dry which tows ok. 1st and second gear fine, anything after that is super sluggish.

I have researched to learn that I should upgrade to 3.73 gearing to help with towing and bigger tires.

Couple questions -

In theory, if I add the trans and engine coolers, installed 3.73 gears, it should bump this truck towing to 8200lbs? or so since the larger tires?

BB tuning is backed up right now and cannot tune for about a month or two. Is there a reason I should wait to get the tune? I know the speedo might be a little off (so I read), and there I have read there is something to do with shift points. Can anyone chime in on this? Or would I be able to jump in the truck and drive it just fine.

What will this do to my MPG? Currently I am getting about 12 average and about 8 while towing.

 

[wsteele]

2012 Tahoe LT 4x4 with GU4 3.08 gears. Volant intake with magnaflow muffler 305 70 17's BB tuned.

After tons of research this is what I believe are the facts.

This truck OEM can tow 5200lbs

with the K5L cooling package and 3.42 gears can tow 8200lbs. KL5 Package I believe to be a trans and engine oil cooler.

I have installed a large trans cooler and might also be installing a engine oil cooler as well.

I have a RV that weighs 4650 dry which tows ok. 1st and second gear fine, anything after that is super sluggish.

I have researched to learn that I should upgrade to 3.73 gearing to help with towing and bigger tires.

Couple questions -

In theory, if I add the trans and engine coolers, installed 3.73 gears, it should bump this truck towing to 8200lbs? or so since the larger tires?

BB tuning is backed up right now and cannot tune for about a month or two. Is there a reason I should wait to get the tune? I know the speedo might be a little off (so I read), and there I have read there is something to do with shift points. Can anyone chime in on this? Or would I be able to jump in the truck and drive it just fine.

What will this do to my MPG? Currently I am getting about 12 average and about 8 while towing.

I have factory 3.73 RA and I towed a 5K lb enclosed trailer for the first 60K miles of its life. Towed like a dream. My lifetime MPG combined with this truck according to my DIC is 14.9 MPG, I never really clocked it while towing but I would guess I averaged about 10.

 

[swathdiver]

2012 Tahoe LT 4x4 with GU4 3.08 gears. Volant intake with magnaflow muffler 305 70 17's BB tuned.

After tons of research this is what I believe are the facts.

This truck OEM can tow 5200lbs

with the K5L cooling package and 3.42 gears can tow 8200lbs. KL5 Package I believe to be a trans and engine oil cooler.

I have installed a large trans cooler and might also be installing a engine oil cooler as well.

I have a RV that weighs 4650 dry which tows ok. 1st and second gear fine, anything after that is super sluggish.

I have researched to learn that I should upgrade to 3.73 gearing to help with towing and bigger tires.

Couple questions -

In theory, if I add the trans and engine coolers, installed 3.73 gears, it should bump this truck towing to 8200lbs? or so since the larger tires?

BB tuning is backed up right now and cannot tune for about a month or two. Is there a reason I should wait to get the tune? I know the speedo might be a little off (so I read), and there I have read there is something to do with shift points. Can anyone chime in on this? Or would I be able to jump in the truck and drive it just fine.

What will this do to my MPG? Currently I am getting about 12 average and about 8 while towing.

K5L also has 700 watt cooling fan motors. Your thinking is exactly right.

The best part about the tune in my opinion is in how the transmission performed afterwards. Black Bear will adjust the tune to compensate for the gearing and tires both in the ECM and TCM. Does your Tahoe have the G80 locker?

I am going to put 3.73s in mine too. But am not upgrading the current 8.6, going to run the semi-floater, the 14-bolt 9.5". The 3.08 carrier cannot accept lower gears without an adapter and is still weak. If you plan to tow, you should get the larger carrier or go for the AXN semi-floater.

 

[swathdiver]

2012 Tahoe LT 4x4 with GU4 3.08 gears. Volant intake with magnaflow muffler 305 70 17's BB tuned.

After tons of research this is what I believe are the facts.

This truck OEM can tow 5200lbs

with the K5L cooling package and 3.42 gears can tow 8200lbs. KL5 Package I believe to be a trans and engine oil cooler.

I have installed a large trans cooler and might also be installing a engine oil cooler as well.

I have a RV that weighs 4650 dry which tows ok. 1st and second gear fine, anything after that is super sluggish.

I have researched to learn that I should upgrade to 3.73 gearing to help with towing and bigger tires.

Couple questions -

In theory, if I add the trans and engine coolers, installed 3.73 gears, it should bump this truck towing to 8200lbs? or so since the larger tires?

BB tuning is backed up right now and cannot tune for about a month or two. Is there a reason I should wait to get the tune? I know the speedo might be a little off (so I read), and there I have read there is something to do with shift points. Can anyone chime in on this? Or would I be able to jump in the truck and drive it just fine.

What will this do to my MPG? Currently I am getting about 12 average and about 8 while towing.

Well, what did you wind up doing?

 

[swathdiver]

2012 Tahoe LT 4x4 with GU4 3.08 gears. Volant intake with magnaflow muffler 305 70 17's BB tuned.

After tons of research this is what I believe are the facts.

This truck OEM can tow 5200lbs

with the K5L cooling package and 3.42 gears can tow 8200lbs. KL5 Package I believe to be a trans and engine oil cooler.

I have installed a large trans cooler and might also be installing a engine oil cooler as well.

I have a RV that weighs 4650 dry which tows ok. 1st and second gear fine, anything after that is super sluggish.

I have researched to learn that I should upgrade to 3.73 gearing to help with towing and bigger tires.

Couple questions -

In theory, if I add the trans and engine coolers, installed 3.73 gears, it should bump this truck towing to 8200lbs? or so since the larger tires?

BB tuning is backed up right now and cannot tune for about a month or two. Is there a reason I should wait to get the tune? I know the speedo might be a little off (so I read), and there I have read there is something to do with shift points. Can anyone chime in on this? Or would I be able to jump in the truck and drive it just fine.

What will this do to my MPG? Currently I am getting about 12 average and about 8 while towing.

Bumping this old thread, maybe he'll get an email alert.