New member here! 6.2 Tahoe diff Id help

[62Towhoe]

Hello GM buddies.

Little intro, I've had my 09 6.2 ltz hoe for couple years now and I love her to death but the 3.42 gears are bugging me a lot towing. Hunting 4-5 while pulling my tow hauler makes me feel bad for the tranny.

I was happy to find the rear is a 9.5 14sf and would assume the front is 8.25 but not positive it isn't the 9.25 (one can dream right?)

It's tough to find solid info on this rig since the 6.2 hoes are not very common.

Any quick visual id marks you guys are aware of?

Cheers!
-Tyler

 

[Doubeleive]

@swathdiver

 

[swathdiver]

Hello GM buddies.

Little intro, I've had my 09 6.2 ltz hoe for couple years now and I love her to death but the 3.42 gears are bugging me a lot towing. Hunting 4-5 while pulling my tow hauler makes me feel bad for the tranny.

I was happy to find the rear is a 9.5 14sf and would assume the front is 8.25 but not positive it isn't the 9.25 (one can dream right?)

It's tough to find solid info on this rig since the 6.2 hoes are not very common.

Any quick visual id marks you guys are aware of?

Cheers!
-Tyler

The front is 8.25". It's up to the task of towing and even playing a bit with lower ratio gears. What is the weight of the trailer and has the engine and transmission been tuned?

 

[Miami-Dade]

Welcome from Miami Beach Tyler!

You are one of the lucky ones to own a 2009-6.2 Hoe!

 

[62Towhoe]

The front is 8.25". It's up to the task of towing and even playing a bit with lower ratio gears. What is the weight of the trailer and has the engine and transmission been tuned?

Thanks! I figured it was the 8.25 but need to know before I buy the ring and pinion. It's all pretty much stock but with 275/60/20 tires which doesn't help.

Trailer gross is 7500 but it tall af and is a parachute behind me. I'm unfortunately in the ****** land of California so tuning is out the window now.

I'm thinking 4.10 should give me the boost I'm looking for and keep Normal highway cruising rpm reasonable.

 

[62Towhoe]

Welcome from Miami Beach Tyler!

You are one of the lucky ones to own a 2009-6.2 Hoe!

Thanks, I spent over a year searching for her. Was the only rig I could find that fit in my parking requirements could tow and had enough seats. Heard there was something like 700 ever made which I had no idea was that rare until recently.

 

[swathdiver]

Thanks! I figured it was the 8.25 but need to know before I buy the ring and pinion. It's all pretty much stock but with 275/60/20 tires which doesn't help.

Trailer gross is 7500 but it tall af and is a parachute behind me. I'm unfortunately in the ****** land of California so tuning is out the window now.

I'm thinking 4.10 should give me the boost I'm looking for and keep Normal highway cruising rpm reasonable.

BlackBear tunes are undetectable.

Ok, so at that weight, you'll of course be using Tow/Haul mode, if she's still hunting for gears, use M4, that's just about 2900 at 70 mph. 4th is maximum cooling so it's ok to run there all day long. 4.10s will deliver 2568 rpms in 5th at 70 mph. Should be plenty of torque.

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving sage advice from the knowledgeable folks on this Forum.

Lots of our California members on this Forum have tunes.

I would recommend a Black Bear Performance tune, which will run in the neighborhood of $600. This tune will modify your ECM and also your TCM (so that shifting performance will also be improved, which can make as much a difference in performance as the ECM tune). And with this purchase, you will be able to obtain future tune adjustments through your AutoCal for a nominal fee for the life of your truck, whenever you make a mod for which a tune adjustment would be appropriate (cam, headers, CAI, tire size change, etc.). You can obtain the tune totally remotely with BBP, and I would suggest that you call @BlackBearPerf and discuss your needs with them, specifically what your towing situation is. Don't think of it as a one-time purchase from a vendor, but rather, think of it as building a long-term relationship with a vendor, who will be at your service for your tuning needs for the life of your truck. You won't be disappointed. A good tune is the best performance mod you can make for your dollar, IMO.

 

[OR VietVet]

Welcome to the forum. Pics please.

 

[Dantheman1540]

The good thing about the 3.42s is that if you end up hurting the factory rear 8.6" axle, a similar year 9.5" 14bolt will bolt right up with no gear changes. I agree with the others try a tune first for sure!

 

[62Towhoe]

BlackBear tunes are undetectable.

Ok, so at that weight, you'll of course be using Tow/Haul mode, if she's still hunting for gears, use M4, that's just about 2900 at 70 mph. 4th is maximum cooling so it's ok to run there all day long. 4.10s will deliver 2568 rpms in 5th at 70 mph. Should be plenty of torque.

thanks yeah i ran the numbers and they seem to match up with what you got. 3.73 didn't seem like enough change to bother the effort.

we sure blackbear is undetectable? commiefornia recently passed the tune sniffing law for smog and from what ive heard they look at the size of the file for your map and if the file size is changed at all it throws a flag. i could see how a piggyback style tune would bypass this but the blackbear is a re-flash.

anyone in ca passed smog this year with blackbear?

getting some pics together now for you all

 

[62Towhoe]

The good thing about the 3.42s is that if you end up hurting the factory rear 8.6" axle, a similar year 9.5" 14bolt will bolt right up with no gear changes. I agree with the others try a tune first for sure!

i figured this had the 10 bolt the whole time until i started looking into gears so i took a closer look and low and behold she has 14 bolts on the diff cover! guess there are some gmt900 tahoes that came factory with a 9.5 after all.

 

[62Towhoe]

Welcome to the forum. Pics please.

You don't want to see the interior. Its a family car lol. Pretty straight except the hit and run ding on fender and tailgate dent from my trailer spotter sleeping on the job.

 

[62Towhoe]

Welcome to the forum. Pics please.

Here's one of the trailer for reference and some other toys of mine.
72 Datsun and 74 K5 which was my first car and still runs strong.

 

[Dantheman1540]

i figured this had the 10 bolt the whole time until i started looking into gears so i took a closer look and low and behold she has 14 bolts on the diff cover! guess there are some gmt900 tahoes that came factory with a 9.5 after all.

Whoa post a pic of that because I was under the impression that only 2wd 6.2 trucks came with the 9.5 you have a gem! Should serve you well for a long time

 

[wjburken]

thanks yeah i ran the numbers and they seem to match up with what you got. 3.73 didn't seem like enough change to bother the effort.

we sure blackbear is undetectable? commiefornia recently passed the tune sniffing law for smog and from what ive heard they look at the size of the file for your map and if the file size is changed at all it throws a flag. i could see how a piggyback style tune would bypass this but the blackbear is a re-flash.

anyone in ca passed smog this year with blackbear?

getting some pics together now for you all

@Doubeleive? Don’t you have a Blackbear tune?

 

[swathdiver]

i figured this had the 10 bolt the whole time until i started looking into gears so i took a closer look and low and behold she has 14 bolts on the diff cover! guess there are some gmt900 tahoes that came factory with a 9.5 after all.

Cool car collection man, love the K5

Whoa post a pic of that because I was under the impression that only 2wd 6.2 trucks came with the 9.5 you have a gem! Should serve you well for a long time

Any GMT900 equipped with a 6.2 and can be RWD will have the 14-Bolt, that includes 4x4s so that includes the 6.2 Tahoes of 2008 and 2009 and the 2010 6.2 Yukon XL SLTs as well.

It would also include the 2007-2009 Suburbans and Yukon XLs equipped with the 6.0 L76 and almost forgot those 2010 Canadian Avalanches with the 6.2 as well.

 

[swathdiver]

thanks yeah i ran the numbers and they seem to match up with what you got. 3.73 didn't seem like enough change to bother the effort.

we sure blackbear is undetectable? commiefornia recently passed the tune sniffing law for smog and from what ive heard they look at the size of the file for your map and if the file size is changed at all it throws a flag. i could see how a piggyback style tune would bypass this but the blackbear is a re-flash.

anyone in ca passed smog this year with blackbear?

getting some pics together now for you all

3.73s are what the 2500s have and the NHT pick up trucks. This allows the 2500 Suburbans to tow over 9,000 pounds and for the NHT pickups to tow over 10,000 pounds. Your tires makes it necessary to go down to 4.10s for the same effect. My daughter's NHT has 3.73s but with 35s they're acting more like 3.42s. It'll get 4.10s or 4.30s someday.

 

[Doubeleive]

@Doubeleive? Don’t you have a Blackbear tune?

I do use a BB tune, but I had a hiccup with a previous hypertech tune. short version is I had the transmission rebuilt and the hypertech would not program back to stock, so BB used the hypertech tune as my stock file, luckily the hypertech has a c.a.r.b. sticker, so I put the hypertech back on for smog and then put the BB tune back on afterwards, I did not try to smog it with the bb tune installed.

 

[Doubeleive]

thanks yeah i ran the numbers and they seem to match up with what you got. 3.73 didn't seem like enough change to bother the effort.

we sure blackbear is undetectable? commiefornia recently passed the tune sniffing law for smog and from what ive heard they look at the size of the file for your map and if the file size is changed at all it throws a flag. i could see how a piggyback style tune would bypass this but the blackbear is a re-flash.

anyone in ca passed smog this year with blackbear?

getting some pics together now for you all

even if you got the bb tune you could just put it back to stock for smog and then put it back on, it does reset the sensors doing that so, always drive it a couple days first on the stock file before going to smog it.