HELP! 2012 suburban 6L80 trans failure

[neffcd]

I need some gearhead advice. I have a 2012 Burb with the 6L80 that has 202k miles. I was towing my boat (20ft Ranger fiberglass) and lost 3,4,5,6 gears. What would be my best route going forward in y'alls opinion? Motor runs good. Are these trannys worth rebuilding? Should I use different parts to rebuild? I have no idea about this stuff so any advice is greatly appreciated. Trying to decide if I should go cheap and sell it or rebuild it good and keep on truckin'. Thanks!

 

[strutaeng]

Please read through this thread:

GM 6L80 Transmission Information Thread

Hi All, Since so many of us own at least one Tahoe or Yukon equipped with a 6L80, I figured I'd start an all-encompassing transmission thread with videos, links and other information as it relates to the 6L80/90 transmissions. I'll get it going with a tear down and inspection video and go from...

www.tahoeyukonforum.com

Are you thinking of rebuilding it yourself? Have you rebuilt transmissions before? Is this your primary use vehicle?

 

[Joseph Garcia]

Let's hear directly from our resident transmission expert for this thoughts and perspectives.

@NickTransmissions

 

[NickTransmissions]

I need some gearhead advice. I have a 2012 Burb with the 6L80 that has 202k miles. I was towing my boat (20ft Ranger fiberglass) and lost 3,4,5,6 gears. What would be my best route going forward in y'alls opinion? Motor runs good. Are these trannys worth rebuilding? Should I use different parts to rebuild? I have no idea about this stuff so any advice is greatly appreciated. Trying to decide if I should go cheap and sell it or rebuild it good and keep on truckin'. Thanks!

Does reverse work?

 

[neffcd]

Does reverse work?

Yes and 1st and 2nd.

 

[NickTransmissions]

Sounds like you lost your 4-5-6 clutch completely and the 3-5-R clutch is on its way out (there's nearly twice as much line pressure avail in reverse at the point of engagement unless you're shifting at WOT into 3rd or 5th so you often still have reverse even when 3rd/5th are no longer functioning. The 3-5-R clutch is on/applied in 3rd, 5th and reverse....The low reverse clutch and 3-5-R clutch are on in reverse. Your 1-2-3-4 clutch is still operable as is your 2-6 clutch but the other two forward shifting clutch packs are shot.

You planning on rebuilding the transmission yourself?

 

[blackelky]

That gives me hope for some more miles before mine goes my tahoe is at 98k

 

[petethepug]

Good question and smart of you to be open to all options. First off, the difference between a total cut rate and maybe questionable trans rebuild would be -$1.5k. So figure you’re looking at that dollar amount up in the air after you take all your time to fix it.

With GM fighting for the strike of their life, it’s probably not a good time to upgrade as the parts warehouses are on strike too. The one in San Diego just went to 24/7 picket lines.

You could make good resale on selling private party as well as a trade, but keep in mind, unless you got a smoking deal on your 1st pick, hope too, always wanted truck, you’d still lose a little equity because new / used vehicle sales are high right now.

When our trans was hinting with a very occasional 2-3 slip on our 08 YXL Denali, we did find our dream truck at a TX Lexus Dlr and drove it back to CA. It gave us time to have a dealership pro Resto the paint & interior and sell it for $1.5k less that what we got our 09 Esky Plat ESV AWD for.

Three years after owning the Esky, the trans went out. I couldn’t be happier because I fully intended on keeping the truck. If you find your dream truck, buy it outright and then sell / fix the Burb when all the pressure’s off.

Do both. Shop for a trans rebuild as well as your dream truck. Keep in mind your Burb is likely due for the items I listed in another thread that are about 1-$1.5k if you buy them off R/A and have the shop install ur parts. Those same parts are 2-3x more in labor and cost is the shop sources them and the trans is not out.

I spent $6.5k for a hand rebuilt trans and all those parts, so I’m good from the 175k I’m at now til 275k clicks later.

 

[solli5pack]

Sounds like you lost your 4-5-6 clutch completely and the 3-5-R clutch is on its way out (there's nearly twice as much line pressure avail in reverse at the point of engagement unless you're shifting at WOT into 3rd or 5th so you often still have reverse even when 3rd/5th are no longer functioning. The 3-5-R clutch is on/applied in 3rd, 5th and reverse....The low reverse clutch and 3-5-R clutch are on in reverse. Your 1-2-3-4 clutch is still operable as is your 2-6 clutch but the other two forward shifting clutch packs are shot.

You planning on rebuilding the transmission yourself?

Just curious. Is rebuilding a transmission at home a legit option for a d.i.y'er?

 

[MWD_CTSV]

Based on Nick's analysis, I would say yes it is worth it to rebuild the 6L80. Aside from the torque converter slip problems (which is more software than mechanical), the most likely mechanical design flaw is the undersized 4-5-6 clutch. So if 4-5-6 is gone and 3-5-R is not far behind, you trans is easily re-buildable with standard consumables.

200K for a 6L80 that tows is a very good life. If the truck is worth $10K good condition running, it is worth maybe $5k with a bad transmission, and probably very little for trade-in at 200K regardless of the trans. So with a quality trans rebuild costing $5-6K, it is your best option to 'buy' another 100K miles plus some extra for other maintenance from a pure dollar per mile stand point.

If you just want a new truck, then a new Suburban with a 10-speed is a very nice option, but you will not get your trans rebuild cost back on trade-in. So in that case rebuilding the trans is not a good idea. Someone may happily give you $4k as-is on a private sale with a bad trans, and trade-in might be $6k with a new $6k rebuilt trans.