GM 6L80 Transmission Information Thread

CTX-SLPR said:

One thing I've noticed is the wide variety of prices on converters, even one claiming "billet covers"
- The big names like Yank, Circle-D, etc. seem to want about $1300 for a billet converter from their websites and they are all higher stall than stock
- There are some more obvious names playing in the high $100's like Monster and ProTorque that seem to hold to stock stall if you want
- Then there's this section down around $500 like the reman on RockAuto or a RECON from Transendence

Not all of these list specs to look for the lockup clutch thicknesses as Nick suggested. How does one go about shopping for something that's a definite step up from the stock JMBX in terms of durability without going all in on increased power handling like a 2600rpm stall Circle-D?

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I'd recommend looking in your area for a reputable torque converter rebuilder...I'm fortunate to have one here in Vegas and he does all my torque converters, regardless of application, stall, configuration, etc...Many of the big converter builders will order the same parts from Sonnax to build the converter; some will have proprietary parts.

The RECON converters are basically stock replications; RECON is a very large converter reman company who builds torque converters for all makes/models sold in the US; they will use the same spec of converter clutch that the factory uses. There's a few others as well...Yank and Circle D specialize in racing / street-strip converters so they don't offer too much in the way of factory stall options. Florida Torque Converters is a good company and builds a variety of converter types for any given year/make/model.

Converter clutch thickness should be .050-.070, BW high energy is preferred.

Nick,

Perhaps an odd idea but since there’s a good number of us who want to rebuild our 6L80’s but there is an investment in tooling, have you ever thought of having one or two of the mandatory tools for rental like auto parts stores. I.e. having the slide hammer for the case pins for rent for cost of the tool deposit and then something like a $20 fee + shipping for the trouble of having to deal with shipping it out on occasion?

CTX-SLPR said:

Nick,

Perhaps an odd idea but since there’s a good number of us who want to rebuild our 6L80’s but there is an investment in tooling, have you ever thought of having one or two of the mandatory tools for rental like auto parts stores. I.e. having the slide hammer for the case pins for rent for cost of the tool deposit and then something like a $20 fee + shipping for the trouble of having to deal with shipping it out on occasion?

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Id never do that for the simple fact thet if someone decided to keep it, Id be out. Way too much hassle for no substantive benefit.

Besides, you're looking at the tooling costs as though they were operating expenses when they are actually capital expenses.

Capital expenditures are incurred to acquire assets that can generate cash flow or reduce operating costs. They can be depreciated to reduce taxable income in most cases or resold to get back some of the initial investment in the even the case for them no longer exists (ie you sell your vehicle and buy one with a different transmission). They are not operating costs that, once incurred in exchange for a service, are deducted straight off the top line with zero potential for cost savings, cash flow generation or skill development on your part.

If you think you can do the work yourself, but for the lack of the special tools, buy the special tools. Its less money in capital costs than you're going to pay someone to do the work for you (operating cost).

Besides, you wont have to guess/hope you're getting what you paid for and will have a skill that will last you a lifetime with the tools to go with it.

Nick,

I get your point about not wanting to hassle with this. I can’t find a listing for the size of the roll pins in the case for the parking pawl, Would you be able to measure one? I’d rather get a slide hammer kit with the collet style ends as I do have more uses for that sort of thing for $350 than just the single size of the DT-48550.

CTX-SLPR said:

Nick,

I get your point about not wanting to hassle with this. I can’t find a listing for the size of the roll pins in the case for the parking pawl, Would you be able to measure one? I’d rather get a slide hammer kit with the collet style ends as I do have more uses for that sort of thing for $350 than just the single size of the DT-48550.

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If the parking pawl housing isnt leaking, no need to change it. You should be able to get the selector shaft retrntion roll pin out with diag cutters...Apart from that, any collet style puller-slide hammer set should work (prob better than the tool itself which isnt nearly as heavy as it needs to be for pulling out that roll pin).

Hi Nick! What an outstanding and informative thread! Only problem is, it's way over my head.....LOL.
Anyway, I have a 2016 Tahoe 4wd Z71. 73K. No problems so far, pulled the dipstick, fluid very clean. I'm hearing the horror stories on this trans. Someone said problems start at 70K, called a local mechanic, he said if you made it past 35K you should be good. Hmmm. Never serviced the trans. Was going to take to get flushed. Coworker took a Honda to get flushed, (110K) and dealership told him not to, things are 'fused' and flush would cause problems. Should I do anything at all?
Thanks, Jerry

jerryksr said:

Hi Nick! What an outstanding and informative thread! Only problem is, it's way over my head.....LOL.
Anyway, I have a 2016 Tahoe 4wd Z71. 73K. No problems so far, pulled the dipstick, fluid very clean. I'm hearing the horror stories on this trans. Someone said problems start at 70K, called a local mechanic, he said if you made it past 35K you should be good. Hmmm. Never serviced the trans. Was going to take to get flushed. Coworker took a Honda to get flushed, (110K) and dealership told him not to, things are 'fused' and flush would cause problems. Should I do anything at all?
Thanks, Jerry

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Thanks, Jerry! Appreciate the feedback...

I'd have it serviced, whether you do a full flush, pan drop w/filter and fluid change or both is up to you but never changing the fluid is what primarily leads to premature failures in these transmissions (followed by the poorly designed JMBX torque converter).

Not sure I'd agree with your local mechanic about being 'good' after only 35k since that would apply to like 99.9999% (i.e. six-sigma level quality) at that point in the transmission's life cycle. We start seeing failures around your mileage (70k) and up, mostly due to torque converter where the trans is a collateral casualty followed by cracked 1-2-3-4 piston and leaking 3-5-R drums, especially in the pre-2012 units.

I also don't subscribe to the widely held belief that flushes cause transmission failures...I hear all kinds of things, including flushes will blow out the seals to flushing dredges up all the contaminants...The problem with those assertions is that seals, sealing rings, etc regularly see 125-150+ PSI at 200+ degrees during the course of normal operation while fluid is continuously circulating everything imbedded within it throughout the transmission constantly...So flushing being the reason a transmission failed (and not due to parts/components already on their last legs, worn, etc) doesn't make any sense to me.

Like any other mechanical device, if the transmission isn't properly maintained then it's not going to last as long as if it were, all other things equal...So you have a better chance at maximizing it's longevity and mean time between overhauls if you keep up with maintenance schedules...Dex6 can go about 55-75k then should be changed (desert/hot arid environments should do changes at 50-60k).

Nick,
Thank you so much for the quick reply! Knock wood, hopefully I'm one of the 'lucky' ones. lol
Thanks again!

Bumping this thread with a new video: Unboxing, Inspecting and Testing a Monster Transmissions' 6L80 Valve Body

Enjoy!

NickTransmissions said:

Dex6 can go about 55-75k then should be changed (desert/hot arid environments should do changes at 50-60k).

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6l80 here (2010 Tahoe LTZ). Have heard from a lot of folks (including a few on here) that 30-35k is the severe schedule that we should be sticking to on these transmissions.

For me, that's about once a year, lol. Is it your opinion that it could probably go another 20k each cycle and be fine?