torque converter replacement question

[opfor2]

I'm going to have a local shop fix my rear main seal oil leak on my 2011 and while they have the transmission removed, I want them to replace the stock torque converter. My question is what is a good heavy-duty replacement for my Tahoe? I use it as a daily driver with some light to moderate off road use.

Thank you in advance.

 

[Marky Dissod]

Reputable companies I've heard of include FTI, Yank, Circle D, Ultimate, or Vigilante; there may be others.
Equally important, have the tcm tuned, specifically the torque converter clutch behavior to lockup only in 5th & 6th, and with little to no slip.

 

[Joseph Garcia]

Circle D is a favorite on this Forum.

 

[OBSandaNNBS]

Reputable companies I've heard of include FTI, Yank, Circle D, Ultimate, or Vigilante; there may be others.
Equally important, have the tcm tuned, specifically the torque converter clutch behavior to lockup only in 5th & 6th, and with little to no slip.

Marky, can you explain this to someone (me) who probably should understand why the lockup tune is beneficial?
I'm chasing an oil leak and was thinking about the TC if it is the rear main.

 

[Marky Dissod]

Marky, can you explain this to someone (me) who probably should understand why the lockup tune is beneficial?

Maybe?
Think of a manual ... PHYSICAL clutch gearbox. Takes a SMALL amount of BRIEF slip to mate the clutch to the flywheel so that everyone else doesn't hate you,
but maybe some family & friends won't mind a mild quick kinaesthetic telltale, otherwise too much time spent slipping wears out the clutch.

Automatic transmissions have a PHYSICAL Torque Converter Clutch. While locked, it improves MpG, but until it unlocks, think of it as a manual.
If RpM changes too quickly, or there's a knock or a misfire, or a change in the number of cylinders firing (17 different firing orders!), you'll also FEEL it.
GM is neither family, nor friend, in that GM will let the TCC slip to prevent anyone in the vehicle, including you, from feeling anything.
Over time this wears out the TCC. When the TCC finally fails, its debris takes out the rest of the 6L80 / 8L90 / 10L80.

 

[swathdiver]

...can you explain this to someone (me) who probably should understand why the lockup tune is beneficial?

Many tuners believe that to extend the life of the torque converter the lockup feature should only happen in the higher gears. BlackBear changes this to 4 through 6 in the 6L80.

Precision transmission however like to keep the lockup feature as the factory intended to maintain the fuel economy. He's usually replacing the original torque converters (B & I in Oklahoma City) with billet ones when he overhauls the transmissions.

We're going to put a new billet cover torque converter in the lifted Sierra when I get around to it, soon. Going to get one from Florida Torque Converters.

CADILLAC, CHEVY, GMC Torque Converter 77-JMBXSD

77-JMBXSD

www.floridatorqueconverters.com

 

[Marky Dissod]

Precision transmission however like to keep the lockup feature as the factory intended, to maintain the fuel economy.

Should be up to the owner / driver how many MpGs to sacrifice to gain trans longevity; whole point of a tune is to suit the owner's / driver's tastes.

 

[OBSandaNNBS]

@Marky Dissod @swathdiver
Thanks for the informative replies! What I'm getting is Billet TC=factory settings and OEM TC=change lockup to higher gears?

 

[Marky Dissod]

What I'm getting is Billet TC=factory settings and OEM TC=change lockup to higher gears?

Just in case, please rephrase the questions?

I'd recommend:
a torque converter with a stall RpM that you're used to (don't worry about that for now) that uses better TCC materials
have tcm tuned to reduce slippage (and 'acceptable' slippage), and only locks up in 5th & 6th, maybe a wee lil bit o' 4th if you're driving miss daisy

 

[Charlie207]

This is also a good replacement, and they somehow lowered the price vs. when I got mine last summer.

Pardon Our Interruption

 

[jaxscuby]

oh the joys of researching for a replacement torque converter..

~300 + 150 core = 450, free shipping for the one from summit..no mention of torque converter clutch (TCC) material thickness
recall our factory TCC wear material is about 0.020 of an inch.

planned obsolescences or repairs..thanks you GM. And if the TCC goes, fails, the transmission rebuild...oh joy..

others offer 0.035, 0.050 & 0.070 of an inch in thickness for TCC material thickness.
obvsiouly, the thicker..more cost..

So if the OEM torque converter clutch material wears out around 100K.
why wouldn't you get a TCC that the wear material last 2x or more as much.

And the material upgraded to Kevlar / Carbon Fiber / or a mix.

at the very least 0.035 TCC thickness and kevlar..499 shipped to the house..
return old TCC for 100 core charge (free shipping)..so 399 for a billet TC..

 

[Marky Dissod]

So if the OEM torque converter clutch material wears out around 100K,
why wouldn't you get a TCC that the wear material last 2x or more as much?

One reason why GM OE TCC material wears out when it does is Engine Half@$$ / Cylinder Confusion,
which explains why disabling this engine bug/feature helps the TCC last longer.
Other reason is that GM OE TCC programming has a lil more slippage than necessary programmed in,
so no one can tell when the TCC applies / lets go, and to mask the feel of any cylinder deactivations / reactivations,
which is just one of the reasons why tcm tuning helps the transmission last longer.

 

[Geotrash]

Like Charlie, I also have the BU60FHD. Mine was made when the product line was still owned by CVC (a well-regarded rebuilder in transmission shop circles). They sold out to VEGE in 2022 I believe, and I don't know if they changed any of the specs. But, it has a flanged hub which provides more rigidity for the impeller and longer bearing life. More importantly though, it also has a billet cover which prevents flexing and makes for less slippage in the lockup clutch, hence a longer service life for it.

Mine is in a 2012 Yukon XL Denali that has been modified to produce more power and torque than stock, and has seen primarily heavy towing duty since I had the TC replaced in 2021. It's been great, and you can feel the difference in uptake on launch, and when I press the go pedal while driving.

I chose this particular TC on the advice of the owner of a local transmission shop who's been in the business for many years.

 

[donjetman]

7 yrs and 70k miles ago I installed a Precision # P4646 (gopnh.com) TC in my 07 Denali 6L80e, cost $218, still going strong.