6L80E Build

Joined
Dec 19, 2013
Messages
7,933
Location
Fort Worth, Texas
6L80E out of a 2010 GMC Yukon XL Denali with a L94 6.2L with 119,xxx miles........And of coarse the Torque Converter failed & filled the unit with Aluminum & Steel debris from the TCC clutch wearing out allowing the Clutch Piston made from Aluminum to grind into the Steel Converter Cover.

The good.....
*The filter did it's job & kept the grindings out of the Geartrain, Valve Body, & TEHCM.

The bad.....
*The Pump Body which is integral to the Bellhousing is trashed along with the Pump Cover/Stator.
*As this happened while the owner was on his way back from a Casino in Oklahoma & he decided to keep pushing it......The 4-5-6 Clutch got burnt down from lack of Line Pressure. All the other Frictions just have normal wear for 120,000 miles


By the time it got towed to my shop.....The vehicle would move under it's own power for about 15-20 seconds then fall out of gear......Let it sit for 10 minutes, Then it would move again for 15-20 seconds. The reason for this is, The filter would get loaded up & starve the Pump....Letting it sit would allow just enough debris to fall out on the filter to get some line pressure back.
I could also hear when the Pump got starved.

The owner thought a Transmission Service might fix it:ROFLMAO:......Yes Sir......It needs a $4,500 Transmission Service!
What will be performed & parts used.....
*OE Pump Body/Bellhousing
*OE Pump Cover
*OE Pump Kit (Rotor, Slide, Vanes, Rings)
*OE Filter
*OE 4-5-6 Steels
*Sonnax Line Booster Kit (Boost Valve & PR Spring)
*Sonnax Pump Primer Spring.
*All Bushings (Durabond)
*All Bearings (KOYO)
*Borg Warner OE style Frictions
*All new Seals & Gaskets
*Seal Aftermarket High Performance "Blue" Clutch Pistons
*Sonnax Billet Converter Cover & Multi Disc Converter Clutch using a stock JMBX Stator & Turbine (Stock Stall)
*New Radiator (Trans Cooler)
*New Auxiliary Trans Cooler
*Tuning via HP-Tuners to turn off the AFM & eliminate the TCC PWM apply.
*Valvoline Maxlife Synthetic LV ATF

If you own a vehicle with this unit......DO NOT ignore the SES light & TCC Slip DTC's! Or any strange trans behavior for that matter! $2,000 of this Invoice could have been avoided. But it's not in peoples nature to be Proactive about Transmissions.....Only Reactive.


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I remember seeing the teardown video from Precision Transmission on one of these and thinking both how cool and how stupid it was to have the pump be part of the bellhousing.
Less chance of the Pump Bushing & Seal being offset of the Crankshaft centerline which IS an issue with ham fisted mechanics not aligning the Pump correctly.
 
Less chance of the Pump Bushing & Seal being offset of the Crankshaft centerline which IS an issue with ham fisted mechanics not aligning the Pump correctly.
Not sure if you have seen any of Precision's videos, but they show a lot of pump bushing wear on 4L60E. The wear is on the lower side and they say it is due to engine main bearing wear. It makes sense to me, but I was wondering if you have noticed it.
 
Not sure if you have seen any of Precision's videos, but they show a lot of pump bushing wear on 4L60E. The wear is on the lower side and they say it is due to engine main bearing wear. It makes sense to me, but I was wondering if you have noticed it.

I think I watched one of their videos because it was linked on this forum.

I have noticed offset pump bushing wear on Gen I & II engines, BUT.....The Dowels fit way loose compared to Gen III/IV/V engines. You literally have to wiggle & pry a trans off the newer engines.

Rarely do I see offset bushing wear on a LSx 4L60E. 4L80E pump bushing wear is a whole other issue that I can go into depth on if you want?
 
clinebarger, your posts are always an interesting read full of eye candy (or strain in this case looking at the mayhem). On a serious note, if I ever need any moderate to intense repair work done, hopefully you'll PM me your shop address and I'd be glad to make a trip a few hours South. Real mechanics are rare these days. One who will open up a transmission is a unicorn.
 
Thanks clinebarger, I always enjoy reading your posts though I know very little about transmissions. I do know enough about my 2005 218,000 mile 4L60E that it scares me to think about it! :eek:
 
Have the manufacturers made improvements to the replacement/aftermarket torque converters for these transmissions to avoid this same problem from happening?
 

Thanks clinebarger, I always enjoy reading your posts though I know very little about transmissions. I do know enough about my 2005 218,000 mile 4L60E that it scares me to think about it! :eek:
DItto. I have a 2008 3/4 ton with a 6L90 with 211,000 miles. I planning on doing a pan drop, filter change and magnet cleanup which I normally have done every 5 years. I’m wondering if I should do a proactive torque convertor change. Would that really help? I guess my goal is to go another 7 years. The tranny would have 300,000 miles by then. Opinions?
 
Overkill.......The sad part is.....The 6LxxE units are well engineered transmissions with a subpar Torque Converter. Parts are very expensive, But not quite ZF expensive. It's weird that TMBX 4L60E converters have a much lower failure rate even with PWM & Constant Slip behind AFM engines.

Reminds me a bit of the 4R100, at least the description. The converter was more than satisfactory for the 5.4L and even the 6.8L V10, but behind the 7.3L diesel, they had failures. The trans itself was ridiculously robust, the converter just couldn't handle the diesel over the anticipated lifespan.
 
So if a guy changed the convertor at 200,000 miles on a 6L80 or 6L90, , is there a good chance the transmission / new convertor can make it to 300,000 miles?
It would certainly increase your chances, Now to be clear.....Your 6.0L doesn't have AFM & in turn doesn't slip the TCC at a constant albeit small RPM differential allowing the Converter to last longer. However.....I still see 6L90E failures in the 225-250,000 mile range.

This is the kit I have my Converter guy use....HERE Fits stock 6L80E/6L90E 300mm JMBX converter cores & converts them to a billet cover Twin Disc
 
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