4l80e compatibility with 4.8/5.3

[FAKKY]

So ..... if you have a 4.8/5.3 engine from a truck/van that came OEM with a 4l60e ......

Couple it with a 4l80e from a different truck/van...

Does it all bolt right up - I read somewhere about having to get a custom convertor and/or spacer made with right bolt holes for flexplate ......but it didnt explain why. I know you need it if the engine is a "true" LS (LS1 example)
But unsure if not a true LS - like 4.8/5.3/6.0.


Also that the 4l60e and 4l80e same/different bolt pattern ?

etc

[clinebarger]

If you want to use the stock (70 Pound) 310mm 4L80E converter, You will need a Flexplate, Crank Spacer, Crank Bolts, & 6 Converter bolts from a '99-'07 2500/2500HD/3500 truck that has a 6.0L/4L80E combination.

A "LS" 300mm 4L60E converter has a extended pilot hub & uses a "Dished" Flexplate with a metric converter bolt circle.

ALL stock 4L80E converters have the same pilot hub spacing as earlier Hydramatic transmissions, Uses a Crank Spacer & a "Flat" Flexplate, 11.50" converter bolt circle (Same as TH400).

Here is a 2005 2500HD VIN if you want/need to buy parts from the dealer......
1GCHK23U15F912051

If you want a lighter....More performance oriented converter, "Most" custom Converter builders can build one with a Extended Hub style 4L60E Cover to fit your "Dished" Flexplate. Circle D, Yank, Vigilante/Precision are some builders that can do this.

[FAKKY]

Thank you !!!

---added

[FAKKY]

Assume if you got a 4l80e with original 4l80e flexplate and spacer and bolts would be a direct swap (just remove the 4l60e flexplate)


How much do you like an aftermarket convertor over stock. Truck will be sub 300 HP for a while ....... so spending an extra $700 on a aftermarket convertor doesnt seem necessary. If you have to sepnd $50 on a new flexplate and $50 on spacers/bolts ...... if using donor flexplate/spacer is not an option ...... might be better just ponying up the $$ though.

[PunishedC10]

That would be correct. Behind my 5.7 ls1 I used an sfi rated TCI flexplate and a Circle D stall convertor. The oem 4l80e torque convertor is heavy!!! But you can adapt it to the 4.8,5.3,5.7 ls motors

[clinebarger]

Originally Posted by FAKKY

Assume if you got a 4l80e with original 4l80e flexplate and spacer and bolts would be a direct swap (just remove the 4l60e flexplate)
That is correct

How much do you like an aftermarket converter over stock. Truck will be sub 300 HP for a while ....... so spending an extra $700 on a aftermarket convertor doesnt seem necessary. If you have to sepnd $50 on a new flexplate and $50 on spacers/bolts ...... if using donor flexplate/spacer is not an option ...... might be better just ponying up the $$ though.

It depends on the Combination & Use of vehicle.
For a performance vehicle, A higher stall is necessary. With a low torque engine like a 5.3L.....The weight of a stock 4L80E converter, Real low stall speed, And the 2.48 1st gear ratio is going to be very detrimental to performance.....Especially out of the hole.

The internal transmission components that have to be accelerated up to speed in a 4L80E in first gear have a lot of heft!

The Overdrive Carrier & Hub , Forward Drum , These are directly driven by the Input Shaft.
The Direct Drum is spun in the opposite direction at 87% of engine speed.
This is easily 40# of weight that has to be accelerated from a dead stop, Then you have a 70# converter......

If your engine makes max torque at 2950, The best thing for performance & acceleration would be a 3000 rpm or a little higher stall converter in the smallest diameter possible.

[downeyballz]

Originally Posted by clinebarger

It depends on the Combination & Use of vehicle.
For a performance vehicle, A higher stall is necessary. With a low torque engine like a 5.3L.....The weight of a stock 4L80E converter, Real low stall speed, And the 2.48 1st gear ratio is going to be very detrimental to performance.....Especially out of the hole.

The internal transmission components that have to be accelerated up to speed in a 4L80E in first gear have a lot of heft!

The Overdrive Carrier & Hub , Forward Drum , These are directly driven by the Input Shaft.
The Direct Drum is spun in the opposite direction at 87% of engine speed.
This is easily 40# of weight that has to be accelerated from a dead stop, Then you have a 70# converter......

If your engine makes max torque at 2950, The best thing for performance & acceleration would be a 3000 rpm or a little higher stall converter in the smallest diameter possible.

That's great info. My Silverado 6.0/4l80e can be kinda slow from a stop but its a lot of fun around town and I like the close gears better than my old denali (6.0/4l60e) plus I trust it more. But the truck defiantly uses more gas!

I did notice the stall speed on my 4l80e is around 2,300 rpm. supposedly higher than the 4l60e converter.

[FAKKY]

Thanks guys

Really wanting to do a 5.3/4l80e just to get on road with idea if I want pwoer later might add a turbo.

Looks like yard wants

$600 for 5.3
$400 for 4l60e
$800-$1000 for 4l80

I can get a new 4l80 for around $1500 out the door ..... stock convertor

will have to decide

[downeyballz]

Look for a parts truck. I have bought a few and was able to sell the extra stuff to cover the purchase price. Vans came with a 4.8, 5.3 or 6.0 mated to a 4l80e. They also have an extra long harness.