Seals to do while its out

[dusterbd13]

So, im doing a 4l80e swap in my 95 because the 4l60e died.

While i have the used 4l80e laying on the floor, what seals should i do? Any other maintenance or checks?

 

[stutaeng]

On the tranny? Probably the front main seal? I don't know that guys actually do that when they swap them?

On the engine, probably the rear main seal. I think this is more prone to leak than the above.

Then there's the guys that think if stuff ain't leaking don't mess with it...

 

[Erik the Awful]

Transmission rear seal is a fifteen minute job. I wouldn't bother if it's not leaking.

Front seal... it's a judgement call. How did the fluid in the transmission's pan look? If it was ugly, replace that seal. If it looked fresh, I'd run it.

 

[dusterbd13]

Little grubby on the fluid, but not burnt.

Whole trans is caked in ****. So i ASSUMED putting some fresh seals was a common thing. Fluid and filter are s guarentee as well.

 

[Erik the Awful]

Caked in junk and the fluid wasn't pristine? Yeah, I'd probably throw the seals on it, and I'm a cheapskate.

 

[dusterbd13]

But, input, output, pan, and....

 

[Schurkey]

What seals are there that are accessible from the outside, or with the pan off?

Transmissions in general:
Torque converter hub seal.
Dipstick tube seal. Check dipstick tube for cracks.
Modulator O-ring. Not applicable on 4L80E
Kickdown or TV cable seal. Not applicable on 4L80E
Bulkhead wire-harness connector seal(s)
Output shaft seal--probably with at least an inspection/cleaning of output shaft bushing and driveshaft U-joint yoke. This may lead to replacing the tailshaft housing seal, if the housing comes off to install a fresh bushing.
Manual shaft (shift shaft) seal
Speedo gear/VSS seal(s)
Pan gasket

If I had a trans sitting on the ground waiting to be installed, it'd take quite a bit of will-power to not install a Transgo shift kit while the pan was off.

 

[df2x4]

Then there's the guys that think if stuff ain't leaking don't mess with it...

Hey, that's me!

The 4L80E I swapped into my red truck came out of a junkyard C3500 with 300K+ miles on the odometer, similarly caked in crap. Slapped it in the truck as-is and it's doing just fine.

 

[Erik the Awful]

I don't know if the 4L80s have the wiring harness issues that 4L60s have, but if so you'll probably want to replace the wiring harness now.

 

[dusterbd13]

Good call all yall! Anyone have a link to a seal kit for cheap? Trying to find this stuff by individual seal on rockauto is maddening.