To change or not to change fluid

[df2x4]

I have always thought about going for 4l80e swap. How big a pain was this. I’ve seen a few write ups but none were all that helpful.

Here's a link to the thread I posted on the swap. Honestly it's not that bad. It was expensive for me, but I didn't do any of the labor myself.

http://www.gmt400.com/threads/97-c1500-4l60e-to-4l80e-swap.38819/

 

[David89gmc]

I have always thought about going for 4l80e swap. How big a pain was this. I’ve seen a few write ups but none were all that helpful.

I don't understand the attraction of the 4L80, except it's stronger in stock form then the 4L60/700R4. A good performance rebuild of your 4L60 will let you keep that very low first gear, 3.06 versus 2.48, which is a great advantage.

You can even rebuild your 4L60 for about $700 if you're mechanical. Watch

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to see one rebuilt by an expert. The books he refers to can be found online as free pdf downloads too.

 

[alpinecrick]

The fluid smells slightly burnt.

That tells me the trans isn't gonna last long......

There is indeed a chance a solenoid could be going, but again, old, dark fluid means things have been cooked and most likely something else will go out. But yes, drop the pan and see what the fluid is like and what's in the bottom of the pan, and what code it's throwing.

The factory 4L60E's will last roughly 150K with regular maintenance, and depending on the load.

Letting the fluid get to the point it's no longer red, and/or smells burnt, will kill a 4L60E sooner than later....much sooner.

I just cooked a 4L60E when the trans cooler line had a hole wore into it (my own dumbazz fault) and my trans guy (whom I trust in a lot) cost me $800 for a Stage 1 minus the 8 clutch pack (I use the 6 clutch pack with Kodene steels).

 

[df2x4]

I don't understand the attraction of the 4L80, except it's stronger in stock form then the 4L60/700R4.

That is the only attraction. I used to be a strong defender of performance rebuilt 60Es, until my V6 truck killed one. I know there are plenty of people out there who run decent power through them, but after my experiences I wouldn't spend a dime trying to beef up a 60E if I had any plans of driving it hard.

There are bone stock 4L80Es running in 1000+HP drag cars that are still in one piece.

 

[ZachMN]

I'm late to this thread but one could pump out the fluid via the cooler lines and do a filter. The filters are made for 100k of debris. Flushing the fluid and replacing with new can possibly help for a while but lack of maintenance could have fried other parts. As far as comparing the 60 to the 80 completely different designs...wouldn't waste my time trying to build a 60. I know the first gear is better but the 80 is built way more stout and they can take a lot more abuse.

 

[Supercharged111]

Plan for the funeral. That tranny is dying. Trans man in a can won't help.

Oh I beg to differ, at least in the short term. Back when I was a kid, we had an 87 G1500 pimp ass conversion van. It had a TBI 350 and 700R4 with 2.73 gears. First gear began to slip/shudder, so we dropped the pan and did a filter swap. We added a bottle of Lucas and topped off with Dex3. The slip went away for an entire year, and then my ass ended up swapping transmissions in the middle of a UP of MI winter. What that meant was that I piled snow around mom's van to keep it warmer underneath. I've tried Lucas in other instances and not been rewarded like I was with the van trans, but when it works it works I'll say that. OP, I'd say your chances of avoiding a full rebuild or trans swap are slim to none, but if you want to take the Lucas gamble it's there.