I'm about to attempt to do my first transmission rebuild. I picked up a 2002 4L80E for 100.00. I've got it tore down because what little fluid was in it was black and smelled awful. Found out the rear planet it chewed up as is the sun gear. I've already found sources for part on the cheap since this is going behind a stock LQ4 for my 72 Chevelle. My question is this....how scared should i be? I've done Gen I small block rebuilds, i've done all kinds mechanical work to all my vehicles. The guts of this thing scare the **** out of me. I just can not afford to pay some one 12-2000 for a rebuild or replacement. I've downloaded the rebuild manual and exploded diagram for reference. Are there certain things i need to be aware of? Common issues and problems with rebuilding? Thanks in advance for any input! Love this site/community.

 

I'm doing a 4l80e swap in my nova too!
I however am letting my buddy (trans guy) rebuild mine.
I like you, are scared s:?t of all the parts in there.
Just as I ( licensed electricians) tell people to stick to what they know and I'll do the work I know.
I'm not saying not to rebuild your trans, I just don't feel comfortable nor have the knowledge of what I'm looking at to do it and potentially ruin the trans and the $1200 converter I will be using.
That and if there's an issue, he will back it up.
Just my .02

 

Just an example of the stand up guy he is.
My son had him rebuild his 2004r in his Malibu.
It had a issue with 1st gear.
He picked the car up took it to his work tore apart a trans he just reblt and did it again.
This was on a junkyard trans of unknown shape.
As it turns out it doesn't want to always go in to 1st automatically so HE'S replacing valve body.
His dime n time.
Something to consider.

 

Sadly, I have no friends that are trans guys, lol. Think i need new friends.

 

I hear ya!
He's not doing it for nothing..
$1000
Well worth it for me as I saved to do this swap.
2 in college at the same time!
1 graduates this year tho.

 

The 4L80e in my Nova is on its way out. Funky shift cable incident and I fused the forward clutches together, so it was in forward gear now matter where the shifter was. Even in park, it would push forward against the pin. Neutral was drive, and reverse was a trans brake. Tried to launch it on the new 'trans brake' and the clutches broke apart.

Drives fine now, but slips under very heavy load. I've read that there are ~3 tools that are needed when doing a full rebuild. I'm thinking about picking up a Jakes Stage 4 rebuild kit and attempting it this winter. I guess you never really know until you try it yourself. I've also been told that my first time could take 12-16 hours, which is a bit discouraging to most people.

 

The guy i took mine to just dropped the pan and it went from 600 to 1200 with out him tearing apart. I didn't question his thoughts i just can't fork out the money. No kids in college, but my 2yo is doing gymnastics and dance class and of course there is day care, lol. Life trumps car at this point.

 

Yeah, the time thing doesn't phase me too much since i have given up on getting on the road this year. it was a lofty goal to start with and this just thre it all out of whack.

 

An excellent source for looking up how to rebuild a 4L80E is to search for all posts by member "clinebarger". Although a relatively new member, he is a pro builder and he has graciously supplemented many posts with pictures. Many of his posts are on the 4L60E (where he greatly helps me answer questions), but many are on the 4L80E.
Plus he tends to answer questions pretty quickly and thoroughly.

 

Thank you for that! I will be sure to look that up and research it.

 

Well, for what it's worth I'm just about finished with mine and have had a healthy level of fear during the whole process. Not so much a fear of the actual work but more of a "I sure hope I haven't missed something" type thing. To say I'm praying I've done a good job is an understatement but I think it should be good to go. Mechanically it is more complex than a basic rebuild on a SBC but if you can build a solid engine from scratch, you have the physical skill set to do it. The issue that I found most prominent was one of knowing what techniques work best and knowing which hard parts are acceptable and which need replacement. For me, the forward clutches burned down to the steels and made a huge mess inside there. The further I dug, the more I found: The Forward clutch drum had grooves in the bore where the Teflon seals ride so it had to go. After that I realized the front planetary was gouged where the Torrington bearing sits so it had to be replaced too. The point being: be meticulous and study everything.

Buy your rebuild kit from a vendor that has both a desire and the time to be helpful. Yes, you can buy from EBay, Amazon or even Transtar direct but you will be on your own. I bought my kit from Jakes Performance because he specializes in this unit specifically. I would be remis if I did not publicaly thank Jake for his patience with my billion questions and for providing the vital tech support I needed. Thank you Jake, I really appreciate it! Jake is direct and doesn't mess around but his answers and prompt and on point. Dana @ Probuilt is well known for being ridiculously generous with his time and knowledge for both customers and Joe Sixpack who hasn't spent a dime with him. Dana is a 700r4 specialist but I have no doubt you could use his parts and tech help to build a good unit.

Also, 100% agreed on Clinebarger. He has been generous in his responses to my questions as well!

Lastly, be careful but courageous. What one man can do, another can do!

S.F.

 

Thanks for the compliments!

I'll help you out if needed, Starting out with a "Blown-Up" Core is not the wisest choice for a beginner, You will have to verify that the failed Carrier wasn't from a "wrong" part being installed on a previous rebuild causing a Lubrication issue. Early Mainshaft, Sun Gear Shaft, Or Wrong rear Cooler Fitting installed in a "Center Lube" unit wrecks havoc on the Reaction & Output Carriers.

If the Output Carrier & Sun Gear got screwed up....So did the Rear Internal Gear (It's Snap Ringed to the Main Shaft)

Check everything out before ordering parts! Don't spend $600 on Hard Parts when you can buy a 2004 & Up core for $350-$600 & hopefully it will have just a burnt Forward Clutch. Buying Core's is like gambling, Luck of the draw!

 

Well, so far the only thing i have seen that is confusing me is the rear planet. From what i ahve seen it is supposed to be a straight cut gear but the one i took out is helical cut. Did i get a franken-trans?

 

What leads you to believe it was suppose to have straight cut gears?

 

All the replacement parts list older models (pre 97) with helical gears and newer ones with straight cut

 

That is incorrect information, Both Early & Late are available with Helical or Straight Gears, It is based on the GVW/GCWR of the vehicle the trans was originally installed in, You don't see Straight Cut Gears in anything under 10,000GVW normally.

 

Lot of useful info here. Thanks guys