This is an epic overhaul video around doing an in-vehicle partial rebuild of the GM 4L80E automatic transmission. I undertook this project on a 1999 Chevy Suburban 6.5L diesel to address DTCs P1870, P0730, and P0756 mostly. But there were some other codes that sporadically were popping up together with these three DTCs every few months and I just got tired of the tranny going into limp mode each time, but didn't want to pull the powertrain for a full rebuild yet.

So, without removing the transmission from the vehicle, we will replace the valve body assembly, pressure manifold switch, rebuild the reverse servo assembly, rebuild the pressure regulator valve and reverse boost assembly, and replace the 2-1 servo assembly along with all new gaskets, check balls and filters using all genuine GM ACDelco parts. The valve body alone would like have addressed the DTC problems, but during the rebuild I encountered a faulty reverse boost bushing and valve assembly so replacing everything was worth it for my time.

The 4L80E first came out in 1991 and was in use with GM in 3/4 ton and up trucks and vans to around 2009 across Chevrolet, GMC, and Holden. The part numbers I give in the video are 2nd design numbers applicable to the 1999 model year, but many are the same for all years and where I am aware I point out the earlier numbers in the video as well. This is a long azz video, but it covers alot of ground so there's something in here for everyone chasing any in-vehicle patial rebuild work with the 4L80E automatic. [Edit] I have put over 500 miles on the transmission since this video without any problems so for me it definitely corrected my issues.

The automatic transmission fluid (ATF) for these models would be GMs DEXRON VI. Your owners manual may specify a different roman numeral (e.g., III) but all have been superseded now by VI.

The eBay and Amazon search links below are paid links, for which I may be compensated and earn a commission, if you choose to buy the parts and tools shown in this video thru them:

GM ACDelco part numbers: 24222077 24223081 24200418 24204253 8684205 8677743 24210956 8675728 8655843 8624391 19207801 104918 8623666 24205250 8623430 24202987 8661798 8680547 24202644 8680549 24202645 8682856 8680551 8661834 on eBay: https://ebay.us/TK3ZaY

If you're looking for TransJel assembly lube: https://ebay.us/bILT2U and on https://amzn.to/3uqIb37

ACDelco DEXRON VI ATF: https://ebay.us/kPWE9J and on https://amzn.to/3AZDP46

And if I've saved you some $$ here, consider some coins for the coffee tip-jar! https://ko-fi.com/drshock

1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009

Chapters:
0:00 - ATF fluid drain
1:58 - Pan removal
8:50 - Fluid filter removal
9:50 - Wiring harness brackets removal
11:16 - Disconnect wiring harness
12:24 - Remove initial valve body bolts
15:16 - Remove shift detent
16:06 - Remove crossover pipe
16:40 - Remove pressure switch
21:18 - Gasket removal
22:02 - Final valve body removal
24:44 - Parts analysis
29:45 - Remove reverse accumulator
33:30 - Remove TCC screen
34:18 - Remove valve assembly
41:08 - Off vehicle reassembly
1:14:37 - On vehicle reassembly
1:41:02 - Testing

Corrections:
1:41:52 - This is just a starting point, the service manual suggests 7.7 quarts total. Start with 4 quarts and add Dexron VI as needed once you warm up the transmission.

#drshock #4l80e #chevytrucks

Disclaimer: DrShock, the alias for the human content creator for this YouTube channel, is not responsible for any damages, injuries, losses, or liabilities associated with any repairs, upgrades, or maintenance performed on yours, or any other, vehicle whatsoever. No warranty, express or implied, is made as to the accuracy or completeness of any information provided within this channel. Viewing and using the “as-is" information of this channel is totally at your own risk. Always wear personal protection equipment and follow appropriate vehicle manufacturer service manual guidelines with original manufacturer parts only when performing any repairs, upgrades, or maintenance upon any vehicle.