Notices
GM Drivetrain & Suspension Chassis | Transmission| Driveshaft | Gears/Rear End/Differential | Traction Aids

4L80E lost 2nd gear

Thread Tools
 
Search this Thread
 
Old 04-15-2008, 06:10 PM
  #21  
11 Second Truck Club
iTrader: (16)
 
Breeze's Avatar
 
Join Date: Aug 2004
Location: Md
Posts: 3,693
Likes: 0
Received 0 Likes on 0 Posts
Default

Man I hate hearing of broken 4l80e tranies. I guess anything mechanical can break though good luck removing and replacing the trans at least youre builder seems to be an honest one.
Old 04-15-2008, 09:20 PM
  #22  
TECH Senior Member
iTrader: (26)
 
kbracing96's Avatar
 
Join Date: Jul 2004
Location: Oakland, OR
Posts: 9,485
Received 30 Likes on 28 Posts
Default

Originally Posted by Stoichiometric
$600 is not too bad. The sprag clutch has a bunch of elliptical rollers that engage in one direction and freewheel in the other. Sounds like yours gripped so hard that it flopped over center.
ya the truck was running like a **** when it happened,
Old 04-15-2008, 09:45 PM
  #23  
TECH Senior Member
iTrader: (45)
 
dirt track racer 81's Avatar
 
Join Date: Jun 2005
Location: Hennessey, Oklahoma
Posts: 9,439
Likes: 0
Received 11 Likes on 5 Posts
Default

Originally Posted by Stoichiometric
$600 is not too bad. The sprag clutch has a bunch of elliptical rollers that engage in one direction and freewheel in the other. Sounds like yours gripped so hard that it flopped over center.
This what happend pretty much in my last trans..i had 1st..2nd would barely grab and 3 and 4 were ok..the cage of the sprag was busted
Old 04-17-2008, 01:53 AM
  #24  
High on diesel fumes
Thread Starter
iTrader: (70)
 
thunder550's Avatar
 
Join Date: Mar 2005
Location: Phoenix, AZ
Posts: 12,658
Likes: 0
Received 3 Likes on 3 Posts
Default

I win, bitch.
Old 04-17-2008, 09:54 AM
  #25  
Resident Retard
iTrader: (31)
 
BlackGMC's Avatar
 
Join Date: Jan 2006
Location: Fort Worth - TX
Posts: 17,216
Received 20 Likes on 16 Posts
Default

Where did you get that tranny jack??? I like it, I have been looking into buying one...
Old 04-17-2008, 11:41 AM
  #26  
High on diesel fumes
Thread Starter
iTrader: (70)
 
thunder550's Avatar
 
Join Date: Mar 2005
Location: Phoenix, AZ
Posts: 12,658
Likes: 0
Received 3 Likes on 3 Posts
Default

My girlfriend bought it for me for Christmas. Harbor Freight. Pretty cheap too.
Old 04-17-2008, 12:46 PM
  #27  
TECH Resident
iTrader: (9)
 
Onetogofast's Avatar
 
Join Date: Aug 2007
Location: Amarillo, TX
Posts: 858
Likes: 0
Received 0 Likes on 0 Posts
Default

Was it a stock 4L80? What are you gonna do to it now?
Old 04-17-2008, 01:03 PM
  #28  
High on diesel fumes
Thread Starter
iTrader: (70)
 
thunder550's Avatar
 
Join Date: Mar 2005
Location: Phoenix, AZ
Posts: 12,658
Likes: 0
Received 3 Likes on 3 Posts
Default

It was a stock 80E with upgraded clutches I think. It's getting the beefy (expensive) intermediate sprag kit this time around.
Old 04-17-2008, 01:25 PM
  #29  
TECH Resident
iTrader: (9)
 
Onetogofast's Avatar
 
Join Date: Aug 2007
Location: Amarillo, TX
Posts: 858
Likes: 0
Received 0 Likes on 0 Posts
Default

How much RWHP is an 80 with clutches and a band capable of handling?
Old 04-17-2008, 01:31 PM
  #30  
High on diesel fumes
Thread Starter
iTrader: (70)
 
thunder550's Avatar
 
Join Date: Mar 2005
Location: Phoenix, AZ
Posts: 12,658
Likes: 0
Received 3 Likes on 3 Posts
Default

This one was supposed to be good to 900rwhp. I think the 1-2 shift was set too firm, which is what causes the intermediate sprag to break or roll over. Probably would have been just fine with a softer 1-2 shift. I was reading last night that in 1st gear the intermediate sprag is traveling at 84% of the input shaft RPM, in the opposite direction. On the 1-2 shift it has to bring a 14 lb drum to a complete stop in a fraction of a second. When the 1-2 shift is too firm (too quick) you are counting on a small sprag to do too much.


Quick Reply: 4L80E lost 2nd gear



All times are GMT -5. The time now is 07:21 AM.