Stick with 80E or go to something else?
08-16-2011, 08:24 AM
#11
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Guys you have to understand that the 4l80e is a fine transmission. But, if you are having multiple failures you need to consider what's going on. In order for it to have a chance it must be built by a reputable builder who knows his business.... but most importantly knows that transmission inside and out.
There are lot's of guys out there who can take a transmission apart and put it back together, but there are only a handful who can take it to a completely different level and be successful at it.
And the baddest of the bad asses are here on PT.net.
g
There are lot's of guys out there who can take a transmission apart and put it back together, but there are only a handful who can take it to a completely different level and be successful at it.
And the baddest of the bad asses are here on PT.net.
g
08-16-2011, 08:30 AM
#12
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Once it was the tune as the stock 80E tune allows lockup in 2nd at WOT. I didn't catch this at the bottom of the 2nd gear apply table when going through the tune on a small screen computer - looked like the table was all maxed out just like a 60E tune. Normally, I would have no WOT lockup in my tune.
I believe the other time it was 2nd that I lost.
This time I did a quick stab at the throttle (.3 sec in the log)from a roll and when I let off it just stayed in 2nd although 3rd was being commanded. When I got up a few more MPH 4th grabbed for about 10 sec, but then it let go and fell back to 2nd. After it did that a couple of times I just slowed down and put it in manual 2nd for the drive home.
I had recently been noticing what seemed like the converter locking/unlocking while the cruise was on(audible variations in engine RPM/blower whine). Logs just showed "Locked." Now that I think about it, could also have been the trans slipping. I did look at the tach a couple of times and it was not bouncing up and down. Think it was around 2200 RPM at 67 MPH(3:73 axle ratio)
I believe the other time it was 2nd that I lost.
This time I did a quick stab at the throttle (.3 sec in the log)from a roll and when I let off it just stayed in 2nd although 3rd was being commanded. When I got up a few more MPH 4th grabbed for about 10 sec, but then it let go and fell back to 2nd. After it did that a couple of times I just slowed down and put it in manual 2nd for the drive home.
I had recently been noticing what seemed like the converter locking/unlocking while the cruise was on(audible variations in engine RPM/blower whine). Logs just showed "Locked." Now that I think about it, could also have been the trans slipping. I did look at the tach a couple of times and it was not bouncing up and down. Think it was around 2200 RPM at 67 MPH(3:73 axle ratio)
g
08-16-2011, 08:38 AM
#13
It could also have been a 3rd gear slip, which was detected by PCM and dropped it out of OD.
In some cases you can lose third gear clutches completely, and the ODs will come on, it will feel just like 3rd but its actually "2nd over".
Do you have reverse?
The direct clutches are the weakest clutch in a stock 4L80E. If the builder didn't address this, they can die quick in a heavy combo.
There are lots of otherwise reputable builders but they can get their **** handed to them trying to build a newer unit for performance use. They may be accustomed to building TH400s, Glides, TH350s, etc where you can buy a box of parts and it will work usually. There aren't many builders who have gotten serious with the hydraulics on a 4L80E.
In some cases you can lose third gear clutches completely, and the ODs will come on, it will feel just like 3rd but its actually "2nd over".
Do you have reverse?
The direct clutches are the weakest clutch in a stock 4L80E. If the builder didn't address this, they can die quick in a heavy combo.
There are lots of otherwise reputable builders but they can get their **** handed to them trying to build a newer unit for performance use. They may be accustomed to building TH400s, Glides, TH350s, etc where you can buy a box of parts and it will work usually. There aren't many builders who have gotten serious with the hydraulics on a 4L80E.
08-16-2011, 10:54 AM
#14
I will have to review that last log file again. O2s have been steady while cruising. I am running the truck OLSD.
I don't think I put in in reverse after I completely lost 3rd. Just drove it straight home and parked it. So I can't say if it is still there or not. It has been wanting to stall lately after a drive if I shift from D to R though. Truck is half apart already.
I don't think I put in in reverse after I completely lost 3rd. Just drove it straight home and parked it. So I can't say if it is still there or not. It has been wanting to stall lately after a drive if I shift from D to R though. Truck is half apart already.
Last edited by DrX; 08-16-2011 at 11:36 AM.
08-16-2011, 10:37 PM
#18
Nothing interesting in that last log file before losing 3rd. Everything stayed pretty steady while cruising. RPMs stayed in the 21XX range at 67 MPH. I was not logging trans PIDS other than Gear and TCC state.
At WOT the TVS 1900s are theoretically moving enough air for 1400 HP combined. I'll be happy if a chassis dyno breaks 1000 RWHP. So far I have not tried putting all the instant torque to the ground, but the slicks are mounted and ready to roll. I don't want any weak parts hangin around when this 6000lb beast gets that kick in the pants.
At WOT the TVS 1900s are theoretically moving enough air for 1400 HP combined. I'll be happy if a chassis dyno breaks 1000 RWHP. So far I have not tried putting all the instant torque to the ground, but the slicks are mounted and ready to roll. I don't want any weak parts hangin around when this 6000lb beast gets that kick in the pants.
