1ImperialSS

iTrader: (5)

once the 60 blows on me, probably a month or so after ntrous, im definitly going with the 80 and stall. thanks guys

tblrk1980

the 4L70 comes in the Trailblazer ss and the vortec max truck

1ImperialSS

iTrader: (5)

yea but isnt the 4l70 just a 60 based knock off, i hear they arent much more reliable and if you are gonna upgrade you might as well get the 80 as long as you have enough power to get it moving

James B.

iTrader: (1)

The 4L60-E, 4L65-E, and 4L70-E are all based on the 700R4. Same gear ratios, same fundamental design limitations.

It's kind of like throwing all sorts of money into a 10-bolt rear end. You can do a better carrier, gears, axles shafts, trusses, cover, girdle, etc. After all of that it's still just a 8.6" rear end. Armed with the knowledge that something is too weak to do the job, why not choose wisely in the first place, spend the extra money now and save yourself thousands in parts, labor, and downtime later on. Take it or leave it!

cbrich

The 4L80E, and TH400 do have parasitic loses but you have to remember what they were designed for, heavy towing in 1 ton trucks, not much on the performance side. There are parts out there that will help with the performance of the 80E and TH400, low first gear, and aluminum drums. I can speek for the low first gear, it's like night and day difference. I would install a set in my truck, but not for sure if the computer can be reprogrammed for the lower first and second gear. Some advise for correcting the first gear is install the next lower gear than what you would install for a 60E. If you descide to put 3.73 behind a 60E, you will want to install 4.10 behind an 80E, but the only downside would be the higher rpms at highway speeds.

The week point of the 80E is the fourth clutch pack, the discs might be large in diameter but the surface area is small, very small. Every 4L80E I have rebuilt (mainly for my dad) the fourth clutch disc have burned up, damn 1 ton dually and 15,000 trailer w/ backhoe.

1ImperialSS

iTrader: (5)

but isnt the 4l80 a good option if you're going to push big power? why would you want to spend 800 bucks on a rebuilt 60e 19 times like some members have when they could just set things straigh with an 80...there are always going to be drawbacks to anythign you do....the 60 once you get any sort of power its going to melt pretty much no matter what you do but the 80, yes it takes some power to get it moving but its almost unbreakable unless you are doing HEAVY towing with a HEAVY truck...plus it gives you more reasons for power adders because one would "need it"

James B.

iTrader: (1)

The fourth gear clutch pack is the weakest link in a 4L80-E, true. Raybestos is now making a Blue-Plate Special pack for the 80-E OD clutch pack. I have also suggested to most people enlarging the 4th's feed a stage larger than the rest of the feeds in the valve body for shift kit installation.

cbrich

I know about the Blue-Plate Special, I have the fourth and overrun clutchs in my camaro (the rest are Alto Red Eagle), they have been out for several years. The best method I found to prevent the fourth clutches from burning up is setting up the fourth clutch pack tolerance to 0.040-0.050", factory spec is 0.040-0.100 (usually around 0.080-0.100). I had to consult my manual and an old plate for this, but how do you recommend on enlarging the holes in the seperator plate since they are square. I guess the square holes could be filed out to the same size of the oil passage. This seems to be more work than required because OD should not be used unless driving on the highway (just my opinion.) I might look into enlarging the seperator plate when I rebuild the tranny in my truck.