greentahoe

iTrader: (2)

I was under the impression that the 5 in the 4L65 reperesented the 5 pinion planetaries used.

James B.

iTrader: (1)

Sorry, you are incorrect.

The 4L60-E has a total of 2 planetaries and 8 planet gears - 4 each.
The 4L65-E has a total of 2 planetaries and 10 planet gears - 5 each.

The 4L80-E has a total of 3 planetaries and 12 planet gears - 4 each.
The 4L85-E has a total of 3 planetaries and 14 planet gears - 4 for the overdrive and 5 each for the two rear planetary gearsets.

Planet gears rotate on a shaft called a pinion, hence the term "5-pinion planetary."

Was there something in my post that made you think I don't know what I am talking about?

BigBlockChev572

iTrader: (7)

Yeah, 4 pinion planets and 5 pinion planets. I was getting confused on the terms, as well I learned from you post. Don't be hatin'!

bludool

For the experts. Looking to upgrade power, first want to change transmissions. Have an '03 tahoe w/5.3. Looking to upgrade tranny before engine upgrades, what are obstacles on the '80 swap? This is a 4wd also, any other issues to worry about. How much power will that tranny rob from a stock engine?

BigBlockChev572

iTrader: (7)

Jim(Parish) did a write up on this.
http://www.neufamily.org/4l80e/4l80swap.html
The 4l80e robs more power than the 60e, percentage wise; I'm not sure.
Philip S.

one03sierra

iTrader: (1)

i would ask james b on here. i think he did a swap on an older one but im sure he can point you in the right dired=ction.

zippy

my buddies procharged 99 tahoe has now had more than 20 street races on it along with many wide open passes on the street including a few wide open 4th gear 130+mph runs and many first to second gear burnouts. other than my work on the valve body and servo's, his trans is the stock one that came in it (standard 4L60E). it's also using the stock 8.5 10 bolt with factory gov-lock. neither have shown an issue yet with 60' times in the 1.9's and over 5000lbs. when it finally gives i'll rebuild it for him and we'll be back out with it again and no 80E swap. the gov-lock is going to be on it's way out though since drifting sucks without a real locker. a detroit locker is going in come spring.

James B.

iTrader: (1)

Hey Zippy,
The transmission and rear end should not be trusted in your friend's Tahoe. Everyone with a blown L31 in a heavy SUV gets away with a few dozen good runs before the carnage begins. Until that gov-lock is swapped out, at minimum, he should be babying it - seriously.

greentahoe

iTrader: (2)

James B,
Do you think a built 4L65 would hold up to a Tahoe with a cammed 5.3, 50 shot (rarely used), and a vortech running 11-12#??? I drive pretty conservatively and so far my stock tranny has held up well (about 80K). This truck will maybe see the track twice, maybe once if it gets a 12 its first time out. I will eventually go with a 6.0, but stay with the same cam. Im curious as to what kills these tranny's so quickly in higher power apps. There is no one anywhere near me that I would trust to do an 80 swap so a friend and myself will do the 4L65. What are your thoughts on this??

James B.

iTrader: (1)

Keeping in mind that my opinion is worth about TWO things: Jack and ****, here goes....

Getting the most out of a 4L60 or 65-E in a high powered application is really a matter of setting up a whole lot of things just right. Even though they can be built and set up not to break, they just cannot serve high power for long. The amount of friction surface is just too small.

Setting up a 6X "right" is a balance between extending the lives of the friction materials as much as possible without putting too much stress on the hard parts. Firmer shifts prolong friction materials life but place greater stress on the hard parts.

The weaknesses in the hard parts are well known:
- planetary carrier casting failure, upgrade to 5-pinion ones from 65-E
- sprag failure, upgrade to Borg Warner 29-element double cage sprag
- reaction shell spline collar fatigue cracking, install aftermarket "Beast" shell
- plastic accumulator piston failure, why GM chose here to save pennies.. ?
- input shaft/drum breakage, aftermarket hardened unit available
- PWM regulator bore wear (P1870 SES), install Sonax fix or TransGo S/K

There are even now hardened output shafts available in the aftermarket.

For frictions the Raybestos Kevlar band is proven. This band is very sticky compared to a stock type band. This has to be taken into consideration when setting up the shift kit. For the 3-4 clutch pack both blue-plate specials and Red Eagle have been successfully used, but I have looked closely at the new Raybestos Z-Pak single-sided clutch pack and I think it has a lot to offer. I don't know of many people running them and have no longevity feedback. The 3-4 clutch pack will be the first thing to expire in a properly built and set up 4L60/65, so I think that ANY improvement possibility there would be worth looking into.

The shift kit firmness needs to be set up taking into consideration the type of friction materials used, apply pistons used for second and fourth, the torque converter, vehicle weight, power levels, shift RPM, and torque management.

Apply pistons for the band have the effect of making shifts more firm, but more importantly they affect how much force is put on the band for a given line pressure. Generally, installing better ones is a good idea. The firmness they add to the shifts has to be compensated for in setting up the shift kit and programming.

Higher-stall torque converters reduce the jolting forces that shifting exerts on the geartrain, however they also produce input torque levels much higher than the stock converter would. In general a higher-stalling torque converter allows you to set up and program more shift firmness without exceeding the hard parts thresholds. This will not necessarily make the friction materials last longer, because the motor will be more likely to stay in the power band after the shift and the higher-stalling converter will be multiplying that power even more.

Torque Management removal is one of the first things on everyone's list of desired programming changes. Obviously this has consequences, so it must be compensated for in setting up the shift kit and the shift programming. There is no positive effect this can possibly have on the transmission as a whole. Shifts will need to be made more firm so that the frictions don't overheat during the shifts, and that will obviously put more strain on the hard parts. If you have to take out TM then accept that it will reduce the life of the transmission - period.

The RPM at which shifts are programmed to take place is important because the higher that RPM is the greater the RPM difference will be between the two assemblies involved with each shift that must be brought to the same RPM by the friction materials. In other words, the delta RPM between those two assemblies increases with input RPM, meaning that the higher the shift RPM is the more work the friction materials have to do. More heat will be produced and this has to be compensated for with additional shift firmness. The additional firmness will prevent the clutches from warping and the band from overheating, but at the expense of putting more strain on the hard parts.

In case it isn't obvious from the above ranting, setting up ANY automatic transmission to shift more firmly than is necessary is mechanical torture on every powertrain part from the belt tensioner to the axle shafts. It seems like every day that I see one more person posting how fun their new tire-chirping neck-jolting shifts are. (sigh)

In summary, if the hard parts are all the best that they can be, making one of these transmissions work under high power is a BALANCE of taking those parts right to the brink of their destruction with carefully set-up and programmed shift firmness in an effort to prevent the over-worked inadequate clutch materials from overheating. Even then it's not going to last.

One term comes to mind - "Band-AidŽ"





And with that, let the flames begin....