4L60E trans upgrade advise

Hi guys,

I have a 2004 Chevy Avalanche that Iv'e owned from new and currently has 109,000 miles on it now. I have kept the service up and truck runs very good with no problems. The trans has also been maintained and fluid and filter was changed 2 times in this period and a external fluid cooler was installed at around 25,000 miles.

I am thinking of getting a cam and a higher stall for this rig and I'm wondering if I need to beef up the 4L60E for these mods with the current age of the unit. I am looking at a stage 2 or 3 truck cam and a 2800-3200 stall and would like to know if I should do any upgrades to the trans at the same time if it's necessary.

Thanks

Big cam and loose converter in a big heavy truck paired with a transmission design that doesn't like high RPM (at least not in first gear) is a Bad Combo.

Oh, I thought this sounded awful familiar. ("Murphy, it's you!"): https://forum.hptuners.com/showthrea...-converter-kit

More of my thoughts on "truck cams", if you're interested: https://forum.hptuners.com/showthrea...ce-what-to-get

The 60E is crippled by the super-deep first gear, which spins the reverse drum at insane speeds in 1st - the band then clamps around the outside of that drum to make the 1-2 shift, so that drum has to go from 12,000+ RPM to zero on the 1-2. You can fix that, sorta, with a different gearset that has a lower ratio 1st gear, but that's more than $1000 last time I checked. And if you're spending that much, it'd be stupid not to also do billet shafts at the same time, which is another big stack of money. At that point you've spent enough to buy and build two essentially stock 4L80Es that can handle the same power.

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Originally Posted by blindsquirrel

Oh, I thought this sounded awful familiar. ("Murphy, it's you!"): https://forum.hptuners.com/showthrea...-converter-kit

More of my thoughts on "truck cams", if you're interested: https://forum.hptuners.com/showthrea...ce-what-to-get

The 60E is crippled by the super-deep first gear, which spins the reverse drum at insane speeds in 1st - the band then clamps around the outside of that drum to make the 1-2 shift, so that drum has to go from 12,000+ RPM to zero on the 1-2. You can fix that, sorta, with a different gearset that has a lower ratio 1st gear, but that's more than $1000 last time I checked. And if you're spending that much, it'd be stupid not to also do billet shafts at the same time, which is another big stack of money. At that point you've spent enough to buy and build two essentially stock 4L80Es that can handle the same power.

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I would argue that a stock 80E can handle alot more power than a built 4L60/65/70E can. I had a 4L60E go in 38K behind a 350 and a built up 4L65E go in 40K. At 78K I put a 100K mile used 4L85E behind it and have never looked back. The 85E laughs at a ~500 hp 6,000 rpm 383 in a 6,500 lbs vehicle pulling a 6,000 lbs travel trailer.

Ok, also I wouldn't be driving it every day neither would I be beating on it all the time. Just thought I would cam it and free up the stall some.

Quote:

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Originally Posted by blindsquirrel

Big cam and loose converter in a big heavy truck paired with a transmission design that doesn't like high RPM (at least not in first gear) is a Bad Combo.

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Couldn't I just lower the 1-2 shift point rpm? I also have a corvette servo in it which was done recently which I forgot to mention.

Sure, that'll help keep the trans alive. Why not pick a cam that makes power in the range that literally every other part of the drivetrain can make good use of?

On the other hand, maybe just go for it. Everybody needs to suffer through driving something with a too-big cam. It's part of growing up I guess, life lessons or whatever.

If you think that's too big of a cam then what should I look into? I am new to this stuff but I saw a bunch of good reviews on the stage 2 and 3 truck cams and thought if I loosen the stall that would help the big rig off the line better and match up good with the cam. Since you seem to have alot of experience and knowledge with these then I am open to any suggestions and advise. I want to cam it and would like to loosen the stall some because GM crippled these trucks from factory and Iv'e always been a GM guy.

Best advice I can give is, just be realistic. Go through your logs and look for how much time you spend above 4000 RPM - because that's the only time you'll feel a big cam doin' its thang. I'd much MUCH rather have the extra goodies below 4000.

A looser converter will help a bunch even with a stock or tiny cam, but more like 2400-2800.

Ok thanks, I will look into some other options then.

Attachment 123279

Numbers like those three are where I'd look. There are not a lot of choices from anybody, not just Comp, in that range. For such short duration I'd rather see 110 or 111 lobe separation, a custom grind is always an option and usually costs the exact same money as a shelf cam.

For comparison, the Melling stock replacement cam for '04 Avalanche is listed as 195/208 @ .050" and 281/291 @ .006" - those are very lazy, slow lobes.

Yes the stock cam is really sleepy. I was thinking of a 212/218 or a 216/220 but I will do some more searching and let you know what I've decided on.

Yes but even those, and nearly all cams called 'truck cams', are doing the thing where they add as much duration as they can get away with without completely murdering the low end torque. Why not a cam that INCREASES low end torque? Who really uses the extra power it'll make from 5500-up? You use the low end tq from a tiny cam with the right design every single time you pull away from a stoplight.

The torque peak is always, ALWAYS, going to be at the same 4300-4400 RPM, because that's determined by displacement and cylinder head flow - it's a 5.3L and has cathedral port heads. A cathedral port 4.8L has its tq peak a few hundred RPM higher, a cathedral port 6.0L a few hundred lower. No cam is able to move the torque peak to something more reasonable, like 3300-3400, like the old Gen1 SBCs. The LS cylinder heads are just too big to get the tq peak down that low. If you had heads with smaller intake ports, or put the same heads on an engine with a lot more cubic inches you could move the peak down.

Or bolt on a positive displacement blower...

Ok something to think about thanks. I will have to call around for a custom grind in this case which is better I guess as it will be perfect for the rig.

I have told this story before, somewhere on this board...

The single worst-but-in-a-hilarious-way combo I ever put together partly as an experiment, partly because I had a pile of random parts was: a completely stock Gen1 Chevy 305 long block; a Comp 280 Magnum cam (only 230/230 @ .050); Victor Jr single plane; 750 Holley DP; TH350 w/stock torque converter. I could hold the brake and go WFO and it would go to 1800 RPM and just sit there doing absolutely nothing. It was the same as if you held it at 1800 in neutral. Let off the brake and it would pull away like a little old lady was driving until it hit 3000 or so and then it'd just blow the tires off and go sideways. No low end torque sucks.