5.3 to 6.0 swap complete... But

So I successfully rebuilt a lq4 6.0.. New rings, BTR stage 3 truck cam,and remanufactured 243 heads.. I went with a mail order tune from Michigan motorsports, and im impressed with the power gains.. This yukon would probably eat an 80s corvette.. Now unfortunately my 220,000 4l60e is slipping after 100 miles on the new engine.. I have some 4l60e parts that i pre ordered, such as a hardened sun shell, corvette servo, and z pack 3/4 clutches.. I plan on rebuilding the trans myself and highly recommend youtubing precision transmission and following richards advice

@NickTransmissions are the best, most informative and comprehensive transmission videos I have found on YT.

He's got a dedicated channel for the 4L60e series.

This is the 2wd Yukon correct? I personally would look I to a 4l80e swap and just get passed any possibilities of future 60e problems. Yes 60s can be built.... but I have killed 3 with a TBI 350, 4 with a 4.3 V6 and my father-in-law killed 2 in his 5.3 Silverado. If I am in the position to put in a built engine, I will never put a 60e behind it. Especially, Especially if it is in a 6.0 SUV.

Mudsport96 said:

This is the 2wd Yukon correct? I personally would look I to a 4l80e swap and just get passed any possibilities of future 60e problems. Yes 60s can be built.... but I have killed 3 with a TBI 350, 4 with a 4.3 V6 and my father-in-law killed 2 in his 5.3 Silverado. If I am in the position to put in a built engine, I will never put a 60e behind it. Especially, Especially if it is in a 6.0 SUV.

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Yes 2wd

strutaeng said:

@NickTransmissions are the best, most informative and comprehensive transmission videos I have found on YT.

He's got a dedicated channel for the 4L60e series.

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Im wondering who would be the best online to buy 4l60e parts from?

Mudsport96 said:

This is the 2wd Yukon correct? I personally would look I to a 4l80e swap and just get passed any possibilities of future 60e problems. Yes 60s can be built.... but I have killed 3 with a TBI 350, 4 with a 4.3 V6 and my father-in-law killed 2 in his 5.3 Silverado. If I am in the position to put in a built engine, I will never put a 60e behind it. Especially, Especially if it is in a 6.0 SUV.

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And its my first rodeo.. I plan on beefing it a bit

Yukonjoe2001 said:

Im wondering who would be the best online to buy 4l60e parts from?

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There are several vendors, from RockAuto, Summit (Sonnax , Transgo and other aftermarket suppliers) and WhateverItTakes (we have a local warehouse here.) The 2 4L80e units I've overhauled I bought the master kits from a gentleman in Georgia that also makes training videos, which is how I got my feet wet: https://transmissionbench.com/4L60Eparts.html

Those kits are always kinda like bare-bones, minimum kits; as you tear into the units, other parts may need replacement and upgrades, depending on wear. It really depends if this is going to be an OEM rebuild with aftermarket improvements vs a all-out build.

Yukonjoe2001 said:

And its my first rodeo.. I plan on beefing it a bit

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Another vote for the 4L80e I absolutely LOVE my 99 Silverado in my signature after I upgraded to the 4L80e (transmission was a part-out special)...but all these units are so old by now, that even the 4L80e would benefit from a freshen up for longevity.

Mudsport96 said:

This is the 2wd Yukon correct? I personally would look I to a 4l80e swap and just get passed any possibilities of future 60e problems. Yes 60s can be built.... but I have killed 3 with a TBI 350, 4 with a 4.3 V6 and my father-in-law killed 2 in his 5.3 Silverado. If I am in the position to put in a built engine, I will never put a 60e behind it. Especially, Especially if it is in a 6.0 SUV.

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Keep in mind the 4l80e is geared significantly different from a 4l60e/4l65e. That means the power curve is going to be different. If you switch to a 4l80e, you may want to regear it, too.

My daughter's 2003 Sierra Denali (LQ4 6.0) has its original 4l65e in it. But we do take really good care of it.

S33k3r said:

Keep in mind the 4l80e is geared significantly different from a 4l60e/4l65e. That means the power curve is going to be different. If you switch to a 4l80e, you may want to regear it, too.

My daughter's 2003 Sierra Denali (LQ4 6.0) has its original 4l65e in it. But we do take really good care of it.

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At 1800 rpm the 60e will be doing 72ish with stock tires and the 80e 67ish. As for the 1st gear difference, he is obviously looking at performance with the engine swap, so a 2600 converter will make up the difference in gearing and most likely give better acceleration than the 60e with a stock converter. And cruise with lockup won't add excessive rpm.

Yeah, the numerically lower gear ratio is kinda of a common misconception the requires a rear axle regear on the 4L80e. Not really on a lighter weight 1500 vehicle. My Silverado has 3.42 gears. 3.73 I think would be ideal. 4.10 probably overkill for daily driving.

Most vehicles that offered that transmission had 3.73 or 4.10s, but that's because they are overall heavier and higher GVWR.

Actually, the opposite is true about the 4L60e-family: the first gear is TOO low (numerically higher), and the 1-2 ratio DIFFERENCE is too much. Do a comparison with the other 4 speeds from the other manufacturer of that era and you will see the odd duck. We've discussed this on a different thread before.

Overall, the 4L80e ratios are much closer to each other, and 4th is actually higher than the 4L60e, so cruising RPM is a bit higher, but only slightly. It's good for highway towing because it puts you higher in the powerband of the LS engines. Once you drive one side by side, you will know what I'm talking about.