4l60 & 4l80 tranny differences

[Nice rig]

What are the differences in these two transmissions??

[Ape0r]

What are the differences in these two transmissions??

 

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Everything.

[redvett]

4L60E is only for 8600 gvw and lower 4L80E is for 8600 gvw and up. The 4L60E is a light duty trans and OEM isnt durable enough for haevy duty unless beefed up. The 4L80E is a HD trans and dosent work well for LD applications due to the power loss since it needs more torque to operate.

[Schmids5.3l]

4L60 is rated for up to 370 ftlbs at the crank, not sure about the 80

[fossil]

The 4L80E is based on the old THM400 series, as the 4L60E is based on the old THM350 series. Anyway, if the THM 400 was mated to a 5.7L engine back in the 70's and 80's without any power loss, I'm sure they would work just fine with todays series of engines which have a whole lot more horsepower than than the engines of the 70's and 80's. GM is just being cheap by not putting in these transmissions into 1/2 ton truck models. As an aside, the 4L60E has shift clucnk due to timing of the bands and clutch packs during a shift (an inherent design flaw). The 4L80E is a different design and utilizes all clutch packs and no bands, thus no shift clunk. You can get a 4L80E conversion from some performance transmission specialty shops that replace the 4L60E, but they are fairly pricy, but then again, you only have to replace your tranny once instead of every 70,000KM.

[rdnkcpa]

The 4L80E is based on the old THM400 series, as the 4L60E is based on the old THM350 series. Anyway, if the THM 400 was mated to a 5.7L engine back in the 70's and 80's without any power loss, I'm sure they would work just fine with todays series of engines which have a whole lot more horsepower than than the engines of the 70's and 80's. GM is just being cheap by not putting in these transmissions into 1/2 ton truck models. As an aside, the 4L60E has shift clucnk due to timing of the bands and clutch packs during a shift (an inherent design flaw). The 4L80E is a different design and utilizes all clutch packs  and no bands, thus no shift clunk. You can get a 4L80E conversion from some performance transmission specialty shops that replace the 4L60E, but they are fairly pricy, but then again, you only have to replace your tranny once instead of every 70,000KM.

 

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Replace every 70,000KM? That is roughly 42,000 miles. I don't think so. I have a 4L60E with well over 100,000 miles that is getting the job done. I have another one with 65,000 trouble free miles.

[redvett]

The 4L80E will not pass todays standards required for a #1500 for emissions & fuel (CAFE) economy. A #2500 does not currently have to pass any fuel economy standards. Its not being cheap its a matter of passing Fed. emissions & fuel economy.

[Schmids5.3l]

I thought the 4l60e was an electronically controllled 700r4. 70,000km? I have that many miles now....its fine and has no 'clunk' plus it has a wait4me so less/no torque management and even more power and its doing fine.

[95Sierra2500]

I thought the 4l60e was an electronically controllled 700r4. 70,000km? I have that many miles now....its fine and has no 'clunk' plus it has a wait4me so less/no torque management and even more power and its doing fine.

 

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That's correct. The 4L60 is an electronically controlled TH700R4. And a stout trans to boot, though not built for hauling for years on end w/o being rebuilt. I've seen them easily go 100k+ miles though.

[larry arizona]

The 4L80E is based on the old THM400 series, as the 4L60E is based on the old THM350 series. Anyway, if the THM 400 was mated to a 5.7L engine back in the 70's and 80's without any power loss, I'm sure they would work just fine with todays series of engines which have a whole lot more horsepower than than the engines of the 70's and 80's. GM is just being cheap by not putting in these transmissions into 1/2 ton truck models. As an aside, the 4L60E has shift clucnk due to timing of the bands and clutch packs during a shift (an inherent design flaw). The 4L80E is a different design and utilizes all clutch packs  and no bands, thus no shift clunk. You can get a 4L80E conversion from some performance transmission specialty shops that replace the 4L60E, but they are fairly pricy, but then again, you only have to replace your tranny once instead of every 70,000KM.

 

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The THM 350 was more efficient than the THM 400. The internal rotating mass of the 400 was much more than the 350. It was a strength thing only for GM to use the 400.

 

The 350 also had a more desireable 1st gear ratio which made it better for racing.

 

But the 350 (although it could be modified for significant strength) was weak by comparison to the 400.

 

The 4L60 is closer to the 700R4 (4 speed overdrive) anyways. THM350 and 400 are only 3 speeds.

[svensk]

I think my 4l60e is on its last legs. It has a 120k miles of pretty hard work on it. I've been babying it as of late hoping to get another year out of her. The guy I bought the truck from towed a camper ALOT with this thing but was very religious about maintnence. Small things are starting to happen like slipping, hard clunks between 1-2, and 2-3 upshifts. That sort of thing.

[pm26]

The 4L80E will not pass todays standards required for a #1500 for emissions & fuel (CAFE) economy.  A #2500 does not currently have to pass any fuel economy standards. Its not being cheap its a matter of passing Fed. emissions & fuel economy.

 

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And being cheap

[mmmikkke]

The 4L80E will not pass todays standards required for a #1500 for emissions & fuel (CAFE) economy.  A #2500 does not currently have to pass any fuel economy standards. Its not being cheap its a matter of passing Fed. emissions & fuel economy.

 

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And being cheap

 

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If we're going to put GM in a vice by mandating higher Corporate Average Fuel Economy, then we shouldn't kick them in the b*lls because they don't put the HD trans in a LD truck. The 4L80 has a lot more friction. Higher friction losses mean lower fuel economy. That's why you don't have a 4L80 option on a 1/2 ton truck. 1/2 ton trucks are measured to calculate CAFE.

 

Complain to some socialist. That's where the blame lies.