Calling all gear ratio wizards.

[R422b]

change your rear gears. 4.11s minimum. your 4l60e keeps going because your builder doesn't know what they are doing. i highly doubt it's from your driving style, but the 4l60e would gain life with a lower gear raitos as well. when you thrash on it or tow pull the lever to 3rd. doing so will also increase the life greatly.

It's a running issue with me. This one made it to 197,360 miles on the original transmission but I got it at 165,000 miles. My last 4l60e failure was a Tahoe I had no history on but the transmission in it when I got it was painted black so I know it was a rebuild or reman and it only lasted me 20,000 miles.

 

[R422b]

Out of all of them I would pick the first one.

That was multiple RPMs on the same transmission.

 

[0xDEADBEEF]

That was multiple RPMs on the same transmission.

LOL. Didn't catch that. I thought they were all at 1800 rpm.

It's on the steep side. My project is doing about that rpm in 5th (NV3500) and I wouldn't like it if not for the turbo.

 

[R422b]

Mmm yeah, 1800 at 80 is way too low. I understand OK may have 80-85mph speed limits with slack enforcement, but I bet you find that 90% of the time you're 75mph and have to be in 5th. I like 3.55 axle with 30% overdrive. For the 6 speed, personally I'd go 3.73 and let it sing if I'm running fast and loose. Lugging a small engine at very high loads is a recipe for disaster.

The t56 magnum would be about 2300 RPM at 75 in 5th gear. I rarely see over 75 so I'd probably usually drive it like a 5 speed. I just haven't liked everything I've read about the 5 speed options.
I wonder how expensive regearing is and is that something I could do at home? I have successfully replaced a 4l60e myself before but an old friend of mine claims that differentials are voodoo.

 

[R422b]

LOL. Didn't catch that. I thought they were all at 1800 rpm.

It's on the steep side. My project is doing about that rpm in 5th (NV3500) and I wouldn't like it if not for the turbo.

It definitely wouldn't win any races. If it wouldn't make it feel more anemic around town than it already does I would be very happy. I am far more concerned with durability and fuel economy than performance. I am working on getting my one ton back on the road so it would do all the real pulling.

 

[RichLo]

The t56 magnum would be about 2300 RPM at 75 in 5th gear. I rarely see over 75 so I'd probably usually drive it like a 5 speed. I just haven't liked everything I've read about the 5 speed options.
I wonder how expensive regearing is and is that something I could do at home? I have successfully replaced a 4l60e myself before but an old friend of mine claims that differentials are voodoo.

Re-gearing can be done at home as long as you take your time and dont get frustrated.

But a lot of people dump the 8.5" 1/2 ton axle if it needs fresh oil, lol. You can shop around for a 9.5 SF 6-lug swap and they often come with 4.10s or 3.73's from the factory. Simple driveway swap and probably the same price as if you brought your truck in for a pro to swap gears in the 8.5

 

[0xDEADBEEF]

It definitely wouldn't win any races. If it wouldn't make it feel more anemic around town than it already does I would be very happy. I am far more concerned with durability and fuel economy than performance. I am working on getting my one ton back on the road so it would do all the real pulling.

The issue is you'll probably spend a lot of your highway driving going back and forth between 5th and 6th. If you don't get on the highway much then it's not an issue.

 

[Scooterwrench]

LOL. Didn't catch that. I thought they were all at 1800 rpm.

It's on the steep side. My project is doing about that rpm in 5th (NV3500) and I wouldn't like it if not for the turbo.

Your running a NV3500 behind a turbo? Torque? Horses?
I have a NV3500 that I was thinking of freshening up to run behind my 400hp 355. I was worried it would grenade that tranny.

 

[pressureangle]

Re-gearing can be done at home as long as you take your time and dont get frustrated.

But a lot of people dump the 8.5" 1/2 ton axle if it needs fresh oil, lol. You can shop around for a 9.5 SF 6-lug swap and they often come with 4.10s or 3.73's from the factory. Simple driveway swap and probably the same price as if you brought your truck in for a pro to swap gears in the 8.5

^^this^^

But yes you can swap gears in your driveway- if you're young, strong, conscientious and infinitely patient. And watch a lot of YouTube videos. I wouldn't touch it, but I'm old and cranky.

 

[R422b]

^^this^^

But yes you can swap gears in your driveway- if you're young, strong, conscientious and infinitely patient. And watch a lot of YouTube videos. I wouldn't touch it, but I'm old and cranky.

Sounds like I should be OK if I decide to go that route then.