LS-400-Atlas 5:1- gearing questions

[mitchw123456]

Alright currently in the middle of a "yj" build and I'm using that term loosely. About the only thing YJ left will be the tub but I don't have to pass emissions with it hence the YJ. Anyway, I've come across a good deal on an atlas 5:1 which is what I had in my last crawler behind a 4.0. We had a love hate relationship, loved it at certain parks and it flat sucked at parks like superlift. I was dead set on a 3.8 for new build but this 5:1 is really a great deal.

So, vs running the 3.8 behind the LS with say 4.88 what are the downfalls of running the 5:1 with axles at 4.10? I'm thinking it should still crawl well but would still be able to have plenty of wheel speed when needed. Also should have stronger gears with 4.10s... Only con I can come up with is its going to put extra strain on the driveshafts. what are the other cons I'm missing?

 

[smbroady82]

Pholmann runs 4.10s and a 4.3 atlas with a healthy 6.0 (475ish hp range), it really surprised me how well it would crawl and then still light them up at will when needed

 

[TBItoy]

only other con would be more torque transferred to the chassis. Good suspension geometry will control it though.

Probably won't be able to tell much difference in reality

 

[1tfrot]

reality is you'll run out of gearing really fast in low range. I'm running a 500+hp 6.0 with 5.38s, th350, and atlas 3.8. I run out of gear quickly, imo, in low range. thankfully I have enough hp to use high range if I want.

it does give me the option to grab some wheel speed instantly, but kinda sucks for trying to go fast in low range. not sure if I would change anything other than running a 3spd atlas and pick the ratios I want

 

[redneckengineered]

Alright currently in the middle of a "yj" build and I'm using that term loosely. About the only thing YJ left will be the tub but I don't have to pass emissions with it hence the YJ. Anyway, I've come across a good deal on an atlas 5:1 which is what I had in my last crawler behind a 4.0. We had a love hate relationship, loved it at certain parks and it flat sucked at parks like superlift. I was dead set on a 3.8 for new build but this 5:1 is really a great deal.

So, vs running the 3.8 behind the LS with say 4.88 what are the downfalls of running the 5:1 with axles at 4.10? I'm thinking it should still crawl well but would still be able to have plenty of wheel speed when needed. Also should have stronger gears with 4.10s... Only con I can come up with is its going to put extra strain on the driveshafts. what are the other cons I'm missing?

I won't even address the axle gearing. The 5.0 gearset will not live behind a healthy LS for long (500+ hp) if you beat on it. I don't know how built your LS is but if you plan on making north of 500 real HP not internet HP you're going to want the 3.0 case. This is advice straight from Advance as well as real world experience. I've grenaded my 3.8 pushing close to 600. It is getting replaced with a 3.0.

 

[pholmann]

I'm very happy with my 4.3 atlas and 4.10's so far.

 

[mcutler]

Re: Re: LS-400-Atlas 5:1- gearing questions

I won't even address the axle gearing. The 5.0 gearset will not live behind a healthy LS for long (500+ hp) if you beat on it. I don't know how built your LS is but if you plan on making north of 500 real HP not internet HP you're going to want the 3.0 case. This is advice straight from Advance as well as real world experience. I've grenaded my 3.8 pushing close to 600. It is getting replaced with a 3.0.

What he said... exactly what I learned researching my new rig.... and why I sought out a 3.0 atlas, lower first great in the trans and 5.43 in the chunks.

Secondary benefit of lower axle gear than the tcase is less torque roll of the chassis...

Sent from my SM-G925R4 using Tapatalk

 

[Forbanger]

I'm running a 5.0 atlas behind a 4.0 and 4.10 gears with 43's. You might be a lil low when you really need to light them up. But you will never run out of power....

 

[kmcminn]

I hope 4.56 and a 3.8 case hold up to 300 hp.

 

[CHASMAN9]

I won't even address the axle gearing. The 5.0 gearset will not live behind a healthy LS for long (500+ hp) if you beat on it. I don't know how built your LS is but if you plan on making north of 500 real HP not internet HP you're going to want the 3.0 case. This is advice straight from Advance as well as real world experience. I've grenaded my 3.8 pushing close to 600. It is getting replaced with a 3.0.

So true, I was running 5.0's in my buggy with 4:10's and a healthy 388ci and it ate output shafts and driveshafts. Regrouped and went with 3.0 and 300m shafts and haven't worried about it since. It ran out of gearing real quick especially if you catch a little bit of air and land on it. I did this at AOP on a bounty hill and said never again. So if anyone needs a whole set of Atlas 5.0 gear set, hit me up, I have them in a box.




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[smbroady82]

I'm going with a 3.0 this go round with 5.13s in the axles. Hopefully around 500hp.

 

[mitchw123456]

Thanks for the info guys.

 

[zukimaster]

I would possibly be interested in that 5.1 transfer case if its a passenger drop and you wasn't going to use it.

 

[mitchw123456]

I would possibly be interested in that 5.1 transfer case if its a passenger drop and you wasn't going to use it.

Drive drop

 

[redneckengineered]

I'm going with a 3.0 this go round with 5.13s in the axles. Hopefully around 500hp.

That's for perfect combo for all around trail riding IMO. Anything between 13.5 - 17.5 drive ratio (gears * t-case) is the sweet spot assuming a LS style motor and typical auto like TH350/400. I've been all over the spectrum, higher, lower and everything in between and I feel pretty confident in that statement.

 

[mitchw123456]

Thanks for the info everybody. Looks like I have found a new motor accidentally. I found a '12 6.0 low miles so the 5.3 is gone. I guess long run I can swap cases easily enough once I get it moving but for the money I couldn't pass up the case.