Best approach to improve strength of front diff and axles on lifted 2007 Tahoe LTZ

[BigRedB]

these have been on my radar for a while, but yea the 2500$ price is hard to commit to , but being pretty much the only one doing it not many options.

4l60e, is not known for its strength and durability - seeing as how its newer i would run it but not dump any more money into it. i've seen stock stock 4l80s outlive built 60s
10 bolt rear end, can be built pretty strong - i opted to swap it out. larger ring/pinion. same style oem g80 locker has a little better rep. axles are similar to the 10bolt but yukon makes replacements for the 14bolt semi float
front diff - being open carrier will likely not break, dont hear to much about axle problems, bearings and seals will wear out.
regearing will help a lot - i have 4.11s with the 6l80, if i had 35s i wouldnt want any less gear for sure..comapre he final drive you may want to get up even more

Thanks for the advice. Im looking long eyed at the transmission. I have a real good torque convertor to replace the OEM. Ive been looking at gearing for the front and rear too, it helps to hear peoples experiences. I need to really decide on the ratio for the gearing, I am just about ready to buy, so I have think long and hard to make up my mind.

I am leaning towards changing gearing in the current set up, I will probably get the CV axles too. I will run it until it breaks and then I will swap in the 480le transmission and larger rear end, ultimately this is what will make me happy. I wish I would have known I would be rebuilding the top end on the engine before I bought the transmission and axle. I made the commitment so now I have to use it til it breaks.

 

[BigRedB]

these have been on my radar for a while, but yea the 2500$ price is hard to commit to , but being pretty much the only one doing it not many options.

4l60e, is not known for its strength and durability - seeing as how its newer i would run it but not dump any more money into it. i've seen stock stock 4l80s outlive built 60s
10 bolt rear end, can be built pretty strong - i opted to swap it out. larger ring/pinion. same style oem g80 locker has a little better rep. axles are similar to the 10bolt but yukon makes replacements for the 14bolt semi float
front diff - being open carrier will likely not break, dont hear to much about axle problems, bearings and seals will wear out.
regearing will help a lot - i have 4.11s with the 6l80, if i had 35s i wouldnt want any less gear for sure..comapre he final drive you may want to get up even more

Thanks for the advice. Im looking long eyed at the transmission. I have a real good torque convertor to replace the OEM. Ive been looking at gearing for the front and rear too, it helps to hear peoples experiences. I need to really decide on the ratio for the gearing, I am just about ready to buy, so I have think long and hard to make up my mind.

I am leaning towards changing gearing in the current set up, I will probably get the CV axles too. I will run it until it breaks and then I will swap in the 480le transmission and larger rear end, ultimately this is what will make me happy. I wish I would have known I would be rebuilding the top end on the engine before I bought the transmission and axle. I made the commitment so now I have to use it til it breaks.

 

[BigRedB]

I’d go 4.56’s with the 35’s and at least swap the rear axle out.

GM half ton axles die due to big tires, high power, and hard use. You’re talking about all three.

Thanks for advice on the gearing, As soon as it breaks, I will definitely install a larger axle.

 

[AJMBLAZER]

Thanks for advice on the gearing, As soon as it breaks, I will definitely install a larger axle.

If you’re spending money on regearing and parts just start looking for that 14SF now. Why spend money on a 10 bolt you’ll eventually replace?

 

[BigRedB]

Thanks for the advice. Im looking long eyed at the transmission. I have a real good torque convertor to replace the OEM. Ive been looking at gearing for the front and rear too, it helps to hear peoples experiences. I need to really decide on the ratio for the gearing, I am just about ready to buy, so I have think long and hard to make up my mind.

I am leaning towards changing gearing in the current set up, I will probably get the CV axles too. I will run it until it breaks and then I will swap in the 480le transmission and larger rear end, ultimately this is what will make me happy. I wish I would have known I would be rebuilding the top end on the engine before I bought the transmission and axle. I made the commitment so now I have to use it til it breaks.

I am replacing the front axles because the Fabtech lift uses spacers with long bolts adapted to the OEM axles because after the lift they are too short to reach the differential. This is in my opinion the weakest part of their lift. I can have the RCV Performance axles made to fit exactly, I will feel a lot more comfortable knowing they are there.

 

[BigRedB]

If you’re spending money on regearing and parts just start looking for that 14SF now. Why spend money on a 10 bolt you’ll eventually replace?

I definitely need to go on the hunt compare the costs, if it is close enough I will reach for it. You see me slowly opening up to the idea because this is how I control the monster, I have the propensity to go hog wild. I am having a great time, I enjoy the build, just as much as the finished product. I am afraid there are so many decisions buying parts for this truck will become a subconscious reflex.

 

[BigRedB]

If you’re spending money on regearing and parts just start looking for that 14SF now. Why spend money on a 10 bolt you’ll eventually replace?

The prices on the axles with the 9 1/2" ring gear aren't that bad. So the rear axle question is solved. I was being a little hard headed, I appreciate the nudge.

 

[BigRedB]

Ok I have the all of the axle questions answered. Now I need to determine gearing.
For the front differential I am doing a limited slip with a helical gear. I am still up in the air on the rear diff. There are a lot of choices, I am considering a locker, but I don't have enough experience to know which type or brand. I will hunt down and post a few, but any advice or prior experience is appreciated.

After I select the type I need to figure out what ratio, Im thinking 4:10 or 4:56. Does anyone know how much of a difference there is driving with either of these or is it close enough to be not a major difference?

 

[BigRedB]

Does anyone have any experience with this? Some of the claims are large, is all of this true? I will list them below.

https://www.carid.com/2007-chevy-ta...submodel[]=WHEEL+DRIVE|4WD+(Four+Wheel+Drive)

Enables a 2 Wheel Drive to outperform a 4 Wheel Drive in poor traction conditions
Gives 4 Wheel Drive vehicles ultimate traction performance
Maximum power to both wheels off the line and in high g turns
Torque transfer limited only by the strength of other driveline components
Dreaded wheel spin is eliminated
Smoothe and Quiet OperationSynchronization mechanism eliminates ratcheting sound typical of locking differentials
Backlash effects are minimized because of special spring/saddle design
Takes 6,000 to 36,000 ft-lbs of torque.
Much stronger than the axles
Improves driveline durability by eliminating wheel spin and the associated driveline trauma
Zytanium construction is 67% stronger than titanium
No wearing surfaces. No friction clutch packs to burn out
Easy to Install Installs in the existing differential case- no need to reset the ring & pinion

Is this real? These are tall orders. I am investigating this further for the rear end and
I would never put a locker at all on an IFS front end, but I am curious about this, I am going to try and talk to the manufacturer.

Does anyone know anything about this?

Sorry for the book.

 

[mikeyss]

https://spicerparts.com/calculators/transmission-ratio-rpm-calculator

This is pretty useful to find out differences in speed and rpm for different rear gears. You just have to know your final transmission ratio, and tire height.

 

[BigRedB]

https://spicerparts.com/calculators/transmission-ratio-rpm-calculator

This is pretty useful to find out differences in speed and rpm for different rear gears. You just have to know your final transmission ratio, and tire height.

thanks a million, I will definitely check this out

 

[AJMBLAZER]

Question- what do you want to do with this truck?

In your first post you mentioned hole shots. Any offroading? If so, what?

Frankly, don’t add a LS or locker to the front axle. The 8.25” isn’t the strongest axle out there. Regearing will help with reducing stress on it but unless you’re doing some serious wheeling you have no use for a traction adder up front. Even if you were aiming for Moab the 8.25” would be on borrowed time with just the open diff.

I’ve used a PowerTrax NoSlip before. Good locker and easy to live with for a full locker. Clunked sometimes and torque steered if you got into it but overall it was well mannered. Offroad it was awesome. Point the truck and go, as long as I had traction on one of the rear tores I was moving forward.
That said, if you’re regearing anyway, go with a full carrier replacement locker like the OG Detroit Locker. Had one of those as well and you can’t beat them for being bomb proof. Handles similar to a NoSlip.
Your vehicle has the advantage of being long, heavy, and an automatic. The same type of locker in a lightweight Jeep can be very quirky on the road.
Again though...a locker is kind of overkill unless you’re going offroading. A factory G80 locker or a helical gear limited slip (Detroit TruTrac comes to mind) would be perfectly good on the pavement.

Lastly, go 4.56’s. Your 4L65E has no reduction in the top gear. Your 3rd is 1:1. Those heavy, tall Nitto’s are going to suck some power so a bit of extra gearing won’t hurt. The rpm difference between 4.10’s and 4.56’s isn’t much. Couple hundred rpm at best and nothing to a fast revving LS motor.
Better to go a touch lower than to find yourself, after all that expense, wishing you still had a bit lower gears.

 

[BigRedB]

Question- what do you want to do with this truck?

In your first post you mentioned hole shots. Any offroading? If so, what?

Frankly, don’t add a LS or locker to the front axle. The 8.25” isn’t the strongest axle out there. Regearing will help with reducing stress on it but unless you’re doing some serious wheeling you have no use for a traction adder up front. Even if you were aiming for Moab the 8.25” would be on borrowed time with just the open diff.

I’ve used a PowerTrax NoSlip before. Good locker and easy to live with for a full locker. Clunked sometimes and torque steered if you got into it but overall it was well mannered. Offroad it was awesome. Point the truck and go, as long as I had traction on one of the rear tores I was moving forward.
That said, if you’re regearing anyway, go with a full carrier replacement locker like the OG Detroit Locker. Had one of those as well and you can’t beat them for being bomb proof. Handles similar to a NoSlip.
Your vehicle has the advantage of being long, heavy, and an automatic. The same type of locker in a lightweight Jeep can be very quirky on the road.
Again though...a locker is kind of overkill unless you’re going offroading. A factory G80 locker or a helical gear limited slip (Detroit TruTrac comes to mind) would be perfectly good on the pavement.

Lastly, go 4.56’s. Your 4L65E has no reduction in the top gear. Your 3rd is 1:1. Those heavy, tall Nitto’s are going to suck some power so a bit of extra gearing won’t hurt. The rpm difference between 4.10’s and 4.56’s isn’t much. Couple hundred rpm at best and nothing to a fast revving LS motor.
Better to go a touch lower than to find yourself, after all that expense, wishing you still had a bit lower gears.

Thank you tremendously for the guidance!!! I love this forum

OK definitely not even a LS on the front end. I will regear it only and be done.

The truck will see very light off road use, I have a 99 Tacoma for my off road adventures. I will use it to tow the Tacoma to the trail head, so it will see mud some sand, sugar sand, slippery boat ramps, Occasionally water and mud during heavy rains I have been known to hit a mud puddle or 2 as I see them in areas along the road. It feels good to get down in it, not too deep only 3/4's of the tire, throwing roost with those mud grapplers.

I like the idea of a locker on the rear end if I only even need it once. I will take a look at the OG Detroit for sure.

Thanks for pointing at the 4.56 ratio, my gut is telling me I wouldn't be happy with the 4.10. I read some where that the perfect ratio for the Tahoe with 35's is 4.28 when calculated but it doesn't exist off the shelf, so intuitively it feels right to gear down to 4.56 rather than gear up to 4.10

Im seeing the dollar signs but Big Red is worth it, no rust only 130k, everything works. Over the life of the truck as things broke I replaced them.

Whew... these parts are adding up, now that Im looking at akk of it. I think the universe has aligned in this moment for me to get all of this done the right way.

The engine rebuild is covered. To get the rest of the stack for Big Red I am sacrificing an 88 Wrangler, I got the wrangler for a sweet price. The owner gave it away due to the jeep death wobble, but that's just a front end rebuild. I was surprised after I got it that the axles were full of mud too, but ironically when I got the Tacoma it came with 2 jeep axles its previous owner was going to do a SAS to the Tacoma but didn't. Soooo, im going to use the axles on the jeep, rebuild the front end, put on new brakes too, tighten up the backlash in the steering gearbox, and put it up for sale. It will provide more than I need for the parts to build the Tahoe, I may even have a little left over to do a few things to the Tacoma. To sacrifice a mopar to build a Chevy somehow seems very appropriate

 

[AJMBLAZER]

If you’re towing then 4.56 is definitely the way to go.

Glad to help. Just trying to help avoid mistakes I made myself in the past.

 

[BigRedB]

I still cant shake the desire to improve the front diff. My heart wants the Chevy 2500 HD front diff it has a 9-3/4" ring gear. I dont see why I cant install one on the front of the Tahoe.

Please correct any errors in my logic...

I would need a shaft out from the stock T-Case to the front diff, 30 spline on one end - 33 spline on the other
I may need to fabricate/modify mounting points on the truck with a bracket etc to install the diff
The axles would need an 8 bolt pattern for the diff connection with a 30 tooth spline on the other end to assemble to the stock bearing hub assembly.

I am sure I can order the RCV front axles in this configuration, at this point to adapt to the 2500 HD front diff with the stock bearing hub assembly, the high cost of the axles is money well spent

I would need to make the shaft between the diff and T Case with a custom spline on one end - this is very possible, not that difficult or expensive

The mounting is a question, I have not physically compared the mounting differences between the 8.5" and 9.75" front differentials, It is possible, straight forward for a CNC mill... I have access to one, I also can model in 3D specify material etc, a bracket or mounting point mod on the truck shouldnt be too bad unless there are unexpected parts in the way (this the portion of the of my plan that needs work)...

Is there any reason this wouldnt work?
Would this impact the std 4wd set up in the LTZ, 4x4 hi, low, AWD, 2wd...
Even if it is unnecessary, I still want to do it, I can do the work, this is one very special truck,

Any advice is greatly appreciated...

This is the last detail... for now