Leaking CV joint?

[Cabin 4]

I'm very interested in the feedback here. The CV issue is the remaining item that's preventing me from leveling up. The issue is the angle of the CVs after leveling up too high beyond OE design margin. I don't see anything in here about how these new CVs can better deal with that out-of-EO spec angle and resulting CV binding. They certainly are claiming higher strength and targeting lifted trucks (but they don't say "Leveled"). I wish the info NAPA provided directly addressed angle/binding, but they don't. That aside, trucks that have true suspension lifts place more stress on all the remaining front components including the CVs even after the front diff is dropped. So a higher strength CV may be a good addition to a Lift as opposed to a Level up where the diff is not dropped. If an angle fix was part of these new CVs, I would think NAPA would have itemized that point in the literature. But let's see. I'm very interested.

 

[Grey]

So, the question I think needs to be asked is who makes a longer cv axle for our trucks so we can add these level kits without worrying about our cv axles? My Google-fu isn't fantastic, and I can't seem to find anything that says, "These are the axles you need." However, I did find these. Could somebody that's more knowledgeable on this topic than I please help point us in the right direction? I found these from NAPA and think they may be a solution, but I truly don't know.

Extended Travel CV Axles - NAPA New Premium C.V. Axles

napacvaxles.com

May be a failure of understanding on my part, but I don't think extended CV's would be the final answer here. The problem is the angle of the joint, which is not going to be solved by additional length. Im surprised by the lack of options for a differential drop for these trucks. Again, I come from a Jeep, so all this is new to me, but it seems like that would be a better option in the long run.

 

[Jmzvet]

I think this is a rare occurrence on these trucks with a 2in lift or less during “normal” driving conditions with proper
installation. No jumping, 4wd power brake burnouts etc.

 

[Transient]

I'm very interested in the feedback here. The CV issue is the remaining item that's preventing me from leveling up. The issue is the angle of the CVs after leveling up too high beyond OE design margin. I don't see anything in here about how these new CVs can better deal with that out-of-EO spec angle and resulting CV binding. They certainly are claiming higher strength and targeting lifted trucks (but they don't say "Leveled"). I wish the info NAPA provided directly addressed angle/binding, but they don't. That aside, trucks that have true suspension lifts place more stress on all the remaining front components including the CVs even after the front diff is dropped. So a higher strength CV may be a good addition to a Lift as opposed to a Level up where the diff is not dropped. If an angle fix was part of these new CVs, I would think NAPA would have itemized that point in the literature. But let's see. I'm very interested.

Reading the Napa info it says stick cv axles max out at 23° of angle. The Napa extending axle max out at 47°. I think we need to contract somebody either with the cv supplier to GM, or GM engineering directly, and find out what the Trail Boss and AT4 able max angle is. As far as I see it, lifting and leveling are basically the same thing. Truck goes up, but wheels didn't. The extending spline shaft I think is also a win. The raising of the truck actually extends the amount of shaft needed. For example, if you take a right angle triangle, where sides A and B for the right angle and side C is the hypoteneuse, of you extends either side A (transfer case to wheel), or side B (ground to transfer case), then side C will also extend. If you recall middle school math, it's the Pythagorium Theorem (A^2+B^2=C^2). Finally, these axles only extend 40mm. Converted to Americanese, that's only 1 1/2". I doubt a 2" increase on side B will increase the length of side C by an inch. For example: 3+4=C, 9+16=25, the square root of 25 is 5. Now, change the formula to 3+6=C, 9+36=45, the square root of 45 is ~6.7. It's a poor, but basic example. It's have to do some research and measuring, and can report back. Clearly, I'm very curious about this.

 

[Cabin 4]

Lift and Level are two different mods. A suspension Lift includes lowering the front differential which is supposed to realign the CVs to correct angle. Leveling is simply raising the body (front level up and or/rear level down) and does not include lowering the front differential. Both Lifting or Leveling front up do impact CVs but in a different way. So looking at this NAPA CV, they are very clear about not using the term "Level", but they do use the term "Lift". Since its pretty universal in the after-market world the difference between Lift and Level, it seems they are very intentional that these CVs are for Lifted applications. Its a nuance in the wording but these companies use nuance all the time in marketing materials. I think its a clue.

 

[GETGONE]

Level is just a marketing term so the front and rear heights are level since trucks are designed nose down with the expectation of hauling heavy loads or towing a heavy trailer causing the rear end to squat down and be more level with the front. Leveling is just lifting the front end 1.5 -2" and leaving the rear stock. A true lift kit lifts both the front and rear of the truck.

 

[Cabin 4]

Level is just a marketing term so the front and rear heights are level since trucks are designed nose down with the expectation of hauling heavy loads or towing a heavy trailer causing the rear end to squat down and be more level with the front. Leveling is just lifting the front end 1.5 -2" and leaving the rear stock. A true lift kit lifts both the front and rear of the truck.

It can be described a number of ways. I think the point is there are significant differences between a true suspension Lift and a Level. The question is does this NAPA CV fix the issue at hand from a Level when leveling includes raising the front body?

 

[GETGONE]

Leveling IS NOT A BODY LIFT!!! A BODY lift replaces the stock bushings between the frame and body with taller ones. If you add something to the SUSPENSION, it is a SUSPENSION lift!

 

[Cabin 4]

Leveling IS NOT A BODY LIFT!!! A BODY lift replaces the stock bushings between the frame and body with taller ones. If you add something to the SUSPENSION, it is a SUSPENSION

I don't consider installing $80 spacers in the front struts as a means to raise the body nose a true Suspension Lift. Thats not how I would describe a suspension lift regardless of what the spacer physically does. There are big differences in how these different approaches achieve lift and or level. Regardless, the CV issue is in play and the question is does this NAPA product address it or not?

 

[mrcolieman]

If I had an extra $10K to throw at my truck i would go this route! A true engineered suspension system that accommodates 37" tires and has 12" of travel with no diff drop... But then again for $10K I could go buy a Jeep to tow behind and beat the snot out of not worrying how am I gonna get home! . 3/8" top 'o' the strut plates for $25 gave me 7/8" lift to offset my winch/bumper weight... That'll have to do for now. Have fun out there!

(pay attention to 3:25 in the video for DK custom inner CV joints...)

4WD Long Travel 2022 Chevy Silverado

2022 4WD long travel Chevy Silverado 1500. This setup includes a Dirt King Fabrication long travel kit, bypass shock hoops, long travel axles, spec foxs hocks in the front, and more! Raceline wheels & Toyo tires.

dirtking.com

 

[Transient]

I went ahead and reached out to ReadyLift regarding the cv axle angles and whether or not the fancy NAPA cv axles would help. The pretty much pooped on the question about cv axle length and angles. Here's their reply via copy & paste.

"Thanks for reaching out,.
We don't suggest 4wd auto to be used due to the larger lift and tires you can see a vibration that is caused by the vehicle sending too much torque to the front driveshaft as it can no longer determine how much is needed due to the lift. This is not related to the CVs or angles they may have. That applies to any lift or tire combination. not just ours. You can run 4wd auto and should not cause any issue with the truck but would have the vibration issue. If you run it in 2wd, 4hi or 4low it shouldn't have any vibration."

Therefore, I have to ask, why did GM bother coming out with different cv axles for the Trail Boss when the GM 2" lift is pretty much a spacer like ReadyLift's?

 

[Gangly]

The GM lift is a not a spacer lift, its just a longer shock. The longer CV's are so that the CV doesn't pull out, or cause damage to the transfer case, when the suspension is at maximum articulation.

That being said, I have yet to see a Z71, even with 4"+ of lift, break a CV. I have seen busted UCA's, but I have yet to see a single broken CV on non TB Z71's, leaving me wondering if the TB CV is really necessary at all.

 

[2KWIK2C]

This is all very interesting. I have ran my TB now for almost 20000 miles with the majority of it off road articulating the suspension in extremes. I had the 6" BDS lift installed professionally and yet to have any issues and I run 4WD Auto almost all the time. Just put it in Off-Road mode and go. The suspension on the TB (even factory) articulates very well. I only have on question after reading all of this. Are you sure driving on the beach something didn't tear the rubber covering the CV joint?

 

[Gangly]

It can be described a number of ways. I think the point is there are significant differences between a true suspension Lift and a Level. The question is does this NAPA CV fix the issue at hand from a Level when leveling includes raising the front body?

I "leveled" my truck by raising the front end with new shocks and springs, not spacers. I did it by means of a "suspension lift". I think you are assuming that "leveling" is only done with spacers or pucks when in actuality a "level" can be achieved by suspension lift, spacer lift, bock removal, lowering kit, or partial body lift.

Spacer/puck kits have been marketed primarily as leveling kits because they are the cheapest form of achieving a level look and any shade tree mechanic can install them, but they are only one of MANY ways to "level" a truck as mentioned above.

Side note:
Spacers/pucks are almost exclusively sold as leveling kits, but leveling kits are not exclusive to spacers and pucks.....if that makes sense?

 

[Cabin 4]

This is all very interesting. I have ran my TB now for almost 20000 miles with the majority of it off road articulating the suspension in extremes. I had the 6" BDS lift installed professionally and yet to have any issues and I run 4WD Auto almost all the time. Just put it in Off-Road mode and go. The suspension on the TB (even factory) articulates very well. I only have on question after reading all of this. Are you sure driving on the beach something didn't tear the rubber covering the CV joint?

With that BDS 6 inch kit, didn't that include lowering the front differential?