GM 2" lift kit questions

[ero2]

So if I were to go with the 2in leveling block that my GM dealer offered for my 2020 elevation, the UCA angle won’t be an issue.  It only would if I went TB lift plus the blocks, equaling 4in ish of lift?

 

Im happy with the ride of the elevation, just want it level, so am thinking the easiest and cheapest option is just the GM blocks?

[SilveradoRST]

On 1/3/2021 at 6:42 PM, Duramax3oh said:

Glad OP got that settled, you shouldn't have any problems.

 

The GM 2" lift comes with new CV axles. I know this has probably been discussed a million times but what exactly do they change from the original stock ones (I believe it's the angle)? Does 2" create enough stress on the original cv axles though? Ie the Bilstein 5100/6112 front strut replacement with 2" lift. Would we really need to get the "trail boss" cv axles or is that not a problem to worry about?

New CV axles are designed "to run at higher running angles."  Straight from a GM reps mouth.

 

 

 

[andrewb24]

I replaced my 2" rough country lower kit with a 2.5" motofab upper kit and during the install I noticed that one of the boots was "messed up" already  from the place that installed the lower rough country kit which is well known and even does work for our local dealer.  I could've fixed with a hose clamp which I  temporarily did  When I finished the other axle outer clamp came off and I had grease on the inner boot that I couldnt find where it was coming from. 

 

I took the truck to the dealer to get them to fix the boots but they were just going to replace both axles so I was going to let them if the wanted to do that but axles were on back order so a month later I brought the truck in to get fixed because axles came in and then they call me after looking again and said they couldn't fix them under warranty so I got a price of about $1200 to $1400 to have them replace them.  So then I started looking for axles online because they were about $75-$100 cheaper than the dealer for each one so I placed an order with one of the GM parts online store and after a few days I got notification the order was cancelled so I called Chevy and talked them down from $260/each to $200/each so I went ahead and bought them and I also let them know I was going to go home and install them in my garage in about 3 hours with regular crappy tools after they told me that it would take them like 8 hours so I did get them installed and spent 3 maybe 4 hours doing so.  I looked over the old axles and found a pin hole in the one inner axle boot  which was hard to even see holding the axle in my hands  and that's where grease was coming from I mentioned about.  I am going to fix them or replace the boots on the old axles and have spares or sell them.  I could've repaired them and placed back on but Didn't want to have my truck broke down that long and the thought of them not being new on a truck with 7k miles.   Anyway I was looking at replacing with trail boss axles to help with the angles but I saw that it was going to be hard to track some available down online and knew that my dealer had the other ones already in their hands so I went ahead and got them.   While I was installing axles I noticed a bad angle with the truck on a jack but after I installed I looked at them  again with the truck on the ground and they looked fine to me although I am not a mechanic by no means.

 

Dont know if this helps your or not. lol

[RWTJR]

18 hours ago, ero2 said:

So if I were to go with the 2in leveling block that my GM dealer offered for my 2020 elevation, the UCA angle won’t be an issue.  It only would if I went TB lift plus the blocks, equaling 4in ish of lift?

 

Im happy with the ride of the elevation, just want it level, so am thinking the easiest and cheapest option is just the GM blocks?

Based on the fact that the TB/AT4 with their factory 2" and the GM OE Accessory 2" lift all use the same UCA as the non lifted trucks, it is safe to infer any lift up to 2" is within the engineered limits of the factory UCA. Anything above a 2" lift is questionable and should probably have a new UCA.

 

JMHO

No expertise implied or expressed.

[Gangly]

18 hours ago, SilveradoRST said:

New CV axles are designed "to run at higher running angles."  Straight from a GM reps mouth.

 

That's a somewhat misleading statement that can lead to misconceptions.  The only difference with the CV's is their length, which allows them to stay in the CV Tri-Pot Joint when the front suspension is completely unloaded and at maximum articulation .  Technically, the stock CV's are long enough, but they are close enough to potentially pull out in EXTREME circumstances so they added a little length to them to make sure they don't come out of the Tri-Pot Joint due to over extension.  That's it, that's the ONLY difference and the ONLY reason for the difference in length.  If you want to get into the mechanical engineering aspect of it you could argue that CV's increased length, while maintaining equal width, makes them more prone to failures in other ways, but they are fairly robust to begin with and I have no worries about failure with them. 

 

Regardless of what lift you go with, or how high you go, non TB CV' angles will be nearly identical to that of a TB CV angles given the same lift.  Again, the only difference is length and that's to keep them seated in the Tri-Pot Joint of the CV under extreme articulation circumstances

Edited January 15, 2021 by Gangly

[Blee]

I’ve been looking at Readylift. They make a 2” kit for the front and blocks for the back. Reviews are pretty good, I haven’t read anything bad. According to recent posts about the CV joint length, it shouldn’t be a problem as long as I stay at 2”. I would like to find the GM pieces but who knows if or when it might be available. 

[lapoolboy]

I want to run the ReadyLift 1.75" leveling kit on my TB suspension.  I want to replace all the shocks with the Bilstein 5100s while it's apart.  Does anyone know if the front Bilstein body is the same diameter as the stock Ranchos?  I want to make sure the ReadyLift spring perch spacer will fit down over the body.  Of course, I'd run them at the stock-height circlip setting to avoid any potential "over lift" issues.

Edited January 15, 2021 by lapoolboy

[RWTJR]

2 hours ago, lapoolboy said:

I want to run the ReadyLift 1.75" leveling kit on my TB suspension.  I want to replace all the shocks with the Bilstein 5100s while it's apart.  Does anyone know if the front Bilstein body is the same diameter as the stock Ranchos?  I want to make sure the ReadyLift spring perch spacer will fit down over the body.  Of course, I'd run them at the stock-height circlip setting to avoid any potential "over lift" issues.

Which READYLIFT kit are you considering?

 

This READYLIFT 1.75" kit intended for the TB/AT4 does not have a "spring perch spacer": https://www.readylift.com/2-25-front-leveling-kit-w-control-arms-at4-trail-bossgm-1500-truck.html

It has an upper strut spacer (goes on top of the coilover) and lower strut spacer (goes under the bottom of the shock).

 

As for the shock diameter, both the Rancho and the Bilstein B8-5100s use the stock spring perch so they should be fundamentally the same diameter.

 

No expertise implied or expressed

Edited January 15, 2021 by RWTJR
left out a word

[lapoolboy]

40 minutes ago, RWTJR said:

Which READYLIFT kit are you considering?

 

This READYLIFT 1.75" kit intended for the TB/AT4 does not have a "spring perch spacer": https://www.readylift.com/2-25-front-leveling-kit-w-control-arms-at4-trail-bossgm-1500-truck.html

It has an upper strut spacer (goes on top of the coilover) and lower strut spacer (goes under the bottom of the shock).

 

As for the shock diameter, both the Rancho and the Bilstein B8-5100s use the stock spring perch so they should be fundamentally the same diameter.

 

No expertise implied or expressed

Apologies....I meant the 2" SST kit they offer for the TB/AT4 with new UCAs and spring perch spacers.  I don't see any issue running this kit with the Bilstein 5100s set at stock height setting, do you?

[RWTJR]

18 minutes ago, lapoolboy said:

Apologies....I meant the 2" SST kit they offer for the TB/AT4 with new UCAs and spring perch spacers.  I don't see any issue running this kit with the Bilstein 5100s set at stock height setting, do you?

I'm no expert but I would think if you run the 5100s set at stock height it should be the same as if you ran the stock Rancho shocks. Of course the Bilsteins will ride differently but the height/lift should be the same.

 

JMHO

No expertise implied or expressed

[TNAT4]

I just had my front Ranchos replaced with Billstein 5100s on my 2020 AT4 (OE 2" lift stock).  Now I'm feeling a "bump" after sharp turns when I straighten the wheels.  It wasn't there before.  I'm taking it back to the shop for them to take a look but any ideas what this could be?  I have a slight rub (running 285/65/20 KO2s) that wasn't there before but this is more of a thump.  The Billsteins are supposed to be set at 1.1 to give me slightly more clearance/level than stock.

[lapoolboy]

32 minutes ago, TNAT4 said:

I just had my front Ranchos replaced with Billstein 5100s on my 2020 AT4 (OE 2" lift stock).  Now I'm feeling a "bump" after sharp turns when I straighten the wheels.  It wasn't there before.  I'm taking it back to the shop for them to take a look but any ideas what this could be?  I have a slight rub (running 285/65/20 KO2s) that wasn't there before but this is more of a thump.  The Billsteins are supposed to be set at 1.1 to give me slightly more clearance/level than stock.

Did the 1.1" level the truck?

[TNAT4]

Pretty close, still a slight rake but much better

[TNAT4]

12 minutes ago, TNAT4 said:

Pretty close, still a slight rake but much better

 

48 minutes ago, lapoolboy said:

Did the 1.1" level the truck?

 

[TNAT4]

On 1/20/2021 at 8:24 AM, TNAT4 said:

I just had my front Ranchos replaced with Billstein 5100s on my 2020 AT4 (OE 2" lift stock).  Now I'm feeling a "bump" after sharp turns when I straighten the wheels.  It wasn't there before.  I'm taking it back to the shop for them to take a look but any ideas what this could be?  I have a slight rub (running 285/65/20 KO2s) that wasn't there before but this is more of a thump.  The Billsteins are supposed to be set at 1.1 to give me slightly more clearance/level than stock.

Turns out it was a loose cam on the UCA