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Posted (edited)

4” BDS lift on 2” 2020 AT4

Custom shop installed. 
 

I recently started having a whirring/whine sound when starting off slowly and maintaining a slow crawl. Almost sounds like riding the clutch with a worn throw out bearing. 

 

Now since winter I’ve been getting groaning and creaking during the same process but pronounced over uneven surfaces. 

I suspected the suspension bolts needed tightening. Going underneath to peek, I found that the front CV axle boots appear to be leaking & spraying grease. Maybe they are making the sounds as they start and as they flex. No tears, seems to be leaking at the seam. Same on both sides. 
 

What is going on here? Is this the culprit?

thanks!
732339FF-3299-4587-865C-19F9A26AB5EE.thumb.jpeg.c4054b92d8c2d9edc199df65b80ae07d.jpeg

Edited by aragrev7
Posted

I don't think the CV is the issue.  They normally clunk when the grease is out.  The noises are worse while turning, especially while backing up and turning.  Are you driving in Auto 4WD mode all the time?

Posted

I had initially driven in 4 auto for the first few thousand km. But had gone to 2WD since (currently at 22000km) because of the issues that have been noted in general and specifically with lift kits. 

Would the leaks be an issue from the lift kit install? I had chosen the BDS kit because I wanted a neutral angle on the axles vs other cheaper spacer only designs. 

Posted (edited)

I'm not familiar with the BDS kit to know what it comes with.  However, that's definitely CV axle grease coming out.  Iirc, the GM lift kit for the Trail Boss/AT4 include new cv axles.  If the BDS kit didn't come with axles I would start to wonder if the axles are long enough. 

Edited by Transient
Posted

bds usually provides a drop kit with their kits.....so longer cv arent needed, idk if his did but usually they do......if it didnt than yeah 4'' is too high without correcting those shafts

 

Posted (edited)

That’s right, the BDS was a full kit with drop. The CV angles were very good. 
This kit:

https://bds-suspension.com/product?kid=1805H

 

I suppose my next question, is what is the fix for the leaking axle, and how would it have happened? Install issue? Bc then the shop should redo it properly. 
If this is a failure issue, then maybe* dealer will look at under warranty. BDS was adamant that their mod doesn’t break warranty issues for parts not replaced. (Dealer also uses this shop for all their mod work too - they go out of house for mods). 

Edited by aragrev7
Posted

I had the same issue with both of my CV boots slinging grease after installing the 6112 kit, dealer replaced both shafts under warranty no questions. Pretty sure 4wd auto is what caused all my issues.

  • 1 month later...
  • 1 month later...
Posted
On 2/1/2022 at 4:13 PM, HeavyChevy1500 said:

@aragrev7any update on your CV issues? I am having the same problem after putting a 4" Rough Country kit on my Trailboss.

Sorry for the delay. Didn't get a notification. They replaced the CV axles under warranty. The service guy tried to tell me, but noticing the lift kit, that my axles were "way out of spec". I told him to try again and take a look, with the BDS lift & diff drop, my axles are closer to factory spec than with the added AT4 2" factory lift. They offered a one time replacement, but the installers said they would stand by it and challenge the dealer should they give me grief about it again.

Does the rough country include a drop to re-align the axles?

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