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Posted

Lowered another yukon. Just like others I've done vibrating issues customer stated are gone. Like I told my service rep here the truck stock design is causing issues. Once lowered the problems are pretty much gone in this case.

 

Ive lowered over 60 new gm suvs with great results

Posted

Lowered another yukon. Just like others I've done vibrating issues customer stated are gone. Like I told my service rep here the truck stock design is causing issues. Once lowered the problems are pretty much gone in this case.

 

Ive lowered over 60 new gm suvs with great results

 

 

Do you have a feel for what part of the lowering is addressing the issues? For example, are you using stiffer springs and shocks? I don't want to lower my truck, heck I'd rather raise is, but if stiffer springs and shocks are part of lowering than the same might work for stock or lifted right height vehicles.

 

Frank

Posted

Pinion angle change along with spring change to progressive and overall height of the truck coming down is the combination which helps. On top of that truck hanukes much better

Posted

This is probably not something you could do as I am sure you are working to keep up with customer demand but.... if it is possible, would you be able to try changing only the springs, test drive, then shocks, test drive,... just to see if one or the other make a difference?

Posted

I use drop spindles nothing changed in front on springs or shocks. Rear oem shocks with shock extenders and just change to progressive lowering spring

Posted

Pic for reference

Norcal, the car looks great.

 

But most of us bought it because it is a truck that rides well. We use it as a truck for hauling and driving on rough roads where cars may not be able to go. Most of these models are 4 wheel drive. Your lowered car would be high centered on the way to my ranch. Lowering it to that level may be acceptable on California roads but it will never work for rough roads or dirt roads. In most of the United States we have main roads that are paved and many side roads that are not paved with huge pot holes. Your car pictured would fail on those roads.

 

You keep posting your low rider cars but they are only an option for NorCal or SoCal type roads, not the rest of America. Get a clue.

Posted (edited)

Sorry to hear that. I also level just the rear to front and customers have no issues. This community is fighting to get results and overall gm messed up. Unfortunately lowering the truck is the fix I'm seeing and the people who want to keep the trucks up high..... there's no fix.

 

I'll keep posting my customers trucks that I do and give results.... so hopefully gm can "get a clue" linear springs are hurting this truck.

 

Leveled rear to front guys like also

Edited by NORCAL SS
Posted

Well.... is it lowering or changing the spring rate? I'd say changing the spring rate is likely since this is a spring-mass-damper system and if you want to change the resonant frequency you have to change one of those.

 

How can one get a hold of a set of Z71 height progressive rate springs? That applies to a truck with issues would be telling.

 

Frank

Posted

you have a liner spring stock. gm didnt make a progressive rate. its not only changing the springs its also the fact that yoru changing the pinion angle as well as how the truck pushes air. for the guys that are keeping stock height your stuck. GM wont fix your trucks and the way the truck was built and being up so high is a issue. my local dealership had 1 of my customers in for weeks at a time. vibrating and ear issues. Did my lowering kit on it (1.5/3 drop which isnt much) and he had no more issues with his. the dealership knows me because of my cars and called me and was like tony what did you do?

 

unfortunitly lowering wont be for everyone. I understand that but i pretty much have more feedback to fix the problem then all these people bringing their trucks to gm for what over a year now.

Posted

But, this does bot prove that ride height did it. Can you cut a stock coil and test on a problem vehicle? That would help to see if lowering vs spring rate fixed it.

 

Sent from my SM-N910V using Tapatalk

Posted (edited)

So you know the trailblazer ss airbags fit inside the rear 15 up gm suvs and even those make the back of the truck ride better. I have tested the tbss bags replacing the oem springs in a 15 and set at oe height it would still shake and once lowered down the airbag the shake is gone 3 inch drop. Once again proving that pinion angle change and vehicle height is the issue

Edited by NORCAL SS
Posted

Once again proving that pinion angle change and vehicle height is the issue

 

Pinion angle and vehicle height may have helped with vibration in some of your customers trucks, but this alone is not the issue. My truck has been totally stock since Feb 2014 and it never shook or vibrated.

Posted

Well.... is it lowering or changing the spring rate? I'd say changing the spring rate is likely since this is a spring-mass-damper system and if you want to change the resonant frequency you have to change one of those.

 

How can one get a hold of a set of Z71 height progressive rate springs? That applies to a truck with issues would be telling.

 

Frank

 

I dropped my unsprung weight big time and noticed a very large improvement in booms/buffets, went from OEM 90lbs to 60lbs; I actually have lifted the front of my truck 1.5" to fit larger tires

Posted

06 April 2016 - 06:58 PM

UPDATE .....

OK that's my story today with my Yukon 2015 with 7000 km.. i went to my dealer told hem that i have vibration / and buffeting sound > they send the engineer to test it and he notes the problem ( good start :driving: ) >

i shows them the GM document ID :(4204876) IT'S ALSO CALLED #PIT5429 . THEY wounder where i got it ...( from this great site :angel: ).they knew that i did change the tiers already and balance them ..so they said they gonna change the propeller shaft immediately without doing ( Pico Oscilloscope )analyzer test . they order it and i wait a call when they get the part ..this was for vibration problem ..but for the buffeting sound they said this is from the roof bows need be resealing..

now am waiting for the part and will keep u update ..

but am wondering why they decided to fix it and order parts without testing the propeller shaft !!!! i hope that gonna help >> wish me luck guys >>>

 

 

OK ,

hi every one .

UPDATE......

I just got a call from my dealer to try my car after they change the propeller shaft. and resealed the roof bows . it took so long cuz the part delayed . any way i tried it and i was shocked it's a huge different NO vibration at all i went until 135 km .

and for buffeting sound they found one of the three bows is unattached the front one but they did them all , to be honest the sound i think is still there but it's much better 90%.

am glad that they could fix some thing finally i will drive without shaking :driving: .

​and here i want to say something that i was so nervous wen they told my the procedure for the roof and how they will tear every thing down i expect it ganna be mass but it was the conversely it was so clean and professional.

i wish u luck guys .

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