Shock & differential spacers

[Icutmetl]

At what point do differential drop spacers & shock extenders become a must when adding front end height? 
 

I want to add an inch to both ends of my truck; the max I want to add to the front would be 1-1/2”. I like the rake, and have garage door clearance issues. 
 

 

 

 

[Waaazooo]

At what point do differential drop spacers & shock extenders become a must when adding front end height? 

 

I want to add an inch to both ends of my truck; the max I want to add to the front would be 1-1/2”. I like the rake, and have garage door clearance issues. 

 

 

 

 

This is a pretty complex question, shock spacers depends upon the shock that you’re using and it’s total travel.

 

Differential drops are really only needed when your CV axle is at too great of an angle to operate without binding. I found that when lifting my truck front end more than a couple of inches the cv angles were to the point of the ribs on the boot were rubbing

 

They were never binding but was at the limit that people told me it was borderline bad. I sit at about 12-15* from horizon, now. I used a 3/4 spacer and it improved enough I was happy. I don’t have an after picture.

 

 

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[Icutmetl]

28 minutes ago, Waaazooo said:

This is a pretty complex question, shock spacers depends upon the shock that you’re using and it’s total travel.

Differential drops are really only needed when your CV axle is at two grade of an angle to operate without binding. I found that when lifting my truck front end more than a couple of inches the cv angles were to the point of the ribs on the boot were rubbing

They were never binding but was at the limit that people told me it was borderline bad. I sit at about 12-15* from horizon, now. I used a 3/4 spacer and it improved enough I was happy. I don’t have an after picture.


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What’s a “two grade?“

 

Assume that stock or stock length shocks are used. 
 

I understand excessive CV joint angles. My question was at what point spacers became necessary. To put it differently & more directly; would differential drop spacers be needed after 1”-1.5”?

[dplarson]

What’s a “two grade?“

I read it as ...too great...

Sent from the demons in my head

[corn18]

Hard to give a definitive answer, but when I was looking to level the front, I jacked up the front and took pics at different heights.  Thread linked below.  I ultimately decided to drop the rear with shackles.  But I did end up cranking in 3/4" of lift on the front.  

 

If I were going to raise the front, I would go 1.5" max without further mods.  Anything higher than that and I would drop the diff, buy new UCAs and get shock extenders.  Basically the full rough country front leveling kit.

 

 

https://www.gm-trucks.com/forums/topic/236884-level-or-lift-2015-2500hd/

[Icutmetl]

1 minute ago, Tom Hole said:

Hard to give a definitive answer, but when I was looking to level the front, I jacked up the front and took pics at different heights.  Thread linked below.  I ultimately decided to drop the rear with shackles.  But I did end up cranking in 3/4" of lift on the front.  

 

If I were going to raise the front, I would go 1.5" max without further mods.  Anything higher than that and I would drop the diff, buy new UCAs and get shock extenders.  Basically the full rough country front leveling kit.

 

 

https://www.gm-trucks.com/forums/topic/236884-level-or-lift-2015-2500hd/

 

Thank you. I’m not going to drop my rear end, though. If I’m understanding you correctly, a +1” change in front doesn’t necessitate spacers- that’s the kind of info I’m after.

[corn18]

1 minute ago, Icutmetl said:

If I’m understanding you correctly, a +1” change in front doesn’t necessitate spacers- that’s the kind of info I’m after.

IMHO, a +1" change in front height using the torsion keys doesn't necessitate spacers.

[gearheadesw]

Ha, I feel compelled to reply, that's my truck's suspension pictured in that link to the other thread.

 

Everyone is saying the right things here. If your shock has longer travel then a stock shock, it may not need a spacer at all. A stock shock, you may want to start adding length in the 1.5 to 1.75 inch territory.

A diff drop is dependent on the rubber fins touching each other as mentioned above, they'll wear out where they touch.

[Waaazooo]

What’s a “two grade?“
 
Assume that stock or stock length shocks are used. 
 
I understand excessive CV joint angles. My question was at what point spacers became necessary. To put it differently & more directly; would differential drop spacers be needed after 1”-1.5”?

Yeah it was voice to text. Ooops. It’s kind of a judgement call. What do you deem as acceptable.


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[Big Whiskey]

Good advice here. On the stock shocks, you can raise the front around 1" without needing to add any hardware. I had a slight bumping/thumping over big bumps and speed bumps with a 1.5" lift in the front (7-8 turns on the factory keys). I added shock extensions, and the noise went away, so that tells me 1.5" is about the limit for factory shocks. If I had a do-over, I would have went with something like the Rough Country 3" kit. I would have installed all the parts, but kept the front around 2.5", which would be just enough to run 35" tires.

[Icutmetl]

8 hours ago, Big Whiskey said:

Good advice here. On the stock shocks, you can raise the front around 1" without needing to add any hardware. I had a slight bumping/thumping over big bumps and speed bumps with a 1.5" lift in the front (7-8 turns on the factory keys). I added shock extensions, and the noise went away, so that tells me 1.5" is about the limit for factory shocks. If I had a do-over, I would have went with something like the Rough Country 3" kit. I would have installed all the parts, but kept the front around 2.5", which would be just enough to run 35" tires.

Thank you; that’s good feedback