Aftermarket rear lift blocks - factory shims in place or not?

[Tx_Bowtie]

I would think its drive-line, since I have no vibration with the shims in and have run factory and 35" tires.  

[lapoolboy]

I agree it's driveline related....I just don't know why my truck is experiencing it and hundreds others aren't.

[lapoolboy]

@Tx_Bowtie:

 

Your factory shims are about 1/4" thick on the big end, correct?  Which way are they oriented?

 

If big end towards the front like mine were, the tapered ReadyLift block cancels it out and is equivalent to running a flat, zero taper block.  

 

 

[lapoolboy]

I spent the weekend experimenting with this issue...

 

I tried the lift blocks forwards and backwards with and without the factory shims.  Problem persisted in any configuration although it seemed worse except with the blocks oriented correctly with factory shims back in place - so that's how I left it.

 

I now have it at the tire shop getting the wheel balance checked, tires rotated, and another alignment done.  Fingers crossed this solves it.  

 

The snippet in Pro-Comp's instructions that say some 2019 4WD 1500s just have driveline vibration may just be the way it is.  I didn't notice any before but maybe the lift amplified it?  

[lapoolboy]

Rebalancing and rotating the tires did nothing.  New alignment one month after the first one did nothing.

 

However, the sales manager for ReadyLift just emailed me and said he would call me to help when he's off his conference call.  He drives a 2019 Silverado also so maybe he has some suggestions I haven't tried yet.

[JR09country]

Rebalancing and rotating the tires did nothing.  New alignment one month after the first one did nothing.
 
However, the sales manager for ReadyLift just emailed me and said he would call me to help when he's off his conference call.  He drives a 2019 Silverado also so maybe he has some suggestions I haven't tried yet.

Have you tried running it in the stock configuration? No blocks and factory shims? Might look funny but could at least let you know thats where your problem is.

Sent from my ONEPLUS A6013 using Tapatalk

[TXguy]

I have an AT4 and put on a Readylift 2” leveling kit which included a 3” rear block to replace the 2” AT4 block. Interesting with the 2” AT4 block my truck did not have any shims. The RL 3” block does have a taper to it. I have not had any issues with with noise or vibration. 

[TJ1004]

Lapoolboy, did you ever get your vibration sorted out?

[Gangly]

Almost every instruction sheet I have read states that the factory shim is retained and the factory shim and lift block should be oriented with the tapered ends towards the front of the vehicle.  If either is off, the angle will be incorrect.  I left my factory shims in and added a 2" block to the rear that had a taper as well.  With both tapered ends pointing forward on the truck, my drive line angles are near perfect and the truck has zero felt vibration in the driveline.

Edited April 12, 2021 by Gangly

[Michael Sawyer]

so, three pages of back n fourth i read and get to page three no conclusion.  what was the verdict pool boy? one thing i noticed running stacked blocks- my leaf springs are saggin ****** hardcore man they have ****in tacoma leaf srping packs on the 1500s an front end parts they are complete ****** boxes.  im glad i aint one of the retards who spent 100k on a half ton pick up to get...what gm delivered.  so i have tapered 3"blocks and the factory 1" blocks on top of them, and a,m running this way til i have time to put my new leafs in i got some 2500 hd packs that came in.  I noticed when i look under the truck it seems like pinion and axle position even have changed and the directions are always piss poor but If your running a zero degree angle, i think thats a problem.  i think you should get flat blocks and see how she goes you want to make sure whatever factory is you match..so id check gm factory specs on pinion angle and determine bet move from there versus asking peoples opinions and referencing instructions for aftermarket lift blocks but not an inclusive aftermarket drive shaft that comes with it.  see what chevy says, bring truck to them and say this things shakin like michael j fox wtf i want it fixed- shoud not void warranty if lift co says its a problem with stock from that year- if your under warranty.  they may have an open tsb related to it stil...check it out.  All my gm trucks have had some ****ed up vibrating shaking and a lot of time it ends up to be rear drum brakes getting broken or stuck using the parking brake or partially engaged.... check into those things