2014 Silverado 1500 axle, tranny, drive line slap source???

[Plumber101010]

2014 Silverado single cab 8’ bed WT 6 cyl.  Just inherited this truck at 96,000 miles and haven’t driven previously so cannot say if instant or has been coming on for a while.

 

So I’m in park and I put it in drive, as I give it gas it will rev up a little bit and then SLAP, POW, sometimes horribly bad and is scary to experience. 

 

If you’re making a mental note and put it in drive and wait a couple few seconds and THEN take off slow it’s a minimal feeling. 

 

The severity is directly related to how FAST or how high you rev it when you initially accelerate from P to D as well as how LONG you wait until you accelerate from P to D.  

 

If you’re not used to doing anything other (like myself) then slapping it in drive and taking off it is humongous loud and entire truck will jerk badly and feels like you just dropped a driveline.

 

I do not think it is tranny related because I have no issues with the transmission itself while driving. No slippage at all and shifts perfectly fine albeit, shifting is to say somewhat jerky and noticeable.

 

What do you all think? Put a notice on the steering  wheel reminding me to baby and pamper it and she’ll be fine for many many moons or is it time to rebuild “something”

[Mike GMC]

U joints maybe?  If that has a 2 piece drive shaft, you might also want to look at the carrier bearing.  That's where I'd start at least.

[Plumber101010]

On 5/22/2019 at 3:36 PM, Mike GMC said:

U joints maybe?  If that has a 2 piece drive shaft, you might also want to look at the carrier bearing.  That's where I'd start at least.

Thanks. Do you think below is the same issue?  Started investigating deeper (Reading) and if it’s the same issue it seems it’s a known problem. Found this post Googling on the forum here

 

The clunk is take-up of driveline slack in the differential and transmission output shaft. The amount of slack will vary from unit to unit. As the unit ages, the clunk will slowly become worse, however it is not a safety or driveability concern. 

 

A variety of different vehicles will have this clunk. For example, both my Toyota Tacoma and my Ford E-350 work van have some type of clunk when you let off the gas.

 

The clunk can be compounded by axle wrap on certain vehicles, however the GM 1500 trucks do not themselves suffer from axle wrap.

 

The re-torque of the axle u-bolts is designed to confirm that axle wrap is not present.

 

Other than checking the u-bolts, the reason GM will not "fix" the problem is because technically there is nothing wrong. Driveline slack is a normal characteristic of a vehicle with a solid axle, divorced transmission and long driveshaft.

 

Driveline clunk can be improved with an aluminum driveshaft. Reducing the rotational mass of the driveshaft will help reduce the shock force.

 

Installation of a u-joint dampener will also help

Edited May 23, 2019 by Plumber101010

[Mike GMC]

Maybe, jack it up and put it in neutral and crawl under it so you can rotate the driveshaft.  You should be able to do any of the issues that way, u joints, bearings, slip yoke sloppiness etc.