General Chirp when shifting out of Park

[HereinDaRockies]

I have not found any reports of this.

When shifting out of P - typically going P -> R when backing out of the garage, there would be an audible chirp, upon initial movement (not upon shifting) - it’s not high pitch like brake squeal, but sounds like a sudden burst of a muffled tire squeal sound.

At first I thought it was the parking brake still grabbing, but I think I have noticed the chirp in situations where parking brake wasn’t applied prior to shifting out of Park.

 

[Tenac]

When going into gear you are chirping tires?? I haven't seen that since a Hurst controlled 900HP Supercharged Bel air my dad used to have. lol

Serious note anyway you can have someone watch the outside of the vehicle when you do this, maybe video? Does it happen every time or just the first time you start up?

 

[C-Mack]

Momentary serpentine belt slip as the gear is engaged and rpm drops sharply? Unlikely on the Grenadier but had a similar issue on another vehicle and traced it down to a failing/weak belt tensioner.

 

[HereinDaRockies]

When going into gear you are chirping tires?? I haven't seen that since a Hurst controlled 900HP Supercharged Bel air my dad used to have. lol

Serious note anyway you can have someone watch the outside of the vehicle when you do this, maybe video? Does it happen every time or just the first time you start up?

It sounds like it.. but there is no sensation of chirping tires… I don’t think tires are chirping.
I am literally shifting from P to R, let go of brake and “chirp!”

 

[Tenac]

It sounds like it.. but there is no sensation of chirping tires… I don’t think tires are chirping.
I am literally shifting from P to R, let go of brake and “chirp!”

High idle or do you let the idle fall to operating idle? I'm kinda curious if its a high idle does it move before the rear brake can fully let go?

 

[HereinDaRockies]

High idle or do you let the idle fall to operating idle? I'm kinda curious if it’s a high idle does it move before the rear brake can fully let go?

Definitely happened during high idle for a cold start.. will pay attention now to see if it also happens outside of those conditions.

Read brakes behave differently depending on idle condition ?

 

[Tenac]

Definitely happened during high idle for a cold start.. will pay attention now to see if it also happens outside of those conditions.

Read brakes behave differently depending on idle condition ?

No not at all, but air in the line can cause something very similar to this as well. Heck even a sticky idler pulley can chirp when load is applied, just thinking out lout on what to possible is.