Rattling metal sound while acceleration

[DmitryGMT800]

Hello everyone! I would like to share my problem. A metal rattling sound started to appear while accelerating. It seems to disappear (or is probably not so clear) while on higher speeds, but when starting off the traffic light it is clearly audible. Some noise can be heard while sitting on traffic light with foot on brake. No noise while pressing gas pedal in Park. I have added links to videos with sound.
rattling noise
rattling noise
02 Tahoe 5.3 4x4 / 400 000 km.
Had starter solenoid replaced by one off Escalade 1 year ago, due to not starting. I suspect the starter gear does not retract fully or wobble freely and thus hitting the flywheel. However, this does not explain the absence of sound while in P.
Had gearbox overhauled with a kit and additional parts after losing 3rd gear 1 year ago.
Any ideas where to dig before I visit the shop?
Thank you!

 

[Fless]

WAG a cracked flexplate comes to my weak mind.

 

[Scottydoggs]

any vibration? u joints click when bad. if its a 4x4 put it in 4 high, see if it vibrates. front axle might be worn out.

 

[Doubeleive]

Hello everyone! I would like to share my problem. A metal rattling sound started to appear while accelerating. It seems to disappear (or is probably not so clear) while on higher speeds, but when starting off the traffic light it is clearly audible. Some noise can be heard while sitting on traffic light with foot on brake. No noise while pressing gas pedal in Park. I have added links to videos with sound.
rattling noise
rattling noise
02 Tahoe 5.3 4x4 / 400 000 km.
Had starter solenoid replaced by one off Escalade 1 year ago, due to not starting. I suspect the starter gear does not retract fully or wobble freely and thus hitting the flywheel. However, this does not explain the absence of sound while in P.
Had gearbox overhauled with a kit and additional parts after losing 3rd gear 1 year ago.
Any ideas where to dig before I visit the shop?
Thank you!

Get under the truck with a rubber mallet and start smacking around, heat shields are the most common culprit, there is one on the side of the transmission and one along the side of the drive line by the gas tank, one by the spare tire and maybe one on each catalytic converter, maybe one around the starter.
if it is one of the bolt on ones tighten it up, if it is on a cat then have it welded

 

[DmitryGMT800]

any vibration? u joints click when bad. if its a 4x4 put it in 4 high, see if it vibrates. front axle might be worn out.

No vibrations at all. Put it in 4x4 modes - same noise. Just tried the reverse - no noise when moving, but upon coming to a full stop - there is same clunking noise for a couple of seconds. looks like starter interferes with flywheel..

 

[Scottydoggs]

ive seen the starter gear not be held in and touch the flex plate before.

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving sage advice from the knowledgeable folks on this Forum.

Put the truck on a lift and raise the truck up while on the lift, so that you can put it drive with the wheels freely rotating in the air. Then go around under the truck and locate the area and source of the noise.

 

[DmitryGMT800]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving sage advice from the knowledgeable folks on this Forum.

Put the truck on a lift and raise the truck up while on the lift, so that you can put it drive with the wheels freely rotating in the air. Then go around under the truck and locate the area and source of the noise.

Thank you!
I am following the advices. Will update on what i discover. Attached are some older photos of my rig

 

[DmitryGMT800]

Update/Solved: Starter solenoid was causing the weak retraction of the gear, so it were touching the flywheel teeth. Solenoid replaced with a new one from Hyundai They seem to be the same construction - fits just right. Only difference was the plug connector on new one instead the bolt-style connector on the old.

Hope this may help in case one does not have access to right parts. Problem solved! No more grinding sounds!

Will order the whole starter assembly though, as the starter had plastic parts inside that broke into pieces while assembly.

Thank you all for assistance!

 

[DmitryGMT800]

There is another issue I have found while under the vehicle: two bottom bolts that fasten the gearbox housing to engine (the oil pan area) are spinning freely - the gear box guys must have over tightened and stripped them. What may be the outcome of this insecure connection and how i may repair the threads? I think using the thread insert may work.