Knocking noise in D and R after high revs

[Truck82]

This knocking noise just started happening after I did a couple high revs in the driveway. It only starts knocking in Drive and Reverse. Sounds just like a rod knocking but obviously isn’t that. I don’t know what else to say but I can answer any questions. Thanks in advance!

 

[squaredeal91]

Check your flexplate for cracks. It's an auto right?

 

[Truck82]

Check your flexplate for cracks. It's an auto right?

Yeah it’s a TH400

 

[Truck82]

Check your flexplate for cracks. It's an auto right?

The flexplate checked out ok. No cracks.
But I found that there is play between the flexplate and torque converter. Is this right or should they be tightened together?

 

[Ricko1966]

The flexplate checked out ok. No cracks.
But I found that there is play between the flexplate and torque converter. Is this right or should they be tightened together?

They should be tight together.

 

[Truck82]

They should be tight together.

Good to know. Still doesn’t fix the problem though because if that was causing the noise then I would hear it in park and neutral, right?

 

[Ricko1966]

Good to know. Still doesn’t fix the problem though because if that was causing the noise then I would hear it in park and neutral, right?

You know it's wrong,fix it. Then see what happens.

 

[77Dmax]

Has the oil pressure dropped?

 

[fast 99]

High revs? how high? Winding an unloaded motor excessively can be very detrimental to longevity.

 

[PrairieDrifter]

Good to know. Still doesn’t fix the problem though because if that was causing the noise then I would hear it in park and neutral, right?

Not necessarily. Especially since it's not loaded in neutral and park.

Cars are strange creatures. They can make any noise sometimes different noises for the same problem, and do it whenever they want or don't want to do it. Temp has an effect on stuff also. Even which way the truck is sitting can change stuff.

One thing when working on cars is for certain, nothing is for certain.

 

[Ricko1966]

Not necessarily. Especially since it's not loaded in neutral and park.

Cars are strange creatures. They can make any noise sometimes different noises for the same problem, and do it whenever they want or don't want to do it. Temp has an effect on stuff also. Even which way the truck is sitting can change stuff.

One thing when working on cars is for certain, nothing is for certain.

I wasn't going to go that in depth he knows he has an obvious problem,which needs fixed before he goes any further. I've done this and this and this and this,and it still knocks. Ohh I tightened the flex plate hardware and the noise is gone.

 

[Truck82]

Has the oil pressure dropped?

No. The motor has very good oil pressure

 

[Truck82]

High revs? how high? Winding an unloaded motor excessively can be very detrimental to longevity.

Two full throttle revs. Just real quick

 

[NickTransmissions]

Two full throttle revs. Just real quick

Maybe one or more of your TC-flexplate bolts has come loose. Whatever it is, fix it and let us know if you still hear/feel the knocking.

 

[Truck82]

Maybe one or more of your TC-flexplate bolts has come loose. Whatever it is, fix it and let us know if you still hear/feel the knocking.

This was it. Don’t hear the knocking anymore but if it happens once… it can happen twice. Is there something I should do to keep them from backing out again?