Knocking noise in D and R after high revs

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NickTransmissions

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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?
How tight in terms of lb ft did you torque the bolts?

Did you inspect the threads at each mounting pad on the converter?
 

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How tight in terms of lb ft did you torque the bolts?

Did you inspect the threads at each mounting pad on the converter?
35 ft lbs.

I didn’t inspect the threads on the mounting pads. I probably should have done that first but all three bolts were loose so I just went ahead and tightened them down.
 

NickTransmissions

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35 ft lbs.

I didn’t inspect the threads on the mounting pads. I probably should have done that first but all three bolts were loose so I just went ahead and tightened them down.
That's the correct spec, I believe. Some blue loctite on each bolt also helps. If they come loose again, replace the bolts & put blue loctite on the new ones. Also check the crank itself for any irregularites in that event.

If they come loose a third time, either helicoil the converter threads or replace the converter
 

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That's the correct spec, I believe. Some blue loctite on each bolt also helps. If they come loose again, replace the bolts & put blue loctite on the new ones. Also check the crank itself for any irregularites in that event.

If they come loose a third time, either helicoil the converter threads or replace the converter
Thank you, I appreciate all the help. I’m going to be rebuilding this engine soon so I’ll make sure the crank and everything is working properly
 

NickTransmissions

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Thank you, I appreciate all the help. I’m going to be rebuilding this engine soon so I’ll make sure the crank and everything is working properly
You're welcome...given the converter came loose, you will want to inspect your Th400's front pump and bushing/seal once the engine and trans are both out. In fact, I'd overhaul the transmission completely if it hasn't been rebuilt in the recent past. This would be good to do especially if the engine will be making a lot more power after the rebuild.
 

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You're welcome...given the converter came loose, you will want to inspect your Th400's front pump and bushing/seal once the engine and trans are both out. In fact, I'd overhaul the transmission completely if it hasn't been rebuilt in the recent past. This would be good to do especially if the engine will be making a lot more power after the rebuild.
It was rebuilt by a shop my grandfather worked at about 25 years ago but then he let the truck sit right after that. It probably has around 1,000 miles on it right now. I wasn’t going to do anything to it when I rebuilt the engine except for a different TC. In the spring I will be going through transmissions class so hopefully I will have a little experience and won’t be so intimidated by opening up a transmission.
 

NickTransmissions

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It was rebuilt by a shop my grandfather worked at about 25 years ago but then he let the truck sit right after that. It probably has around 1,000 miles on it right now. I wasn’t going to do anything to it when I rebuilt the engine except for a different TC. In the spring I will be going through transmissions class so hopefully I will have a little experience and won’t be so intimidated by opening up a transmission.
Awesome, man! Great to hear you'll be taking transmission building classes...You can get ahead in your studies, if you'd like by checking out my TH400 Information Thread, if you haven't already seen it. I have compiled quite a lot of info there, would be a good resource for you.
 

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Awesome, man! Great to hear you'll be taking transmission building classes...You can get ahead in your studies, if you'd like by checking out my TH400 Information Thread, if you haven't already seen it. I have compiled quite a lot of info there, would be a good resource for you.
Great, I will definitely be checking out that thread. I will also check out your YouTube. It looked to be really helpful.
Thank you again
 

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