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More 727 Issues (locked up??)
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WhatISit View Drop Down
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    Posted: Jan/29/2023 at 11:06pm
This is a freshly rebuilt transmission--not by a shop, mind you.

After getting the trans rebuilt we had an issue with our Hughes torque converter not providing clearance for the counterweight on the flexplate. The first converter was initially installed with no clearance and was tight (unable to spin) when the trans was bolted to the engine. It was then taken back apart and it didn't *appear* to have caused any damage to the transmission.

Today we got everything fitting correctly and got it bolted up to the engine again. Clearances were good, converter spins fine, etc. I put the driveshaft on and realized that the driveshaft won't spin in neutral. The car is up on jacks, and there is no binding on the front pump with the new converter as I mentioned. We took the driveshaft and tail section off that holds the parking sprag and it still doesn't turn. We even tried loosening the bands to see if maybe they were too tight and that didn't make a difference either.

It locks instantly like it's in gear or park. Not sure what could even be causing it to bind up like that. Did I cause unseen damage to the front pump with the first converter that was too tight? Is there something else going on we should look for? Any help or input would be great. Thank you!
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Points: 16611 		Post Options Post Options   Thanks (0) Thanks(0)   Quote purple72Gremlin Quote  Post ReplyReply Direct Link To This Post Posted: Jan/30/2023 at 8:22pm
Take it out of park.
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Points: 6884 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Trader Quote  Post ReplyReply Direct Link To This Post Posted: Jan/30/2023 at 9:05pm
Have a read through this thread, likely the problem:
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Points: 3314 		Post Options Post Options   Thanks (0) Thanks(0)   Quote 1970390amx Quote  Post ReplyReply Direct Link To This Post Posted: Jan/30/2023 at 10:59pm
Park should not be an issue at this time, original post said he has taken the tail housing off. You said it was taken apart and nothing appeared to be damaged. What was taken apart?
1970 390 4speed Bittersweet shadow mask AMX
1970 Amx missing most everything, or in a box
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Points: 462 		Post Options Post Options   Thanks (0) Thanks(0)   Quote RandyB Quote  Post ReplyReply Direct Link To This Post Posted: Jan/31/2023 at 10:21am
It could be your converter is not on correctly or something wrong with it  and is being bound by the crankshaft.
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Points: 0 		Post Options Post Options   Thanks (0) Thanks(0)   Quote WhatISit Quote  Post ReplyReply Direct Link To This Post Posted: Jan/31/2023 at 10:30pm
Tailshaft was taken off, so park is not the issue. Every gear was tested and it's locked in every gear. The converter was spinning freely with everything bolted up. The trans is still locked up removed from the engine. I'll take a look at that thread, Trader.
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Points: 0 		Post Options Post Options   Thanks (0) Thanks(0)   Quote WhatISit Quote  Post ReplyReply Direct Link To This Post Posted: Jan/31/2023 at 10:37pm
Originally posted by 1970390amx 1970390amx wrote:

Park should not be an issue at this time, original post said he has taken the tail housing off. You said it was taken apart and nothing appeared to be damaged. What was taken apart?


So far it was just the tail section taken off. We wanted to rule out the parking sprag. We'll be digging in further in the coming days.
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Points: 3314 		Post Options Post Options   Thanks (0) Thanks(0)   Quote 1970390amx Quote  Post ReplyReply Direct Link To This Post Posted: Feb/01/2023 at 2:01pm
I dont believe that anything to do with the converter can stop the output shaft from turning. With the converter off the trans does the input shaft turn? If you take the pump bolts out does the pump move like the insides are pushing out?
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Points: 0 		Post Options Post Options   Thanks (0) Thanks(0)   Quote WhatISit Quote  Post ReplyReply Direct Link To This Post Posted: Feb/01/2023 at 3:34pm
Originally posted by 1970390amx 1970390amx wrote:

I dont believe that anything to do with the converter can stop the output shaft from turning. With the converter off the trans does the input shaft turn? If you take the pump bolts out does the pump move like the insides are pushing out?

Haven’t tried yet, but we’ll be checking it all out soon.
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Points: 0 		Post Options Post Options   Thanks (0) Thanks(0)   Quote WhatISit Quote  Post ReplyReply Direct Link To This Post Posted: Feb/03/2023 at 11:48pm
The rear servo was locked up engaging the band. I’m replacing the whole piston assembly with a billet one they sell on eBay. 
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