Moparts

727 question

Posted By: RebelDart

727 question - 12/01/13 06:49 PM

Was going to replace a leaky pan - question about the stainless ball - assuming it's a part of a valve assembly, somewhere. I haven't driven the car further than around the block (restoring)also debris caught by filter appears to be gasket material - analysis/ suggestions ?

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Posted By: RebelDart

Re: 727 question - 12/01/13 06:49 PM

pic 2

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Posted By: RebelDart

Re: 727 question - 12/01/13 06:50 PM

pic 3

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Posted By: PC-CHARGER

Re: 727 question - 12/01/13 06:52 PM

There are a number of check balls in the valve body but near impossible for them to fall out without the valve body coming apart if they were all installed in their proper locations. Possibly a bearing ball from the output shaft bearing if it came apart now or at some time in the past?
Posted By: RapidRobert

Re: 727 question - 12/01/13 07:01 PM

If you have the pan back on/it filled up I'd drive it & see how it acts. If you are still undone like the pic(s) show you could pull/seperate the valve body & see if all the check balls are present. My Q would be who had the valve body open last or who rebuilt the trans
Posted By: RebelDart

Re: 727 question - 12/01/13 07:01 PM

I'll check the bearing as best I can - this ball has at least two flat spots on it - I have not seen what the balls in the valve body look like as this is a first for me ..... would they be (or should they be)perfectly smooth ball bearing or do they show hard use ? I'll take a close up in a second. If they should be smooth then this definitely has hard wear - more like tailshaft bearing as you suggest ....
Posted By: RapidRobert

Re: 727 question - 12/01/13 07:06 PM

Yeah I was wondering about that flat spot myself. The ones in the VB would be round. wondering if it was a loose extra one that got crushed a bit during assembly but I think that would have caused a noticeable problem during the assembly process
Posted By: RebelDart

Re: 727 question - 12/01/13 07:08 PM

This "bearing" definitely had issues at some point - can't imagine it could have gotten in this kind of condition serving as a check valve, definitely serious/hard wear - prolly as you suggested - output shaft bearing from previous "issues" as this tranny was recently rebuilt ...........

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Posted By: PC-CHARGER

Re: 727 question - 12/01/13 07:09 PM

As was posted, the check balls in the VB are perfectly round.
Posted By: RapidRobert

Re: 727 question - 12/01/13 07:11 PM

when you get to it post what you see in the output shaft bearing
Posted By: RebelDart

Re: 727 question - 12/01/13 07:18 PM

Still in virgin territory - I have play in the output shaft (tail side) so I may have opened up a can o' worms. What's involved in replacing the bearing or I'm I best off to drop it off at a shop ? Can I get a confirmed visual diagnoses or no (removing the seal now) ..... thanks guys
Posted By: RebelDart

Re: 727 question - 12/01/13 07:30 PM

This bearing appears too small for input/output shaft ball bearing _ measures like 7/32 ?
Posted By: OldMoparMan

Re: 727 question - 12/01/13 07:35 PM

I have seen many ball bearings that have crashed in electric motors and I have never seen one loose a ball without tearing the cage to pieces. Usually they lock the motor up or spin the race in the housing damaging the fit. The only other ball it might be is the detent shift position ball but you would have trouble shift if that is the case in my opinion.

I have a 518 valve body apart right now so if you need any sizes shoot me a PM
Posted By: JohnRR

Re: 727 question - 12/02/13 12:25 AM

Quote:

This bearing appears too small for input/output shaft ball bearing _ measures like 7/32 ?




I was going to say it is way too small for a rear support bearing , it is more the size of the detent ball for the shift lever.
Posted By: OldMoparMan

Re: 727 question - 12/02/13 01:06 AM

I just measured the detent ball from my valve body and it is .343
Posted By: RebelDart

Re: 727 question - 12/02/13 01:24 AM

Just borrowed a caliper - around .210, sure this isn't from any carrier bearing - where's the detent bearing/ball located ?
Posted By: RapidRobert

Re: 727 question - 12/02/13 01:39 AM

Quote:

where's the detent bearing/ball located ?


In the side of the valve body, held in by the rooster comb
Posted By: OldMoparMan

Re: 727 question - 12/02/13 01:57 AM

The detent ball is located on top of the valve body on the shaft that the gear selector hooks on to it along with the spring it sets the valve body in the correct gear position. But your saying the one you have is just under a 1/4" so unless someone has been in there and lost the original I would guess now that it has come from somewhere else.
Posted By: RebelDart

Re: 727 question - 12/02/13 02:04 AM

I'm gonna have to check this out further this week - I have a really sloppy shifter - hard to find a sweet spot in Park for ignition to work, very slight detent feel when going between positions. Maybe this is the detent ball ? Would'nt/couldn't the ball get really worn/deformed over years ? Could it have come and made it's way to the pan ?
Posted By: OldMoparMan

Re: 727 question - 12/02/13 02:09 AM

OK that sounds like the detent ball so you will have to drop the valve body to check it out, here is a crude pic.

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Posted By: RapidRobert

Re: 727 question - 12/02/13 02:10 AM

Quote:

Would'nt/couldn't the ball get really worn/deformed over years ? Could it have come and made it's way to the pan ?


that ain't normal wear, something has mangled it
Posted By: OldMoparMan

Re: 727 question - 12/02/13 02:20 AM

Here are some links that may help you out the first one has the ATSG manual listed for download and the second has the detent repair kit listed part way done the page.
http://www.mymopar.com/index.php?pid=22
http://www.transmissioncenter.net/727transmission.htm

Good Luck
Posted By: Swedcharger67

Re: 727 question - 12/02/13 11:05 AM

Here is what the input shaft looks like with the ball in the center.
The ball is there there to block an oil passage if I have understood it correctly. The thrust washer between the input and output shaft is supposed to carry the load, again just my understanding.

The flat spot in the ball was caused by the machine shop going a bit too deep when replacing the bushing.

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Posted By: RapidRobert

Re: 727 question - 12/02/13 03:34 PM

Quote:

The flat spot in the ball was caused by the machine shop going a bit too deep when replacing the bushing.


Ding ding ding we (may) have a winna
Posted By: RebelDart

Re: 727 question - 12/07/13 05:35 PM

This here's better pictures (haven't had time this week) Notice the ball is pretty mangled , not even close to round , still looks like a mangled bearing, dunno. Is it too small for the detent ball ?

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Posted By: RebelDart

Re: 727 question - 12/07/13 05:36 PM

Nuther shot

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Posted By: RapidRobert

Re: 727 question - 12/07/13 05:50 PM

obviously it's been banging around in there loose for a long time & the trans was working OK (for the most part I'd think) for quite awhile for it to have been up & running long enough to do that amount of long term damage. As oldmanmopar said if a caged ball bearing cage lost a ball it've shredded. To me it sounds like either a ball bearing got loose that wouldn't affect the trans operation & I'd think all of em would need to be accounted for for proper operation or an extra ball from another trans at a tranny shop got dropped inside during the overhaul but that dont seem likely . That mystery may not be solveable. Myself I'd open it up including the valve body & verify that every ball is there that is supposed to be there & if so button it up & call it good.
Posted By: RebelDart

Re: 727 question - 12/07/13 06:06 PM

10-4 , better safe than sorry , probably be good experience anyway as I've never pulled a valve body before , just want to get this thing back in the car ! Always something .................
Posted By: RapidRobert

Re: 727 question - 12/07/13 06:30 PM

only caveat on the VB is you want it either right side up or upside down (I forget which) & is that referenced to with the tranny belly up horizontle on the bench or as it'd be in the car, so when you seperate the 2 halves the balls that are in there dont fall out but instead stay in their pockets to be easily accounted for
Posted By: OldMoparMan

Re: 727 question - 12/07/13 08:03 PM

Valve body removal is fairly easy first you should go here and download the A727-A804 torqueflite service manual, it gives in detail all about repairing these transmissions.
http://www.mymopar.com/index.php?pid=22

If the detent ball is missing you will see that without taking the valve body apart.

If the spring section is in good condition you can order just the ball and possibly the spring to get it back in good working order.

This link is to Jegs for the TCI 220000 shift kit if you click on the instruction s you can download a copy that shows in general how to disassemble the transmission while in the car.
http://www.jegs.com/i/TCI/890/220000/10002/-1

Take your time and don't force any parts and you should be ok with this repair.
Good Luck
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