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mysterious 727 endplay

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Neal Zimmerman

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This is sure to try some patience. Ok I have been rebuilding a 1978 BB 727. Came from a truck or van I believe cause it had the 4 gear planetaries. Also has the metal cloverleaf style thrust washer.
I did not check original endplay, I know, my bad.
I have been working from the Munroe book.
I cant get any endplay! Somethings wrong.
I did put all new bronze ( brass?) thrusts from John Cope. But those are back in the output shaft area AND To my knowledge the three washers that control endplay are the two red fiber disks ( Stator support and between the front and rear drums) and the metal or fiber shim between the input shaft and output shaft.
I have taken it apart several times to put in thinner thrust washers and still nothing. I've got a bunch of parts , I am sure its assembled correctly, I went real slow and double and triple checked everything.
I am checking endplay with the extension housing bolted on, That is correct, yes?
Could the new bronze thrusts be causing this>??
 
Yes I had to swap in a couple worn items, but I cant figure how this would do this to my endplay. I took a rear drum from a 74 because the 78 rear drum was seriously used up. I replaced the rear sprag with an A and A ultimate sprag. I also removed the belleville spring from a 76 unit. I maintained the case, oil pump tail housing and shafts that were in the 78 unit. I have all my thinnest fiber washers in there already. I'm considering transferring it all to a 76 case and see what happens,
 
Does the circlip go on the rear planetary spline OK.
Check the tail extension housing if the bolts are too long they will push the sprag drum forward
Have you tried putting together without the thrust washers is it still binding
Also is the pump support & the front drum a matched set
 
Are you 100% sure all the clutch discs of both clutches are fully engaged with the hubs?
 
oldkimmer said:
So your mixing lock up and non lock up parts together? Is that correct?
Click to expand...
no , none of these are lock up units, I made sure of that. Not all later trans were lockups and from what I understand BB Lock up trannies were kind of rare.
 
HEMIB said:
Does the circlip go on the rear planetary spline OK.
Check the tail extension housing if the bolts are too long they will push the sprag drum forward
Have you tried putting together without the thrust washers is it still binding
Also is the pump support & the front drum a matched set
Click to expand...
These are all good suggestions- The clip goes on fine , I think tonite I will try assembling with no thrust washers and see what it does,
 
If the clip goes on the output shaft with about .015" clearance, the back end is fine. Make sure that lobed thrust washer is fitting right into back of input shaft assembly. In my experience, when this happens, there is a clutch plate not properly engaged.
 
Put up a pic of the pump support & input shaft metal seal area
 
OK guys I'm back with my 727 endplay problem thread and although you all had good suggestions, the problem was not any of them. It was the all new rings and bushings. I sat down and thought about this long and hard. I pulled all the thrust washers out, no difference, then I stumbled upon[ the idea of new bushings and rings. I found the bushing that goes in the stator support was SUPER tight on the input shaft. What caused this, I don't know, I wonder if the bushing got kinked upon installation ( I had a shop install all the bushings) . I polished out the bushing with some fine sandpaper until I could spin the shaft fairly easily. Put it all back together, still couldn't get endplay, then I thought of removing all the guilty iron rings, and reassembled it. I got Immediate endplay.
I guess I will reinstall all the old rings instead of new ones and see if it still achieves endplay
 
Neal Zimmerman said:
OK guys I'm back with my 727 endplay problem thread and although you all had good suggestions, the problem was not any of them. It was the all new rings and bushings. I sat down and thought about this long and hard. I pulled all the thrust washers out, no difference, then I stumbled upon[ the idea of new bushings and rings. I found the bushing that goes in the stator support was SUPER tight on the input shaft. What caused this, I don't know, I wonder if the bushing got kinked upon installation ( I had a shop install all the bushings) . I polished out the bushing with some fine sandpaper until I could spin the shaft fairly easily. Put it all back together, still couldn't get endplay, then I thought of removing all the guilty iron rings, and reassembled it. I got Immediate endplay.
I guess I will reinstall all the old rings instead of new ones and see if it still achieves endplay
Click to expand...
Process of elimination...
 
Could be catching on a ridge or bearing normally they slide easily even with the steel rings
 
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