First questions on my 727 rebuild journey

[miller]

Sorry to hear your not feeling good. Been there. Heck, that trans ain't going anywhere. But, sure understand wanting to get it done!

Yup...must be the old man thing. Make coffee 4 am, everyday. Haven't slept late, since my first son was born, almost 45 years ago.

 

[AR67GTX]

Got the planets cleaned up and reassembled in the case. It came in a little tighter than I was expecting - about .003 end play with the thinnest of the two snap rings I have. I figure once the assembly lube that is smeared over every possible surface dissolves, I should pick up a bit more. I think the factory spec was pretty tight on the low side so probably OK.

I think that #8 thrust washer could have a babbit surface. It was kind of rough on planet side and wasn't smoothing out too well even with emery cloth. The other side looked pretty virgin however so I just polished it a little with 2000 and Mothers polish, flipped it over and went with that. I could see in the rear wall of the annulus gear where the planetary had started scuffing it up as the case started hitting it but with the new planetary there shouldn't be any contact in that area now.

 

[miller]

It came in a little tighter than I was expecting - about .003 end play with the thinnest of the two snap rings I have.

Yeah, for end clearance, that's pretty close. Take a couple big handfuls of common sense, and toss them in...that's what I do. As long as the #8 washer's thickness is the same, all around (no high spots), that's what you get. All it is, is a broad 'bearing' surface. I usually check my clearances, and endplays, dry, so I know exactly what I have. Lubes will take up some of that space, not telling real numbers.
But, like on your rear planetary, once in place...if it spins, with no resistance, should be good to go. If there's any drag, need to find out why, and correct it. If you feel comfortable with it, it should work fine!
Seems to be looking better, every step.

 

[AR67GTX]

Shop manual min planetary train end play was a little greater than I was thinking - .010 inch. I thought it was .006 inch. So. . . guess I'll see if the nearby Transmission shop has one, or if not, I'll order a .050 selective snap ring and put the assembly aside for now. I trial fit the clutch packs and pump and figured out where I am there on end play, so I think with that snap ring I will be ready to button it up.

 

[oldbee]

Assembly lube? I always thought that was liberal amounts of ATF! LOL. Good luck 'AR', it should work, then you'll feel better(after worrying,worrying about it).

 

[AR67GTX]

Yep - it well - as long as I don't take any short cuts. I don't want to have to pull this thing out again if I can avoid it. I'll be 66 next week - got other projects I need to move on to and tackle.

 

[oldbee]

++++++++++++1. Gets hard to get up from reclining on the garage flloor,huh..LOL. Been there,try to do the same.

 

[miller]

Shop manual min planetary train end play was a little greater than I was thinking - .010 inch.

Another option would be to take the new planetary to a machine shop, and cut it for the needed endplay. That one you got, especially if it's foreign made, easily just a hair too thick. Guess those people can't read numbers right. Either way works.

 

[AR67GTX]

I thought about filing a few thousands off the front nose of the front planetary but I think I will try to find a proper snap ring instead. I think the next size is around .050 and that should pick me up another 5 or 6 thousands and put me real close to .010.

The amount of wear on that rear planetary case is still a bit of a mystery to me - I don't get the sense this is a high wear transmission from the rest of the parts. It still seems they should have put a copper thrust washer there to protect the aluminum.

 

[miller]

Agree with you, wondering why on the #8 washer. Probably why they gave a wider surface on it, and that aluminum against aluminum wouldn't work either. But, for the most part, the planetary cage just floats in place, with the proper endplay. That, and it might keep pretty much off the washer from gear thrust direction. It's been working.

Yes sir, on the thinner snap ring, probably your best bet!
Just going with past experiences, do what you have to do! These things work a lot better, when their put together right.

 

[AR67GTX]

I'm back - had some sinus head crap, had to wait on a snap ring and went to Colorado for my Dad's 92 birthday.

Did some reassembly this morning and looking for some reinforcement (hopefully positive) before I button things up.

I got a .051 in snap ring for the front of the rear shaft which is .06 inch less than the one I had on it. Without actually pulling it apart that should get me to .009 inch play on the planetary train, although I suspect it will loosen up slightly more once all the assembly lube is dissolved.

Test fit the clutch pack and pump after installing a .101 thrust washer behind the pump and things looked good so I went ahead and installed the rubber seal ring on the pump, reinstalled it and torqued to 175 in-lbs. Double checked the end play after moving the input back and forth until it was solid and got .041 which is just over the min. of .037.

But then I remembered in Carl's book that he said to force the rear shaft forward before checking play at the input shaft. So I tapped it forward and held it while re-checking the input again and I got .020 end play - which is the total input/clutch pack/pump endplay.

So I have about .009 in the planetary and about .012 play in the rear bearing/snap ring to tailhousing assembly (from deduction). And I have .020 in the clutch pack/input shaft/pump assembly.

Although Carl says to check drivetrain end play in this manner (output held forward) I don't think I'm actually seeing any specifications stated for this approach. He has planetary end play at .010 to .044 inch and Drivetrain end play in Case at .037 to .084 inch. Does he mean on the Drivetrain end play to be .037 to .084 with the output held forward???? I slathered a good layer of assembly lube on all of the thrust washers so I wouldn't be surprised to gain 4 or 5 thousands additional play overall as soon as I run it but even so that will still leave me over .010 shy of that .037 inch spec. If that's to tight, then I will have to pull the pump again. I'm hoping some of you guys can weigh in on this.

By the way, this little rig I made up to pull the pump from the case works great. It's got to be better than fooling with slide hammers.


Thanks

 

[AR67GTX]

I think I may have resolved this issue so deleting - will know for sure when I get the transmission installed and operating. Still appreciate input on the end play specs in the previous post.

 

[miller]

In the handbook, page 140, under pump, describes how to check it...between .036" and .084". Note it tells you to have the pump 'gasket' in place. Did you?
Moving the shafts forward, and backwards, moves the assembly lube out of the way, to get an accurate reading. Yeah, then he tells you to move the 'input' shaft (front) to the rear. That's when you check the endplay, using a dial indicator.

In effect, what you do is push the output shaft forward. With both shafts full forward, mount the indicator, and zero it. Then, push the input shaft towards the rear, and take the reading...endplay.

 

[AR67GTX]

Hi Miller,

Yes I had the gasket in place and the pump fully seated although not fully torqued tight.

The confusion for me is in the disassembly section he doesn't discuss anything about holding the output forward - just move the input forward and backwards and look for between .036 -.084. I had .067 in on mine.

Then under assembly he goes into the additional steps of pushing the output forward but still uses the .036 -.084 figure - two methods but same tolerance.

I would just as soon have end play on the low side as that's typically recommended. So, is .020 with the output held forward just plain too little and asking for trouble? Overall I still have .041 overall and every portion has some end play - rear bearing, planetary train and the clutch pack section. Seems like it should be OK to me but I haven't had the experience of fixing these things. I can put a thinner #1 thrust washer in (think I have a .084) which will put input end play at about .037 in on the input shaft and about .058 overall with output end play added in.

 

[dvw]

I set the trans on the output shaft. That holds every thing up. Then pull up on the input shaft that's your end play. To be honest its not really that critical.
Doug

 

[AR67GTX]

I set the trans on the output shaft. That holds every thing up. Then pull up on the input shaft that's your end play. To be honest its not really that critical.
Doug

Thanks Doug - so you wouldn't be all that concerned with .020 end play? I figure it will open up a few thousands when the assembly lube washes off the thrust bearings, etc.

 

[dvw]

Doesn't bother me at all. On toringtons I run near zero.
Doug

 

[AR67GTX]

Great - I'm going to get on with finishing this thing up and putting it in the car.

I was re-reading my Plymouth service manual and noticed in it that they don't suggest doing anything with the output shaft when checking gear train end play. They describe it as "drive train end play". I can only conclude that the .036 to .084 spec for end play is for all output and input combined - all unit end play. But I see the importance of checking it with the output shaft pushed forward also - to make sure the clutches and reaction shaft have some free play and aren't bound up.

 

[miller]

Seems like it should be OK to me but I haven't had the experience of fixing these things. I can put a thinner #1 thrust washer in (think I have a .084) which will put input end play at about .037 in on the input shaft and about .058 overall with output end play added in.

Sounds to me your getting experienced! Next one will be much easier!

Yeah, go with the .084 #1. If you have all your endplays in range, including the overall, it will fly. These things are no different than other builds, just need the play, to be able to work. I personally like the way Mopar pieces are made, over the others. Just seem built right!

 

[miller]

Ha! Must be that time in the morning...