First questions on my 727 rebuild journey

[dvw]

Rear planet end play is really a non issue as long as the rear planet shim and 3 bronze thrust washers are installed, it will be fine. Regular end play. 3 items, fiber washer behind the reaction shaft support, fiber washer behind the front drum (in the recess), input/output thrust washer. I drop the front drum over the rear drum, then install this assy as a unit. No need to install everything to air check as stated earlier. Was I unclear on the procedure?
Doug

 

[AR67GTX]

Doug - not unclear - I checked the clutches with 35 lbs of air and they activated fine. I'll check them again - I think I have plenty of time to play with them.

I'm just puzzled as to why the planetary train seems to have more end play in it now than when I disassembled it. They make metal shim washers to go between the front planetary and the rear clutch can. I think the safest thing to do is get of set of them and get the end play down to something in spec.

No shims (fiber or steel) go between the overrunning clutch and the low/reverse drum - is that correct?

 

[dvw]

Inside the rear drum below the planet there is a shim. Also if the sun shell was removed from the sun gear there is a shim. Then just the 3 thus washers.
Doug

 

[miller]

I must be missing something - these are the original planetary sets except for the sun gear which shouldn't make a difference.

Probably a dumb question, but gonna ask anyway. Just because the sun gear is not the original, okay? There should be no way, I think, but is there any dif in the overall length, between old/new? Second question...any chance the sun gear is installed in the shell 'backwards'? Keep in mind both ends of the sun gear are involved with end play. So, just asking.

A comment on your 'stand', but also the assembly. In your photo, you have the tail shaft housing already mounted up. I've never tried dropping in the guts of the trans, like that, so I'll say I do not know, if that would mess with any end play.
Like I mentioned before, and like it shows in the 'book', starting with the empty main housing, the planetary gear train assembly installed into it, as the book shows (pg 136), and on from there. But, once the assembly is mounted, putting the housing on a stand, without the tailshaft housing in place, but shaft though a hole, allows the stacking of the remaining assemblies from the front...all the way to the pump.

But, if what you have is working for you...good enough.

 

[AR67GTX]

No dumb questions here. There is a long end and a short end of the sun gear so I was careful to get it positioned correctly in the shell.

I initially assembled the planetary gear train on the shaft and inserted it all into the overrun clutch. Then I installed the governor and the bearing (with all the (&*?? clips). Then I installed the tail housing.

What I forgot to do was check the end play per his direction in the book which is from the back of the reverse drum to a shoulder on the output shaft. My measurement was after installation by making sure the shaft was seated forward all the way and then measuring under the snap ring to the front planetary hub. Not sure it makes much difference.

But clearly the pilot point on the input shaft is holding the rear clutch pack forward and the front planetary shell is sitting back due to the excess end play - creating that appearance of the lugs not fully down in the recesses of the shell. Don't understand why it didn't look that way to start with. The only other thing could be the seating of the governor (but the snap ring is in place) or something that was to go between the governor and rear case reinforcement. Or I seated the rear case reinforcement more solid than before - but I don't see how the bolts would not have pulled it in.

I'm going to order the steel shim stock and shim some of the end play out of the planetary and go on. Limiting end play can't harm anything in the long run.

 

[miller]

I'll only guess here. Sure no friggin' expert, since I don't mess with them all day long.

Just wonder if, since you have the tail housing, and parts in place, that could be interfering with the main case parts. I've always just assumed there was a reason why, the main case assemblies were dropped into place, even before the governor was installed.
Considering how it all goes together, I would have my short stand near the workbench.
Getting the first parts into the main case (on the bench), then to the stand, shaft through hole (in stand), and drop the assemblies into the case from the 'top'. All the way to the front pump. Yeah, it's heavier, now!

But, besides the first shaft, into the main case...nothing, that's located in the tail shaft.
Not until the assembled main case gets flopped (lol) back onto the work bench, pan side up. That's when I install the tail shaft parts and pieces, including the governor.
Right...wrong...hell, I don't know. But, always worked for me.

 

[AR67GTX]

I was trying to follow Carl Munroe's book and assembly instructions where he put the tailshaft and planetaries in the case, assembled the governor/bearing, installed the tail housing, and then installed the clutch packs. But heck if I know.

I am going to order an extra tail housing gasket just in case I have to go back and start all over again.

 

[miller]

Tail housing gasket should be okay. I'd just suggest slipping the housing back off, governor, and get it back to just the bare shaft out the main case. Might make the difference.
Not that much too it. Many of us that have done this stuff for years, tried different ways, and found out...so, that's why! No big deal. Besides, practice makes perfect, eh. I've done the same thing!

I'm a couple years older, and still learning things as we speak. Working on a 727 is what turned me into a mechanic, in the first place. One of those...heck, I can do that. At least you can work with your hands. More than some can say.

 

[miller]

Spent a little time glancing through Carl's handbook. Now I see why it tells you to install the tailshaft housing...it's assuming you have a 727 rotating stand. There's stand mounting lugs at the sides, on the outside of the main case, that the stand mounts up to. Of course, no problems with the tailshaft housing mounted, using one of those stands.
Sorry...that clean slipped my mind.

Without one of those stands, or something like it, to rotate the trans vertical, is why I build mine as described. No way to set the main case vertical, if the tail housing is in place. Simply a short stand, with a 10"x10" plywood, hole in center, is what I use.

Whole reason is, alot easier to drop the assembled clutches, and such, in like that, going straight down. Gravity at it's best.

On your excess free play...do you have the thrust washer installed, that goes between the output, and input shafts? If it's a fiber type, also takes a hardened steel washer.

 

[AR67GTX]

On your excess free play...do you have the thrust washer installed, that goes between the output, and input shafts? If it's a fiber type, also takes a hardened steel washer.

Miller - yes I have the steel thrust washer on the pilot tip of the output shaft but it doesn't affect the end play on the planetary train because the snap ring is on the larger shaft.

I'm kind of thinking now that it was probably a coincidence that the output shaft was shoved forward and the input shaft and clutch units shoved to the rear when I pulled the pan and took that photo - showing the rear clutch seated deep in the planetary hub. I've checked and triple checked each of the no. 3 through no. 8 washer, thrust and plate shims shown to fit in the planetary gear train in Carl's book.

 

[miller]

Miller - yes I have the steel thrust washer on the pilot tip of the output shaft but it doesn't affect the end play on the planetary train because the snap ring is on the larger shaft.

I have to keep reminding myself, that your working on a trans, that had already been messed with (my words for one touched by anyone, besides the factory).
The snap ring you mention does set endplay...but, only for that pinion carrier. Simply allows free play in that cage, in it's limit.
Might get a little confusing here...the #3 thrust washer. Okay, you say you have the steel washer in place. Both on your 69, and my 67, should be the same type (kinda).
My #3 washer was originally the fiber type, that also uses a thin steel washer with it for a rotating surface. But, my fiber washer was breaking down, so I went looking for another. Local shop told me those fiber washers were getting hard to find. Also said an easy swap was a bronze (?) washer, to replace the fiber one, that would last much longer. He happened to have one, and it slipped right in. Don't remember the years, but either one would fit, though only up to a certain later year (1975?).
Not positive (old age), but pretty sure the new, and improved washer was bronze. Any 727 experts out there?

Will admit, from experience, it's easy to put a part in the stack wrong, and it screws everything up.

 

[miller]

Had to check myself...yes, the #3 thrust washer is either fiber (early), or bronze (later).

Do you remember what you took off? Another evil thought...it wasn't there to begin with...or, only the thin steel one, I mentioned. That would be your too much endplay.

 

[AR67GTX]

That's the same thing I was saying about end play on the planetary sets. My #3 thrust washer is steel with a couple dimples in it. The one I got in the kit looks just like it. I would have to look again but I don't think I have any fiber shim washers on the output shaft. I sort of figure they stick with steel on the planetary train as the angled gear teeth in the planetaries probably create some longitudinal loading on the shims when in operation - not sure. Carl's book says to use steel shim washers (special type) between the two planetary sets to take up end play. Those are what I've ordered.

It sounds like any excessive end play at the pump is taken up with a thicker shim between the reaction shaft and the front clutch pack. I think Doug mentioned that to.

Thanks

 

[miller]

My #3 thrust washer is steel with a couple dimples in it. The one I got in the kit looks just like it.

Thinking that might be part of the problem. #3 thrust washer is not steel! Only, if it is the real thin steel washer I mentioned, that is used WITH the fiber type washer.
#3 fits on the output shaft, over the cut-down front tip, that goes into the recess hole, on the rear of the input shaft, making a spacer 'between' the two shafts.

Need to add, that the #3 thrust washer, has never been with any overhaul kits I've gotten. It was always a part that had to be gotten, on it's own, or in a washer kit.

Understand about the other shims/washers your talking about.

 

[AR67GTX]

I did order a separate washer/shim kit - actually ended up with two of them because 2 kits were somehow stapled together. I didn't have a fiber washer in that area just the steel one. I'll see if either of the kits have a small one but I don't think so.

 

[miller]

Okay...fingers crossed. If the washer kit is for your year trans, should have the right #3 in it.

Might be something I don't know, lol. Though, knowing the two ends of the input/output shafts move against themselves, needs a 'bearing' surface between them. A steel washer, would just be a rubbing block, wearing the ends down.

 

[AR67GTX]

You were right about the shim - it is some sort of composite material. I never got it up close enough to my eyeball to notice that. The replacements are copper - brass but they both measure exactly .060 inch so I will re-install the original one.


What is the 3-eared thrust washer for - an earlier model torqueflite?

 

[miller]

What is the 3-eared thrust washer for - an earlier model torqueflite?

If the washer w/ears, the ears are outwards on the washer...that one is for later 78-up 727s.

That photo is perfect, showing the two different #3 washers! Tried looking for one, with no good results. Good find...good reference!

Which one was the 'original'? Either way, either will work. The one metal washer is made of bronze, alot tougher than brass, or copper, and will probably out last the fiber washer.
Those are not (stock) selective sizes...usually the selective size washers are behind the pump, to set overall endplay, if I remember right.

But, again trying to remember, for that #3 washer (maybe either one), think they also take a thin hardened steel washer, just for a clean riding surface. The steel washer should go onto the output shaft first, since the larger end surface of the output shaft is splines. All the steel washer does is make a flat, smooth surface, on top of the spline's ends...so the splines don't cut into the thrust washer.
Can't locate any reference on it, though.

 

[dvw]

The input/output thrust has 3 factory choices. The fiber and round bronze thrust washers are interchangable and require nothing else. The 3rd type is the "mickey mouse" shape which only goes one way into the same shaped recess in the back of the input shaft. There are no other steel shims or washers located in that position. The planteary endplay is set with the shaft on the bench, not installed in the case or in the tail shaft. The output shaft will always move forward and back when it is installed in the case with the tail shaft bolted on. This is because the snap ring holding the tail shaft bearing can move fore/aft in the tail shaft housing itself. It is not a precise fit.
Doug

 

[AR67GTX]

Thanks - that pretty much answers my questions on the planetary end play and shims. I hadn't thought about the bearing snap ring controlling end play in the case - I was mistakenly thinking the governor bearing on the case reinforcement must control that. I decided last night to go ahead and pull the tail housing and shaft back out and check it on the bench. I don't see anything that looks like it would have wear causing end play to grow - but considering part of my reasons for pulling this thing apart was planetary whine - I want to put it back as right as possible. Maybe excessive end play contributed to that strange wear pattern on the sun gear and somehow to the loud whine. Who knows.

Have to put in a pitch for Makco transmission parts - they ship quick. I ordered shims and a gasket Mon morning and they were on my door step Tues evening.