Now I know why 904 was having issues

[Woods74]

Everything accept the fact it's still brass and not a babbit bushing...

 

[Creedmoor]

If only someone had told me before I bought the kind that will ruin my tranny.

 

[Woods74]

If only someone had told me before I bought the kind that will ruin my tranny.

You can get a babbit bushing at o'reilly's.. Pioneer Part # 755100...

 

[Creedmoor]

You can get a babbit bushing at o'reilly's.. Pioneer Part # 755100...

If that's true, I'll take it apart and do it again. I'm still kinda thinking I should have driven it in just a sixteenth more. I'll call o'reallys in the am. If they have it, I'll be cleaning up gobs of Vaseline. Yay.

 

[TrailBeast]

Didn't hear back, so decided the way I had it will have to do. Staked, packed, ready for bolts. Look copacetic?

Perfect.

Leave the big rubber ring off until you get the endplay ready.
But DON'T forget it when you actually install the pump.

Don't sweat the bushing depth too much, but I always put them just a hair below flush with the inner edge (next to the pump gears)
The pump gears are what puts a side load on that bushing so it always made sense to me to put the bushing closest to them.
Never had a problem with those types of bushings, but as mentioned "softer hub metals" sure could wear faster.

 

[Creedmoor]

You can get a babbit bushing at o'reilly's.. Pioneer Part # 755100...

Out with the new and in with the newer. $2.69. Because Babbitt is basically a better behaving bushing. Now, the front clutch. But first, a lip seal question.

My kit came with three big lip seals. Two are identical while the third is just a hair larger in diameter. Looking at the old ones, one is indeed just slightly bigger. When I took it apart, they looked the same, so they went into the old parts bag without getting marked. I measured both front and rear clutch pistons at the smallest diameter the seal will have to go over to get to its groove. The front piston is 4.435", while the rear is 4.552".

So, should I use the slightly larger seal on the rear or stretch one of the two identical seals to fit?

Oh, why are the front frictions thicker? Heh, I did keep track of that. :cheers:

Thanks guys.

 

[Creedmoor]

Think this stuff will be OK for the lip seal install? It's a lot thicker/stiffer than Vaseline.

 

[Woods74]

Your the man! That's fine, ATF works too.Did you get a lip-wizard with that kit to help install the seals?

Glorified 2L bottle material!

 

[Creedmoor]

No. Didn't get a lip wizard (man, it's hard not to laugh at that!). Looks like it works like a shoe horn. Bet a nicely trimmed lid from a half pint sour cream container might work. Just work your way around both sides of the seal, inner lip first, right?

Any idea on the seal and frictions size question?

Thanks.

 

[TrailBeast]

I use a feeler gauge ground down to a taper with smooth sanded edges for installing lip seals, but almost anything will work with a little patience.
You just don't want to trim anything off the rubber when it goes in the bore is all.
Even a rubber band around the lip seal and stick the piston in the freezer for 20 min works pretty well.

On the lip seals, if there was a question about which one goes where I would put them both on their pistons and see if they have about the same tension.
Stretching them is not a good idea because the sealing edge could get pulled away from the piston bore.
I have seen some that were a little sloppy on the pistons be just fine, if that helps what you are seeing any.

On the discs, are you pretty confident that the old ones are thinner due to wear?
If you can get all of them in the drum and still have the clearance you need then everything is fine there.
If not, you may have to do some creative stacking as I have at times had to use 2 steels side by side to get tight enough, or shave the pressure plate or even the piston for a drum to get the clearance I needed.
Or if I had a lot of clearance, I might shave the pressure plate AND add another disc and steel.

 

[AJ/FormS]

Chryslers clearance specs are pretty generous. Back in the day when I was doing Powershift trannys, the rule of thumb was .010" per lined plate, minimum.
I like to set the hi-drum on the tight side of the spec, but often let the forward drum fall to the high side of the spec; afterall the piston has plenty of travel,and it has that big old belville on it, and it only engages once when engaging any forward gear and thereafter remains engaged in all forward gears. And I'm kindof partial to that slightly delayed engagement into Drive, cuz it's easy on the overrunning clutch. But if I know for sure the engine is gonna have a high idle, then I might relax the high a bit, cuz I hate that harsh engagement into reverse,in the morning as I back out of my stall, with the fast-idle still engaged, and the line-pressure maxed out.

 

[mad accountant]

Just finished reading through this, and boy do I wish it was around when I did my first one a couple of years ago. But, on my first rebuild I didn't replace the rear sprag springs and rollers and guess what failed about 200 miles later? Talked to a couple guys afterwards and was told that it's an automatic to replace those every rebuild since they're so cheap.

Is this something that the OP and the rest of us 727 newbies should worry about?

 

[TrailBeast]

Just finished reading through this, and boy do I wish it was around when I did my first one a couple of years ago. But, on my first rebuild I didn't replace the rear sprag springs and rollers and guess what failed about 200 miles later? Talked to a couple guys afterwards and was told that it's an automatic to replace those every rebuild since they're so cheap.

Is this something that the OP and the rest of us 727 newbies should worry about?

I reused them if they looked pristine, and just knocked any glaze off the hub, but for us I would def recommend to replace it with a bolt in.
It's one of those things that probably won't fail with normal use, but the fact that it is in the back of the trans makes it all the more tempting if a person can do it.
It can ruin the case depending on how it fails, so...

JMO anyway.

 

[Creedmoor]

Thanks for all the advice guys. I think I'm going to give the freezer method for the lip seals a try first.

Beast, none of the old frictions were very worn at all. The rear set were all thinner (.064") than the ones from the front (.082"). The new frictions in the kit were packed in two separate groups. One set miked at .087" and the other at 0.68. So, do the thinner ones go in the rear pack or am I supposed to mix n match to get a good clearance number?

Lemme know.

Thanks.

 

[TrailBeast]

Thanks for all the advice guys. I think I'm going to give the freezer method for the lip seals a try first.

Beast, none of the old frictions were very worn at all. The rear set were all thinner (.064") than the ones from the front (.082"). The new frictions in the kit were packed in two separate groups. One set miked at .087" and the other at 0.68. So, do the thinner ones go in the rear pack or am I supposed to mix n match to get a good clearance number?

Lemme know.

Thanks.

You know, I don't remember on that.
It does seem familiar that the direct pack had thinner discs, and maybe even a different pattern in the material.
I think one clutchpack had smooth discs and the other waffled surface.
But like I said, I don't remember.
If I am right about the surfaces being different I don't think mixing is a good idea.
BUT, if they look the same and the only difference is thickness I'd mix em without a single hesitation.

Google might help if no one here knows the answer.

I'll see what I can find.

 

[70aarcuda]

the direct pak which is the rear drum takes the thin ones...the front clutch pak thats the thick ones usually .086 plus or minus..

 

[AJ/FormS]

The important things are to get the stack clearance into spec and to presoak those discs. I believe the thicker waffle discs can take more abuse, so they always go into the hi-drum.
I would not put the pistons into the freezer with the lip seals already on. I've never had to resort to that. But if the lip seals are frozen hard, well,that won't work.
Just use plenty of silicon O-ring lube on the lead in chamfers. You don't need to slather it in there, but make sure every sq mm of the chamfer has at least one molecule of grease on it. Then a matching smear on the lip seals.Then straight down she goes.It will practically fall in there.
But if you accidentally fold over the lip seal(it's always the outer), I have a trick.Firstly; a new lip seal can take quite a beating.As long as it hasn't split, it's good to go.Then, there is enough room in there to bias the install. What I mean is, when it is correctly installed, it is possible to move the piston from side to side, compressing the lips into the bores. Knowing this, You can start the outer lip seal by holding the piston at a very slight angle. Ima thinking 2*to 3* or so. Then push the piston hard over into the bore, and drop the other side down, gently, wiggling the high side back and forth, but always keeping the piston hard over on the low side.The final inch can be tricky, and sometimes needs help.I only use this method if I have previously folded the lip. And I put the folded part on the down side, and, in first.I never fold the lips any more!
But really, with the silicon lube, the things practically assemble themselves.

 

[TrailBeast]

the direct pak which is the rear drum takes the thin ones...the front clutch pak thats the thick ones usually .086 plus or minus..

Yep, just found it, so I would have to say to not mix them.


"Because the direct drum is a dynamic apply, the waffle grooves cut in the clutches allow it to relieve the fluid between the plates. That's why the direct clutches are waffled and the rear clutches are not. The rear clutch is on in all forward gears so it never really gets a dynamic apply"

It was quite some time ago that I was doing transmissions professionally, so part of my problem is just plain memory.
The fact that I did all the major brands and types makes it hard to separate one from the other in memory.

 

[TrailBeast]

The important things are to get the stack clearance into spec and to presoak those discs. I believe the thicker waffle discs can take more abuse, so they always go into the hi-drum.
I would not put the pistons into the freezer with the lip seals already on. I've never had to resort to that. But if the lip seals are frozen hard, well,that won't work.
Just use plenty of silicon O-ring lube on the lead in chamfers. You don't need to slather it in there, but make sure every sq mm of the chamfer has at least one molecule of grease on it. Then a matching smear on the lip seals.Then straight down she goes.It will practically fall in there.
But if you accidentally fold over the lip seal(it's always the outer), I have a trick.Firstly; a new lip seal can take quite a beating.As long as it hasn't split, it's good to go.Then, there is enough room in there to bias the install. What I mean is, when it is correctly installed, it is possible to move the piston from side to side, compressing the lips into the bores. Knowing this, You can start the outer lip seal by holding the piston at a very slight angle. Ima thinking 2*to 3* or so. Then push the piston hard over into the bore, and drop the other side down, gently, wiggling the high side back and forth, but always keeping the piston hard over on the low side.The final inch can be tricky, and sometimes needs help.I only use this method if I have previously folded the lip. And I put the folded part on the down side, and, in first.I never fold the lips any more!
But really, with the silicon lube, the things practically assemble themselves.

The lip seals soften up right after they go in, and freezing them has always been the method to get the lip in drum area's that cannot be gotten to with a tool. (and they don't feeeze hard, just stiffer so they stay in a compressed shape for a few min)
Volvo and Mercedes 4or5 speed auto's (I think it was) had multiple lip seals (pistons within pistons)for applying the clutchpacks at different speeds and pressures so it was mandatory to freeze the inner seal because you couldn't get to it.

The only difference really was that we had plastic cup tools that slid over the seal to hold it down until it got cold enough to stay on it's own so it could be installed.
Pull the cup/tool off and drop it in the bore right away.

They can be put in like you said also, by working the edges in but I don't know if someone who doesn't know what kind of pressure you can get away with should do it.
Might end up with a folded lip and find out when it's air checked.

 

[AJ/FormS]

Oh I get it; using a cup to keep the lips up tight. Or maybe a belt.Yeah, so, if I ever need an alternate method, I'll try to remember this freezer trick.
I think it was TH350/400s that have at least one blind install. It's been a lotta years since I built one of those; over 30 Ima thinking.
Thx TB

 

[Creedmoor]

Thanks fellas.

Now I'm fighting getting the piston into the front clutch. Tried the freezer thing twice with no joy. Tried the homebrew lip wizard with no luck either. Really seems to be hanging up on the inner seal in the drum. When I take the inner seal out, its pretty easy to put the piston in working around the outer seal with the wizard thing. Put the inner seal back and it's like a hard stop. Just seems like that inner seal sticks out there too far. I've double checked it as the exact sames size as came out and made sure it was seated in its groove properly.

Inner seal should have the lip facing into the drum right?

Frustrated right now. :banghead:

 

[TrailBeast]

Thanks fellas.

Now I'm fighting getting the piston into the front clutch. Tried the freezer thing twice with no joy. Tried the homebrew lip wizard with no luck either. Really seems to be hanging up on the inner seal in the drum. When I take the inner seal out, its pretty easy to put the piston in working around the outer seal with the wizard thing. Put the inner seal back and it's like a hard stop. Just seems like that inner seal sticks out there too far. I've double checked it as the exact sames size as came out and made sure it was seated in its groove properly.

Inner seal should have the lip facing into the drum right?

Frustrated right now. :banghead:

Yea it's a pain in the backside sometimes, and yes the seal goes in there the way it doesn't want to go.

Something small, thin, smooth and flat, put down pressure on the piston with one hand and run around both inner and outer seals alternating between the two with your lip tool.

I'm trying to think of a common household thing to use for the tool, but I'm drawing a blank besides a tapered and polished feeler gauge.

 

[Creedmoor]

Thanks Beast. I've made a decent tool out of milk jug plastic. I'll keep trying. Back in the freezer again.

 

[TrailBeast]

Thanks Beast. I've made a decent tool out of milk jug plastic. I'll keep trying. Back in the freezer again.

I don't think milk jug plastic is stiff enough. (maybe)

A 1/4 inch slice off an old credit card would probably do it though if you smooth the edges so it doesn't hang up on the rubber and cut it.

 

[Creedmoor]

The milk jug stuff works good for the outer seal. It ssems like credit card thick stuff wouldn't fit. It's that dang inner seal hanging this up. Since its lip is facing away from the chamfer on the inside of the piston it seems like you wouldn't need to help it any. I even used a .008". feeler gauge to see if that would work. It fits and is just stiff enough to be able to work it around. Using both of these at the same time and pushing pretty damn hard (putting most of my weight into it), it still won't go.

I just wanted to put both clutch packs together today and I can't even get past step two!

I must be doing something wrong.

I need beer.