904 Transmission Stopped Going Into Gear

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I haven't read anywhere in here that you checked the ring wear surface inside the replacement direct drum. I saw lines in it in the pic. I'm leary because they incorrectly sent you a 3-plate; so if they didn't even check that, then they maybe didn't check the ring surface. If you can feel wear then it's no good and must be replaced. Unless you can use thrust washers to place it laterally so that the new rings ride on an unworn surface. But ring wear is usually pretty wide because it is caused by the direct drum wobbling. If you try to machine ridges out then the rings won't seal.
 
This is what the ring surface in my direct drum looks like:
20180908_125829.jpg


There are shiny wear bands but they do not have a perceivable lip that I can feel.
 
That's good. Did l mention you can put 4 plates in a 3 plate drum by using a forward clutch lower pressure plate on the top?
 
I have almost everything back together, its very exciting but I am worried about a couple things:


I slid the direct drum on the pump in order to do an air pressure check of the clutch as recommended in the book:
20180908_131829.jpg

The pressure test worked and the piston compressed the clutch stack but the direct drum was very tight on the pump. Felt like the new bushing in the drum was too tight on the pump. I had to smack it with a rubber mallet to get these two things together and apart for this test. I also checked for burrs/shavings in the bushing and it looks good. Thoughts?


20180909_203917.jpg

Does this look right? I slid the direct drum and forward drum together, got all the disks to align, and then dropped that whole assembly into the front planet shell. This was not easy, but will some wiggling and rotating, I got it to slide in as shown here. The direct drum/forward drum sub assembly seemed "wobbly" even when I got it fully engaged (I hope).

After installing the oil pump and extension housing, the input shaft does spin but it is pretty stiff and hard to turn by hand.

20180909_200234.jpg

When I try to measure the endplay, I can hardly make the dial indicator needle move and can not get a real measurement. Again, the input shaft does rotate stiffly and has a little bit of "wobble" to it if you shake it.

The results of my air pressure tests:
20180909_203908_edit.jpg


Thoughts?
 
We don't pound the trans together.. Find out why it's binding. This why l don't recommend replacing all bushings; they can become distorted. That bushing will fry without correct clearance. The direct drum is not fully engaged in the sun gear shell probably because one of the forward frictions are not engaged with the splines. Remove the front drums and band and remove the clutches and reinstall the drums and pump without the pump oring or band. Then check endplay. Also check the bottom forward friction for damage on the teeth. But first get that direct bushing clearance straightened out.
 
CudaFactHackJob said:
We don't pound the trans together.. Find out why it's binding. This why l don't recommend replacing all bushings; they can become distorted. That bushing will fry without correct clearance. The direct drum is not fully engaged in the sun gear shell probably because one of the forward frictions are not engaged with the splines. Remove the front drums and band and remove the clutches and reinstall the drums and pump without the pump oring or band. Then check endplay. Also check the bottom forward friction for damage on the teeth. But first get that direct bushing clearance straightened out.
Click to expand...

That's pretty much what I figured. I will pull some stuff out and have a look.

On the direct drum bushing, what can I try to open it up a little? high grit sandpaper and polishing compound?
 
Duster Captain said:
That's pretty much what I figured. I will pull some stuff out and have a look.

On the direct drum bushing, what can I try to open it up a little? high grit sandpaper and polishing compound?
Click to expand...
When I had high/tight spots on a bushing I would rub the shiny spots with a smooth steel shaft like a chrome screwdriver shaft to flatten them down.
Sanding soft metals like bushings can leave rocks imbedded in the material.

You might be able to put the drum on the hub and tap with your mallet all around the edges of the drum to get it to smooth the bushing down.

Is it just the picture or is that bushing kind of trashed on the edges?

20180908_131829.jpg
 
TrailBeast said:
When I had high/tight spots on a bushing I would rub the shiny spots with a smooth steel shaft like a chrome screwdriver shaft to flatten them down.
Sanding soft metals like bushings can leave rocks imbedded in the material.

You might be able to put the drum on the hub and tap with your mallet all around the edges of the drum to get it to smooth the bushing down.

Is it just the picture or is that bushing kind of trashed on the edges?

View attachment 1715222155
Click to expand...

Good point, I might give the rubbing/tapping methods a try.

The edges are a but rough because my bushing driver always shifts a little bit when I drive a bushing and makes a little ridge on one side. Once its driven in I go back and "shave" off any ridges with a razor. I realize that that is not optimal and probably contributed to my tight bushing. It is what it is.
 
Duster Captain said:
Good point, I might give the rubbing/tapping methods a try.

The edges are a but rough because my bushing driver always shifts a little bit when I drive a bushing and makes a little ridge on one side. Once its driven in I go back and "shave" off any ridges with a razor. I realize that that is not optimal and probably contributed to my tight bushing. It is what it is.
Click to expand...

Ok, gotcha.
Also it does look like the two drums are not quite together.
One clutch plate not aligned on the splines could cause your end play to be tight as you mentioned.
If this is the case and you find it isn't all the way seated you may have the opposite problem with your end play.
 
The seam on that bushing looked a little opened up. You need the right size tool for the bushing that you're driving in. It was probably distorted when it got cocked sideways and opened the seam causing a high spot elsewhere. Replacing bushings isn't as simple and easy as it might seem. I can beat them in with a big washer, but I've been at it a while. If that bushing is distorted; not touching the drum all the way around, you need to remove it and install a new one. Replacing all the bushings is a lofty goal for a beginner and chances are one or two won't go in right, causing more problems than just a slightly worn bushing would have.
 
That direct drum looks like it has too much clutch clearance by about .040. Did you align the pump halves with a large adjustable clamp? Did you grease the gears into place and fit the pump (without the cover on) onto the converter to make sure the center gear is actually centered? And after it's bolted together, check it over the converter again.
 
I did grease the gears in place and slide the pump (without cover) onto the torque converter to ensure that the splines got aligned and centered. I then packed the pump gear cavity with grease before putting the halves together.

I did not use a large adjustable clamp on the pump. I used 2 bolts with the heads cut off as locating pins. I screwed them into the case in holes 180 deg apart, slid the gasket on them, then slid the pump halves on, secured with a few original bolts, then replaced my "locating" bolts and torqued everything to spec.

Of course, Im going to have to take that all apart now, fighting the tight grip on the drum bushing....
 
CudaFactHackJob said:
Replacing all the bushings is a lofty goal for a beginner and chances are one or two won't go in right, causing more problems than just a slightly worn bushing would have.
Click to expand...

Fair enough, but at the same time, there is only one way to learn. Every bushing I replace is done a little better than the previous one.
 
That does nothing to align the pump halves. And what does the direct clutch clearance measure? Do the forward clutch too just to make sure. Sometimes the stator support bumps the center pump gear; that's why you refit the pump to the converter after the halves are bolted together.
 
I misunderstood what you were saying about the pump. I was talking about installing the complete pump and you are talking about bolting the halves together, my mistake.

Are you saying the manufacturing tolerances on the pump halves bolt holes are loose enough so that when all the pump halves are lined up enough to install all bolts and everything is torqued to spec, the pump halves can still be seriously misaligned? That seems.....like a serious design flaw.

CudaFactHackJob said:
Well, you aren't learning anything if you're gouging the bushing with the wrong tool.
Click to expand...

I'm not sure what you mean by this.

I have a bushing driver set and I am learning how to use them properly like anyone starting out. Part of that learning process is making mistakes, observing the results, and correcting the method (driver alignment, amount of driving force, etc). Did you pick up a bushing driver set on your first day and start perfectly installing bushing or did you mess a few up and learn from that?
 
I read that you use a razor blade to clean up the bushing after it's installed on a regular basis. STOP! That's the wrong size bushing driver. It has to fit snug and have a large enough flange to put even pressure on the bushing. But I thought you said you were a machinist or repair person dealing with close tolerances etc... Don't accept that type of an installation. It's no good and it's inviting the bushing to spin if it is distorted. The 904 has no design flaws...no transmission does..it is what it is and we work with these parts accordingly. The proper method is to align the pump halves with an adjustable clamp. Just like a th350, th400, th200 and a few more. And don't even get me started on the A4LD and C3 and 5r55e.. And that's without the o-ring installed. And you still have to align the holes by turning the halves until they line up.
 
Back in about 1981 I bought two Ford C6 pump bushings because I wanted to install one into a th350 direct drum because it was wider. I took it to a machine shop to pay an expert to press it in. I said here I have two. He said he just needed the one. Couple minutes later he came back asking for the second one. I never paid anybody to mess up bushings for me after that. Truth is, If you want to install bushings, make sure you have plenty of extra on hand. Because now you have a messed up bushing that needs to be removed and replaced but you had only the one. If the bushing has binding areas; that means it also has areas that won't even touch the pump. See, this is why I said before to leave the bushings alone unless they're really destroyed; but in which case, the journal on the hard part would probably also be worn; requiring replacement. I buy bushings by the ten pack now. I mess one up every once in a while but I never try to save it. It goes into the trash; just like that one in your direct drum should. Because it will wear out in short order and be a lot looser than the old one you removed. (Others' results may vary..)
 
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Send that three plate direct drum back and have them send the four plate; maybe it will have a good bushing.
 
I've had to take it back apart because it does not look like the Input shaft/forward/direct drum assembly does not seem like it's seating properly Into the front planet shell as my pictures show.

I think I'm getting all the frictions and steels to line up but it feels like the input shaft contacts the output shaft and won't let the front seats assembly go in any further. The input shaft feels very "wobbly" when it gets too this point and won't go any further.

I've also tried taking off the output shaft thrust washer but that does not seem to make a difference.

Thoughts?
 
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