help needed with 904

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Ok new day. really would love to know what I'm fixing? Thinking out loud here: why is this transmission that was rebuilt lose reverse? Why is the oil so dark? Why is it That the reverse 4th clutch packs (have not pulled them apart yet though) okay and the one/two clutch packs are all dried out and burnt looking? Why is it when I put air to the apply reverse it didn't make a clicking sound just more of a wishing through sound? And for some reason when I pulled the pump off the front it seems like there wasn't a gasket there like there should be? Now I start to wonder if the person who rebuilt this last time miss something? Like is something just messed up in the valve body also to make this other stuff happen? Or is the pump bad and not giving it enough fluid? Remember the motor was all plugged up and he was having major overheating problems. Just wanted to make sure that I don't go through all this just to have the same problem LOL


TrailBeast said:
Ok, now look at all the corresponding surfaces where rings ride to make sure they are fairly flat and don't have grooves in them.
Inside the pump stator where the shaft went through, the front drum where it rides on the pump stator and the governor housing.
All the places where rings ride.
If you want to crack the pump open go ahead, but note which side of the inside gears is up because you want them to go back in the same way later so they don't have to mate with the pump surfaces again and cause a loose pump.
You will be changing the bushing and seal both anyway, so you will need to open it up.
There is only 2 parts in there, so no big deal on anything falling out and getting lost.
See you tomorrow most likely.
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j par said:
Ok new day. really would love to know what I'm fixing? Thinking out loud here: why is this transmission that was rebuilt lose reverse? This very well could be just a bad lip seal on the reverse servo, and why some replace that servo with a billet unit. (sometimes the OE servo cracks or flips sideways making reverse go away)
Why is the oil so dark? Why is it That the reverse 4th clutch packs (have not pulled them apart yet though) okay and the one/two clutch packs are all dried out and burnt looking? The direct clutch pack drives almost everything in the trans, and is the one that usually burns up. AND the fluid burns from the heat of the clutch pack slipping. Why is it when I put air to the apply reverse it didn't make a clicking sound just more of a wishing through sound? Again, probably a bad seal on the reverse servo piston.(they also crack and allow fluid through instead of holding the band tight like it should.) And for some reason when I pulled the pump off the front it seems like there wasn't a gasket there like there should be? There should be a gasket, and it's dark like the pump casting, so you may have just missed seeing it. Now I start to wonder if the person who rebuilt this last time miss something? Like is something just messed up in the valve body also to make this other stuff happen? Or is the pump bad and not giving it enough fluid?
It's possible, but very unlikely that the VB caused this.
The pump is pretty easy to see damage on, so a visual inspection usually points out any pump issue's.
That is also why they put pressure test ports all over the outside of the trans, so a person can verify pressures to each function of the trans.
Some rebuild a trans and forget to blow out their cooler lines so it get's contaminated again right away.
Remember the motor was all plugged up and he was having major overheating problems. Just wanted to make sure that I don't go through all this just to have the same problem LOL
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Today should be hard parts disassembly, cleaning and inspection for any damage.
When you get your rebuild kit it should include clutch discs, steel discs, a front band and gaskets, rubber seals and such, as well as new oil rings where the drums and stuff rode on shafts.
The rear band for reverse is usually reusable. (budget minded) unless the drum it rides on is burned (blue or black) or the material is flaking off.
I like to sand the band a little to break up any polished hard surface on the material.
The valve body probably doesn't need to be disassembled unless a kit is going in it.
It can be flushed and blown out to get the crap from the burned clutches out of the passages.
The valves can be moved with a pocket screwdriver or pick to be sure they move freely.
The pump bushing and seal can be knocked out as you will need to replace those.
Just be a little careful about dinging the inside surface where the pump gears ride.
Red Locktite is a good thing to use on the new bushing when it goes in to insure it does not move.
When you are ready to put the new bushing in we will talk about staking the bushing.

These are just FYI's which I will be giving you to keep in mind as you go.
Also keep in mind it has been a few decades since I did these for a living, so I'm not going to be perfect.
Others may chime in with things I haven't mentioned yet or forgot about.
 
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j par said:
1-2 I'm not sure if this is from sitting or what but I did take my finger and wiped off what was seemingly a soot of black right now where it looks Orange
View attachment 1715042605
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That is burned clutch material and I'll bet when you open that pack up will will see a lot worse than that.:D
If I remember correctly, those clutches are normally an orange color.
 
So 70aarcuda was just telling me that the front servo is different in my 68 transmission. So now when I order a rebuild kit and most all of them are 72 and do I need to worry about that front servo seal being in there or?
 
I'm probably looking at the cheaper kits that don't have the steel plates. I'm certainly not finding anything local so I'll probably have to send away for it and it will be a couple days.
 
J par,
One other thing was when you have the drums apart for cleaning you need to get down in all the little grooves and corners inside them with something like a toothbrush sized wire brush.
Centrifugal force of the drum spinning packs all kinds of garbage in the grooves and corners.
 
Well I gotta head to Harbor Freight for some more gloves and some C clamps. I wanted to look for some C clamps at the last swap meet but it rained so bad I just wanted to get out of there. I will order a rebuilt kit today(Lord willing). Til then I gots keep takin this apart..
 
10-4 any thoughts on the original problem? I would hate to think I'm rebuilding this just to have the same problem that it was having


TrailBeast said:
J par,
One other thing was when you have the drums apart for cleaning you need to get down in all the little grooves and corners inside them with something like a toothbrush sized wire brush.
Centrifugal force of the drum spinning packs all kinds of garbage in the grooves and corners.
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j par said:
10-4 any thoughts on the original problem? I would hate to think I'm rebuilding this just to have the same problem that it was having
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What I have seen so far is normal "needs a soft parts rebuild" stuff.
I call steel plates soft parts because I believe they should always be replaced with new clutch discs.
You know, the indication I see is that the throttle pressure stuff might not have been hooked up or not adjusted right, because that clutch you showed is what burns up first because of low TP. (like when a member says he doesn't have the kickdown hooked up, and we warn them that it will burn it up)
That is what it burns up.

Looks like a basic rebuild to me, as long as the sealing ring lands are ok.
You need to check where the rings run inside that aluminum where the park gear hub goes as well. (called the governor support)

IMG_0380.jpg
 
It looks as if it may have been Emery cloth or something but it feels good
20170429_110042.jpg


TrailBeast said:
What I have seen so far is normal "needs a soft parts rebuild" stuff.
I call steel plates soft parts because I believe they should always be replaced with new clutch discs.
You know, the indication I see is that the throttle pressure stuff might not have been hooked up or not adjusted right, because that clutch you showed is what burns up first because of low TP. (like when a member says he doesn't have the kickdown hooked up, and we warn them that it will burn it up)
That is what it burns up.

Looks like a basic rebuild to me, as long as the sealing ring lands are ok.
You need to check where the rings run inside that aluminum where the park gear hub goes as well. (called the governor support)

View attachment 1715042701
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j par said:
A seal is different if I use a cable to shift the transmission?
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Cable shifted meaning the old pushbutton style trans, not like ones that were changed from column to floor shifters.
That extra kit covers some of the older style stuff, and what AAR was talking about for 60-71 only trans.

Governor support looks ok as long as the new rings fit snug. (they should be fine)
 
trans-go sposed be best kits for mopar automatic trans from all ive seen n studied on here...but i have no first hand knowledge of this...
 
dirty white boy said:
trans-go sposed be best kits for mopar automatic trans from all ive seen n studied on here...but i have no first hand knowledge of this...
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I have first hand knowledge and my opinion is the same. :D
Running a stage 2 in my 42RH right now, and have used Trans Go kits in about every American made trans there was when I was doing it.
 
Those are my videos you are watching:).
Yes, so far I stopped at 16 because I put this to this to the side over the winter. I have it completely back together now other than a few odds and ends. I'll be finishing the series soon.

The rest of this post was removed because 1. I'm only interested in helping people that are serious about learning something, and 2. I don't like my posts parsed through for anything that can be sniped about. Use whatever adjective you want to describe that position but that's the way it is.
 
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TylerW said:
Those are my videos you are watching:).
Yes, so far I stopped at 16 because I put this to this to the side over the winter. I have it completely back together now other than a few odds and ends. I'll be finishing the series soon.

As a first timer, some tips:
1. Don't start tearing it apart unless you plan to totally rebuild it. There's nothing at all you can tell by splitting the valvebody or air testing it. Mine checked out ok and didn't have excess debris in the pan, and third was still burned up. Either stick it in the car and see how it works as is, or overhaul it.

2. If you overhaul it, you need a good manual such as the ATRA versions or even better, use an appropriate year FSM(Chrysler manual). You can use my videos for tips and ask here, but go by the manual first and foremost. When you ask on forums you get so many random bits of advice and opinions, that although they are well-menaing, it just confuses you.

3. You need a clean bench with good lighting. You need kids and wife out of your way. You need to plan to clean and clean and clean.
4. Any bushing that doesn't look new has to be replaced. The front pump bushing replacement can be considered mandatory and that takes a large bushing driver set which you can't get at HF. I bought a used Matco set off eBay. You need a complete kit which has steels, bushings and soft parts. I got mine from Oregon Transmission parts. You don't need whoopty-do alto clutches or kevlar or anything else on a street car. In fact, the use of such is discouraged due to their altered friction characteristics and especially since they are usually thinner to encourage people to try to fit more clutches in the clutch pack, and as a consequence they do not absorb heat well. Also, the front band should be the good original cast-iron style unless it's a much later unit. They don't make those any longer, and they are a superior piece compared to the flimsy "flex" bands they keep pushing on people these days. I won't use one of those after seeing how sloppy it was. You CAN have the cast-iron band relined. In fact, there is a place in Muscle Shoals west of here that does just bands, and they had an exchange unit on the shelf ready to go. With my core it was a whopping $5.00

5. You need to know what converter that is. I know guys keep saying to use higher-stall converters, but the converter stall speed needs to be less than whatever your cruise(60-65) speed rpm is, or otherwise the converter will be slipping some all the time and generating heat. That's often disregarded but you want a transmission to run cooler, not hotter. Plus, some 8.5:1 CR 318 with stock heads(for example) will be an unpolished turd trying to drive 2.93 gears through a loose converter. Don't follow the "bigger *****" mentality.

6. That transmission with the rust in it has been saturated by water, and I would consider it a parts transmission at this point. The case might even be corroded.

7. You can find out what year they both are down to the DAY by looking at the numbers on the driver-side pan rail. There's a letter code, then numbers that are the 10,000 day calendar date. Plug them in to a search and it tells you what day of what year it was produced. If you luck out one might be an A999 but not likely. The partial VIN's are on the passenger side bellhousing.
8. Don't experiment with homebrew throttle-valve linkages. That's the fastest way to burn up a TF. The guys that engineered those linkages knew what they were doing. Either use the factory linkage or use the LOKAR kit like I did after decided I didn't want to fund some guy's retirement for a set of correct 4bbl linkages.

Again, don't start disassembling it hoping to learn as you go without a guide. You'll have a big pile of parts left that you'll haul out to the curb. Good luck!
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Well all that was a bit late since he has it all torn down already.:D
You saw the "budget" and "temporary" parts of his posts, right?
I have rebuilt transmissions that were full of water or coolant and though it can cause some damage to parts it's not nearly as serious as you make it out to be.
These things are far from rocket science, but some mechanical and hydraulic requirements do have to be met.

Scaring the crap out of him by telling him he can't do it even with help is not going to do anyone any good.
He can do it, and some of us can help as he goes.
My congratulations and thanks on the video's as they help a person to see what they are getting into before they try it themselves.
 
j par said:
This could have been some drying out and rusting from just sitting but again it was in a climate control garage and covered
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Any water in the oil. Saw a Fix Or Repair Daily trans that had been sitting for some time, and the plates looked like that. Water had gotten into the trans and created a funky sludge.
 
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