A904 front planetary and washer question

[weaverjsnw]

First off its a 1964 dodge dart pushbutton. I have an aluminium 3 pinion front planet and a 4 pinion rear. The washer that sits on the hub of the front has been bouncing around beating up the hub and inside of the washer. I cannot find a replacement so far. I have seen there are 4 pinion planets in two sizes 5" and 4 3\8" . Could I use one of these as a replacement? The one I have is fine except for the hub. Is that repairable? Any advice is appreciated. Thank you...

 

[weaverjsnw]

Ok anybody try repairing aluminum castings with a tig welder? I gotta find a way to fix this problem. Hate to junk the tranny over this.....

 

[TrailBeast]

A pic of the exact problem area's would be nice.

Usually the sun gear, planet set and ring gear should all be replaced as a set, but it has been done to replace one piece only of the three wear matched set.
The downside can be early failure of any of the three pieces due to mismatched wear
Other than that they can end up a little "whiney" from that mismatch.

A washer for the same size planetary should be obtainable through most any decent local shop due to them being used in so many transmissions, but you do have to use the one used for your size planetary gear set if I remember correctly.

Also A&A transmission parts online probably has at the very least used ones.
904 planet - A&A Transmissions

 

[weaverjsnw]

Thank you very much. They don't specify whether 3 or 4 pinion or anything else. I suppose it will depend on the output shaft. I'll have to get a hold of them and see what they say. I wasn't sure if I needed to replace everything on the output and hope it would fit or what. This brings me much closer to solving the issue thank you I will post an update when I know more.

 

[weaverjsnw]

As you can see the snap ring has worn a groove in the washer. The washer has a flat on the inside and loosely sits in a groove on the hub. That is where the damage is. The hub and washer no longer fit together like they are supposed to.

 

[TrailBeast]

As you can see the snap ring has worn a groove in the washer. The washer has a flat on the inside and loosely sits in a groove on the hub. That is where the damage is. The hub and washer no longer fit together like they are supposed to.

The year of the trans is what determines the shaft needed, and if I remember it was something like 66 up is one spline and 66 down was another so it shouldn't be too hard to get the right one.

 

[Duane]

Thank you very much. They don't specify whether 3 or 4 pinion or anything else. I suppose it will depend on the output shaft. I'll have to get a hold of them and see what they say. I wasn't sure if I needed to replace everything on the output and hope it would fit or what. This brings me much closer to solving the issue thank you I will post an update when I know more.View attachment 1715208417 View attachment 1715208417

That is very common. My 904 with low gear was worn the same way.
I think it is from thrust pressure of the helical gear set. Should be able to purchase a new washer.

 

[AJ/FormS]

Do not mix 904 planetarys with 998/999 mainshafts and vice-versa. The mainshafts have a different spline configuration while spline-count is the same. If you install the wrong mainshaft it WILL fit ........ But in a few miles Ziiiiing the aluminum splines will tear out of the planetary..... and then you'll be walking.
Actually I think it was an across the board change in the 80's. In which case it would mean ALMOST the same thing; If you need a planetary, and don't have a donor trans, you are gonna need to match the years carefully, to avoid the dreaded spline-failure.
I seem to remember MoparAction did an article on this.

 

[Duane]

Do not mix 904 planetarys with 998/999 mainshafts and vice-versa. The mainshafts have a different spline configuration while spline-count is the same. If you install the wrong mainshaft it WILL fit ........ But in a few miles Ziiiiing the aluminum splines will tear out of the planetary..... and then you'll be walking.
Actually I think it was an across the board change in the 80's. In which case it would mean ALMOST the same thing; If you need a planetary, and don't have a donor trans, you are gonna need to match the years carefully, to avoid the dreaded spline-failure.
I seem to remember MoparAction did an article on this.

I thought the spline problem was the soft aluminum and the later models went to steel planetaries. Any chance you could find that article.

 

[TrailBeast]

I thought the spline problem was the soft aluminum and the later models went to steel planetaries. Any chance you could find that article.

A&A will know which ones will fit what.
AJ is correct about the splines/planet issue's, but I couldn't remember the exact details.
I do know it has to do with how deep the splines fit though.
One works and the other will strip the center out of the planetary set hub, and it has zero to do with the aluminum or steel.

 

[Duane]

A&A will know which ones will fit what.
AJ is correct about the splines/planet issue's, but I couldn't remember the exact details.
I do know it has to do with how deep the splines fit though.
One works and the other will strip the center out of the planetary set hub, and it has zero to do with the aluminum or steel.

I did not know that. I have heard there are spline pressure angle incompatibility on certain year 727s but never heard that on the 904.

 

[TrailBeast]

We had a planetary gear set rebuilt kit back when, where you could replace the needle bearings, pins washers and shims for the gear side play, so I rebuilt a crapload of them back then.
I recently did some searches for one of those kits when the planet went on my 904.
When I realized it would cost about the same to fix my 904 as to replace it with a 42RH overdrive I did that instead.

 

[weaverjsnw]

If I had a 66up donor could the output shaft and everything on it be put in the 64 case? No response from AandA yet. I'll give them a call tomorrow. I've seen both sizes of washers but only the 4 pinion planets in two ring gear sizes. Almost bought one with the ring gear and washer from Cobra but decided it wasn't the right one. Overdrive would be nice. How much trouble would that be in my dart?

 

[AJ/FormS]

IDK on all counts, here
I think up to and including 66, all older aluminum case guts interchange.

TrailBeast has the scoop on installing the A500

Check out the gear stuck in your sunshell. It should be the same size on both sides. This indicates the standard 904 ratios.

If it has a one-piece sun-gear, with two different sized gears cut onto it, , that would indicate the wide ratio A999 gearset.
Your planetaries have to match that sungear, and as you probably have seen, the front and rear are different.
The A500 will let you run any pumpkin you want; and the bigger the better.... they say. But honestly if you can hit 60mph at the top of second, that is about all you need; so 4.30/4.56s will get you close,lol.

Hooking it to the pushbutton? Hmmm,you're on you own there.

 

[weaverjsnw]

A&A does have my parts. He said he needed the inside spline count of the planetary to make sure I get the right one. Haven't been able to order them yet. Thank you everyone for your input. I learn something every time I come here. I sure do appreciate the wealth of information and experiences shared here. I know I wouldn't have done as.much to my car as I have without this website and everybody who comes here. Thank you again.....

 

[Duane]

A&A does have my parts. He said he needed the inside spline count of the planetary to make sure I get the right one. Haven't been able to order them yet. Thank you everyone for your input. I learn something every time I come here. I sure do appreciate the wealth of information and experiences shared here. I know I wouldn't have done as.much to my car as I have without this website and everybody who comes here. Thank you again.....

If he asked for the spline count only , that would imho imply there is no variation in the pressure angles of the splines on a 904 as I said earlier. Only the number of splines. I have only heard of pressure angle differences on the 727.

 

[AJ/FormS]

If he asked for the spline count only , that would imho imply there is no variation in the pressure angles of the splines on a 904 as I said earlier. Only the number of splines. I have only heard of pressure angle differences on the 727.

I think MoparAction covered it about 20years ago
I have first hand experience with the mismatch machining out the aluminum splines in just about 20 miles

 

[Duane]

I think MoparAction covered it about 20years ago
I have first hand experience with the mismatch machining out the aluminum splines in just about 20 miles

I would like to see that article just for my own personal knowledge.