A500 overdrive unit, can't get it apart

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fshd4it

fshd4it

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I'm rebuilding an '89 A500 for my '64 Barracuda, but the direct clutch assembly won't compress enough to remove the clutch hub snap ring. I'm using a 12 ton press, not out of stroke, and the direct clutch hub falls away more than enough to remove it's snap ring (the outer one). I never had this problem with the 5 or 6 other O/D units I've taken apart. You can see the snap ring in the picture, it will pull out of it's groove, but just won't clear the bevel on the direct clutch hub. If I had another 1/32" I'd be golden, but it's just not happening. Any ideas?

20180806_182504.jpg
 
trying to get a video posted from you tube

the dam video wants to start have way thru it...go to youtube and search for

Dodge a318

there is a video showing the disassembly of the a518/rh42
 
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Thanks Tony, I'll look that up, if only for a trick or two. I'm starting to wonder if something hasn't come apart inside, using up a little more space than it's supposed to.
 
tried to copy and paste it but the video would start at 38 minutes...at that point they had it torn apart...
 
fshd4it said:
I'm rebuilding an '89 A500 for my '64 Barracuda, but the direct clutch assembly won't compress enough to remove the clutch hub snap ring. I'm using a 12 ton press, not out of stroke, and the direct clutch hub falls away more than enough to remove it's snap ring (the outer one). I never had this problem with the 5 or 6 other O/D units I've taken apart. You can see the snap ring in the picture, it will pull out of it's groove, but just won't clear the bevel on the direct clutch hub. If I had another 1/32" I'd be golden, but it's just not happening. Any ideas?

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Please be careful there with that big spring, I am sure you know that.
 
BigBlockMopar said:
Can't you pull-up on the center hub, or support from the other side?
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The center hub is actually the sun gear, it has a thick disk attatched to it which retains the back side of the spring. So I have the full 800# of the spring pushing down on it. After looking at the diagrams again, it appears it's just the spring that's not compressing enough, nothing else is coming into play. I haven't torn one of these apart in over a year, guess my memory is a bit fuzzy. I've moved on to cleaning the valve body while I think on this for a bit.
 
fshd4it said:
The center hub is actually the sun gear, it has a thick disk attatched to it which retains the back side of the spring. So I have the full 800# of the spring pushing down on it. After looking at the diagrams again, it appears it's just the spring that's not compressing enough, nothing else is coming into play. I haven't torn one of these apart in over a year, guess my memory is a bit fuzzy. I've moved on to cleaning the valve body while I think on this for a bit.
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Good idea, you do not want a mishap with that powerful spring.
That is a job to be done with full concentration and alertness imho.
 
fshd4it said:
The center hub is actually the sun gear, it has a thick disk attatched to it which retains the back side of the spring. So I have the full 800# of the spring pushing down on it. After looking at the diagrams again, it appears it's just the spring that's not compressing enough, nothing else is coming into play. I haven't torn one of these apart in over a year, guess my memory is a bit fuzzy. I've moved on to cleaning the valve body while I think on this for a bit.
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These might help you.


And this one at about 16 min.
A possible different way of doing it.
 
Wondering? if the large wavy ring has snapped/ broken and is somehow jamming in there?
 
Trailbeast- Thanks for the videos, never done it the way either of them did. Pressing the spring with the unit still in the case would put more strain on the front bearing than I'd like, and I think the second guy's gonna have a helluva time getting that unit back together with the spring still between the hub and the sun gear. Funny how he didn't show the snap ring for the direct clutch drum come flying out.
67Dart273- The large wavy snap ring isn't in there, but the heavy snap ring that holds the spring plate to the sun gear is. It could have broken I suppose, but how it would interfere with the spring is beyond me, since the spring is constantly under pressure. Just somtimes more than others.
 
Well, that solves that dilemma. I pulled the O/D direct clutch, spring and hub as a unit, looks like the Torrington thrust bearing in front of the planet let go and mushroomed the back of the spring plate. I'm guessing the lube holes in the tailshaft are plugged with crap from the burned-up main direct clutch. Hub was jamming up tight against the flair, not giving me enough room to pull the retaining ring. Time to dig up more parts. Thanks to all for the replies.

20180807_120805.jpg
 
fshd4it said:
Well, that solves that dilemma. I pulled the O/D direct clutch, spring and hub as a unit, looks like the Torrington thrust bearing in front of the planet let go and mushroomed the back of the spring plate. I'm guessing the lube holes in the tailshaft are plugged with crap from the burned-up main direct clutch. Hub was jamming up tight against the flair, not giving me enough room to pull the retaining ring. Time to dig up more parts. Thanks to all for the replies.
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Yea, that would explain it alright."D
I did a Volvo 5 speed auto one time that one of the clutch packs just would not separate from the drum/shaft that acted like that.
Ended up buying all the pieces because they were so welded together inside.
 
I'm thinking a loss of lube. The intermediate shaft is rifle and cross drilled to supply oil to the O/D unit's bearings. Holes are too small, plug up pretty easily, and there goes your overdrive. Seen them cooked way worse than that before. The aftermarket shafts are drilled larger to help prevent it.
 
fshd4it said:
Well, that solves that dilemma. I pulled the O/D direct clutch, spring and hub as a unit, looks like the Torrington thrust bearing in front of the planet let go and mushroomed the back of the spring plate. I'm guessing the lube holes in the tailshaft are plugged with crap from the burned-up main direct clutch. Hub was jamming up tight against the flair, not giving me enough room to pull the retaining ring. Time to dig up more parts. Thanks to all for the replies.

View attachment 1715207998
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If my memory serves me, that is a common problem that is said to be caused by the plate that takes the spring load is too thin.
The aftermarket ones are upgraded and stronger. I believe the one I purchased had a note with the parts explaining this. There is also a stronger aftermarket spring available.
 
I think I've seen those, they're Sonnax pieces if I remember right. This trans is an '89, so there's probably no factory improved parts in it. I'm going to replace the whole hub/spring/planetary assembly (obviously) so I'll be looking into making some upgrades. Surprisingly, the intermediate shaft is perfect...not a scratch, no hot spots, nothing.
 
fshd4it said:
I think I've seen those, they're Sonnax pieces if I remember right. This trans is an '89, so there's probably no factory improved parts in it. I'm going to replace the whole hub/spring/planetary assembly (obviously) so I'll be looking into making some upgrades. Surprisingly, the intermediate shaft is perfect...not a scratch, no hot spots, nothing.
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Sonnax has many nice pieces for these trans.i got my parts from Patc
I cannot remember if those parts were sonnax.
The trans go kit fixes many problems in the valve body.
The sonnax shift valve design is superior imho to the trans go but trans go fixes everything else. IMHO.
 
I've never heard of anyone making a different gearset for them. They were all .69, regardless of application, some just had more discs in the clutches.
 
AJ/FormS said:
Does that unit draw it's oil off the main supply-line in the maincase-output shaft? Ok then I see it. Thanks.
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Yes it does, and my money is on that Torrington bearing breaking roller pins and then seizing causing the bearing outer race to spin on the plate it sits on.
 
Strangely, there's no shrapnel. No metal or needles anywhere, nothing but sludge in the pan. It could have been cleaned out during a filter change, but the extension housing was clean as well. Maybe it's been redone, and the bearing was left out? Not sure if that would give a crazy amount of endplay however. Seen stranger things happen.
 
I just pulled apart a 1990, A518 yesterday, it had the EXACT same problem, Torrington bearing burned up. I saw sonnax had improved parts for that, and it's also recommended to machine a 45° chamfer around the inside of where the bearing rides, to allow more lube to work into the bearing
 
Interesting. I wonder if that's where all the O/D failures begin, and like I said I've seen worse. First one I rebuilt was so bad the truck stopped moving, but he'd been driving it with the trans temp light on for a while.
 
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