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HK CD 401 idler tires confusion!

smead

smead

AK Subscriber
Subscriber
Hi AK - I sure hope someone can help me fix this deck. At first, I thought the tape eating was a bad pinch roller, then I suspected belts, dreading what I've read is an extremely difficult job to rebelt this deck.

But upon disassembly, roller as well as belts look ok. But clearly the rubber on the secondary motor clutch and adjacent idler wheel are shot.

But here's where I am confused, looking at the photo of these, you can see two round rubber orings, one has snapped. But this surely isn't the original rubber right? I would expect a square tire? Or would there have been no tire at all, and instead the adjacent idler wheel tire fits in the clutch slot? I'm almost thinking the idler wheel tire wore down, then instead of replacing, someone just hacked a work around by putting these two orings around the clutch to make contact with the adjacent worn idler tire?

Unfortunately, the service manual I have is not helpful in that it does not even show the idler wheel or tire in the cassette mechanism parts diagram? It does show the clutch, but does not indicate whether or not it has a rubber tire around the spindle? Surely not 2 orings!?

Making things more challenging is that while I do find idler tires for the very close one year newer cd 491, I cannot find idler tires for the 401?

Can anyone tell me if they are the same? Other source for original 401 tire?

Will the readily available nakamichi sankyo transport tires work? I did read over at tapeheads that they may be the same.

Can anyone confirm whether or not there is a separate rubber tire on the clutch?

I would really appreciate it if someone can help me get this fabulous sounding deck fixed right. Thank you.
 

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No one with any cd 401 experience here?

Since posting this, I've convinced myself the orings on the left clutch pulley was a hack job, perhaps to work around the worn idler tire on the right clutch pulley.

I am also pretty sure the tire on the right clutch pulley is indeed a nakamichi sankyo transport tire based on the measurements of my old one. I have ordered a couple.

But what I still have no idea about is whether or not there was also a tire on the left clutch pulley before some knucklehead put on orings. I don't think the same nak tire that goes on the right side is it as that looks too tight with both pulleys having that tire. Either there was no tire, and a new full dimension tire on the right will fill in the gap, or there was a different thinner tire on the left pulley. I'm thinking it's the former, but I did see a diagram in another 401 thread where a member indicated the latter (2 tires). I've reached out to him..

Anyone know? I cannot find any pictures of the 401 transport with the faceplate off to confirm, and again service manual no help!
 
They are very nice decks -- I have one that I put away last year just to use another deck for a while. I'll take a look next time I'm at storage and see what I can see. I may also have some photos of the transport still from when I took mine apart.
Just heading out the door when I saw this, I'll check my photos later today to see.
Cheers.
 
Is Fig. 15 on pg. 6 of the service manual the part in your picture? If so, it seems to show two flat tires. The o-rings are probably an earlier repair bodge .
 
smead said:
But what I still have no idea about is whether or not there was also a tire on the left clutch pulley before some knucklehead put on orings.
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Yes. The grooved wheel suggests a tire goes on it. When a plastic wheel contacts a tire directly, it is usually flat or slightly convex.
 
willyrover said:
Is Fig. 15 on pg. 6 of the service manual the part in your picture? If so, it seems to show two flat tires. The o-rings are probably an earlier repair bodge .
Click to expand...
Yes and I cannot believe I overlooked that! I was way down on page 23 or so looking at the detailed parts diagram where for some reason they don't show the tires. Arg! Thank you all for this!

So now I know there should be a tire on the left pulley, can anyone tell me the size? The one on the right appears to be the nakamichi sankyo transport small tire which I've ordered.

I measured the left pulley diameter at around 9mm, the channel is about 3mm. But I have no clue what the OD should be? Based on the photo and what I see inspecting mine, it's gotta be a pretty thin tire. Maybe an OD around 10-11mm?

Anyone know for sure?

Thank you so much!
 
Not sure of exact measurement, but the outer diameter shouldn't be too critical.

You'll need to match the inner diameter and the thickness so the tire fits tightly on the wheel and choose an OD so that the tire is about twice the depth of the channel.
 
Still hoping to find that elusive OD measurement and a source for the tire. I currently have 3 close options from 3 different suppliers. I'm tempted to try all 3, but that means shipping times 3 :(.

The one that is 11.9x8.1x3.5 seems pretty darn close, but it's .5mm wider than the channel on the white pulley which looks to be exactly 3mm.

Would it still work if the edges lay up over the edge of the guide lips on the pulley? I'm thinking it would?
 
smead said:
Still hoping to find that elusive OD measurement and a source for the tire. I currently have 3 close options from 3 different suppliers. I'm tempted to try all 3, but that means shipping times 3 :(.

The one that is 11.9x8.1x3.5 seems pretty darn close, but it's .5mm wider than the channel on the white pulley which looks to be exactly 3mm.

Would it still work if the edges lay up over the edge of the guide lips on the pulley? I'm thinking it would?
Click to expand...

Contact Marian Mihok and ask him, I am sure he can provide what you need:

Homepage - FixYourAudio

fixyouraudio.com fixyouraudio.com
 
Took a look through my photos but I have so many I couldn't locate the damn things. I know I took a fair number of photos while i had the transport apart, just have to look again. The deck is unfortunately still stored away from my home.
 
titanstats said:
Took a look through my photos but I have so many I couldn't locate the damn things. I know I took a fair number of photos while i had the transport apart, just have to look again. The deck is unfortunately still stored away from my home.
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Appreciate you trying. I've reached out to Marian, hopefully will get some answers/options.

I will definitely post photos of the 401 clutch tires once I get the right ones on there!
 
I heard back from Marian and he unfortunately has nothing close to that size.:(

I cannot believe that I cannot fix this beautiful deck because of the unavailability of a $5 tire.
 
smead said:
I heard back from Marian and he unfortunately has nothing close to that size.:(

I cannot believe that I cannot fix this beautiful deck because of the unavailability of a $5 tire.
Click to expand...
Next you can contact:
webspareparts.com

WebSpareParts - Vintage Audio Spare Parts

Vintage Spare Parts & Drive Belts For Turntable, CD DVD Player, Cassette Deck, Reel to Reel, Walkman, 8 Track, VCR VHS & Betamax, Radio, Boombox
webspareparts.com webspareparts.com
I believe it is possible to rerubber your idlers by sofh.it for example, but it will cost not $5 but much more.
 
smead said:
I heard back from Marian and he unfortunately has nothing close to that size.:(

I cannot believe that I cannot fix this beautiful deck because of the unavailability of a $5 tire.
Click to expand...
That sucks. Took another look through my photos over the last few years, I seem to be able to find pics of everything except that deck.
I'll be over where the deck is in storage this weekend and can pop the hood on it -- what do you need exactly?
 
titanstats said:
That sucks. Took another look through my photos over the last few years, I seem to be able to find pics of everything except that deck.
I'll be over where the deck is in storage this weekend and can pop the hood on it -- what do you need exactly?
Click to expand...
Thanks! I need the same photo I showed above - close up of the clutch pulleys. That would help me guesstimate the OD of the tire on the white pulley.
 
I have CD401 and I left alone my clutch tire and well as the belt ( I got belt but it turned out too thick ) rewind is not the best but at least it works.
I can say for sure that 401 shares tape mech with hk300xm ( Looks like I can swap the whole clutch assembly between them )
But I cannot speak for size of tires.
When Ihave removed the clutch assembly I did not measure anything.
 
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Here is the post about hk300xm

Harman/Kardon HK300XM issues

Anyone familiar with the transport in these decks? My capstan belt is fine, and the rear spindle will turn, but the take-up spindle won't move. With the faceplate as far off as I can get it (stupid glued-in logic controls...), I can see a small plastic flanged wheel that contacts a larger...
audiokarma.org
It might help
 
Now we're talking! Thank you so much, especially for the hk300xm tip. I searched around for that and stumbled on that very ak thread you later noted. Indeed same pulley. There is not only a close up photo of the clutch showing the white pulley tire, but also the measurements:

8-8.5mm ID, 10.5-11mm OD, 3mm wide

Which was real close to my guesstimate.

Now can anyone point me to a source for this tire? The closest I could find was from wjoe.com at 11.9x8.1x3.5, but I think the OD is too much.

Almost there!?
 
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