Request, service manual or help to change belt on tape deck Akai 4000D

[pdegro]

Hello all,

I recently got this Akai 4000D tape deck.
It is in good condition, complete and working but the capstan belt needs to be changed.

I already asked member floppybootstomp but he sold the manual together with the tape deck.

So, looking for a step by step guide on how to replace the capstan belt for a Akai 4000D.

Anyone??

Best regards from Belgium.
Pierre
(pdegro)

[pde2000]

You've probably seen Tony's post here;  http://www.lencoheaven.net/forum/index.php?topic=16090.0

The chassis needs to come out of the box, so remove two screws from bottom and four screws from back (feet).

Then you will see that the capstan flywheel has a large frame supporting the bearing, that has to be removed to get the belt on/off.

It will be easier to get the belt over the motor spindle if the front is also stripped.

use a small hex key to loosen and remove the head block selector switch knob.  Then loosen the two philips screws for the headblock cover and lift off.  The play and fwr/rev levers have philips locking screws, the pinchwheel retainer just screws off, and the pause lever also is held on by a small hex. The other knobs just pull off, and more philips screws are removed to lift off the facia's.

My 4000ds has not needed any new belts so i have not done this myself,  but i have had it apart, like Tony, and it is quite well made generally.  If I have to i could strip mine down to help guide you.

edit; just noticed Tony said he just loosened the capstan bearing to make space to get the belt over (very fiddly and care not to loose the ball bearing)  rather than remove the entire brace.

[pdegro]

Hi Paul,
Thank you very much for your reply and guide.
I want to change the belt because at the last quarter of a 18cm reel there is some flutter, and lower speed.
This is increasing as the reel goes on to the end.
This deck is still original, so a new belt and some inside cleaning and re-greasing may revive this set.
First I will look where to buy a new belt.  I have model 4000D.
If I cann't manage to change the belt, I will send a message, maybe pictures would help.
This is my first tape deck I try to restore, so all experienced help is very welcome.
Best regards,
Pierre

[pde2000]

Your problem could be that the friction clutch for the supply spool needs loosening/lubricating.  That's much simpler and easier than replacing the drive belt.

[pdegro]

Your problem could be that the friction clutch for the supply spool needs loosening/lubricating.  That's much simpler and easier than replacing the drive belt.

Hi Paul
Thanks for this suggestion, I will look into it next week.
Starting with opening the deck, and will take some pictures.
Best regards, Pierre

[pdegro]

Your problem could be that the friction clutch for the supply spool needs loosening/lubricating.  That's much simpler and easier than replacing the drive belt.

Hi Paul,
Today I changed the capstan belt and, in the mean time, the counter belt as well.

Can you tell me something more about loosening/lubricating the supply spool? How to do this?

Best regards
Pierre

[pde2000]

here's a manual;  http://home.btconnect.com/gmb/4000D.pdf

here's a service manual;  http://sportsbil.com/other/Akai/AKAI%204000DS%204000DS%20MKII%20SM.pdf

pages 9/10 describes adjusting the friction clutch (4000d is the same as 4000ds in this aspect, and most)

Well done for changing the belts.  Does this mean that you are still getting wow at end of side?  That would mean that there is too much friction definitely.

The friction clutch does not require any stripping down to access, as you just remove the one philips screw on the reel table.  Again i have not done this adjustment myself as there is no fault on mine, but i am happy to have a go myself to assist you.  But seeing as you have done the belts already then you must have skills - no joke.

[pdegro]

here's a manual;  http://home.btconnect.com/gmb/4000D.pdf

here's a service manual;  http://sportsbil.com/other/Akai/AKAI%204000DS%204000DS%20MKII%20SM.pdf

pages 9/10 describes adjusting the friction clutch (4000d is the same as 4000ds in this aspect, and most)

Well done for changing the belts.  Does this mean that you are still getting wow at end of side?  That would mean that there is too much friction definitely.

The friction clutch does not require any stripping down to access, as you just remove the one philips screw on the reel table.  Again i have not done this adjustment myself as there is no fault on mine, but i am happy to have a go myself to assist you.  But seeing as you have done the belts already then you must have skills - no joke.

Hello again, and thanks Paul for these links.
First I'll put some pics on how I changed the captan belt.

A look on the inside:



This nut must be loosened a few turns:



Now this bracket can be moved and the belt can be pulled over the flywheel:



The hardest part is to pull the old belt through the front here. A long pair of tweezers is a useful attribute.



Close-up of the place where the old belt should come out:



The new belt is going in through the same path, this is also a bit of fiddling.
When you restore the bracket there should be 0, 3 mm. clearance remain on the flywheel.


Now, with the new belt, there is little improvement.  At the end of a reel there still is some flutter and tape speed reducing...
I'll put a new post on this item soon.

Greetz,
Pierre

[pde2000]

That bearing brace is much better designed for changing the belt - nice.

A possible way of reducing the friction of the feed spool would be to run the tape with the pinch wheel disengaged but without amplifying the output, as this will let it run as fast as possible.  Some prerecorded tapes were supplied on reels with much larger hub diameters, like the professional ones that have a NAB hub instead of 1/4", and i suppose that was to prevent the supply reel ever having to get up to this sort of speed.

It could after all be just a matter of having been left idle for too long.

[tso533]

I would like to thank you for this post, I have just had to replace my belt and without this as a guide, I am not sure what I would have done, thanks very much

-tso533

[pdegro]

I would like to thank you for this post, I have just had to replace my belt and without this as a guide, I am not sure what I would have done, thanks very much

-tso533

You're most welcome. Glad this has been a help for you.
Have fun with this nice deck.  Mine is still up and running.

[Kent T]

There's two idler wheels, there's the pinch roller (which gets dented up when careless users don't stop the machine, or leave it in pause). Also the motor needs maintenance. Especially with age. Bear these items in mind.

[billyjk]

Hi - new to this forum.  I wanted to pull this thread back from the depths to say THANKS for this!

I just got a GX-4000d and I am going through the process of cleaning it up and getting it ready to transfer some old family tapes.

This thread refers to two different decks: the GX-4000d and the GX-4000ds interchangeably.  Which machine did the OP have?

Also, where there instructions that the OP used to replace the capstan belt?  I may have to do that, and can't find any real descriptive info to use to accomplish that task.

Thanks again!
-bjk

[Kent T]

A note: This tape deck has idler wheels, belts, and the pinch roller. All the rubber needs to be in top condition for best results. The machine is simple, basic mechanically speaking, but very competent in good order. Don't be surprised if your machine needs some rebuilt rubber and mechanical overhaul.

[pde2000]

After playing through my collection of pre-recorded tapes I have started having the same problem as the OP.  Having ordered a new drive belt I stripped the deck down in readiness but..... the belt is in great condition.  I had not thought to clean the pinch roller, and this was what was causing the w&f.  As the large spool puts a strain on the tape path any loss of grip at the capstan allows a jerky motion.

I know this is an old thread but it may be useful to somebody in the future looking for answers.  It was after all the most obvious and simple solution.

These old Akai R2Rs are bomb proof - mine fell off a top shelf a couple of years ago and the cabinet got dinged but the only damage is cosmetic.



edit:  there seems to be an intermittant fault with the motor run capacitor causing loss of torque. The capacitor is 2.5uF (500V ish)

subedit:  nothing wrong with the capacitor but the spindle sleeve was a bit loose.  I have added a friction washer between the sleeve and the nurled knob and now there is no hint of w&f  

sub subedit:  replaced the belt (from Malvern Hills) and now the performance is rock solid.  The old belt was a bit knackered