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Akai 4000ds MK-II idler wheel lubrication

H

henrylr

Active Member
I bought an AKAI 4000DS MK-II new in the 1970s and it worked well for many years. but hasn't been used in the last 5 years. I tried it yesterday and the take-up reel didn't rotate. I took the cover off and saw the idler wheel was rotating but the reel wasn't. I've viewed some youtubes showing AKAI repairs and learned that worn idler wheels and/or low torque caused by worn springs can be the cause. I bought new wheels and that made a slight improvement, but the torque was quite low. I've also read that shortening the spring can increase torque, but I didn't want to cut the spring. So, using pliers I grabbed the spring above the frame where it locks into the hole, pulled it out of the hole, rotated it two turns, to tighten it, and secured it back into the hole. Now the reel rotates well with plenty of torque. And, while some youtubes showed idler wheels being replaced they didn't show or give any info on lubrication. My Akai has one wheel with a nylon bushing and the other with a brass bushing and there is no trace of any lube in the wheel bushings or on the spindles. My question is would the idler wheel with the nylon bushing not need lubrication and the one with the brass bushing need lubrication? And what type of lube should be used?
Thanks
 
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I decided to lube both the nylon bushed and brass bushed idler wheels. I tried an adhesive oil, like Renotac, a sticky oil typically used for vertical turntable spindle bearings. The nylon bushed wheels spun well but some oil ran down to the spindle base and then down the arms they are attached to. So, I cleaned those wheels and spindles with isopropyl and applied Shell Alvania (GADUS) grease, it works great and doesn't run. The sintered brass bushed wheel had no oil runout, so I left it with the adhesive oil.
 
I've replaced belts and lubricated most moving parts, but not the tape drive capstan. I've seen a youtube showing that capstan being disassembled, cleaned and reassembled. It showed a felt ring under the metal cap and said it was for keeping oil in the spindle bearing. Mine has the metal cap and there is a small opening in it. Is that opening for adding oil, to the felt ring, so it gets into the spindle bearing?
Thanks
 

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I just popped the cap off with a very small plier and there is no glue, and it just snaps back on. So now I can slide off the felt washer and lube the spindle with a few drops of the 20w synthetic oil. And I finally found lube instructions is the service manual for the Akai 4000D R2R. This manual has much more detailed info than the other 4000 series manuals.
 
I just popped the cap off with a very small plier and there is no glue, and it just snaps back on. So now I can slide off the felt washer and lube the spindle with a few drops of the 20w synthetic oil. And I finally found lube instructions is the service manual for the Akai 4000D R2R. This manual has much more detailed info than the other 4000 series manuals.
 
My thought that applying oil on felt ring might lubricate the spindle was wrong. The video shows that the felt ring inner diameter sits around the outer diameter of the bearing. So, I'm guessing it purpose is to keep oil, migrating out of the front edge of the spindle, from running down on the capstan body and parts below.
 
Are washers used on the pinch roller spindle, either in front of or behind the pinch roller? I've looked at many of the Akai service manuals, for decks that have pinch rollers, and they don't show any washers, but some part numbers in the parts list are followed by an X and it is stated they are not shown.
Thanks
 
The reason I ask is that I just completed cleaning and lubing the motor, flywheel spindle and other moving parts and replaced belts, and when I started it, without the pinch wheel in contact with the spinning capstan, it was very quiet. When I put it into play, the pinch roller was spinning, and there was a bit of noise seeming to come from area of the pinch roller. I happen to have a couple of .01 thick teflon washers and put one on the pinch roller spindle, then put the pinch roller on the spindle and secured it with the cap. It is now much quieter. Maybe it was the back face of the brass bushing rubbing against the bottom surface of the steel spindle. has anyone experienced this?
 
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