Nagra IV drive belt replacement, how to

[Roy Cross]

Hello,

I have a nice IV-L. Pulled it out recently and have been test recording with it. Nothing serious at this point. The drive belts need replacing. I've ordered both belts. I can't find any video of a "how to". Anyone have any leads? Or do I make one as I do mine?

It "looks" simple enough, but I'm aware that all is never easy inside any sophisticated machine. I do have the service manual, but it does not offer tips on belt replacement.  

Thanks!

Roy in Montreal

 

[Mark Dunn]

I only have the instruaction manual. From the diagrams at the end, looks like you go in from underneath. I'd say the battery compartment comes out first. As a frequent repair café volunteer I'd certainly have a go, but I don't know your level of confidence. 

Get yourself a good set of screwdrivers and try not to chew up too many screw heads.

Does whoever you ordered the belts from have any info?

Edited August 26 by Mark Dunn

[Roy Cross]

Thanks, Mark. 

The top actually is on a hinge and flips open. Access to the inside is the easy part. Various covers need to be removed it seems to slip the belts off their pulleys.

[Dave Beling]

Replacing belts on Nagra III or IV is fairly easy. Open the top deck and put it so motor faces you. Remove 4 hex screws securing motor plate. Then carefully lift complete motor plate and put it aside. Underneath is phonic wheel and capstan, so be careful. After lifting you gained access to take up belt, which is threaded between phonic wheel and motor plate. Supply spool belt is exchanged also with motor plate lifted. 
 

it’s easier to show rather than tell. If you have any problems I can send you more pictures how to do it.

[Roy Cross]

Amazing! Thank you!

Waiting for the belts to arrive. This diagram will be very useful!

[Roy Cross]

Motor plate is hindered by wires soldered to the motor. I think I can liftit up, but certainly won't be able to set it aside.

[Roy Cross]

On 8/29/2026 at 2:52 PM, Dave Beling said:

Replacing belts on Nagra III or IV is fairly easy. Open the top deck and put it so motor faces you. Remove 4 hex screws securing motor plate. Then carefully lift complete motor plate and put it aside. Underneath is phonic wheel and capstan, so be careful. After lifting you gained access to take up belt, which is threaded between phonic wheel and motor plate. Supply spool belt is exchanged also with motor plate lifted. 
 

it’s easier to show rather than tell. If you have any problems I can send you more pictures how to do it.

I was able to replace the feed spool belt (which is also the rewind). That belt was the rougher of the two. I'll tackle the other tomorrow.

[Dave Beling]

Lift silver cup up from the motor. Then you should be able to move plate with motor more freely.