Grundig slipping tuning mechanism. - UK Vintage Radio Repair and Restoration Discussion Forum

Pilot Mariner · 2nd Dec 2025, 10:10 am

Members may remember the saga with this Grundig 5097 earlier this year.

https://www.vintage-radio.net/forum/showthread.php?t=218004

Over the past few months, the tuning started slipping when set to VHF – this is a known issue with the clutch mechanism on many Grundig sets where the VHF (or AM) pulley slips against the flywheel due to wear or contamination.

A quick fix I found is to insert strips of sticky backed felt between the pulley and the flywheel with the sticky side applied to the flywheel. When set to AM the pulley can be moved against the spring to create enough gap for the felt to be inserted using a pair of tweezers.

This can easily be done with the chassis in situ.

There is now sufficient grip for the flywheel to turn the pully over the entire width of the tuning dial.

I don’t know how long this will last but at the moment it is holding its own, or is there a better material than sticky backed felt anyone could suggest?

bobbyball · 3rd Dec 2025, 7:12 am

I have several Grundig models with the same tuning arrangement, including one that had a flywheel made of "monkey metal" and that had swelled and was catching. Managed to change it from one off a scrapper but keeping all the pulleys in place while pulling the shaft out was fun. This one was also slipping and I had some left over foam sheets that I had bought from Hobbycraft ("Other suppliers are available") and that I had used to make new cone support surrounds for the bass speakers in my big Grundig radiogram. These sheets are available in a number of colours (I chose yellow 'cause I could see it best) and are about 1-2 mm thick and very strong. They were also absolutely ideal for making some "washers" that I managed to fix inside the slipping tuning mechanism of the other radio and do the same job (well) as my fellow Forum Member above has had success with his felt strips.

vinrads · 3rd Dec 2025, 9:20 am

Nice fix ! I have done the same using a piece of thin rubber to make a washer ,a smear of contact glue to one side .Was the original a foam washer?. Mick.

bobbyball · 3rd Dec 2025, 6:26 pm

No there's no washer as such, just some sort of strange "rough" surface on one of the pulleys that seems to wear down with time, becoming less and less effective until it just slips. Never did work out what the original material could be!

2nd Dec 2025, 10:10 am	#1
Pilot Mariner Heptode Join Date: Jun 2003 Location: Burntwood, Staffordshire, UK or Kabaty in Warsaw Poland. Posts: 617	Grundig slipping tuning mechanism. Members may remember the saga with this Grundig 5097 earlier this year. https://www.vintage-radio.net/forum/showthread.php?t=218004 Over the past few months, the tuning started slipping when set to VHF – this is a known issue with the clutch mechanism on many Grundig sets where the VHF (or AM) pulley slips against the flywheel due to wear or contamination. A quick fix I found is to insert strips of sticky backed felt between the pulley and the flywheel with the sticky side applied to the flywheel. When set to AM the pulley can be moved against the spring to create enough gap for the felt to be inserted using a pair of tweezers. This can easily be done with the chassis in situ. There is now sufficient grip for the flywheel to turn the pully over the entire width of the tuning dial. I don’t know how long this will last but at the moment it is holding its own, or is there a better material than sticky backed felt anyone could suggest? Attached Thumbnails

3rd Dec 2025, 7:12 am	#2
bobbyball Octode Join Date: Jul 2011 Location: Stockport, Greater Manchester Posts: 1,519	Re: Grundig slipping tuning mechanism. I have several Grundig models with the same tuning arrangement, including one that had a flywheel made of "monkey metal" and that had swelled and was catching. Managed to change it from one off a scrapper but keeping all the pulleys in place while pulling the shaft out was fun. This one was also slipping and I had some left over foam sheets that I had bought from Hobbycraft ("Other suppliers are available") and that I had used to make new cone support surrounds for the bass speakers in my big Grundig radiogram. These sheets are available in a number of colours (I chose yellow 'cause I could see it best) and are about 1-2 mm thick and very strong. They were also absolutely ideal for making some "washers" that I managed to fix inside the slipping tuning mechanism of the other radio and do the same job (well) as my fellow Forum Member above has had success with his felt strips. __________________ Robert

3rd Dec 2025, 9:20 am	#3
vinrads Dekatron Join Date: Feb 2009 Location: Chesterfield, Derbyshire, UK. Posts: 4,058	Re: Grundig slipping tuning mechanism. Nice fix ! I have done the same using a piece of thin rubber to make a washer ,a smear of contact glue to one side .Was the original a foam washer?. Mick.

3rd Dec 2025, 6:26 pm	#4
bobbyball Octode Join Date: Jul 2011 Location: Stockport, Greater Manchester Posts: 1,519	Re: Grundig slipping tuning mechanism. No there's no washer as such, just some sort of strange "rough" surface on one of the pulleys that seems to wear down with time, becoming less and less effective until it just slips. Never did work out what the original material could be! __________________ Robert