Seat back lever knob repair

[col320ce]

Has anyone tried repairing this lever knob. It's broken on both my seats? I'm wondering if I can tap the square section or drill the centre out and put a rod in there and tap that...

[DaveB]

It must be a common problem, one of mine is broken too. So hopefully somebody's already done it and can advise.
Either way would work I reckon. The rod insert possibly stronger? Easier would be to weld on a short section of threaded rod. I think the plastic knob would cover the join. However the heat might have some unpredictable effects.

[col320ce]

I thought about welding but I don't have the skills or tools and thought that it probably would need rechroming afterwards.

[chumps]

When I bought my SL it had a broken rod like yours. It bothered me so I looked for a new seat mechanism but could not find one. So for a temporary fix (25 years ago) I measured the thread length on the good side and ground the broken rod round down to the amount of thread length. Then used a die to cut the threads the same size as the threads in the plastic knob. It looked and worked great. I have never given it another thought. In my opinion it is poorly designed mechanism. Chumps   

[col320ce]

I think that will be the easiest fix. As both mine are broken I don't know what the threads pitch/length etc is but I think I'll be able to work it out when the new knobs arrive.

[DaveB]

Good to know thanks Chumps. I agree it's poorly designed, too slender.
Col could you please post the thread information when you have it? I checked mine and, like yours, both are broken.

[col320ce]

Will do Dave.

[col320ce]

4mm 0.7 thread
I threaded about 20mm
I rounded it to about 4.5mm with an angle grinder then tapped it with a larger dye to make it round then hand filed to 3.9mm about then final dye.
Took about 10 minutes.

[DaveB]

Got that thank you.