Author Topic: Seat back lever knob repair  (Read 2972 times)

col320ce

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Seat back lever knob repair
« on: February 13, 2021, 07:47:31 »
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...
Col

1964 230SL
1965 250SE coupe
1993 320CE Sportline
And George, the infamous 1992 Ford Laser

DaveB

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Re: Seat back lever knob repair
« Reply #1 on: February 13, 2021, 20:43:47 »
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.
DaveB
'65 US 230sl 4-speed, DB190

col320ce

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Re: Seat back lever knob repair
« Reply #2 on: February 13, 2021, 21:39:10 »
I thought about welding but I don't have the skills or tools and thought that it probably would need rechroming afterwards.
Col

1964 230SL
1965 250SE coupe
1993 320CE Sportline
And George, the infamous 1992 Ford Laser

chumps

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Re: Seat back lever knob repair
« Reply #3 on: February 14, 2021, 00:27:21 »
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

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Re: Seat back lever knob repair
« Reply #4 on: February 14, 2021, 02:20:46 »
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.
Col

1964 230SL
1965 250SE coupe
1993 320CE Sportline
And George, the infamous 1992 Ford Laser

DaveB

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Re: Seat back lever knob repair
« Reply #5 on: February 15, 2021, 01:35:02 »
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.
DaveB
'65 US 230sl 4-speed, DB190

col320ce

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Re: Seat back lever knob repair
« Reply #6 on: February 15, 2021, 02:15:10 »
Will do Dave.
Col

1964 230SL
1965 250SE coupe
1993 320CE Sportline
And George, the infamous 1992 Ford Laser

col320ce

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Re: Seat back lever knob repair
« Reply #7 on: May 14, 2021, 03:22:40 »
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.
Col

1964 230SL
1965 250SE coupe
1993 320CE Sportline
And George, the infamous 1992 Ford Laser

DaveB

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Re: Seat back lever knob repair
« Reply #8 on: May 15, 2021, 02:35:09 »
Got that thank you.
DaveB
'65 US 230sl 4-speed, DB190

 

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