Author Topic: Need help on where to use rat tail file on turn switch  (Read 5060 times)

rutger kohler

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Need help on where to use rat tail file on turn switch
« on: October 25, 2012, 07:38:33 »
I have just about finished refurbishing my turn switch, thanks to several excellent posts on the subject thanks. On reassembly the Lever stays on and cancels 100% turning right and stays on 85% turning left (cancel is fine).  There is a description on how to file a curve, in the switch, in the Technical manual but I can't identify which and where it is. I assume it is on the exterior as there is no mention of disassembling the switch.

I think it may be the stop that prevents the roller arms moving any closer to the centre?  Can someone help plse?
1969 280 SL Manual gear shift
1972 280SE 3.5 auto

w113dude

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Re: Need help on where to use rat tail file on turn switch
« Reply #1 on: October 25, 2012, 11:24:15 »
I think it may be the stop that prevents the roller arms moving any closer to the centre?  Can someone help plse?

I just looked at one I had out and Yes it's those rollers that drop in to two notches that makes it stop and cancel, sometimes those rollers or roller pins are so worn that makes it very difficult to stay in place. but can be saved. lets face it what ever you do will be a lot less than $500 USD for a new unit.

Cheers,
 

rutger kohler

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Re: Need help on where to use rat tail file on turn switch
« Reply #2 on: October 25, 2012, 20:01:38 »
Hi Shaun, yes both the rollers on my unit had completely worn though on one side!  I machined new ones up, and also one of the rivets that holds the roller arm was gone so I replaced that.  I need to be absolutely sure you mean  filing the actual switch die cast body on the outside where the roller arms come to rest.  This would mean that the roller arm could move closer to the centre?  Have tried to take a photo but they come out blurry.

cheers

Rutger Kohler
1969 280 SL Manual gear shift
1972 280SE 3.5 auto

w113dude

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Re: Need help on where to use rat tail file on turn switch
« Reply #3 on: October 25, 2012, 21:19:19 »
Hey Rutger,

It's hard to explain just take your time when filing do very little at a time if you over file it wont work right

rutger kohler

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Re: Need help on where to use rat tail file on turn switch
« Reply #4 on: October 30, 2012, 19:20:19 »
Hi, have finished the repairs to my turn switch successfully. as mentioned the two rollers were each worn through completely on one side, so I machined new ones out of brass.  The measurements for the rollers are 3mm ID x 4mm OD x 5mm long if others wish to do this.

One of the rivets holding the roller arms had let go on the top as is common. I was not successful in locating the wire drill and tap mentioned in an earlier post, in fact in the town that I live no one could supply machine screws smaller than 3mm or 1/8".

I decided I would have to use a 3mm screw but didn't want the roller arm  to run on a thead as it would soon wear down. I drilled and tapped the casing 3mm but only used the taper and intermediate taps to keep the thread fairly tight in the casing.

A 3mm cap screw, 50mm long, was then purchased and I used a split 3mm die and gradually extended the thread down the shank until it left just enough unthreaded shank under the head to allow for the roller arm thickness and a tiny bit of end clearance. This takes quite a bit of patience and trial. (The split die was gradually tightened over 3 or so runs so as to get a good thread profile)

The head of the cap screw was then ground down so that it would end up just below the die cast rib, in the casing, and thus not foul the other moving parts of the switch when it was reassembled. (it ends up about 1mm thick)

The roller arm was then mounted onto the cap screw which was then screwed into the casing by hand and when the threaded end cleared the casing on the other side two 3mm nuts were locked up against each other and used to finally tighten the cap screw into position.

It was not possible to use loctite in this operation but  the cap screw tightened up well against the casing at the end of the thread.(you could leave the end of the thread proud and peen it over if you wished, but be sure to mount a piece of steel in a vice to support the ground end of the cap screw if you do this) The surplus thread was then cut off with a junior hacksaw.

I also took the opportunity to ressurect the flash function for the headlights as the wires had been disconnected in the bakelite plug under the dash.  Thanks to earlier posts this was easy.
1969 280 SL Manual gear shift
1972 280SE 3.5 auto

450sl

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Neil Thompson

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Re: Need help on where to use rat tail file on turn switch
« Reply #6 on: October 31, 2012, 19:52:35 »
Good video but quite different to 113 switches
1964 230 SL RHD DB304 Horizon Blue
1957 190 SL RHD DB180 Silver
1988 R107 300 SL RHD DB199 Blue Black
1978 C123 230C 2dr Auto RHD Silver