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My speedometer cable is broken, right? 1980 300SD

Started by WrightSounds, 06 January 2014, 08:07 PM

WrightSounds

Hey Everybody,
Went to run an errand yesterday and very quickly realized my speedometer and odometer weren't working.
I pulled the instrument cluster and the speedo cable connection there looked good and tight.
Although looking under the car where it leads to the transmission it appears to have broken.
I'm not 100% positive though so I took a quick video: http://www.youtube.com/watch?v=2bdAMDk5Wac

I'm pretty proud of myself for getting the instrument cluster pulled out without breaking anything so I'm kind of excited to potentially fix this on my own. I see how to unscrew the speedo cable from the back of the cluster but I don't see how to remove it down by the transmission,
where it has seemed to have broken. I've searched here and at Peachparts and I keep reading how this is an "easy" job so I'm
getting my hopes up. Also, as usual, couldn't find it in the manual here in the library. And I'm hoping somebody could confirm that this is indeed the correct cable I would need to fit in my 1980 300SD? http://www.ebay.com/itm/Mercedes-W116-280S-280SE-450SE-Speedometer-Cable-Gemo-116-542-01-07-/151107519767?pt=Motors_Car_Truck_Parts_Accessories&fits=Year%3A1980%7CModel%3A300SD&hash=item232eb5c517&vxp=mtr


Thanks in advance for any info!

polymathman

OK, you broke the cable housing. That is a bit more work than the cable itself, an easy job. You have to trace the old cable housing all the way back to the instrument cluster - it runs through the floor, under the mats. You will have to get the part number from EPC, realize that is WAY much, then scrounge a replacement from a salvage yard.

You might... see if you can clean out the housing end fitting that is still in the transmission and then square up the end of the cable housing and glue or fasten it in to the fitting. The cable housing will be shorter, so you will have to shorten the cable end that goes into the cluster by the same amount.
Look at it until you know how it all works, then think about it.

Sorry it wasn't an easy fix.
190sl 1957 rusting away
250S 1968 long gone
280SE 1976 got hit, parts
280SE 1979 running fine
C320 4Matic 2005 for wife -Mercedes after MIT

WrightSounds

Thanks for the reply polymathman.
Is the cable housing the black "sheath" or "tube" that covers the cable? Does it have a function besides protecting the cable? Is the housing a separate part than the speedo cable itself? Unfortunately I can't use the EPC because it's not supported by the Mac I use.
I've removed all the floor mats and traced it from the back of the cluster down to where it's broken.
I'll get under the car again and see if I can grasp some more understanding. I "kind of" understand what you mean by gluing or fastening it back to the fitting but I'm not sure why I'd have to shorten the other end at the instrument cluster?
Thanks again for the reply!

Working on a car is very new to me (I build and repair guitars for a living so I'm used to fixing things) and I'll admit I'm petrified of getting near the transmission. I've changed the oil, the fuel filters, fixed the air filter canister housing, and most recently replaced the brake master cylinder. I got a $150 quote from my indie mechanic to fix this problem. That's seeming reasonable compared to my already growing trepidation. :-\

WrightSounds

Quote from: WrightSounds on 07 January 2014, 11:18 AM
I "kind of" understand what you mean by gluing or fastening it back to the fitting but I'm not sure why I'd have to shorten the other end at the instrument cluster?

I think I know what you're talking about now. If I clean and square up the housing and pull it over the fitting and attach it somehow it will need more slack from the instrument cluster side, right?

Squiggle Dog

My speedometer cable did the same thing as yours; the housing pulled away from the fitting, but the center cable was still intact. I was able to push the housing back into the fitting, and have been driving it trouble-free for years. If the fit is snug enough, pushing the housing back into the fitting may fix it.

If you need to remove the cable at the transmission, remove the bolt that goes through the clamp on the transmission, but make sure to remove the bolt all the way! Otherwise the speedometer cable won't slide out because the bolt fits into a groove on the fitting.

I will check the part number for the 300SD speedometer cable. By the way, your transmission looks cleaner than most.
Stop paying for animal cruelty and slaughter. Go vegan! [url="https://challenge22.com/"]https://challenge22.com/[/url]

1967 W110 Universal Wagon, Euro, Turbo Diesel, Tail Fins, 4 Speed Manual Column Shift, A/C
1980 W116 300SD Turbo Diesel, DB479 Walnut Brown, Sunroof, Heated Seats, 350,000+

Squiggle Dog

The part number for the 300SD speedometer cable is 116 542 01 07 and has a list price of $83.00. If you are an MBCA member, you can get up to a 15% discount on that price. The cable on eBay you linked to will work. AutoHausAZ sells an OEM Gemo brand for $44.92.

If your housing won't stay in the fitting, you could try crimping it lightly with some dykes or a punch.
Stop paying for animal cruelty and slaughter. Go vegan! [url="https://challenge22.com/"]https://challenge22.com/[/url]

1967 W110 Universal Wagon, Euro, Turbo Diesel, Tail Fins, 4 Speed Manual Column Shift, A/C
1980 W116 300SD Turbo Diesel, DB479 Walnut Brown, Sunroof, Heated Seats, 350,000+

WrightSounds

Thanks a TON squiggle. I was hoping you'd chime in since you have the same car and your previous posts/tutorials are top notch.  ;)

I got under the car this morning and jammed the housing back in as best I could. Started it up and it works. We'll see how long it lasts!

Thanks again for the info guys!
-Matt

polymathman

Yep - if you shorten the cable, you will have to remove as much from the cable end in the speedometer. The end is squared off, and a bit can be removed.
You might go ahead and get a new cable even it you replace just the housing or repair it. It goes in from the transmission end and is the "easy repair".
Squiggle Dog is right, it can be done, you just have to be ingenious.
190sl 1957 rusting away
250S 1968 long gone
280SE 1976 got hit, parts
280SE 1979 running fine
C320 4Matic 2005 for wife -Mercedes after MIT