Has anyone fixed the cluster potentiometer in situ? - Page 2 - PeachParts Mercedes-Benz Forum

okyoureabeast · #16 04-18-2019, 07:56 PM

Quote:

Originally Posted by JHZR2

I remember that. Ive been on here for a long time, since the mercedesshop days (2002ish). There are some older diys about cleaning the prisms and doing all kinds of great stuff if one looks way back.

You can’t sleays trust color balance in pics. Thanks for the link and info!

It won't be the warm glow you're used to with incandescent. Trust the LED color temp ratings instead.

If it says white 4.8k, I'd trust that it's going to be 4.8k. If you want that Amber color, I'd find a set with that color temp.

May I offer a clipable light for your dash in case you get stuck out at night

JHZR2 · #17 04-18-2019, 09:44 PM

Lol. Love the clip on light!

JHZR2 · #18 07-01-2019, 12:48 AM

To follow up on this, it is possible to pull the potentiometer with the cluster in place.

All one needs is a stubby #1 Phillips screwdriver. Then it slides right out the back, assuming Thor kickoanel is off and you can reach from behind/under, and then slide it off the posts.

Then just need to clean and solder a jumper. Pics when I have a chance.

vwnate1 · #19 07-01-2019, 12:07 PM

I find it simple to remove the entire binnacle, as soon as you can slip your hand behind it, reach in and undo the speedo cable so you're not risking kinking or otherwise damaging it by yanking on it .

I always lube any speedo cables when I get access, liquid graphite is the preferred lubricant .

It takes the car raised and safely supported to reach the always filthy & greasy transmission end of the cable along with a 10MM ATF socket, extension and knuckle or wobble, more work than benefit .

My first thought was 'yes, one can reach the potentiometer from the footwell but why ?' .

Cleaning all the dust out of the binnacle and polishing the inside of the clear lens makes an amazing improvement too .

JHZR2 · #20 07-01-2019, 12:55 PM

Quote:

Originally Posted by vwnate1

I find it simple to remove the entire binnacle, as soon as you can slip your hand behind it, reach in and undo the speedo cable so you're not risking kinking or otherwise damaging it by yanking on it .

I always lube any speedo cables when I get access, liquid graphite is the preferred lubricant .

It takes the car raised and safely supported to reach the always filthy & greasy transmission end of the cable along with a 10MM ATF socket, extension and knuckle or wobble, more work than benefit .

My first thought was 'yes, one can reach the potentiometer from the footwell but why ?' .

Cleaning all the dust out of the binnacle and polishing the inside of the clear lens makes an amazing improvement too .

It is simple. I’ve done it many times before. This specific car for whatever reason is very sensitive to cable routing and speedometer bounce. Just is what it is. And I don’t want to have bounce because it affects cruise control too.

Alas, in unscrewing and rescrewing, the cluster was pushed out and in a bit. Enough that the speedometer now has a slight bounce at all speeds. Ugh. And yes, it’s a new cable, we’ll lubed, etc.

h3ffe · #21 07-01-2019, 01:22 PM

This is accurate.

You can also pull the cluster out slightly and take it apart with things connected (with that stubby screwdriver). I recently took my buddy's 240D cluster apart to paint the needles, clean and refresh the housings, jumper the potentiometer, gauge trim rings, etc. We didn't disconnect the speedo cable or the oil pressure gauge line. Did most of it in place.

It wasn't particularly fun to do all that in place, but his oil line on the back of the gauge had previously been overtightened, so we opted not to remove.

Quote:

Originally Posted by JHZR2

To follow up on this, it is possible to pull the potentiometer with the cluster in place.

All one needs is a stubby #1 Phillips screwdriver. Then it slides right out the back, assuming Thor kickoanel is off and you can reach from behind/under, and then slide it off the posts.

Then just need to clean and solder a jumper. Pics when I have a chance.

DeliveryValve · #22 07-01-2019, 04:43 PM

Sometimes you can get a connection going on a rheostat by turning and pressing down and turning the knob several times. Just working it back and forth. The idea is several sweeping motion of the wiper will get a contact going again. But if the rheostat is acting difficult, then removal will be necessary.

.

JHZR2 · #23 07-02-2019, 02:09 AM

Quote:

Originally Posted by DeliveryValve

Sometimes you can get a connection going on a rheostat by turning and pressing down and turning the knob several times. Just working it back and forth. The idea is several sweeping motion of the wiper will get a contact going again. But if the rheostat is acting difficult, then removal will be necessary.

.

Not on this one or on my 240d. They used to be like that.

This one the “spring” inside was hanging out the bottom. Wasn’t going to go back to working.

While I would have probably turned the lights back a tad on a working potentiometer, full blast isn’t really that bright...

DeliveryValve · #24 07-02-2019, 11:28 AM

Well there you go. Sometimes you just got to go in there and remove it...

vwnate1 · #25 07-03-2019, 10:02 AM

Coming here is like going to school only better ~ I get to learn things I enjoy learning and at the same time get to read differing life experiences and views....

All FOR FREE no less

.

JHZR2 · #26 07-03-2019, 11:31 AM

So now I can’t get my speedometer back to normal (the reason a I had concern to start).

The needle does one of a few things:
1) bounces about 10 mph up to 20 (somewhat normal) then wobbles at higher speed
2) bounces less at low speed and just oscillates at higher speeds
3) smooths but has moose and requires me holding it in a certain position.

The cable is new. It was lubed. I’m thinking the speedometer itself is somewhat sensitive. I had lived the input shaft bushing previously.

vwnate1 · #27 07-03-2019, 10:31 PM

Hopefully you lubed the speedo bushing previously....

.

Maybe it's time to lubricate it again ? .

Try some synthetic oil ? .

Or send the speedo head out for rebuilding .

JHZR2 · #28 07-03-2019, 11:56 PM

Quote:

Originally Posted by vwnate1

Hopefully you lubed the speedo bushing previously....

.

Maybe it's time to lubricate it again ? .

Try some synthetic oil ? .

Or send the speedo head out for rebuilding .

Not my first trip to the rodeo.

Speedometer cable/speedometer bounce woes

Can re-lube of course. But as you can see from there, it’s just a heightened sensitivity.

vwnate1 · #29 07-04-2019, 04:33 PM

Got it, bummer, this .

Diseasel300 · #30 07-04-2019, 06:29 PM

Quote:

Originally Posted by JHZR2

Not my first trip to the rodeo.

Speedometer cable/speedometer bounce woes

Can re-lube of course. But as you can see from there, it’s just a heightened sensitivity.

Hopefully you didn't get any of that grease in the bronze bearing on the speedo head. If you did, it's now junk, no amount of lubing, oiling, or special sprays will bring it back. The grease will block the pores, gall the bronze, and game over. Non-detergent lightweight oil (such as Zoom turbine oil) on bronze bushings only! People often think grease or "3 in 1" type oils are fine and they're simply not, it's a band-aid until they dry out and ruin the bushing!

Since lubricating the bushing was clearly the issue in your previous thread, it's time to revisit it. Assuming it's free of grease, flood the bearing with a quality turbine style oil and let it soak for a period of time, the pores of the bronze need to soak up the oil so it can "sweat" when it warms up.

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