W126 cluster rebuild - need help - PeachParts Mercedes-Benz Forum

eatont9999 · #1 01-14-2013, 09:46 PM

All,

I am trying to use parts from several different clusters to make one good cluster for my 300SD. I found a near perfect cluster from a 1991 300SE and even the needles still have their orange color. My goal is to add an outside temp sensor as well as re-beautify the cluster. I want to use the housing from the 1991 300SE because the light tunnels are in very nice condition and the rest of it is very clean. It also has a temp sensor unit. The problem I am having is that I need to change out the plastic strips that run along the bottom for the idiot lights. My car does not have ABS or SRS or ARS, etc and I need to have the glow plug light, etc. I don't know how to replace these strips and the front face of the cluster seems to be molded to the rest. Is this going to be possible or do I have to destroy the cluster just to get at the strip for the idiot lights?

Also, any tips for removing and replacing the needles will be appreciated.

Thanks!

shadetree77 · #2 01-14-2013, 10:21 PM

been there, done that, got the t-shirt, and a cracked bottom cluster. it is indeed sealed in there. i wasn't very careful tough since it was for my beater and it only cracked one line on it it. i'm thinking if you can use a dremel and cut the sides it might work. i pulled some needles (if they're nice) off junkyard gauges with a little tool i have (no idea what it's called but it looks like a miniature pickle fork). i never swapped needles on gauges; i'd be afraid of the accuracy after removing and replacing needles

jimandsuzy · #3 01-14-2013, 10:41 PM

Other people have used 2 spoons to put equal pressure on each side to pop them off. Cloth or something soft under spoons.

charmalu · #4 01-14-2013, 10:48 PM

Iam not sure if the 126 spedo face has it but the 123 face does. On the edge of the face to the right of the pin the needle rests on, there is a small white mark. lift the needle over the pin, and it should line up with the paint mark. when you replace the needle, line it up with this mark.

Charlie

jay_bob · #5 01-14-2013, 11:08 PM

Quote:

Originally Posted by eatont9999

I need to change out the plastic strips that run along the bottom for the idiot lights.

On the outer edges of the cluster, at the bottom left and right, behind the lip, are two small slots. The legend strips slide into these slots. A small hooked probe works great - there is a hole in the end of the strip. A suitable tool can be made from a paper clip.

After 20+ years they can be in there rather snug...

eatont9999 · #6 01-15-2013, 12:49 AM

Quote:

Originally Posted by jay_bob

On the outer edges of the cluster, at the bottom left and right, behind the lip, are two small slots. The legend strips slide into these slots. A small hooked probe works great - there is a hole in the end of the strip. A suitable tool can be made from a paper clip.

After 20+ years they can be in there rather snug...

Interesting. After looking at a few clusters, I don't see what you are referring to on the left and right sides. I don't see any way to access the strips. Could you post pictures or if I did, could you point out what you are referring to? Sorry, I am just not seeing it.

The two spoons method is interesting. I wonder if it would really work. The last thing I want to do is damage some otherwise good needles for the sake of color. I can try to find the neon orange paint and re-paint what I have but I do want to transfer over the clock since mine does not keep good time.

I'm thinking about hooking up the efficiency gauge to the transmission modulator for effect and possibly timing shifts more visually. I dunno. I want to make that into a boost gauge at some point but until I find the appropriate sized components, it has to function as a vacuum gauge for now. I also have the dilemma of the "Unleaded Premium Only" verbiage on the face near the fuel level gauge. I might be able to have one of our artists black out and re-write "Diesel Fuel Only" or the like but blacking out the current text will not likely contrast.

vstech · #7 01-15-2013, 01:24 AM

Quote:

Originally Posted by jay_bob

On the outer edges of the cluster, at the bottom left and right, behind the lip, are two small slots. The legend strips slide into these slots. A small hooked probe works great - there is a hole in the end of the strip. A suitable tool can be made from a paper clip.

After 20+ years they can be in there rather snug...

Hmm
I've had several clusters apart, and the 123 and 126 clusters generally have glued in icon plates.... I'll look closely at the lower sections tomorrow...

MBDFahrer · #8 01-15-2013, 05:54 AM

I have actually done this exact procedure on my car using a cluster from a 91 300SE. If you carefully separate the fabric along the bottom of the cluster, it exposes the groove and even a little notch for you to grab the icon strip with a pair of tweezers.

If my back isn't bothering me too much, I'll try and get some photos tomorrow.

jay_bob · #9 01-15-2013, 06:08 PM

Just bear in mind the Diesel and gas tachs are different.

Diesel is 1 pulse/rev off the harmonic balancer pickup, gas is from the ignition and has however many pulses/rev based on your cylinder count.

If you try to use a gas tach on a Diesel it pins out at 7k as soon as you crank the engine. BTDT.

eatont9999 · #10 01-15-2013, 06:59 PM

Quote:

Originally Posted by jay_bob

Just bear in mind the Diesel and gas tachs are different.

Diesel is 1 pulse/rev off the harmonic balancer pickup, gas is from the ignition and has however many pulses/rev based on your cylinder count.

If you try to use a gas tach on a Diesel it pins out at 7k as soon as you crank the engine. BTDT.

Good to know. I figured the gas tach would not work and I did not plan on using it. I will steal the needle from it and swap the clock mechanism into a Diesel tach, though. That or I will paint my old needles. I have not decided yet.

I just need to get those idiot light strips out. I'll take another look at the cluster tonight. I hate to destroy the felt on the bottom but if that is what it takes...

mach4 · #11 01-15-2013, 07:20 PM

Quote:

Originally Posted by jay_bob

Just bear in mind the Diesel and gas tachs are different.

Diesel is 1 pulse/rev off the harmonic balancer pickup, gas is from the ignition and has however many pulses/rev based on your cylinder count.

If you try to use a gas tach on a Diesel it pins out at 7k as soon as you crank the engine. BTDT.

Also be aware that the later diesels had a pickup on the flywheel housing and the tach amp was replaced by the EGR controller as the source of the feed to the tach itself. These had yet a different tach module.

MBDFahrer · #12 01-16-2013, 01:05 AM

As promised, here's the images of where to access the strips for the cluster. I kept the fuel/engine temp/oil pressure dials and the tach from my car but the speedo from a 500SEL since my car has a differential swap. I also have the outside temperature display installed in mine.

In order to access the strip, just carefully peel back the bottom fabric. I used a hobby knife and just lightly cut the adhesive.

I also included a shot of my cluster (the speedo needle needs to be repainted):

eatont9999 · #13 01-16-2013, 11:01 AM

Thanks Jason! I figured out how to get the strips out last night. Your pictures will help anyone else who is looking for this info. I turned the oven on very low, removed all the components from the cluster housing and placed the housing in the oven for a few minutes. The adhesive for the bottom felt warmed up enough that it could be easily peeled back to access the idiot light strips. This method allowed me to put the felt back in place without damaging it or messing up the adhesive.

I might add that I painted my old needles with L'Oreal "L'Orange" 410 nail polish but it is a little too red and makes the needles hard to see in low light. I will search for a more neon orange paint and re-paint them. I also need a flat paint to reduce the glare on the needles.

The oil/gas/temp cluster from the gas car does not seem to work well on a Diesel. No temp reading, no lights, fuel gauge seems off and the empty light is lit with 1/2 tank, GP light stays on all the time. The wiring must be different for the gasser. I guess I'll have to use the Diesel one and hack in the efficiency gauge and face.

jay_bob · #14 01-16-2013, 01:11 PM

Paint: try Testors hobby paint

F-O-T gauges: ensure you have the connector clocked properly. It is possible to insert it wrong either by brute force or if the keying pin is broken off.
If this has happened look at the pin numbers on the connector and the circuit board. Then use white paint to make a witness mark for future reference.

As far as I know, Gas and Diesels do not have any differences on the F-O-T other than the words on the front. And if you have a gas model with the Econ gauge it can be repurposed as a Boost gauge.

eatont9999 · #15 01-16-2013, 12:27 PM

Fluorescent paint for speedometer needles:

Fluorescent Speedo & Gauge Needle Restoration Paint - HiPo Parts Garage

The price is right. Cheaper than the nail polish!