Instrument cluster lights VS bloody arm

[cadurning]

In an attempt to repair the instrument cluster lights on my '72 W108 I followed the instructions in the MB factory manual. All I ended up with was a bloody arm and still couldn't reach the knob on the back of the inst cluster. Can the back of the instrument cluster be accessed through the speaker opening or by removing the pad on top of the dash? The dash pad needs to be replaced anyway.

[tjohnson]

My '72 108 had dead dash lights...been sitting for 15 years. Even with the park brake unbolted and out of the way my big ol hand wasn't going in there. I used a can of electronic cleaner and made a double length applicator straw to put it right at the rheostat from behind. gave it a good spray and worked the knob for a couple of minutes. Tested the lights and nadda.......but the next day I cranked her up, turned on the lights and they lit right up! Been working ever since. Have fun

[bwostosh]

Undoubtedly one of the most difficult operations on the whole car. My hand barely can get at the knob from on my back, the seat way back and the bracket which holds the electrical connection unscrewed and out of the way.

Now try to put it back ON!

Being legal blind, a great sense of touch, nimble fingers does the job easily.

[Pooka]

I never thought about going in through the speaker hole.

Push the driver's seat all the way back, lay on the floor under the steering wheel collum and remove the insulation pad that covers up the wiring and such so you can see up under the dash area.

Reach up slowly and carefully behind the instrument panel and feel for some knurled knobs that hold the instrument pod to the dash board. These knobs are just like the ones that hold the taillights in if you need to know what you are feeling for.

I seem to recall that there are three of these knobs that will need to be removed, but you never know. After all these years and previous owners one, two or perhaps all three of the knobs could be missing. The instruments will stay in the dash with no knobs at all, so they may all be missing.

Once all the knobs are off you can push the instrument cluster out from behind. It is only held in by the friction of a rubber "band" that goes around it and the wriing and the speedo cable that is attached to it plus the instrument pod. There is ususally enough slack in these lines that you can pull them it out far enough to undo them.

CAUTION::::: The water temp and the oil pressure on the 108 are not gauges; they are instruments. It has been about ten years since I have pulled one of these, but I recall having to take some special care when removing this part of the cluster.

[280SE Guy]

The cuts should heal in a few days

If you can't get your hand/arm all the way up there to get the knob loose maybe you have a friend or one of your neighbor's teenagers that has a smaller hand/arm configuration that would be willing to help you out.

I had my dash out to clean the inside of the guage glass and change all of the light bulbs (as long as was in there) this spring and got many cuts on my hand/arm. Said a few choice words too. My biggest fear was getting my arm stuck up there with no one around and the garage door closed, forgot to have a phone handy when I removed the knob but had my phone within reach when I reinstalled the cluster. bwostosh is correct, one of the damanding things about this job is to get the knob back in place and screwed on. I have heard that many have not re-installed the knob, are you sure yours is still in place? You should be able to see it with a flashlight, it is white in color and is close to center of the cluster.

Good luck

[JMela]

I was able to change out my dash bulbs w/o pulling the cluster. You can feel around for the raised 'paddle' of the bulb knob, unscrew and remove. Pop a new bulb in and replace.

We'll have a 108/ 109 get-together one of these days where you have to show the wrist abrasions from this procedure to get in the door.

[cadurning]

JMela,

You must be the guy, that we often joke about, who has 3' long arms that are 1/8" in diameter.

The cluster really should come out since I suspect that the dimmer has shot craps. I would be happy to show my badges of honor at a get together. It would be nice just to get my arm close to the cluster. Did you go in between the park brake handle and steering column or to the left of the park brake handle? Perhaps I'm not holding my tong correctly.

[tjohnson]

CA, I just noticed that you are from Magee. Bring your 280 up here to Kosciusko and we'll pull it in the shop and stare at it! The brake lever will have to be unbolted and moved aside. My wife is the answer here for such occasions....small hands and very patient. She helped yesterday to change a headlight in my f250 that noway I could do. She has done vettes, Mercedes heater controls.....only have to be sure not to say cuss words during her visits out to the shop or she'll leave you to your frustration! good luck

[cadurning]

tjohnson,

Yep I unbolted the park brake and tried shoving my arm to the right and left of the brake.

Funny that you should mention heater controls. That's another project. Kosciusko is a doable distance from Magee. I just may take you up on the offer. November & December are out, too many plans have been made for me by the boss. But hey there is always January, 'cept by then you may want to get out of the "cold" country and come down to Magee to thaw out.

Are you aware of the Euro Fest in Ridgeland that was held the last weekend of October? We had a great time and I managed to beat out some Ferrari's with my Alfa. Next year is expected to be even better.

http://www.renaissanceatcolonypark.com/euro_fest.php

[124Coupe]

Originally Posted by bwostosh

Now try to put it back ON!

LOL! I left mine off in case I need to access the cluster again

[Tomguy]

Originally Posted by bwostosh

Now try to put it back ON!

Tell me a 108/109 owner who put it back on, and I'll ask him if he regretted it in the future. Yes.

I got lucky. The mechanic who last worked on my 4.5, after he replaced the speedo cable, left the knurled nut OFF and my life was as easy as slide out, slide in.

[cadurning]

Tomguy,

You are indeed a lucky man. It appears that my car is a total virgin. When the bulbs burned out they were never replaced. When the rear brakes started making noise, heck, they just took the calipers off. When the bushings fell off of the shift linkage, they just let it be. When the upholstery came loose from the front of the seat pans, why fix it, the seats are bouncier this way. When the knobs broke off of the climate controls, just throw the knobs in the glove box. When the aux fan started making noise just pull the fuse.

There are some blessings in having an unmolested car, but, yet again there are some curses like the knob on the back of the cluster.

[Pooka]

Leaving the knobs off when replacing the cluster seems to do no harm. The first time I knew there was a set of knobs back there was after I had been through several of these cars. Not all of them were mine, you understand.

I think I finally looked back there when just pulling on the front of the cluster failed to bring the cluster out. As I recall this was on a 6.3, so I thought it was just an upscale, 109/6.3 kind of thing untill I ran into on another car that was 'only' a 108. Then it came to me that all that had gone before me had left the knobs and that little metal bracket they screw onto off after servicing the cluster.

I had never noticed the cluster falling out of the dash, and if it did I guess I could have always pulled it out and installed the bracket and the knobs.

[Tomguy]

Originally Posted by cadurning

When the rear brakes started making noise, heck, they just took the calipers off.

Stories like this and ones from my friend from MS make me scared to death to ever drive in Mississippi, Alabama, or other states with such lax inspections!

[cadurning]

There is a god!!

After much blood, sweat, & cursing the MB engineers I was finally able to shove my arm up far enough to get the inst cluster nut off. I would have posted a pic of the arm but my camera battery is dead and I didn't want to wait for it to charge. The instrument lamp dimmer was at fault for no cluster lamps. For the fix I soldiered a jumper wire across the dimmer and now I have lights. I took the advise of the learned sages and didn't even look to find where the nut dropped. So if there is ever a next time there won't be as much blood shed.