Center Instrument Cluster

[dirtrack49]

Hi all,

I am trying to get to my screaming speedo and have come to a stop at the center cluster. Got the tach out OK, but I can not get the oil pressure line at the gauge to come apart. Looks like the oil line is aluminum with a 10mm fitting, into possibly a brass 14mm fitting.

Has anyone run into this problem? I know it has been together for the past 48 years and I am wondering if the two metals have had some type of chemical reaction that has caused it to seize up?

Has anyone been able to get behind the center cluster by pulling it out far enough with the oil line and temperature gauge capillary still attached.

Thanks for any and all suggestions and help.

Tom L.
66 230SL Auto


 

[merrill]

Tom
hi,
yes, you should be able to get the speedo out without removing the center cluster entirely.

In this scenario i have found the easiest way is to lay on the floor and reach up and unscrew the speedo.

If you cannot remove the center cluster, removal of the speedo is easier than re installing, that is when you will need a helper.

you will need to lay on the floor and try to get the bracket and nut on while your helper holds the speedo in place.  If you are lucky the bracket will stay in place while you try to get the nut started.

one tip is to take some tape and wrap it around the nut leaving a small tail of about 2 inches.
That way if you drop the nut or need to fold your hand to get in place behind the dash you are able to use the tail as a way to hang on to the nut.

[dirtrack49]

Thanks Matt,

I will take another look at it.

About how far can I push the center cluster out without removing the oil pressure line? I am really concerned about tweaking the line if I move it out too far. Or, should I attempt to remove the line to make better access?
 

[Jonny B]

I did this on my 250 SL a couple of years ago (and it was for a squeeling speedo). I was able to push the center cluster out by maybe 2 cm. I have relatively small hands, and was able to get in behind to access the knurled knobs. It was an exercise in patience and contortions. If you do a bit of searching, on the site, you should be able to get some further details. I did not take out the steering wheel or the front seat, but I probably should have, it makes the "on the back" exercise a tad easier.

[George Des]

Loosen the oil line connection at the bracket under the hood and you will allow yourself some additional slack to push the center gauge forward.

[dirtrack49]

Thanks Jonny,

Were you able to push the cluster out 2cm without removing the oil pressure line?

What did you end up doing with the squealing speedo?

Thanks, Tom L.

[Jonny B]

Yes, I was able to leave all the tubing in place for the center cluster. My mechanic (Silver Star Mercedes in Escondido) sent the speedo to a person in San Diego who did the job. He replace/repaired the plastic gears (don't know how extensive) for ~$230, including the transport to SD and back. I did the removal and install.

I don't have an exact measurement for the distance, but that is pretty close. I just did not want to pull that apart, and I was very careful of the temperature unit (that is sealed, no disconnecting of that one!). I did not loosen the connection as George indicates, but that types like a pretty reasonable precaution.

[Naj ✝︎]

Thanks Jonny,

Were you able to push the cluster out 2cm without removing the oil pressure line?

What did you end up doing with the squealing speedo?

Thanks, Tom L.

There is no danger in unscrewing the oil line from the back of the center cluster. You may lose a drop or two of oil...
You should be more concerned about looking after the water temp. capillary tube. If you release it from all the clips in the engine bay, you will be able to pull out the cluster out to give you working room. Now would be a good time to clean up the instrument glass and change all the bulbs.
To get the center cluster out, you can undo the back cover and remove the temp gage from the cluster and take the cluster indoors to remove the glass and change bulbs.

Naj

[Jonny B]

Naj,

A very timely reply! I was helping a friend this morning/afternoon remove most of the dash pieces in prep for a bunch of tidying up (and ultimately repair of the heater core). We did not pull out the center cluster completely but just pushed it out of the hole, about the 2 cm I typed earlier. But the glass is cracked and needs to be replaced. So now we have a bit more detail. Thanks!

This time we did pull the seats and steering wheel, oh my! Does that ever make the job easier!

[Naj ✝︎]

hi, JB,

I'm sure you know that the dimmer knob is held by a circlip on the inside of the glass.

Naj

[Jonny B]

Naj, meaning that it comes off with the glass, correct?

[dirtrack49]

Sorry all for not getting back sooner. I finally got to work again on the instrument cluster. George and Naj had the right idea about relieving the temp capillary and oil line. Everyone else was on the right track and certainly helped out.

I simply did what Naj suggested concerning the temp capillary. You can pretty much give yourself all the slack that you could ever want by simply feeding the capillary through the firewall as you relieve it from it's clips in the engine bay.

George might of been referring to separating the oil pressure line in the engine bay from it's bracket. Or maybe he was referring to what I ended up doing by separating the oil line bracket from the bracket that attaches to the brake power booster.

In any case, I have the center cluster out passed the dash panel without taking off either of the two lines. I most likely if needed, could bring it out even further to disassemble it altogether.

Now the optimist in me tells me to lube the speedo cable and grease the speedo and put it all back together and see if the damn speedo will stop screaming at me.

Wondering if after I do that, I should take a drive and see if everything is up to par before reinstalling the three instruments???

Wish me luck. I will follow up with the results.

Thanks again to all.

[mmizesko]

dirttrack49

Warning!  If you went through this much trouble with the dash, don't experiment....  The howling instruments could be a plastic gear, which needs replacment.  Go to speedometer.com, mail it to them in Austin TX, and have them do a complete job so you don't have to do it again.  Definitely worth the $175 or so.  Then work on replacing the broken cluster glass and unseizing your oil pressure line.

Mike Mizesko
Columbus, OH

[ctaylor738]

If you have a variable-speed drill, you can test the speedo before you put it back in the car.  You just need to find a small screwdriver bit that can fit in the drive. 

[mmizesko]

Chuck,

The drill works, but my howling was very temperature dependent. My tach wouldn't howl unless the ambient temp was below 50 degrees or so.  I still recommend a professional refurb.  Dirttrack, And while you're at it.  change your bulbs, and even switch to LED's.  My 2 cents.....

Mike Mizesko
Columbus, OH

[dirtrack49]

Thanks for all of the input. I am awaiting some new dash seals (instrument gaskets) before reinstalling the instruments. By the bye, I found some on eBay for $29.99 US plus tax and shipping for all three seals. I noticed that the big vendors wanted a minimum of $22.00 each for the same. Even though my purchase is much lower compared to the big vendors, the price is still ridiculous! I probably should have just made some from bulk material.

I think I will give the drill a whirl to see if the damn speedo makes noise before installing. I am assuming that you insert the screwdriver bit as a tight fit and turn it in a clockwise direction as if tightening a fitting??? 

If I had any sensibility, I would just send the thing out to be overhauled. The people in Texas quoted me anything from $85-125 to fix it. Sounds rather reasonable when I compare the price of parts from some of those vendors.

TIA 

[Jonny B]

I will ditto what Mike typed about the temperature, but only in my case, it was for the speedo.

If you can get a good job done for the $85 range you mentioned, that types like a decent deal to me.

[Manfred Wicht]

I have not tried to disconnect the line from the cluster but If you give it some slack from the engine compartment side ( maybe even disconnect the line at the engine)  you should be able to pull it out of the dash.  I did it on mine because it is a pain to try and disconnect when inside the dash.

Hope this helps

Manfred

[dirtrack49]

As a follow up to my problems with the squealing speedometer, Mike was right all along. If you take the time to take the dash apart, it would be better to send the instrument out the first time for repair or overhaul.

After I got the speedo out, I attempted to lube the cable and also lube the inner shaft at the speedo housing. I tried to check the speedo with a variable speed drill (in reverse), and found that the speedo now was erratic and caused the needle to jump. Being an optimist, I reinstalled the instruments in the dash and took a test drive. The speedo was very erratic for the first mile or so. After a couple of miles it began to settle down to a steady read out. I thought that I had  fixed it up until about mile seven when it started up squealing once again. I opened up the hood and moved the speedo cable a couple of times and the squealing stopped. However, each time I did this the noise would reappear in short order.

My conclusion is that either the speedo cable at the housing is binding, or the internal mechanism of the instrument needs lubrication or has worn parts.

I will be taking the dash apart once again and this time sending the speedo out for repair.

[mgandrew]

Under hard braking only. Cable has been replaced.

Bezel is foggy.

Any Ideas?

Mark