140 Speedometer swap

[crucifyd]

1989 GT

I recently swapped in a FM 140mph speedometer for the original 85mph.

1. the needle wanders 2-3mph above 40mph. I think it does it at lower speeds also but it much less of a wander so it is almost not noticeable.
The original did not have this issue at all.
If not I think I can live with it but is there a fix for this?

2. I didn't notice until I drove at night but both odometers have their own plastic "window" (not sure what to call it).

The odometers look hazy and brown, they are actually quite hard to read and it just looks bad.
It's actually worse than the photo below makes it look as I took it during daylight in the garage.
Is there possibly a plastic film that was never removed?

or

Is there a way to remove the "window"?
(My original 85 and my broken FM 160 speedometers do not have the "window" at all, as in you could directly touch the numbers.)

 

[Mustang5L5]

The bounce is inherit to drag/binding as the mad head drags the speed cup. SOmetimes there is binding in the bushing so you get a little bouncing. You can try lubricating the backside bushing with think oil like watch/jewler's oil and see if that helps.

You can try cleaning the window. They were not shipped with plastic as far as i can tell from the small number of NOS units i've handled/seen. To clean that, you will need to pull the needle off, and then remove the two screws from the rear to separare the face from the body. Then you can try cleaning the window.

The windows are not common and likely a running change by Ford from early cars. Standard 140's don't have them. I do not believe they can be removed from the face. I think it's molded to the entire plastic face frame. I have a FM 140MPH on my shelf that I can double check for this later.

 

[Blown88GT]

I bought a new FM 140 the first month I bought the car new.
It was the 1st mod I did in 1988.
I still have the OEM one stored away.

I don't see a window on my FM 140.

 

[Mustang5L5]

My 140 does have a window, but the 160 I have in the car does not.

I want to say I’ve seen some early ‘87 clusters with windows on the 85mph speedos. Ford probably made a running change at some point.

BTW, It does not appear the window can be removed. It is part of the face.

 

[90sickfox]

My white face 160mph motorsport gauge does not have the plastic over the windows

 

[Mustang5L5]

Took mine apart to see about cleaning.

As you can see (actually it's tough to see) the window is part of the frame. SO it's not removable. The green trim is separate. The clear window is part of the clear frame.

Not sure when they removed the window, but this is a E8 plastic frame (over an E7 if you can see)

After a little cleaning, not sure if it made an improvement or not

What's behind there if anyone is curious

 

[Mustang5L5]

Also, there is a subtle difference between the FM 140 and the standard 140. The swept face area is larger for the FM unit. You can notice it comparing the speed readings under 20MPH.

My angle may be bad here, but the 0MPH tick on the FM speedo is equal to the small tick mark UNDER the 0MPH on the standard 140MPH. The standard also has a needle stop. SO when you reset the needle on the standard, you pull the stop and adjust it to that tick mark. Then lift and reinstall the needle stop.

On the FM, no stop. Install needle pointing to 0

ALso you will notice 20, 60 and 120MPH have two dots. My assumption is these are calibration marks. The needle needs to be between these during the calibration sequence. You will also notice the dots are tighter on the FM unit.

I used to have a good spreadsheet somewhere where you can use a drill with some tape and ahandheld tach, to output an RPM and see if the speedo needle read correctly.

 

[Mustang5L5]

The SSP Certified calibration speedos are similar to the FM unit, but I assume these actually have paperwork to certify they are within the allowable tolerance.

 

[crucifyd]

Haven't had a chance to get back into the dash to see if I can clean the odometer "windows" but will at some point give it a try.

At this point the wandering / bouncing needle seems to have settled and is almost non perceivable.

 

[crucifyd]

finally took the speedometer out and attempted to clean the windows.

As Mustang5L5 said, the window is part of the green frame. When I got into it the tabs on the side looked like they might enable removal and I was able to pop the frame loose at the top but it looked like it was glued on where the two tabs are at the bottom so I stopped and did not take it any further out. I think the top was also glued originally, but it has failed, which is why I was able to start to remove it.

After deciding it wasn't a good idea to continue I cleaned the windows the best I could, put everything back together and reinstalled.

It was still daylight when I finished and, with the lights on, I could still see the brown haze in the windows (neglected to say before that the haze is not noticeable with the lights off). It seems like it is a bit better but it is hard to tell without running it in the dark. I'm hoping it made enough difference so that I can "live with it". I prefer the FMS 140, to the ones that were put in from the factory, due to those having more hash marks. If I got another one, I assume it would have the windows and the odds of it also being hazy would be pretty high...

 

[AeroCoupe]

If you are not opposed to shipping it to get fixed maybe the company Limp used can clean the lenses.

Posts #3 & #9:

Anyone tried the daniel carpenter repo speedo cable? E9BZ-9A820? 79-95..

Bouncing Speedo below 20mph is getting on my nerves in the beater. It needs a cable, Speedos fine when I run it in a drill, gears fresh. I have an old nos ford service cable E9BZ-9A820 but not wasting it on this, its 69" for use with a vss.. Dc has a repo of it for Around $25 listed as 79-95...

stangnet.com

 

[90sickfox]

If you swap to LED dash bulbs it just might help your issue.

 

[Mustang5L5]

If you do LED's, i recommend installing a reflective material in the cluster housing to help with light distribution. Seems it's worse around the speedometer because that large body blocks a lot of the light. With LED's, it could use a little extra help.