Speedometer gearbox disassembly

[Richsuz]

Hey guys, not long ago while not looking for it, I ran into a picture tutorial on how to take apart the speedo gearbox. Now that I need it I can't find it. My 650GL started a humming noise during a 400km ride and quit working. The gear seems frozen. The dealer has one for a GT 380 new, but I dont know if it will work. Its from a 1973 bike. I really would like to find the pictorial, but am unable to find it.

I know there is a sort of a worm gear inside it, as I saw in that pic.

 

[BassCliff]

Hi,

This one, perhaps?

• How to get inside your gauges
  Get inside those gauges without destroying it.

Have you tried turning the gauges upside down and putting a little lubrication in the cable holes?


Thank you for your indulgence,

BassCliff

 

[Steve]

Are you looking for information on the speedo (instrument) end or the wheel end? :-k

.

 

[Richsuz]

Basscliff: this is the wrong end.
Steve: I am talking about the speedo gear at the wheel side. I was able to take the circlip off and the two washers that come out. I found a little damage in the two protrutions that drive the gear and that the gear itself is hard to turn in one spot. I also opened the end that drives the cable and the worm gear seems good. I need to open the rest to clean and check, and I need to fix/replace the washer with the dogs.

 

[waterman]

I have been where you are at. I found it simpler to just buy a used speedometer drive off of ebay than to try and fix original. Maybe others have fixed their units.

If you do go the ebay replacement route, please note that gL speedo drive is different than the standard g model, and they are not interchangeable. It is not readily apparent unless you closely look at the inner face, the gL outer rim is farther away from the drive gear. Sadly most ebay sellers only show the outside view of the drives which is about useless.

You will need one similar to this:

http://cgi.ebay.com/ebaymotors/SPEE...9699064QQptZMotorcyclesQ5fPartsQ5fAccessories

Not like this:

http://cgi.ebay.com/ebaymotors/SPEE...5668348QQptZMotorcyclesQ5fPartsQ5fAccessories

Do you see the difference? Generally, and I use that loosely, the L model use the same drives across the model line, thus a 650 gL can use a similar year 550L, 850L, or 1000 L speedo drive. You may want to check parts numbers to confirm which bikes and years cross reference exactly, don't rely on my memory alone. Even some of the later models, Madura comes to mind, use the same drive.

If you pick up a used item, clean it out thoroughly and grease it up, should work fine for years. I got into this predicament when my brother scavenged the drive unit off of my then parts bike 650g for his 1000g. Of course, later (still) I am restoring this parts bike and needed to find a replacement.

 

[Richsuz]

heading out to compare the one for the gt 380. Different part number, but if it fit, it works right? There will be no difference in the number of turns I hope

 

[salty_monk]

Depends on the front wheel size I would think

 

[BassCliff]

Hi,

I did a quick search and found this post regarding speedometer gearbox repair...

http://www.thegsresources.com/_forum/showthread.php?t=127604

I also seem to recall someone posting more detailed pictures, but I haven't found that post yet.


Thank you for your indulgence,

BassCliff

 

[Richsuz]

This is the sameone I found. The one I was talking about had pics, and showed the inside dogs partially chewed up. The guy put like a spacer in there to force the dogs to catch. I am happy to announce that I did find a used part, for $18. It;s in and running (after a good cleaning, inspection and regreasing.

I will try flattening the old part to bend the lips the other way and invert the part, now that I have a working unit, its a crap shoot how long it will last.

 

[SqDancerLynn1]

The speedo gear box was never meant to be taken apart. If to service it? Wash it out with solvent good and fill 1/2 way with a silicon grease/ water proof..

 

[Suzuki_Don]

You can pull the gears out and check for wear and regrease as Lynne says. The only trouble is the seal if damaged is not available as far as I know (it keeps the grease in).

 

[Richsuz]

ok, you all, we are good for the moment. I am still puzzle about my inability to use the search function and find the bloody picture tutorial. FRUSTRATING!