Tonti Speedo Cable failure - suggestions?

[kidsmoke]

Yesterday on a VERY hot 240 mile day in flyover country, the speedo cable on the G5 gave up. Tach is fine. No Speedometer and more importantly, no odometer. Haven't taken a look yet. Wondering from those who have done more than maintain these old machines: which end of the cable is more likely the culprit: Inside the instrument cluster, or back in front of the U-joint where it enters the housing?

This is the dash of the bike, for reference:

[blackcat]

The cables on my Tonti frames seem to always break at the transmission. No idea why, maybe lack of lubrication?

[kidsmoke]

They're cheap to replace and readily available. I'm wondering if there are common related issues? Do the cables snap at the ends? In the middle somewhere? Is there something related to lubrication at either end contributing?

If I buy one and throw it on the bike and there's no fix, where am I looking first? I'd hate to buy a cable only to find it's not the cable itself....

[Antietam Classic Cycle]

Like Tom wrote, they almost always break at the transmission. Grease the cable, especially down near the transmission, and they last a long time. Routing also plays a part - no sharp bends.

[kidsmoke]

Like Tom wrote, they almost always break at the transmission. Grease the cable, especially down near the transmission, and they last a long time. Routing also plays a part - no sharp bends.

107,000 miles. Routing hasn't been messed with AFAIK

What fails exaclty, Charlie? The metal tip strips? Or snaps off?

[larrys]

Used to be able to buy speedo repair kits at NAPA auto parts stores. You got a long inner cable that you cut to length and add the crimp-on end. I used one to fix my SP 1000 speedo cable. Don't know if they are still available.
Larry

[Antietam Classic Cycle]

107,000 miles. Routing hasn't been messed with AFAIK

What fails exaclty, Charlie? The metal tip strips? Or snaps off?

The tip twists off usually.

[blackcat]

Used to be able to buy speedo repair kits at NAPA auto parts stores. You got a long inner cable that you cut to length and add the crimp-on end. I used one to fix my SP 1000 speedo cable. Don't know if they are still available.
Larry

The last time I bought one it was almost the same price as a new cable so now I just keep an extra cable hanging around.

[kidsmoke]

appreciate the feedback. Looks like I was making more out of it than necessary. New cable incoming.

[pehayes]

Disconnect the lower end of the cable from the transmission fixture.  Might be enough exposed core to clamp with your electric drill and spin up gently.  You can turn the rear wheel and watch the transmission fixture to see which way it is supposed to turn.  That test could verify that the instrument is still good.  DO NOT remove the fixture from the transmission if you can avoid it.  Just pick or pry the broken end out of the transmission drive.  Removing the transmission fixture raises more complex issues related to thrust washers, etc.  Keep us posted on what you find when you disconnect the cable.

Patrick Hayes
Fremont CA

[centauro]

I never owned a G5, but an SP, which is equipped with 90-degree cable drives under the Speedo and Tach gages.
If the G-5 has the same 90-degree drive, it is possible that the coupling to the gage, made of plastic, cracked, and the drive backed off, so the inner cable no longer engages the instrument. Both of my drives cracked and disconnected. I installed hose clamps to prevent them coming off.

[chuck peterson]

And then there’s the time…mine stopped, ordered new cable, 4weeks later …

I discovered the connection loose at the speedometer end. 1 full turn and it worked

Ymmv

Speedometer cable still sitting on a shelf somewhere from 20 years ago…just in case I need one for a bike I don’t own..

[wirespokes]

I had airheads for 25 years and never a speedo or tach cable problem. Got into Guzzis and had enough failures I made a jig to swage the square end on the cable. Eventually I discovered that the cables aren't an inch too long, so make sure they're routed the most direct (shortest) route with the widest sweeping bends. Lube them with a light weight moly grease. Mine seemed to break (snap) at the gauge.

I didn't replace the housing, just the inner cable. If the housing looks bad, then replace it, but I've never replaced one yet, just the inner.

I found the inner cables on ebay for seven or eight bucks shipped. And they're long enough I can get two cables from one kit.

[Dukedesmo]

Don't know if a common failure but the speedo cable on my LM2 had cracked at the housing that screws onto the back of the speedo, previous owner had 'repaired' it with a small hose clip that holds it in place nicely.


A year or so into my my ownership the rev counter stopped working and I saw the same thing had happened, causing the cable to fall off the rev counter so I adopted the same repair technique and it has been fine since.

[Chuck in Indiana]

107,000 miles

Sounds like a warranty issue..

[John A]

Sounds like a warranty issue..

That’s just what I was thinking. They don’t make ‘em like they used to alright. The next thing will most likely be the tach light bulb. I could find a place for that worn out bike here…

[kidsmoke]

Sounds like a warranty issue..

That’s just what I was thinking. They don’t make ‘em like they used to alright. The next thing will most likely be the tach light bulb. I could find a place for that worn out bike here…

Haven't given up on the ol' girl just yet. Such a cream puff, just loves to run. New set of plugs, she was getting 40 MPG Suday. Crossing the local resevoir as the sun rose, fog hovering over the water, throbbing at 4200 rpm...I'll manage a $16.00 cable every so often if that's the price of admission .

Sunday's running buddy.

[Canuck750]

Last year I replaced my 1972 Eldorado instruments with a single gauge bezel from an Ambassador and fired a new Chinese made GPS speedo. The speedo / odometer has L / R signal and high beam indicators and is back lit. A simple power lead to a switched terminal on the fuse box and used two sided tape to adhere the tiny antenna to the handlebars. Works great!  No more cables, accurate, clean smooth needle movement. I had to machine an aluminum reduction ring for the smaller diameter gauge to nest into the Ambassadors dash. I am going to fit more of these onto some more of my vintage bikes that keep having erratic speedo needle movement.

[Tom]

 

[Chuck in Indiana]

Haven't given up on the ol' girl just yet. Such a cream puff, just loves to run. New set of plugs, she was getting 40 MPG Suday. Crossing the local resevoir as the sun rose, fog hovering over the water, throbbing at 4200 rpm...I'll manage a $16.00 cable every so often if that's the price of admission .

She's a good old girl.. 

[n3303j]

Various owners have mentioned greasing the cable at installation. That might be okay for southerners that never see temps below 50 degrees. But it is best to use proper speedometer cable lube up north to assure reliable long term service of this flex cable drive. Any good auto supply store should still stock some. The product is graphite suspended in a liquid carrier. The carrier evaporates leaving a dry and slick coating on the cable and housing. This product is impervious to operating temperature extremes.

[MattP]

What i do by the longest cable at parts store silver solder the end,you wont beleive how nice it wickes up ,then grind it sq less than a minet.i havd spliced to shorf cablez go gether just tin the ends grind a  taper wrap a thin cpper wire to hold together  hit with tarch thengrind off excess. Of  ourse the mend should be in a rather stright run. Yeh i told my freind this tool maker, said he made aswadging tool i demensrtaed how fast and eZy he got mad would not show me his great tool.  Silver solder and flux not led tin d
 I have joined 2 clutch cables. Oh the car cable i got was much limper witch bends around corners with less forse i did notice a increce of top end.

[n3303j]

Yup! SilBond 45 and Borax Flux followed by judicious use of a file produces a proper square end on any flex drive cable. Been doing it for years. Never worried if a cable is too long. It can always be made shorter.
Silver solder & Flux also works for shortening brake, throttle and clutch cables. Seems I can never get quite the proper length cable for the older bikes. So I shop for one that is too long but has the proper ends. Then into the shop until it fits.

[kidsmoke]

Disconnect the lower end of the cable from the transmission fixture.  Might be enough exposed core to clamp with your electric drill and spin up gently.  You can turn the rear wheel and watch the transmission fixture to see which way it is supposed to turn.  That test could verify that the instrument is still good.  DO NOT remove the fixture from the transmission if you can avoid it.  Just pick or pry the broken end out of the transmission drive.  Removing the transmission fixture raises more complex issues related to thrust washers, etc. Keep us posted on what you find when you disconnect the cable.

Patrick Hayes
Fremont CA

Guess what.


Finally got around to this. Square tip was busted off the cable, and I could not find one to extract. This did not sit well with me so, long since forgetting Patricks council, I pulled the Fixture. Can't get it back in.

Any thoughts? I've got the manual up but cannot find a drawing. If anyone has one that would be wonderful.

Thanks in advance.

[guzzisteve]

Now you did it, the pinion sits in a hole on a ledge, shaft goes in hole with a washer on the ledge. When you pull it out usually washer drops off ledge into trans.
If you can't get it back in maybe washer is cockeyed. To get it right and washer back on ledge you need to pull swingarm & boot. Back off output shaft nut thrust washer & ring gear of speedo drive set with small bearing ball to put washer back on ledge.

Unless you can do it through the hole for unit w/pick.

[Antietam Classic Cycle]

Stick a "magnet on a stick" down into the hole and see if it grabs the errant washer. 

[kidsmoke]

Stick a "magnet on a stick" down into the hole and see if it grabs the errant washer.

That worked at the outset, before I understood fully what I was facing. I attempted to place the driven gar back in with the thrust washer on the tip held with grease. I now realize you must first perch the washer on the ledge, below the apex of the driven gear. Dug out my inspection mirror and all became clear.

I'm gonna have to retrieve it another way.

Steve, can you elaborate again on your approach? I'm clear through backing off the output shaft nut....How am I actually retriving said washer???

[guzzisteve]

It slides to the bottom and may be too big to come out the drain. I would get a magnet drain plug & call it good, it'll stick & stay unless you can get it from next to output shaft you'll have to pull cover.
Can't remember if you pull seal & nut w/gear if it could come out by rotating trans w/liquid in it. Like fill w/gas to let run out the output shaft hole.
I know you can put a washer in on the ledge w/ a pick & magnet and hold it in place w/pick while you pull magnet stick back out.
Figured you may flush the old washer out that same place.
You could also try to flush it out the oil fill hole,it's a big hole.
Hard time thinking-------------------

[John A]

I have a small magnet attached to a bendable copper wire that worked for me. I think I bought it off a tool truck that came to the god forsaken airport that I worked at.

[kidsmoke]

It slides to the bottom and may be too big to come out the drain. I would get a magnet drain plug & call it good, it'll stick & stay unless you can get it from next to output shaft you'll have to pull cover.
Can't remember if you pull seal & nut w/gear if it could come out by rotating trans w/liquid in it. Like fill w/gas to let run out the output shaft hole.
I know you can put a washer in on the ledge w/ a pick & magnet and hold it in place w/pick while you pull magnet stick back out.
Figured you may flush the old washer out that same place.
You could also try to flush it out the oil fill hole,it's a big hole.
Hard time thinking-------------------

I completely understand. 

Thanks gents. Time to get busy