Speedometer Issues |
Post Reply | Page 12> |
Author | |
72FordGTS
Admin Group GTS.org Admin Joined: 06-September-2005 Location: Ontario, Canada Status: Offline Points: 5802 |
Post Options
Thanks(0)
Posted: 17-October-2020 at 6:51AM |
I noticed when I have driven my car the last few times my speedometer is not working correctly. I know the RPM vs speed on my car and I noticed that the RPMs seemed slow for the given speed. Sure enough, when I checked the speed against the GPS, the speedometer was reading much faster than it supposed to (ie says I am going 70 but only doing 60). It seems like when I wound out the car to high speed, the speedometer was hesitant to drop back down as I slowed. It almost acted as if it was "sticking" as the car slowed. I also noticed at one point the needle bouncing over a 10 mph range even thought I was pretty steady speed wise.
So my initial thought is that the speedometer cable needs to be lubricated, but you would think that if that was the issue the speedometer would read slower not faster. I was also thinking maybe the speedometer itself needs to be overhauled. Any thoughts on this?
|
|
Vince
1972 Ford GTS Sportsroof - Survivor, One Family car GTS.org Admin |
|
72 RS 351
Senior Member Joined: 04-September-2014 Location: Knoxville TN Status: Offline Points: 2765 |
Post Options
Thanks(0)
|
These mechanical speedometers rely on a spinning ring to turn the dial/needle, there's a small gap between the two components. It's said that you should not touch those parts when it's all out, to keep skin oil off of them, which will affect the accuracy. I'd guess something is amiss with the actual speedometer, the cable should be all or nothing, perfect or broken, being dry would make it drag a little, makes the needle jittery etc, not smooth. I like the old type, you can take them apart and easily reset the odometer compared to later kinds that are hell to work with. I'd say take it out and look it over closely, clean the spinning parts lightly with a clean paper towel and alcohol etc.
|
|
Don
73 Ranchero "Sport 72 front end", floor shift/console, planning EFI 7000+ rpm 351-4V &4R70W 73 Ranchero GT 351C-4V &4R70W for sale later. 92 Lincoln Mark VII SE GTC, OBDII 347/4R70W |
|
72FordGTS
Admin Group GTS.org Admin Joined: 06-September-2005 Location: Ontario, Canada Status: Offline Points: 5802 |
Post Options
Thanks(0)
|
If this is the speedometer, I may just send it to Tachman to get it rebuilt. I am not sure if anyone here has used him before? I emailed him for a price. Neither the speedometer or the cable have been touched on the car since new, other than having the cable disconnected for various repairs.
The speedometer is mostly smooth, other than like I described where it suddenly started bouncing about 10 mph at highway speeds. A new cable is cheap, but I am not sure if the aftermarket ones are worthwhile or are junk like so many parts today.
I was hoping to figure out which was the problem before I get the car stored in the next week or so. |
|
Vince
1972 Ford GTS Sportsroof - Survivor, One Family car GTS.org Admin |
|
72FordGTS
Admin Group GTS.org Admin Joined: 06-September-2005 Location: Ontario, Canada Status: Offline Points: 5802 |
Post Options
Thanks(0)
|
No response from the Tachman. Anyone know of a decent speeometer rebuild/recalibration service?
The car is going away for winter on the weekend. Anyone else have any ideas if this is a speedometer or a cable issue?
|
|
Vince
1972 Ford GTS Sportsroof - Survivor, One Family car GTS.org Admin |
|
72 RS 351
Senior Member Joined: 04-September-2014 Location: Knoxville TN Status: Offline Points: 2765 |
Post Options
Thanks(0)
|
How about a company that does speedometer upgrades, changing the face and speed range? Are there many of those, and are they easy to find? They would do calibrations for sure, how much who knows. I had a business here locally that I had to use in the early 90's, I had an issue with my 86 Crown Vic police model. It was a good $75 I recall to adjust it, it had gotten off by several mph at highway speeds. That was in an old part of town and most of those have gone away here.
|
|
Don
73 Ranchero "Sport 72 front end", floor shift/console, planning EFI 7000+ rpm 351-4V &4R70W 73 Ranchero GT 351C-4V &4R70W for sale later. 92 Lincoln Mark VII SE GTC, OBDII 347/4R70W |
|
Rockatansky
Senior Member Joined: 30-July-2010 Location: On The Road Status: Offline Points: 6059 |
Post Options
Thanks(0)
|
i'd have a look at it before jumping the shark, could be as simple as some fuzz in the gizmo? Vince do you have the 'Northern' speedo with km's on the outside and miles around the inside? any thoughts to changing the color and/or recal'ing it to a higher mph with new gauge faces?
Edited by Rockatansky - 23-October-2020 at 4:36AM |
|
72 GT Ute
|
|
72 RS 351
Senior Member Joined: 04-September-2014 Location: Knoxville TN Status: Offline Points: 2765 |
Post Options
Thanks(0)
|
Ditto, if it hasn't been out in a long time, try cleaning the drum parts with rubbing alcohol and a lint free rag of some kind. If you do that, feel them first by hand and see if there seems to be anything on them, an oily feeling, or dust etc.
|
|
Don
73 Ranchero "Sport 72 front end", floor shift/console, planning EFI 7000+ rpm 351-4V &4R70W 73 Ranchero GT 351C-4V &4R70W for sale later. 92 Lincoln Mark VII SE GTC, OBDII 347/4R70W |
|
californiajohnny
Moderator Group Joined: 05-October-2013 Location: winlock, wa Status: Offline Points: 14606 |
Post Options
Thanks(0)
|
mine was jumping at low speeds come to find out the cable wasn't in all the way after having it apart
you can pull the trans end and check the plastic drive gear... i've seen worn teeth do that before, and spin it by hand see if it is smooth or sticky??? |
|
JOHN
74 GRAN TORINO S&H CLONE 74 VETTE CUSTOM 90 S10 BLAZER 4X4 LIFTED 77 CELICA CUSTOM 75 V8 MONZA SUPERCHARGED 79 COURIER VERT. SLAMMED 75 VEGA V6 5 SPD 70 CHEV C10 P/U 68 MUSTANG FB CONVERSION |
|
Rockatansky
Senior Member Joined: 30-July-2010 Location: On The Road Status: Offline Points: 6059 |
Post Options
Thanks(0)
|
good call Johnny, check both ends, pull the cable out of the liner for best visual
|
|
72 GT Ute
|
|
72FordGTS
Admin Group GTS.org Admin Joined: 06-September-2005 Location: Ontario, Canada Status: Offline Points: 5802 |
Post Options
Thanks(0)
|
Thanks, great advice guys. I took the cluster out and pulled the cable out of the sleeve. The cable seemed to turn fine to me, but the speedo end was pretty greasy. What's the best thing to clean up the cable and lubricate it with before I put it back in?
I will look at the speedo a little more closely later. If it looks like I can just clean it up, I will do so. Otherwise, I will try to find a rebuild/recalibrate shop. The gear on the tranny end looks okay. Rock, the speedo is in miles, just like the US versions. We didn't switch to metric until 1978, so all our cars were in miles until then. However, my dad did put a sticker/overlay he got from the Ford dealer in the late 70s on the speedo that shows the big kms and small miles. I will show snap a pic later and post it.
|
|
Vince
1972 Ford GTS Sportsroof - Survivor, One Family car GTS.org Admin |
|
Rockatansky
Senior Member Joined: 30-July-2010 Location: On The Road Status: Offline Points: 6059 |
Post Options
Thanks(0)
|
Grease? they used to have an air powered cable lubing tool that would push grease up the cable from the bottom and usually up into the speedo head and all over the inside of the cluster, if you're into that kind of thing? does yours have the large diameter housing adapter that can rotate to mesh the driven gear to the output shaft, or am i thinking of some other kind of transmission? i was pretty sure you'd find something on the bottom side since that's the last place it's been messed with AFAIK. was the cable routed smoothly from the speedo bullet through the firewall? could it just be dry on the top end? if it's sticking up and winding up then releasing the energy that might cause the needle to bounce?
|
|
72 GT Ute
|
|
72 RS 351
Senior Member Joined: 04-September-2014 Location: Knoxville TN Status: Offline Points: 2765 |
Post Options
Thanks(0)
|
Yeah, the cable needs to be moving smoothly inside the sheath, the right amount of proper grease etc. Any binding like from a bent spot or pinched section could make the cable bounce or wind up. I'm not sure what the best grease would b, I'd want it as thin as possible but something that will survive and last for a decade and more.
|
|
Don
73 Ranchero "Sport 72 front end", floor shift/console, planning EFI 7000+ rpm 351-4V &4R70W 73 Ranchero GT 351C-4V &4R70W for sale later. 92 Lincoln Mark VII SE GTC, OBDII 347/4R70W |
|
72FordGTS
Admin Group GTS.org Admin Joined: 06-September-2005 Location: Ontario, Canada Status: Offline Points: 5802 |
Post Options
Thanks(0)
|
I know grease, but what type is the question? I also have heard graphite powder, also heard using ATF.
I don't think mine has the large diameter housing adaptor. The transmission end looks similar to this one: The cable is routed smoothly and it seems to move smoothly in the sheath. I check to make sure that it wasn't damaged it looks okay.
|
|
Vince
1972 Ford GTS Sportsroof - Survivor, One Family car GTS.org Admin |
|
Rockatansky
Senior Member Joined: 30-July-2010 Location: On The Road Status: Offline Points: 6059 |
Post Options
Thanks(1)
|
|
|
72 GT Ute
|
|
californiajohnny
Moderator Group Joined: 05-October-2013 Location: winlock, wa Status: Offline Points: 14606 |
Post Options
Thanks(1)
|
if it has goobs of thick sticky bearing grease you may need to try and clean out all that crap! atf or oil would work or graphite if its clean and dry (it could goob up with grease in there too) i'd say thin grease like white lithium type maybe? something that don't thicken up over time!
|
|
JOHN
74 GRAN TORINO S&H CLONE 74 VETTE CUSTOM 90 S10 BLAZER 4X4 LIFTED 77 CELICA CUSTOM 75 V8 MONZA SUPERCHARGED 79 COURIER VERT. SLAMMED 75 VEGA V6 5 SPD 70 CHEV C10 P/U 68 MUSTANG FB CONVERSION |
|
72FordGTS
Admin Group GTS.org Admin Joined: 06-September-2005 Location: Ontario, Canada Status: Offline Points: 5802 |
Post Options
Thanks(0)
|
Thanks for the links Rock and for the advice John and Don. I may try to get some speedometer specific lube. I would tend to think a thinner lube might work better than a thick grease. After fiddling with the cable, I am more convinced it's a speedometer problem though. Like I said, the cable moves pretty smoothly and I saw no damage to the sheave. To add fuel to the fire, my gas gauge started reading way low too. It was full, but showing about 3/8's of a tank.
As for the speedometer, here is what it looks like. As you can see, it has an overlay to show kms. I doubt I can remove it now after being on there for over 40 years, so I might just keep it because it's kind of a unique piece. It's not as noticeable in when in the car (the angle of this photo makes the outline of the overlay very obvious). |
|
Vince
1972 Ford GTS Sportsroof - Survivor, One Family car GTS.org Admin |
|
72 RS 351
Senior Member Joined: 04-September-2014 Location: Knoxville TN Status: Offline Points: 2765 |
Post Options
Thanks(0)
|
200mph, cool. I'm old you know, I cannot read the fine print. I'd like the speedometer to go to 140mph, that's a good figure for most cars.
|
|
Don
73 Ranchero "Sport 72 front end", floor shift/console, planning EFI 7000+ rpm 351-4V &4R70W 73 Ranchero GT 351C-4V &4R70W for sale later. 92 Lincoln Mark VII SE GTC, OBDII 347/4R70W |
|
Rockatansky
Senior Member Joined: 30-July-2010 Location: On The Road Status: Offline Points: 6059 |
Post Options
Thanks(0)
|
might as well give it a new Instrument Cluster Voltage Regulator say that real fast five times while chugging a beer and check / clean the contacts of the PCB welcome to my world. it's not always something, it's always something else too
|
|
72 GT Ute
|
|
72FordGTS
Admin Group GTS.org Admin Joined: 06-September-2005 Location: Ontario, Canada Status: Offline Points: 5802 |
Post Options
Thanks(0)
|
Do you know where I can get one? I guess just hunt for one on eBay? Now that I have the cluster out, I might as well give it a good once over. I do have a new repro PCB, but my original still looks solid, which is why I haven't swapped it yet.
|
|
Vince
1972 Ford GTS Sportsroof - Survivor, One Family car GTS.org Admin |
|
Rockatansky
Senior Member Joined: 30-July-2010 Location: On The Road Status: Offline Points: 6059 |
Post Options
Thanks(0)
|
is this it? and i just accidentally ran across speedo cables on Rockauto, cheap like <$15 under the Interior heading IIRC
|
|
72 GT Ute
|
|
72FordGTS
Admin Group GTS.org Admin Joined: 06-September-2005 Location: Ontario, Canada Status: Offline Points: 5802 |
Post Options
Thanks(0)
|
Yes, that is it. I just checked the part number in the catalog and it is correct for the gauge cluster cars (std gauages use a different part). That is way cheaper than the NOS motorcraft ones on eBay. I just hope it's not a made in China special.
Yeah, i saw the speedometer cables are still available. I will try to lubricate mine first, as I question if the aftermarket ones are any good. Parts all seem to be offshore junk.
|
|
Vince
1972 Ford GTS Sportsroof - Survivor, One Family car GTS.org Admin |
|
72 RS 351
Senior Member Joined: 04-September-2014 Location: Knoxville TN Status: Offline Points: 2765 |
Post Options
Thanks(0)
|
Dorman parts are the current standard for later cars, and they are expanding to other makes and years. I wonder where those are made, because they make so much. Lots of it is appreciated, but much of it is low quality also. I like that voltage regulator too. Is that for a 9v battery, I always wondered why they had those odd terminals?
|
|
Don
73 Ranchero "Sport 72 front end", floor shift/console, planning EFI 7000+ rpm 351-4V &4R70W 73 Ranchero GT 351C-4V &4R70W for sale later. 92 Lincoln Mark VII SE GTC, OBDII 347/4R70W |
|
72FordGTS
Admin Group GTS.org Admin Joined: 06-September-2005 Location: Ontario, Canada Status: Offline Points: 5802 |
Post Options
Thanks(0)
|
I took the speedo out of the cluster and it looks in excellent shape. No dirty or rust, it looks nearly new, although I am sure there is some wear. Those speedometers have a top jewel design and the jewel becomes oblong from use over time. We can rebuild it, re-magnetize the shaft, new jewels and calibrate, should be good as new. I might send it off this winter, but I will fiddle with it a bit more in the mean time. On the fuel gauge, I was wondering if anyone has bench tested one before? I was going to try and rig something up to vary the resistance to ground, from 10 ohms to 70 ohms to see if the gauge reads properly. Just not sure the best way to go about it with the cluster out of the car. Any ideas? |
|
Vince
1972 Ford GTS Sportsroof - Survivor, One Family car GTS.org Admin |
|
Steve M.
Senior Member Joined: 08-June-2019 Location: Florida Status: Offline Points: 1740 |
Post Options
Thanks(0)
|
Good question,
I did test the fuel, oil pressure and temperature gauges in the sport cluster that I installed in my 1976. I don't recall the exact ohms.(13) I think. I did notice that they're all the same. They all work in the car as accurately as any 1970s technology can be. |
|
Steve M.
|
|
Big Bird
Senior Member Joined: 25-August-2013 Location: New York Status: Offline Points: 4194 |
Post Options
Thanks(0)
|
A lot of "bouncing speedos" are caused by a burr or a dry spot on the cable.
|
|
"What we do in full frontal view, is more honest than your cleaned-up mind."
Randy 1979 T-Bird 2005 F-150 STX RCSB 4.6, 3.55 LSD How the Heck does a REGULAR CAB SHORTBED weigh over 5200 pounds? |
|
handsofstone
Senior Member Joined: 13-April-2018 Location: Northeast Status: Offline Points: 3941 |
Post Options
Thanks(0)
|
Headers can cook them as well.
|
|
72FordGTS
Admin Group GTS.org Admin Joined: 06-September-2005 Location: Ontario, Canada Status: Offline Points: 5802 |
Post Options
Thanks(0)
|
So to update this thread, I finally got my speedometer back from from ISI and it's still not reading accurately. It now reads way slower than actual speed, but seems to be smooth and consistent. Oddly, I clocked a distance and the odometer seems to be reading accurately. I am hoping it's not something with the speedometer rebuild, because I don't want to send it back. I will drive the car a bit more and continue to check the accuracy of the odometer.
I removed the speedometer cable and lubricated it with white lithium grease. It seems to move smoothly when installed, but it does hit a tight spot when installing. Anyone have any ideas?
|
|
Vince
1972 Ford GTS Sportsroof - Survivor, One Family car GTS.org Admin |
|
handsofstone
Senior Member Joined: 13-April-2018 Location: Northeast Status: Offline Points: 3941 |
Post Options
Thanks(0)
|
How far off is the speed? Try a different gear after driving say 10 miles on the dot. If the speed and odometer are both off you will know.
|
|
Big Bird
Senior Member Joined: 25-August-2013 Location: New York Status: Offline Points: 4194 |
Post Options
Thanks(0)
|
Earlier in the thread you said you have an overlay converting to Kilometers.
Any chance that is inaccurate or installed wrong? (off-center maybe?) Since the Odometer and speedometer are driven by the same cable, any problem before the speedo head would be a shared problem. Only one part working sounds like a problem in the rebuilt unit.
|
|
"What we do in full frontal view, is more honest than your cleaned-up mind."
Randy 1979 T-Bird 2005 F-150 STX RCSB 4.6, 3.55 LSD How the Heck does a REGULAR CAB SHORTBED weigh over 5200 pounds? |
|
72FordGTS
Admin Group GTS.org Admin Joined: 06-September-2005 Location: Ontario, Canada Status: Offline Points: 5802 |
Post Options
Thanks(0)
|
So I figured out the problem. The speedometer was my problem with the bouncing needle and inaccurate readings I was having last year. The cable is fine.
Since the install of the rebuilt speedometer, it made no sense that the odometer was reading accurately, but the speedometer was off. Randy was on the right path when he indicated it might have something to do with the overlay. When ISI calibrated the speedometer, they calibrated mph to the kilometer scale (which are the big numbers on the overlay), which is why it was reading so low. So now, when it shows 50 km/h, I am actually going 50 mph. I used the GPS on my phone and the speedometer very accurate now when I use MPH, within 1 mph or so. So Don was right when he said I have a 200 mph speedometer - I think this has to be the first 200 mph speedometer in a Torino!
Here is a pic of the speedometer. The big numbers on the outside are supposed to be in km/h, but it is now calibrated for the big scale to be MPH. So I am assuming this was an honest mistake by ISI, especially since no 1972 car has km/h from the factory (Canada didn't get metric speedometers until the late 1970s). On top of that, the US cars that have km/h scales have the km/h scale as small numbers. What do you guys think is the best way to get this resolved? I don't want to send my speedometer back and wait to another 4 months losing out on the best driving time. I am hoping I can bring it to their attention now, but wait until the fall to send it back to ISI. I would also think they should be doing the recalibration for free, although I will probably get stuck paying shipping at least one way. Any advice is appreciated. |
|
Vince
1972 Ford GTS Sportsroof - Survivor, One Family car GTS.org Admin |
|
Post Reply | Page 12> |
Tweet |
Forum Jump | Forum Permissions You cannot post new topics in this forum You cannot reply to topics in this forum You cannot delete your posts in this forum You cannot edit your posts in this forum You cannot create polls in this forum You cannot vote in polls in this forum |