Speedometer

Finally sorted my overheat issue thanx to Lynn Miner, Mike Drew, Alan Watkins, and UV550000. Took a while with multiple vacuums from the UV550000, and multiple bleeds on the radiator and intake.

wrt speedometer issue - doesn't register when driving. I had previously installed 90 degree adaptor at the speedometer. With the cable disconnected from the transmission, the speedometer runs right up when turning it with a high speed drill. Only thing I noticed at all was somewhat of a loose fit of the blade at the end of the speedometer cable into 'connector in the transmission port' (for lack of better description). However, even with the cable backing out, it wouldn't have been enough to remove the blade from the transmission connector.

I'm not going to get into transmission, but if there is an easy fix I am missing, would like to know before buying the Speedhut GPS speedometer.

Thanx
Mark
SPF MKII

Mark,
Unsure by your post, but do you have a 'corrector box' between the cable end and the trans? That's the adaptor that Olthoff sells to correct the speedo reading since RBT doesn't change the internal speedo gear for different r&p ratios. At any rate I don't think your cable end should feel loose on the trans connector. It should fit firmly in the slot.

muttsjet said:

wrt speedometer issue - doesn't register when driving. I had previously installed 90 degree adaptor at the speedometer. With the cable disconnected from the transmission, the speedometer runs right up when turning it with a high speed drill. Only thing I noticed at all was somewhat of a loose fit of the blade at the end of the speedometer cable into 'connector in the transmission port' (for lack of better description). However, even with the cable backing out, it wouldn't have been enough to remove the blade from the transmission connector.

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Mark -- just a vague thought based on bad experience with some flex-shaft devices (like hand-held polisher/grinder). At the speedo end, where the end of the cable has been stamped into a square cross-section, there needs to be some kind of collar that allows the cable housing aka outer cable to force the inner cable into engagement with the speedo drive (that is to keep it from sinking down into the outer cable). If that collar is missing or is too close to the end there is no such action. So if you then disconnect the transaxle end to drive it with a drill, and in so doing push the inner cable into engagement, it would appear to work and mask the missing or misplaced collar. Then (so the theory goes) you go to reconnected to the transaxle and the inner cable slips out of engagement up at the speedo end.

Long story short, try disconnecting at transaxle end again, and see if it's possible to pull the blade fitting out enough to disengage from the speedo. If you can do that, you might have your culprit.

And another random thought based on painful experience. With some speedo cables it's possible for the "ring nut" at either end, particularly if it's large in diameter, to become distorted out of round. This could happen, for example, of someone stepped on it. This can cause the ring nut to get started in screwing on to the transaxle, but then not want to go all the way on, leaving the cable kind of rattling around. The fix is to take it off and look at it end on and see if it's still absolutely circular. If it's not, you might be able to squeeze it back to circular with a pair of channel locks or a vise. But it should spin onto the transaxle and have a distinct sense of bottoming when fully screwed on.

Quit fooling around and buy the Speed Hut GPS unit - you will love it. Dead accurate, needle regardless of tire sizes you might decide to use. no needle jump and they have units that go to 200mph and match most GT40 insturments.

40 bud tell us more abought your gps speedometer witch one did you buy is their a delay.how many miles are on spedo and if power is lost will your mileage still be kept

I bought the Speed Hut unit before they started making the complete set of insturments for the GT40 market. Losing power doesn't seem to be a problem. Mine is installed with an off/on switch. That way when it sits for extended periods there is no power going to it. It takes about a minute for it to warm up and get its signal when I first get in and turn it on. It has a small digital window at the base of the gage as well as the standard needle. This allows showing your speed in KPH, the time, acceleration over distance etc.. Great unit check it out on their web sight. I have put about 1000 miles on the unit since installing.

Thanks for post 40 bud i wanted to get feedback from somebody that has a speed hut spedo not the people that sell them.i am building a mkiv and am trying to deside what spedo to use.from what photos i can find(not many)looks like mkiv has one tack in the middle of dash and no spedo so i am trying to find a large spedo and mount it in the center or find a unit all in one any suggestions are welcom.

40 Bud is right, you can't go wrong with the speed hut gauges, my speed hut gauge has a electronic pick up rather than GPS, I wish they had the GPS unit before I bought mine.

Hi Guys

In Sydney we are fast becomming known as the city of tunnels.

There a numerous tunnels in and around Sydney some of which run for many kilometres and require a working speedo as they are all fitted with speed cameras.

The trouble with GPS units is that they stop working in the tunnels where you need them most.

At least a speedo with cable or sensor unit will always work.

The other thing which may become a problem for us is our rego authorities are asking us to prove the validity of our speedo calibrations and how they were achieved.
I don't know how you would do that with a GPS unit as they won't accept us using a GPS nav unit's speed to compare against a speedo reading.

Dimi

Can I ask which unit you guys bought from Speedhut? My speedo bounces around like it on a hot frying pan. Where did you pull power from and where did you route the antenna wire and mount the antenna? Thanks

MHNCO said:

Can I ask which unit you guys bought from Speedhut? My speedo bounces around like it on a hot frying pan. Where did you pull power from and where did you route the antenna wire and mount the antenna? Thanks

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I bounces around because of car motion, or just on its own? Yikes.

I have the one from their "set" of GT40 instruments. FWIW I gave it power from the center console aux. power circuit and the ignition signal from the ign. switch. I placed the antenna on the right side of the dash just under the lower rear corner of the windshield. Of course mine's never left the garage but it does sit there very accurately indicated the speed. :lipsrsealed: Seriously it does get a satellite fix without any needle bouncing.

awatkins said:

Of course mine's never left the garage but it does sit there very accurately indicated the speed.

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So push it down the driveway and report.................

All very interesting. SpeedHut has a March sale, and the only thing preventing me from pulling the trigger is GPS vs pulse. I'm more inclined to go old school pulse. After all, I still want a speedometer after the next atmospheric thermonuclear burst.

awatkins said:

I bounces around because of car motion, or just on its own? Yikes.

I have the one from their "set" of GT40 instruments. FWIW I gave it power from the center console aux. power circuit and the ignition signal from the ign. switch. I placed the antenna on the right side of the dash just under the lower rear corner of the windshield. Of course mine's never left the garage but it does sit there very accurately indicated the speed. :lipsrsealed: Seriously it does get a satellite fix without any needle bouncing.

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Once you get moving it starts to bounce to the point it's unusable. Its as if the cable binds and releases binds and release. I think I will pull the trigger tomorrow on a Speedhut unit.

http://www.google.com/url?sa=t&rct=...q9SnDg&usg=AFQjCNEY6ue272hyK9iW0pGQhQsm6h-4Ag

I had these guys build me a new cable with less bends. Erratic jumping around virtually stopped. Total cost was about $100.

MHNCO said:

Once you get moving it starts to bounce to the point it's unusable. Its as if the cable binds and releases binds and release.

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Interesting, mine bounces as well but no where near that bad. I will say mine reads about 6 mph too fast but I have not had the desire to replace it yet. I am waiting for my cable to break before I tear the car apart (again) to replace it.

Kevin

Am I wrong to assume that to swap out for the Speedhut unit is a fairly simple and straightforward process? Unscrew the access panel on the passenger side of the dash and everything is right there? Disconnect the cable, remove the existing speedo, run the wires down to the ignition switch for power and ground. Where does one route the antenna wire if they mount the antenna on the top of the dash?

fsts2k said:

Interesting, mine bounces as well but no where near that bad. I will say mine reads about 6 mph too fast but I have not had the desire to replace it yet. I am waiting for my cable to break before I tear the car apart (again) to replace it.

Kevin

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Do you have the Olthoff adaptor at the transaxle end? It corrects for the too fast speedo, but mine reads a little on the slow side now. I can see the benefit of an electronic speedo.

A dry cable will "bounce" If you don't lube it, it will break.

You might be able to fix your bouncing cable issue by removing the cable, hanging it from one end, tape a plastic bag on one end so that it will drain from a small hole in one corner into the cable. Seal with some tape. And fill with a some light oil, about 5 weight, (not WD40). Allow it to run through over night and reinstall.

This will fix a dry cable for quite a while. It is a pain in the ass however to get the cable out of the car. I have considered trying to pressure feed oil through the cable in place but I never got around to figuring out how.

The Speedhut GPS option really makes a lot of sence to me and I am going to install one in my SLC when the time comes.

I think that if you have a fiberglass dash board then you don't have to mount it above the dash. You can simply put it up underneath. The fiberglass isn't a shield to radio waves and should not block the gps signal anymore than the glass windshield.

They are on sale now for $237 through today... just ordered mine.