Speedometer Calibration

[StainlessBullet]

My new D' has a 170mph speedometer installed and it's way off on it's speed. What has to be done to calibrate to the correct speed? I'm assuming I'm going to have to ship this thing off to a specialty shop somewhere?

[chris williams]

It may be the angle drive that's way off.... My 85mph speedo with it's OE angle drive was pretty much spot on, when the angle drive failed I replaced it with one from SpecialT auto it works well but the speedo is now out (reads lower than your actually driving) it may be that this is your issue rather than the speedo itself?
Chris

[David T]

It may be the angle drive that's way off.... My 85mph speedo with it's OE angle drive was pretty much spot on, when the angle drive failed I replaced it with one from SpecialT auto it works well but the speedo is now out (reads lower than your actually driving) it may be that this is your issue rather than the speedo itself?
Chris

Drive over a measured mile (or more, the more the higher the accuracy) and check the odometer. If the odometer is accurate then you just have to have the speedometer calibrated. If the odometer is NOT accurate you have a problem with the angle drive or the cables. The speedometer is calibrated at 1,000 RPM's equaling 60 MPH. To calibrate the speedometer it must be removed from the car. If you don't have the right size tires that WILL affect the odometer AND the speedometer. You can also do a rough check with the Tach vs Speed chart. Just be sure to use the correct one, the one for the 5-speed is different that the one for the auto. Or GPS.

[Delorean3610]

Can you clean or lube the angle drive? And how would you do it?

[David T]

Can you clean or lube the angle drive? And how would you do it?

You can't clean it unless you take it off the car and take it apart. Usually it is just lubricated once a year when you lube the front end. To lube the angle drive you jack up the car, and take off the left/front wheel. Remove the cable from the angle drive and loosen it so you can rotate it. Rotate it till you can get to the little screw in it's side. Remove the screw and squirt some grease into it. It shouldn't take much. These instructions apply to the original angle drive. If you don't have an original some of the replacement angle drives do not have a screw to lube it with. While you are there check to see if you have the bracket to hold the speedometer cable. It attaches to the brake caliper and keeps the cable from drooping. While you have the wheel off check the dust cover. The center hole must be square and fit onto the cable enough and the cover should be tight between the wheel and the rotor so it doesn't slip.

[Delorean3610]

Thank you, I have a 170 that is off also. It reads high, about 10-15 mph higher.

[Delorean3610]

What lube or grease should be used? I have a bunch of different kinds.

[StainlessBullet]

When my GPS said I was doing 80mph, the speedo showed 50mph. I'm pretty sure the odometer is ok. I set the trip odometer when I picked up the car and it stayed in line with how many miles I traveled according to my GPS.

Once this Tennessee ice-apocalypse is over, I'll double check with another run.

[David T]

When my GPS said I was doing 80mph, the speedo showed 50mph. I'm pretty sure the odometer is ok. I set the trip odometer when I picked up the car and it stayed in line with how many miles I traveled according to my GPS.

Once this Tennessee ice-apocalypse is over, I'll double check with another run.

I guess I am old fashioned, I use the mile markers on the highway. All main highways (interstates) have them. The longer the course the higher the accuracy. The way to do it is to also try to maintain exactly 60 MPH, it keeps the math simple to check the speedometer. If the odometer is not accurate you cannot have an accurate speedometer so check that first. The weather is so bad here the car isn't coming out till Spring! The roods are WHITE. Not from snow (at least not right now, they are white with SALT! It's about 10 degrees now going down to around 4 overnight with 3-6 inches of more snow tomorrow.

[StainlessBullet]

The weather is so bad here the car isn't coming out till Spring! The roods are WHITE. Not from snow (at least not right now, they are white with SALT! It's about 10 degrees now going down to around 4 overnight with 3-6 inches of more snow tomorrow.

I can certainly sympathize with you. Tennessee will salt the heck out of the roads when there is even a slight chance of snow or ice. The day I bought the car I had to drive 150 miles on salt covered interstate to get home. That really killed me too. I know first hand what salt will do to the frames on these cars and I'm still cringing at the thought. I have yet to get a chance to wash the car and that was two weeks ago.

[David T]

I can certainly sympathize with you. Tennessee will salt the heck out of the roads when there is even a slight chance of snow or ice. The day I bought the car I had to drive 150 miles on salt covered interstate to get home. That really killed me too. I know first hand what salt will do to the frames on these cars and I'm still cringing at the thought. I have yet to get a chance to wash the car and that was two weeks ago.

As bad as it is on the frame it is awful on all of the fasteners. When you go to take things apart they just break off.