Thread: What it is the error tolerance in a LR speedometer?

Originally Posted by PhilipA

Like the transfer case gear from a SWB for instance?
Regards Philip A

Would that have had the same overall gearing as a LWB but just a different speedo drive to allow for the smaller tyres? If so then that is probably the explanation since there were other signs that the vehicle had been assembled fom someone's spare parts bin. They must have done a good job though. It gave me very little trouble in all the time I owned it.

Originally Posted by Bushie

That actually aligns pretty well with what I have been told by the local highway guys, they were working on 10% + 3kph over the speed limit ie 100kph would let you go up to 113 before being booked.

I think the fixed cameras operated by the (NSW) RTA are a different story though.

The new demerit point is for speeds < 15kph over the limit.

Martyn

Years ago when radar was still very new, a member of the police force who was the guest speaker at an Apex Club meeting told us that they when they were set up on the Hume Highway, they set the alarm to go off at 15 over the limit.

I asked him if that was because they got all the customers they could handle at that speed or because they were the people who most needed to be pulled up, but he didn't really give me a straight answer.

I suspect that it would have been because on the Hume Highway just out of Yass they would have had more customers than they could handle if they pulled up people who were only 5 or 10 over the limit.

I suppose with speed cameras and everything automated, that problem no longer exists, so they can grab as many as they want.

if you can prove your speedos accurate and you have the GPS logging turned on AND you have the recording increment set to per .5 sec AND the HDOP of the GPS is marked at less than 3m you can use it to beat a speed camera.

HOWEVER....

don't try this unless your absolutely certain that you're in the right, other wise you get the heftier set of fines AND the court costs....

Would that have had the same overall gearing as a LWB but just a different speedo drive to allow for the smaller tyres?

AFAIK yes ( but I am not a Series trainspotter)
Regards Philip A

Originally Posted by Chucaro

I remember few years ago a light post in Hobart was detected of doing over 100 kph

and as a result the light pole cannot hold for nor apply for a licence for 3 years....


Horries speedo is about 60km/h out....when Im doing 60.......
Vets speedo is 780k out...as in its in a box with me and he is waiting to be brought down to join it!!!

When I first set up my 2A, I fitted 7.50R16s and a fully checked out 1408 speedo. I set it with a GPS to read about 2.5mph (4kmh) optimistic. Of course, with advancing wear on the tyres, it now probably reads even more optimistic.
In almost eight years owning it, and thirteen years driving, I have never been pinged speeding. I learned very quickly to get out of overdrive through school zones, though.

Dan.
69 2A 88" pet4, 74 3 109" pet4, 68 2B FC pet6.

Originally Posted by PhilipA

Like the transfer case gear from a SWB for instance?
Regards Philip A

All Series Landrovers (except Stage 1 and a few very early 80") have the same diff ratio and the same speedo gears on the back of the transfer case.

However, there are at least a dozen different speedos fitted, and for the purposes of this discussion, the variable is tyre size, and specifically the speedos fitted as standard to swb and lwb. These assume a 7.50 tyre on the lwb and a 6.00 tyre on the swb. Fit 7.50s (as is commonly done) on the swb, and you need to fit a lwb speedo or your speedo will underread. Same problem if a swb speedo is fitted to a lwb.

For interest, some of the other factors that changed the speedo fitted:-

Six - went to a higher speed
S3 vs S1,2,2a - different cable connection
80" - smaller speedo
S3 and S2a after suffix D - warning lights in speedo
Kph or mph
Trip or no trip

John

So if I understand you correctly, the most likely reason for my speedo and odometer in my Series III LWB being pessimistic is that it had the speedo from SWB.

IIRC the cable had the plastic clip to attach it to the speedo head.

It's all academic now as I sold the Series III a couple of years ago, but I often wondered what the explanation was.