Author Topic: Speedo issue  (Read 182 times)

Offline craigb

  • Full Member
  • ***
  • Posts: 179
  • THANKS 25
  • Location: NSW
  • REMLR No: 488
Speedo issue
« on: April 30, 2021, 02:51:18 PM »
It's almost that time of the year where the old Rover has to pass an inspection for rego. There are two main issues identified (well, three if you count all the RFSV bits that I'll remove ahead of the inspection) - windscreen needs replacement and that's being done in the morning; and the speedo.

The speedo has been alternately a pain in the bum and an "I'll get to it later" issue. When I purchased the vehicle it was fine. If I recall it began reading slightly over when I went with the split rims and hi-milers, but it wasn't drastically out.

At some stage during my last transit of the Nullarbor the speedo cable crapped out and I went to using a speedo app on my phone. When I returned home I swapped out the cable and all was well until another big trip when the speedo just stopped working.

I took it in to a mob to get fixed and they told me the speedo gauge had jammed up. I dutifully purchased one for it from Paddock Spares in the UK, wishing to avoid the Perentie Tax on basic 110/Defender parts. Then I took it back to the same mob and they installed the new speedo for me. Unfortunately it reads about 20km over at 80km/h. The odometer is out too.

I queried this and was told that it couldn't be adjusted/calibrated any further. I had just shelled out a bunch of cash on a new speedo and on installation by professionals, so I just lived with it. However, it's all come to a head now and I need to replace or repair the speedo before I can get the wee beastie re-registered.

What causes the speedo to over-read? Is it hard to fix?

Please note I don't want a GPS speedo. As it is I rely upon a GPS app which doesn't work in tunnels. I already have to pay tribute for a speeding fine in a new motorway tunnel the other day because I was 5km over the speed limit. Mechanical options only please,
ARN 49-215 Truck, Utility, Lightweight, FFR, Winch, MC2 "Frankie" -1989
ARN 101-001 Trailer, Cargo, Ton, 2 Wheeled, Aust. No. 5 - 1963

Offline fc101

  • Hero Member
  • *****
  • Posts: 600
  • THANKS 55
  • Location: Canberra
  • REMLR No: 243
Re: Speedo issue
« Reply #1 on: April 30, 2021, 04:12:36 PM »
From what you have said I would say the gears in your new speedo are no correct (the old ones should work).  If your speedo person does not know how to fix this you need to go to another business - they will be able to source the right gears for your application.  Not sure if a Perentie speedo is the same as a standard civilian 110 diesel but worth checking as tfr case and diff ratios should all be the same, as would speedo drive ratio and speedo head ratios.  May not of course but unlikely.

Be aware that GPS speedos are illegal and an immediate roadworthy fail if spotted.

Offline Mick_Marsh

  • REMLR Inc
  • Veteran
  • *
  • Posts: 2023
  • THANKS 107
  • Location: Western Victoria
  • REMLR No: 310
Re: Speedo issue
« Reply #2 on: May 03, 2021, 11:46:27 PM »
From what you have said I would say the gears in your new speedo are no correct (the old ones should work).  If your speedo person does not know how to fix this you need to go to another business - they will be able to source the right gears for your application.  Not sure if a Perentie speedo is the same as a standard civilian 110 diesel but worth checking as tfr case and diff ratios should all be the same, as would speedo drive ratio and speedo head ratios.  May not of course but unlikely.

Be aware that GPS speedos are illegal and an immediate roadworthy fail if spotted.
What he said.

On the speedo dial there should be some numbers. I'm going by another Leyland car so I assume Landrovers are the same.
Let's say this number is 760 (I don't know what it is for a Perentie). This means the speedo accepts 760 turns per km.
Are the numbers on your two speedos the same? If no, you bought the wrong one.

Alternatively, I had a strange mix of speedos, diffs and speedo output gears in another Leyland car I have. The speedo was way out. From memory, when it read 75 I was really doing 100.
I took it to a speedo place and he measured the revs per km the gearbox was putting out. He then made a ratio box that converted what the gearbox put out to what the speedo accepted.
REMLR # 310, MVCA # 364, 101 Club # 2188, MHG #101
29-417 101 GS, 30-248 101 Rapier Tractor. 30-238 101
34-597 Crump & Cornish 1 ton Cargo Trailer
RT21 RAAF Track Tactical Trailer, 234-671 RAAF Track Tactical Trailer

Offline Hot Rover

  • Sr. Member
  • ****
  • Posts: 397
  • THANKS 98
  • Location: Toowoomba Qld
  • REMLR No: 319
Re: Speedo issue
« Reply #3 on: May 04, 2021, 12:31:32 PM »
You need to replace with a VDO unit the same as from a late model Defender. The have a transponder which you can buy new or source from a wreck. Very easy mod and very accurate speed reading after calibration.
Cheers
Rod
108-545 1963 Series 2A FFW
51-441 1991 Perentie GS (RamRod)
Series 2 Safari (Matchbox)
173-621 1/2 Ton Trailer, Aust No5

Offline Mick

  • Veteran
  • ******
  • Posts: 1279
  • THANKS 171
  • Location: Melbourne
Re: Speedo issue
« Reply #4 on: May 04, 2021, 06:58:54 PM »
Hi Boys ,

I agree with Rod , the conversion is really easy and the speedo is very accurate.

The part required for gearbox is around $150 new. The more modern VDO speedo is brighter and much easier to read at night.

I picked up a 2nd speedo for $250

Cheers,

Mick

Offline craigb

  • Full Member
  • ***
  • Posts: 179
  • THANKS 25
  • Location: NSW
  • REMLR No: 488
Re: Speedo issue
« Reply #5 on: May 07, 2021, 05:08:13 PM »
Thanks for the advice, gents.

A lot to think about. I'll get it done by early August and I'll report back with how it went.

Cheers!
ARN 49-215 Truck, Utility, Lightweight, FFR, Winch, MC2 "Frankie" -1989
ARN 101-001 Trailer, Cargo, Ton, 2 Wheeled, Aust. No. 5 - 1963

Offline Lionelgee

  • REMLR Inc
  • Full Member
  • *
  • Posts: 175
  • THANKS 19
  • Location: Bundaberg
  • REMLR No: 353PY
Re: Speedo issue
« Reply #6 on: May 07, 2021, 07:40:47 PM »
Hello Craig,

If you want to stick with the original gauge and have not quite reached the stage of feeling that you have been throwing good money after bad... I would recommend this crew in Brisbane https://www.ottoinstruments.com.au/. I have used them in the past to restore a set of old Smiths gauges and would not hesitate in accessing their services again. I think it is at least a second generation family business.

No I have no link to the business - we just happen to share the first name.

Kind regards
Lionel