MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB Technical - What is the % Life used indiactor on a '75 MGB?

I had a 1975 MGB in my shop for a new clutch this week. There was a small yellowish plastic box attached its firewall which had a speedometer cable coming in from the transmission and another going out to the speedo. I had never seen anything like it. It showed 44. The brand name is Smith's, like the speedo. What is this 44% of the life of? I did not see or feel a way to reset it, like after an oil change. A '77 which came in today did not have this option. The '75 had no owner's manual. I did not see any mention of the unit in the manual for the '77, but I didn't have time to read the whole thing. I figured someone here would know about it.
Chuck Asbury

Just guessing, sounds like an odometer for to trigger the EGR service idiot light. Done with computers these days.
Andrew Blackley

its an egr/emissions timer/counter .The light comes on on the dash and you push in a little button on the side of the box the light goes out that is if the system is still hooked up and working slim chance-RIC
R E L Lloyd

I thought that this box indicates how much smoke is left in the wires. It shows 100% is used up on my car, and now smoke is leaking from the wires at various places in my wiring harness. Where can you get the smoke refilled?
Wayne Norman

NO NO Wayne! You misunderstood my post. This thing is a Smiths product, not a Lucas product. I hope you are not using "slow blow" 1482 amp fuses. See: http://www.landroverclub.net/Club/HTML/Humor_electrics.htm
Chuck Asbury

Chuck
I read your link to the electrics humour. Best laugh I have had in a long time.
Thanks
Jim Webb

Sick puppies...the lot of you.
J.T. Bamford

Hey All,

BMC called the little plastic box, the "Service Interval counter". It was supposed to indicate when service was required to the EGR/Emissions system, by turning on an indicator lamp. It was also supposed to be turned off and reset by using a special key which came with the car.
The box usually packed it in not too long after the 2nd service was required, and could cause the speedo to "go south" as well. It wasn't used very long. I think '75 and some '76 models only, were equipped.

JR
JR Ross

My early 76(02/76) has one, now reads 351% at 100,500 miles. Speedo still works fine. I have never noticed any wires attached to it. Emmissions stuff has been removed.
Pete Haburt

This thread was discussed between 30/08/2003 and 08/09/2003

MG MGB Technical index

This thread is from the archive. The Live MG MGB Technical BBS is active now.