Brantz gearbox sensor

[Dazzer]

Hi Guys

 

Has anyone modified a Brantz gearbox sensor to fit an A type box?

 

Unsure what the thread type is on an A type, however, I'm pretty sure It's not M22x 1.5 or M18x1.5 as on the Japanese or Ford/GM type Brantz gearbox sensors.

 

A few competitors on a recent rally had them fitted, but didn't get around to getting the low down.

 

Any details gratefully received.

 

Cheers

 

Darren

[Tr4Tony]

Hi Darren

 

Easiest way is to machine down the brass drive to the correct thread, but why do this when the cable sensor works so well (so long as the cable doesnt snap!) or the rotating sensors can be used on the front hub or the propshaft ? There is so little room between the box and the chassis that I am sure it would get munched the first time the gearbox rotates on cornering. This happens more than you would imagine and is the reason that the dodgy repro gearbox mounts fail often.

 

I have run a wheel sensor for a while and it seems 100% reliable ..... and given that I fitted it whilst lying on the ground at scrutineering on the Rally of the Tests last year, with Peter Banham's tools, in the rain and under some time pressure, there was every opportunity for me to make a balls of it .....

 

Regards

 

Tony

[Nigel 628]

Tony: where did you mount the sensor on the front hub?

 

I prefer this method as it doesn't suffer from wheelspin error, but the usual 'target' on most cars is the disc mounting bolts which are too inaccessible on a TR4 for the Terratrip sensor plus bracket to get close enough to 'see'. The problem is compounded by the issue of damage from flying stones.

 

I currently have a speedo cable sensor for the Brantz RetroTrip which was installed when I bought the car, but have added a Terratrip 202 and a prop U/J sensor; the Terratrip has the facility to swap between the two sensors, which is handy if one packs up. On my Wildcat offroad racer I have two sensors, one each side of the propshaft, each wired separately to the Terratrip. (4x4 so no advantage in front hub mounting, but a bigger chance of those flying stones wiping a sensor out!)

 

You'll find the vast majority of rally cars use the universal magnetic type sensor, Darren. Easiest is the prop U/J location, but make sure you use thickish steel for the bracket so it won't bend in use.

 

Regards

 

Nigel

[Tr4Tony]

Hi

 

I mounted the wheel sensor through the bracket which holds the caliper on, so that it senses the 4 hub bolt heads as they pass by. Tricky to line up properly, but because of its location its well protected and seems to last the course.

 

Regards

 

Tony

[Dazzer]

Hi Tony

 

The wheel sensor does sound interesting is it a Brantz part?

 

I've basically become paranoid after the cable did snap in France, and although the cable sensor had worked perfectly for two years, it then became problematic to fix.

 

Firstly as a quick get us by, I managed to salvage two inches of the old inner cable. I cut down the outer and mounted the cable sensor on the angle drive on the gearbox, leaving the cover off the tunnel and doing without speedo/trip.

 

This worked OK for a couple of sections.

 

Next day I fitted a new cable and refitted the cable sensor... the cable lasted all of the morning then snapped again! this time taking the centre of the cable sensor with it. So we completed four days of regularity with no brantz, speedo or trip... interesting! However my trusty navigator managed to bring us in 1 sec, a couple of 3 secs a 9 sec and a 12 sec on 30 -40 kilometres sections with speed changes...! The cunning plan was to pick a time between competitors we knew to be very good, when that didn't work, timing distance between kilometre marked road signs and hoping they were accurate to gauge speed (the small blue signs are definitely more accurate for future reference) and of course going the right way always helped. (2000 rpm no overdive approx 42KPH)

 

When we returned to the UK I stripped the cable and angle drive out and scrapped the lot. I've now re routed the cable directly into the box, straight into the drivers footwell and up and around to the speedo, avoiding the exhaust system AKA Neil Revingtons 6VC.

 

A TR5 had the sensor on the box on the rally, although I really like the idea of a back up system and the wheel or prop sensor does sound favourite, yes I've had two gearbox mounts go in two years.

 

All the best

 

Darren