Speedo Gear Drives

[RET]

I've recently swapped the old Powerglide out of my FE and put a Trimatic in instead.  Unfortunately, this has rendered the speedo inoperative.

My driveline combination is 13" 185/80 series tyres and 3.36 diff ratio.  The gear-drive that was in the 'glide had the speedo reading as near to true as makes no odds.  So my question is this:  will the gear-drive from the 'glide fit the Trimatic?  For that matter are the gear-drives from later manual boxes interchangeable with auto ones?  I ask this because I have determined that 173 manual LH and LX Toranas had the same 3.36 + 13" rim combination, so that should be the right drive for my setup too.

I really don't want to faff around trying different gears to figure this out by trial and error because due to the shape of the tunnel/sub-frame the back of the box has to be dropped to get the cable in and out. :-/

Any help appreciated.

cheers
RET

[mcl1959]

Richard, don't know about the tri having the same gear as the powerglide but I do know that there doesn't seem to be a gear available to lower the speedo reading to correct.
I have 3.08 diff and 13 inch wheels as well
The Torana speedo head has different internals which must slow it down.  I am currently trying to put a Torana speedo head in a FE guage which is difficult since the drive points downward instead of back.
The cable I used is HG auto which bolts up to either the FE speedo or the Torana speedo

Ken

[Glenn 'Stinky' Stankevicius]

I can't help with what gear to use, but any proper gauge shop should be able to recalibrate you speedo to suit, somewhere like http://www.gaugeworks.com.au/services.html

I have also heard of correction boxes that can be used to adjust ratios. No leads on that one though.

[fcfromscratch]

Hi Richard,

I was originally going to go with a Tri but ended up with a 'glide.  The speedo cable that I got from CRS (with the 3/4 chassis) for the Tri was certainly no good for the 'glide, and so had to have another one made.  My experience (although memory is fading) was that the driven gears were quite different to suit the different driven head shapes.  I happened to have a couple of driven gears to suit the Tri....I'll chase them up if you like and take a pic or two and send 'em to you.........I'm fairly confident that you need a Tri driven gear but which one for your wheel/diff combo, I'm not sure....

cheers.....Brad

[FCwagon]

Hi Richard,
I've been through the same with my FB speedo and unfortunately it was a lot of "Faffing" around trying different gears. You probably already know there's 9 different ration gears for a Tri. I've got all sizes (except the lt blue which is in mine) if you need one.
My speedo head had been recalibrated for a really high ratio diff and because it was in such good nick I wanted it to stay. A speedo mob down here wanted near $200 to recalibrate. I ended up trying 5 different gears until I reached a suitable conversion reading.
cheers,
Leigh

[Flamed_FE]

RET

There was a thread started many moons ago detailing all the different colors and how many teeth they had and how to work out what one to use depending on your set up (tyres, gear box and diff).  How ever, bugger if I can find it.  I even looked in the tech section.  Closest I came was

http://www.fefcholden.org.au/cgi-bin/yabb/YaBB.cgi?board=howto;action=display;num=1089123589;start=12

and

http://www.fefcholden.org.au/cgi-bin/yabb/YaBB.cgi?board=hotup;action=display;num=1027515452;start=

I'll check the acticles folders at home in case it was in there rather than here.

Cheers
Al
Flamed FE