MadaboutKitcars

Hi all
I have a gt6 diff compleat with spring and half shafts drum brakes and some bushers for sale here in suffolk £150.00 or good offter all in good working order please call 07951858197 Post code CB8 9SA

Any idea what ratio it is?

I'm not sure if I'll be interested, but i know that whoever does have this off of you will want to know

Dave

i dont know were do i look for this

this may help

WHAT DIFFERENTIAL DO I HAVE?

There are a number of ways of identifying a differential – wither by counting the crown wheel teeth and dividing by the number of pinion teeth (eg c/w 35 pinion 9 = 35/9 = 8.39), or by counting the number of turns the front flange requires to turn both output flanges through 360 degrees (or one output flange through 720 degrees) – just more than 3 ½ means 3.63, just more than 4 = 4.11

If it's a 3.27:1 from a UK or US spec non-overdrive GT6, or a German spec overdrive model it'll have 'KC' stamped on the casing somewhere.

If it's a 3.89:1 from a UK or US spec overdrive car (or Vitesse with or without overdrive) it'll have 'KD' stamped on the casing, although I'm struggling to find the code on my old Vitesse diff now I've changed it for a reconditioned 'KC' unit that has an 'E' stamped over the 'C' !!

Depending on your tyre size the 3.27:1 will give you around 21mph/1000rpm and a theoretical top speed of about 130mph (156mph with overdrive!) while the 3.89:1 will give about 18mph/1000rpm and hit the red line at 110mph (130mph with overdrive).

So, fitting a 'KC' diff to a non-overdrive Vitesse gearbox gives roughly the same final drive ratio as an overdrive equipped car, while fitting the 'KC' diff to a car that already has overdrive gives you around 26mph/1000rpm and the potential to reach very scary speeds indeed...

Suitable mods I've seen recommended are to change to a 3.27 on a non overdrive Vitesse, fit a 3.63 to an overdrive one and change the 4.11 to a 3.89 on a Herald (on models where it'll fit). And if you've got a really early Herald or Herald van with a 4.55 or 4.875:1 diff fitted I'd buy some earplugs, just ask Phil J!

The link below should help.

http://www.teglerizer.com/triumphstuff/spit_and_gt6_specs.htm

matey, you have WAY too much spare time!

mister towed

can you say that in some sort of english for me to understand i have 1300 herald wots the best diff then ..

Sorry if it was a bit over technical.

To make it simpler, the lower the number of the final drive the lower the revs will be at any given speed.

A standard Herald 1300 has a 4.11:1 differential. This means that the prop shaft has to go round four and a bit times to turn the back wheels round one full circle. The GT6 without overdrive came with a 3.27:1 differential so the prop shaft only has to go round a tad over three and a quarter times to turn the rear wheels once.

This'll give you more relaxed cruising, a theoretically higher top speed and better fuel economy but, you'll lose some flexibility - the ability to accelerate from low speed in a high gear.

Obviously, those of us lucky enough to have the extra torque and power of a 2 litre six can run taller gearing and still vary our speed in traffic without constantly going up and down the gearbox, unless we fancy hearing that six cylinder roar.

With a Herald 1300 four pot you'll most likely have a 4.11:1 diff so at 60mph your engine will be turning over at 3,500rpm. Changing to a Vitesse 3.89:1 diff would drop that to 3,300rpm while a 3.63:1 from a 1500 Spitfire would reduce it even further to 3,100. With the Spitfire diff fitted though when the traffic slows to 40mph you'd only have 2,000rpm on the clock and with only 60bhp you'd probably need to drop a gear to pick up speed again.

As for which diff is 'the best' well, that really depends on your personal preference.

I know we're hijacking the for-sale thread here, but i hope you don't mind Kevin as this is quite a useful discussion and may help you sell your kit!

To build on what Towed said, Even though i've got a 2L, my diff is currently a 4.11:1 (don't ask!) and i don't have overdrive so at the moment my Sammio drives like a diesel! I can pull off in 1st or 2nd and basically drive everywhere in 3rd or 4th and only drop to 1st when i stop as i've got so much torque for the gearing and the lighter weight of the car.

So i'm switching to higher gearing by changing my diff. I looked into what diff to choose and while i would have loved to have gone for a 3.27:1 everything i read and everyone i talked to said that they were "fragile" and so for the time being i've ended up getting a 3.63:1 which is currently being cleaned and will be fitted _soon_ (ish).

Depending on how that alters the car, i may do an overdrive conversion at some point in the future in order to get better high end. Or if i can find a 2nd hand 3.27:1 for a good enough price (hence my other post to see if anyone had one laying around?), i may have a tinker with that, as making these cars lighter really does make them..... nippier!

A few years ago I fitted a dolomite 1500tc engine (same as spitfire 1500) and box into a 13/60 herald saloon along with a 3.27:1 diff and it was very nice to drive. 3rd was a much more useful overtaking gear and pulling away in 1st on hillstarts was easy. 70 mph was a comfortable cruising speed compared to about 50 mph in standard trim (4.1:1). After I sold that car it passed through several hands and turned up again in the north east in a poor state bodily. It would be an excellent donor if anyone could find it as the chassis was really solid.

gt 6 diff

hi all the spring has know been sold so the diff and half shaft are still here
for sale the diff has stamp on it
leys js39 v2717 and on the case A20 THESE ARE ALL THE LETTER i can find on the case when i got it i was told it a gt6 diff all parts are triumph 19.69/70 i think

I can't find a code on my Vitesse diff either.

The ultimate test for the final drive is to put a chalk mark on the input flange and another chalk mark on one of the drive shaft flanges, then turn the input shaft and count how many times you have to turn the input flange to get a full turn of the drive shaft. If the diff's out of the car and the drive shafts are turning in opposite directions then I understand it'll take half as many turns of the prop-shaft flange to turn each drive shaft flange once. So, if it takes about three and a quarter turns of the prop flange to get the drive shaft flanges to turn twice it's a 3.27:1 non overdrive GT6 diff. If it takes just over three and a half turns it's a 1500 Spitfire 3.63:1. Just under four turns then it's a 3.89:1 Vitesse (or GT6 with overdrive diff). A little over four and it's a Herald 4.11:1.

I'll have a play with my Vitesse diff in the morning and see if this holds true.

Oh, and anyone interested in performance tuning their Triumph could do worse than to read this -

http://www.kolumbus.fi/triumph.tr6pi/Vizard_Tuning.pdf