3.8 Auto to Manual Advice

[oldtimer]

Hi All,
Just for information, all diffs used to have a small metal tab with two numbers stamped on indicating the ratio in use. The tab was/is located on one of the diff rear cover panel securing bolts. Doubtless many of these will have disappeared over the years. I can't for the life of me remember the numbers to give an example. Should that tab still remain you will find two numbers something like 16/ 66 ( just a guess ) the small number being the number of teeth on the pinion and the larger number being the teeth on the crown wheel, so by dividing 66 by 16 will give you the ratio in use.

I am familiar with the ratio's quoted above, all of which have been around for donkey's years (however long that is) the 3.54 in particular is associated with auto boxes and appears in a variety of models.

Salisbury and ENV were axle/diff suppliers to Jaguar for many years but I really don't have a clue as to the situation today. My modern S type most likely has a Ford Diff

Well, I hope that bit of information helps

Oldtimer

[340jag]

I have done the conversation , but it was a long time a go , my 240 Auto is now a 3.4 manual overdrive , I scraped a 240 manual and stripped it of all the parts , the transmission tunnel is wider on the Auto as said, and taller on a manual , so your have to cut out the top of the Auto tunnel , so the gear selector and stick will fit , manual cars have a different shape tunnel ,so you cant use the panel that bolt's on the manual on the Auto,I think the prop is different too , a tape measure will find that out once fitted , I think I had a little trouble with the Centre console as well , the sides are different at the front end , making the 2 panels that bolt to it different as well
Wires will need sorting , but a good wiring diagram will show that ,
Carpets will be a different shape !
I found a pic that shows the Tunnel , give you some idea what you need to do !