the ratios in gearbox is an interesting subject and I put together the list
of ratios below for our local jaguar club magazine the only missing ratios
is for 3.8 litre E type. which I now have.
First gear is way to low for an XK ie 3.375 the CR ratio is much nicer at
2.98 but if you drop a set of 2.4 MK1 / MK11 non synchro gears hey presto
you have a very usuable first gear at a price a lot less than finding an XK
CR gearbox. Even MK2 3.4 etc is an improvement and is very close to CR ratio
Several people have asked me what the gear ratios are in Jaguar gearboxes.
This of course affects the driveability of a car. This information is of
course important when different gearboxes are being fitted and differential
ratios changed. Someone else can interpret how the change in these ratios
will change the way your jag drives and accelerates.
MKV, MKVII, XK120, XK140, XK150
XK120, XK140, XK150 close ratio when fitted
MK2 2.4 litre
3.4 / 3.8 MK2 / S Type, 4.2 MKX, 420, E Type 4.2 2+2
E Type Series 1 3.8 Coupe /Roadster
E Type Series I 4.2 Coupe / Roadster
XJ 2.8 / 4.2, E Type Series II and V12 E Types
Overdrive on XK140 / XK150, MK1, MK2
1 Jul 2007 10:53:33 +0200
The gearbox ratios for the overdrive boxes were the same
(there was also a close ratio version but that’s not
dependant on having an overdrive). With the overdrive fitted
Jaguar changed the default rear axle ratio.
For the XK150 without overdrive the normal axle ratio was 3.54:1
With the overdrive the ratio was 4.09:1 giving an effective
3.19:1 ratio with the overdrive engaged.From: “Ken Green” firstname.lastname@example.org
Subject: Re: [xk] Gearbox options
I found the gearbox ratios for 120 moss box as:
does anyone know if the moss box with overdrive is the