Rear diff ratio

Tjclare · Post by **Tjclare** » Mon Mar 07, 2016 8:46 pm

I have a S2 DHC 1970 4.2 USA import called Winston :) with the following numbers on the dash:
sn-6332/01A 1312. I have never driven the car yet (striped to bare metal at the moment) and was looking for advice regarding the drive I should expect once complete, am I correct in assuming I have a 3.31 diff? Is it wise to alter this ratio? It's matching numbers so don't really want to change the gearbox.

41. Jaguar offered the following optional differential ratios on the E-Type ? 2.88, 2.93, 3.03, 3.31, 3.54, 3.77 and 4.09 depending on date, country and application.

Post by **mgcjag** » Mon Mar 07, 2016 8:57 pm

Hi Whats your name.....the number you refer to is the number on the speedo and originally would tie up with the diff ratio....however it may have been changed at some time so to be sure of the diff you need to find out what it is.....look for a small tag attached to the cover plate with the ratio stamped on it.....your missing out on your list the 3.07 which is a very popular choice for US conversions .......ps Winston will be refered to as an ots in the UK....

nefematic · Post by **nefematic** » Mon Mar 07, 2016 9:43 pm

Hi _______,
the numbers stated are from the speedo, you have the 3.54 Powerlok rear end. Have a close look at the rear end differential, you should find two aluminum tabs under the diff cover bolts stating the ratio and the Powerlok. Many have changed the ratio away from the US version and/or the gearbox to achieve more favorable driving on european roads.
Martin

iani · Post by **iani** » Mon Mar 07, 2016 9:45 pm

nefematic wrote:Hi _______,
the numbers stated are from the speedo, you have the 3.54 Powerlok rear end. Have a close look at the rear end differential, you should find two aluminum tabs under the diff cover bolts stating the ratio and the Powerlok. Many have changed the ratio away from the US version and/or the gearbox to achieve more favorable driving on european roads.
Martin

1970 S2 might not be a Powerlok unit, these were optional by this point.

Ian

Alty Ian · Post by **Alty Ian** » Mon Mar 07, 2016 9:48 pm

Almost certainly a 3.54 diff if its a manual and original with that speedo reference 1312

christopher storey · Post by **christopher storey** » Mon Mar 07, 2016 10:54 pm

I have no idea where the " 41 Jaguar offered " numbers come from . 2.93, 3.77 and 4.09 were never fitted to Es, and 3.03 does not exist. 3.07 was the Standard European ratio from about 1964 onwards , late 3.8 and all European 4.2s . Your car being North American is almost certainly 3.54 which will have the tag 46/13 on the final drive

Tjclare · Post by **Tjclare** » Mon Mar 07, 2016 10:55 pm

Thanks guys, I will check tomorrow on the diff. It is a manual gearbox
Has anyone got the same setup? If so, what is your your perspective on the drive,
Thanks Tony

Tjclare · Post by **Tjclare** » Mon Mar 07, 2016 11:03 pm

41. Jaguar offered the following optional differential ratios on the E-Type ? 2.88, 2.93, 3.03, 3.31, 3.54, 3.77 and 4.09 depending on date, country and application.

For the record this paragraph came from the this forum in technical E-TYPE FAQs Beginers guide

Tony

Alty Ian · Post by **Alty Ian** » Tue Mar 08, 2016 9:11 am

Tjclare wrote:Thanks guys, I will check tomorrow on the diff. It is a manual gearbox
Has anyone got the same setup? If so, what is your your perspective on the drive,
Thanks Tony

With a 5 speed box its fine as the 5th gear compensates for the higher revving at lower gears, with a 4 speed manual box 3.07 diff is the best overall IMO.

Link:
BBcode:
HTML:
	Hide post links

Link:
BBcode:
HTML:
	Hide post links

Link:
BBcode:
HTML:
	Hide post links

Link:
BBcode:
HTML:
	Hide post links

Link:
BBcode:
HTML:
	Hide post links

The 'E' Type Forum

Rear diff ratio

#1 Rear diff ratio

#2

#3

#4

#5

#6

#7

#8

#9