Lotus Elan and Lotus Elan Plus 2 Forums

You have been told incorrectly Jeremy. It is a straight swap, the hole spacing and size are the same.

It should be noted that there are 3 flange sizes. 85, 92 and 105mm. The Elan size is the 92mm diameter flange, but I suspect that many have been changed over the years.

Leslie

I have swapped old Ford non Lotus diff noses with new replacement Lotus rear diff housings or original Lotus diff housings without any problem with bolts between the two.

cheers
Rohan

On my Plus2, I used a 3.9 housing from a Cortina and swapped in a 3.5. Everything bolted together including the larger pinion flange that matched the prop shaft flange that mated to the original 3.7. It appears that the pinion seal leak I currently have, is probably a worn portion of the pinion flange where the seal contacts the flange. Debating the use of a seal saver vs a universal flange from Burtons. My S2 has the smaller flange. I have a new 3.5 ring and pinion to install and another Cortina diff, but need to source a small flange. There was a significant difference in acceleration between the 3.7 and the 3.5 in the Plus2. But, a more relaxed cruising rpm.

prezoom wrote:On my Plus2, I used a 3.9 housing from a Cortina and swapped in a 3.5. Everything bolted together including the larger pinion flange that matched the prop shaft flange that mated to the original 3.7. It appears that the pinion seal leak I currently have, is probably a worn portion of the pinion flange where the seal contacts the flange. Debating the use of a seal saver vs a universal flange from Burtons. My S2 has the smaller flange. I have a new 3.5 ring and pinion to install and another Cortina diff, but need to source a small flange. There was a significant difference in acceleration between the 3.7 and the 3.5 in the Plus2. But, a more relaxed cruising rpm.

As far as I'm aware if you buy any new flanges from any company they will not come with a flange shield - this shield is good for two things : 1) stops dirt, girt and water etc getting into the seal face; and, 2) if the diff breather gets blocked a build up of internal pressure may try to blow the seal out - a flange with a shield should stop this happening, or will make a leak not quite as disastrous as one with the seal completely blown out where no shield is fitted.
To get an old shield to fit a new flange is fairly easy but a seal face repair is a much simpler fix.

Many thanks for the replies - and so quick !
I've got to the time of life where relaxed cruising is more important than out and out acceleration so the comments regarding that are useful too.
Thanks again
Baggy