Lotus Elan and Lotus Elan Plus 2 Forums

I picked up a later differential for my S1 which means the drive flange doesn't match the drive shaft. The normal cure for this is to change the input hub in the differential. Since the pinion shaft nut is staked and a Nyloc besides I rather doubt I could get the correct preload setting back by changing hubs so I would like to change the flange on the drive shaft.
Are the U joints the same from the earlier shaft to the later or would I have to change the whole drive shaft to accomplish the change??

Kurt

Kurt
I am experiencing the same issue with my S3. I've traded a 3.9 for a 3.55 and to solve my problem I am swapping out the differential flange. According to the Elan guru (Rohan), it can be done by precisely referencing the position of the pinion nut on disassembly. It turns out I am rebuilding the diff anyway so I will be setting the pinion bearing preload using the crush spacer method. Replacing the pinion flange was easier and more straightforward for me. I may have the pinion flange you need if you decide to go that route.
Regards,
Chris

Somewhat in the same boat. What I'd really like to see is an adapter plate to bolt to both types. The plate would fit between the propshaft flange and the diff flange. I'm thinking there's plenty of room in the tailshaft
of a 4 speed or sliding spline of the 5 speed shafts to take up the difference of an adapter plate. The plate
can be, oh, say, maybe 1/4 inch or 3/8 inch thick. What say the 'inventors' out there?

Thanks for the input folk's but haven't got the answer to my query yet. May not need it though. Rohan, apparently knows the 3.9 early hub is the same length as the later hub in which case indexing to the same spot would make sense. That was my major concern so I may just swap the hubs. I like the idea of an adapter plate. Which could be added to a long list of bits to improve and update!

Kurt.

Nomad
You raise a good point about the lengths of the two pinion flanges. Rohan did tell me to make sure the lengths are equal. Otherwise you will have to go through the crush washer process.

nomad wrote:Are the U joints the same from the earlier shaft to the later or would I have to change the whole drive shaft to accomplish the change??

The joints are the same, not sure who might be able to supply the correct flange yoke.

CBUEB1771 wrote:

nomad wrote:Are the U joints the same from the earlier shaft to the later or would I have to change the whole drive shaft to accomplish the change??

The joints are the same, not sure who might be able to supply the correct flange yoke.

Ah, the old source of supply conundrum! I would think it a common Ford item from somewhere in the past. Surely one of our supplier's would have it. My 50 year old U joints should probably be changed anyway and a different flange would be the simplest by far.

Kurt.

nomad wrote:

CBUEB1771 wrote:

nomad wrote:Are the U joints the same from the earlier shaft to the later or would I have to change the whole drive shaft to accomplish the change??

The joints are the same, not sure who might be able to supply the correct flange yoke.

Ah, the old source of supply conundrum! I would think it a common Ford item from somewhere in the past. Surely one of our supplier's would have it. My 50 year old U joints should probably be changed anyway and a different flange would be the simplest by far.

Kurt.

The U-joints themselves are known as U-50's, a standard English Ford item and used on most European small rear drive cars. Hardy-Spicer (GKN) ... K5-GB150 (sealed/ no grease fitting)

No fear finding the U joints....the flange to the diff might take some hunting.

Kurt.

Kurt,

It occurs to me I have a spare +2 driveshaft lying about, which could give you the newer rear mating yoke from the driveshaft, assuming the u-joints are the same.

It will be Wednesday or so before I am able to measure the mating yoke bolt circle and u-joints.

NZ was awesome, btw.

bitsobrits wrote:Kurt,

It occurs to me I have a spare +2 driveshaft lying about, which could give you the newer rear mating yoke from the driveshaft, assuming the u-joints are the same.

It will be Wednesday or so before I am able to measure the mating yoke bolt circle and u-joints.

NZ was awesome, btw.

Hi Steve.....I'll drop you an E-mail.

Kurt