Roto flex couplings

[rgh0]

A Spyder chassis is a good preventative as they are substantially stronger in these areas

But for a standard Lotus chassis make sure the rubber mountings are in good condition and the diff torque rods are tight at both ends. It seems to me that most times the damage is caused by the diff moving excessively under load due to loose mountings or failed rubber bushings and this then damaging the chassis.

A small reinforcing plate to triangulate the chassis lip in the area of the diff rod toque rod connection would be worthwhile reinforcing as I see this area distorting in many Elans that are driven hard.

An additional plate, cut out to match the chassis cut out and brazed on the top surface of the chassis in the area of each upper diff mount would be an added precaution but requires the body off and may be overkill as I suspect all the failures I have seen in this area were due to earlier failures or looseness in the diff torque rods

cheers
Rohan

[Lotus 50]

I just looked at the inner couplings. No cracks, just a bit dirty. I checked my records - last replaced in 1990.

[Lotus 50]

RD sells a bracket to stiffen the diff mounting

http://www.rdent.com/

Differential Stiffening Bracket


Introduced by Lotus on the Elan Sprint, this part can be installed on any Elan or Plus 2. The brace connects the two differential mounting bolts and picks up one bolt on the differential housing, strengthening the overall assembly to prevent damage to the differential mounting "ears." Highly recommended for any Elan or Plus 2, whether equipped with rotoflex couplings or c-v rear axles.

Ref. 36R0033 $72.00