Lotus Elise Service Notes page 24

Lotus Service Notes Section TDL
AF.3 - REAR SUBFRAME & LONGERONS
The rear ends of the chassis siderails are linked by a fabricated sheet steel subframe which provides rear
suspension mountings, and an anchor point for the engine rear steady bar. At each side, an extruded box
section 'longeron' is rivetted and bonded to the top surface of the subframe, and extends rearwards to provide
rear body support. On cars built prior to September '98, an aluminium sheet floor is rivetted between the
longerons, with a boot front bulkhead bolted to the front edge of the floor. On later cars, the floor panel and
bulkhead are replaced by a 'boot box' moulded integrally with the rear clamshell.
To remove rear subframe assy.
1. Remove the rear clamshell (see sub-section BN.5).
2. Remove exhaust catalytic converter and muffler, and if necessary, drill out the rivets and remove the
exhaust heatshield.
3. Disconnect the parking brake cables and rear brake hydraulics, and remove both rear suspension assem-
blies complete with driveshafts.
4. Release the electrical components mounting plate from the LH longeron.
5. Release the engine rear steady arm from the subframe.
6. Release the roll over bar stays from the damper top mount tapping block, and remove the two bolts each
side securing the subframe to the chassis flange. Withdraw the subframe and longerons as an assembly,
together with the floor panel on early cars.
Note that it is not generally possible to separate a rear longeron from the subframe without damage to
one or both components. If a longeron is damaged but the subframe is to be re-used, the longeron must be cut
from the subframe.
Fitting rear subframe
When bolting the subframe at each side to the chassis rail rear flange, ensure that the anti-corrosion shim
plate is interposed. The lower fixing bolts should be inserted from the rear, and the upper bolts from the front.
Torque tighten the bolts to 45 Nm.
If longerons are already fitted to the subframe, fit the rear damper mount tapping block to the chassis
before fitting the subframe and after bolting up the subframe, secure the roll over bar stays using the M10
caphead screw and washer at each side to pass through the longeron and into the damper mount tapping block.
Torque tighten to 45 Nm.
If no longerons are fitted to the subframe, fit the subframe to the chassis, and then fit the longerons to the
subframe as follows:
Fitting rear longerons
1. Ensure that at each side, the top surface of the subframe is free of zinc flashing, including the outside top lip
of the subframe. Dry fit the longeron to ensure that the channel in the extrusion fits onto the outside edge of
the subframe, with the longeron lying flat on the subframe top surface. The damper mounting tapping
blocks may be fitted before the longerons for easier access, or alternatively, to ease fitment of the longerons,
the tapping blocks may be fitted afterwards by feeding down the inside of the longeron.
2. Clean the mating surfaces on the subframe and longeron using Betawipe VP 04604 (A082B6150V) as
directed in sub-section BM.5.
3. Prime the whole of the mating faces of the subframe and longeron with Betaprime 5404 (A082B6337V) as
directed in sub-section BM.5.
4. Apply a 'zig-zag' bead of Betaseal 1701 (A082B6281F) or Betamate E2400 (A082B8415V) to the primed
surface of the subframe as detailed in sub-section BM.5.
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