241
Warning for all RV8s
Inspections at Brown & Gammons of the steering rack mountings on a V8 Roadster built from a LHD rubber bumper MGB roadster reimported from the US and on an RV8 have revealed serious cracks in the steering rack mounts on the crossmember. As the consequences of a complete failure would be serious, members with both chrome and rubber MGBGTV8s, V8 Roadsters or GT conversions built from Factory rubber bumpered shells or RV8s need to have the mounts inspected as a matter of urgency. (Mar 06)

V8 crossmember with the steering rack mounts highlighted in red. (Diagram: V8 Parts Manual)

Further investigation of this failure is continuing but the preliminary analysis is that the steering rack mounts on the V8 crossmember extend further forward and at a shallower angle than those on the chrome bumper MGB, so the mechanical advantage applying the load to the steering rack mount is greater. It applies to both the chrome and rubber bumpered V8s because the MGB crossmember was changed for the MGBGTV8 - it was raised by an inch from the chassis leg and the rack had to be moved forward. The RV8 also suffers from this too. Power understeer in corners loads up the steering rack housing which is fitted across the car and with the greater power in a V8, that effect can be greater.
Crack on one side of the the V8 steering rack mount is quite clear. Ron Gammons reports the hairline crack was in the "U" shaped mount and not on the welded joint with the crossmember. (Photo: Brown & Gammons)

The examination of your V8 must be done with the road wheels in contact with the ground so the weight of the car loads the suspension and tyres. It is best done with the car raised up on a lift and then the steering wheel is turned from side to side placing a high load on the steering rack and its mount. Very careful inspection with good lighting is

Crack on one side of the V8 steering rack mount is quite clear. Photos of the cracks in the V8 steering rack mounts have been sent in by Brown & Gammons which show the extent of the crack very clearly. Details of the repairs and strengthening of the mounts have also been provided. (Photo: Brown & Gammons)

essential to ensure any movement in between the mount and the crossmember is detected - particularly any fatigue cracking of the weld between the mount and crossmember and any cracking of the mount itself.

Should a crack be discovered, besides welding the crack, strengthening gusset plates can be added between the steering rack mount and the crossmember to reduce the effects of the flexing which will have been increased by the larger and more grippy tyres available over recent years. We should add that the same steering rack and mount situation exists with the rubber bumpered version of the four cylinder MGB models, although they do not generally have the same degree of power understeer loading, so a similar inspection is recommended. See RV8NOTE242.

The failure reported above was detected by Ron Gammons following a road test of Chris Hunt Cooke's V8 Roadster carried out on completion of work on the front suspension. Ron did not feel entirely happy with the feel of the car and upon return to the workshops at Baldock popped the car up on the lift. It was then that the hairline fatigue crack was spotted. As this is such a potentially dangerous fault, Brown & Gammons are offering to undertake checks on members' V8s for a modest inspection fee of only £25 including VAT. The checks do not take long but the inspection is best made with the car up on a four post lift. As the utilisation of the two four post lifts in the B&G workshops at Baldock is high, the inspection of a V8 is best done by appointment. That arrangement should ensure the lift will be clear when your V8 comes in which will mean the checks can be carried out conveniently while you wait or pop round to the local café nearby for a coffee.

Contact B&G on 01462 490049 to book an appointment. (25.11.05)
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