Austin Seven Failures and How To Avoid Them

PART 1 - THE SEVEN ENGINE

Click here for part 2 - flywheel, gearbox & clutch

Click here for Part 3 - Propshaft & Real axle

Click here for Part 4 - Suspension, Steering and Brakes

Click here for Part 5 - Electrical and Ignition

 

BROKEN CRANK

                   *  Crack Test

                   *  Line Bore 3 Bearing

                   *  Fit Phoenix

 

LOOSE FLYWHEEL

                   *  Riding On Key

                   *  Fit Out Of Engine To Ensure Oil Thrower Clearances etc.

                   *  Lap Onto Taper

                   *  Really Tight – Use Impact Driver with a 3/4" socket/bar on flywheel. Think about Loctite

OIL PUMP

*   Vanes: Flats go on bottom

*   Check pressure release is clean & not rooved

*   Check springs

*   Make sure gear on very small key

*   Loctite gear nut

 Front bearing lip broken

*  careless bearing removal

*  trying to fit wrong bearings

*  inspect carefully for cracks

*  replace ring – Vince does them.

 Split cam followerS

*  difficult fault – misfires at high speed –sticks in guide

*  check before fitting

*  avoid over tightening (& under tightening!)

 Sheared studs

*  what made of ? – EN36?  Dave Cochrane uses EN16t

*  beware cheap

*  leave good original alone

*  use Studlock

*  avoid over tightening

*  helicoil if slack

  Front camshaft bearing

*  replace peg with 5/16 bolt with washer (tap bearing in situ)

*  can use socket headed screw

 Head gasket

*  flat surfaces

*  no corrosion

*  assemble with grease smeared on

*  ensure correct gasket (HE or LC)

*  can be either way up (usually seam up)

*  torque to 20 ft lbs in correct sequence

 Oil leak rear main

*  modern lip seal on smooth surface or use speedy sleeve repair

*  worn out Quickthread

*  loose rear main

*  oil thrower missing/ wrong way round /not crimped

*  oil return hole not lined up in carrier

*  three different flywheel boss sizes (so use lip seal!)

*  make sure seal casting is drilled correctly

 Split crankcase due TO little end bolt

                     *  use new HT bolt with spring lockwasher & Loctite

                     *  use internal stainless shakeproof

                     *  loose bolts split 1 in 12 conrods 

 

 blocked oil jets

                     *  change oil regularly

                     *  beware multigrade detergent oil unless oilways scoured out

                     *  use monograde oil

                     *  use oil filter if doing high miles

                    

Broken top water manifold bolt

                     *  use stainless stud

                     *  inspect carefully – make sure not cracked strap (use nut under?)

                     *  tighten carefully

 

Broken side manifold bolts

                     *  same as top

                     *  when repairing do not drill/tap into bore

                     *  use hacksaw blade as drill stop

 

Cracked block

                     *  watch out for sludge around bottom of bores

                     *  watch out  base of no. 4 bore can be thin when sleeved

                     *  change block if cracked from centre stud

 

                                                                       

 I hope you find this useful,  Phil Whitter