Originally Posted by Pattojnr
ok tonight i looked at my spur gear problems. i know the engine screws to the mount were the main culprit, but i want to sort this out once and for all.
so i looked at the 2 speed shaft with the engine removed. i stated to ZOOM on sunday about a bit of movement from the bearing that sits in the alloy side brace. seems a wear pattern of load has caused this. the alloy is shiny on one section of the side plate. so remedy was to pin punch around the bearing hole to close up the worn section. no wno more side movement from the shaft. so refitted the engine. with the 2nd spur fitted to the shaft, i set the mesh. couldnt get it square on pinion. but it meshed ok. so now fit 1st spur. mesh was too loose. so i moved the engineto mesh 1st correctly. then removed it again to see how the 2nd gear mesh was. the engine wasnt square to the spurs. so this remedy was to make the engine mount screw holes in the chassis, bigger towards the rear diff. then made the cutout or countersunk section bigger also. so i could now move the engione a bit closer to the rear diff. i then reset the mesh and now the engine is square and the mesh is 100% better. this with the removal of 2 speed shaft movement, i hope fixes the spur problem for me.
The failures result from the the 2spd bearings slipping in the housing when the gear engages. The best fix is to drill out the spacer between the bearings and press fit a single larger bearing kike Mugen does. If you don't have access to the equipment needed to do the drill / press fit mod then simply replace your worn housing and ca new bearings in place. The ca fix doesn't hold up as well as the press fit mod but should stay solid a full season or close to it.
Regarding the motor mount screws it is important to NOT USE the stock screws that come with the car, their solid flat heads has a tendency to slip & distort the chassis around the motor mount. The best solution is to use flat heads screws with counter sunk washers. The self centering washers will ensure the screws are perfectly straight and not slip.
Mark