B) Extra strength in the carrier as well as tie extra gears can be had from companies such as Crown, Speed Unlimited etc. These units come complete with heavy duty carriers, extra gears shafts, block, and pins. This is about the best solution to differential modification as far as performance and cost are concerned. See photo.
C)A third solution is the VW optional ZF limited slip differential. This unit puts power to both rear wheels, and is the best answer for dragrace cars. It will cost you plenty, though.
7)Final drive side plates .The stock side plate is weak and can flex under full power which will let the ring gear climb away from the pinion gear. Vehicle application is of prime consideration here. Proper set-up of ring and pinion should eliminate any problem in all but very powerful street machines. In off-road racers, drag cars or road racers, the abuse these parts under go is tremendous. You must begin with a properly set up ring and pinion gear. Next, use either the aluminum or the steel final drive side plate offered by several companies. You should also add a set of axle tube retainers or axle tube flange supports. See photo. This sandwiching eliminates outward movement and flexing: keeping the ring gear fully engaged, (toward the transmission - not the bell housing, it is here torque force is maximum). Drill out and retap these four - then replace with larger studs. As an alternative you can drill two holes com pletely through the case (at the top and the bottom stud points) closest to the transmission. Use two long bolts instead of the usual studs. The reverse gear on the rear part of the main shaft may have to be grooved to clear the one bolt. The axle tube retainer supports also help prevent leaks due to the warped steel flange.
8) Ring Gear VW offers you two rear end ratios in their parts dept.: a 4.375:1 and a 4.125:1. For maximum durability the 4.125:1 should be used. It comes standard on '67 and later bug trans. The gear mounts with eight bolts instead of the usual six. Old buses will have this ratio also. If you're not sure what ratio you have, count the teeth on the ring gear and divide it by the number of teeth on the pinion gear. A good idea would be to radius all sharp edges and glass bead blast the ring and pinion before vou assemble things. Use loctite, stock bolts, and locking washers - safety wire if you want extra insurance.
9)Ring and pinion lash Although the factory specs are .004" -
.101" for lash tolerance, the .010" setting is most desirable for racing conditions. Why? Gearbox heat from operation causes expansion and things get tight.
10)The pinion shaft and main shaft
A) Replace the c-oncave washer, its shim(s), and spacer sleeve
with special BeCu washer and spacer. They are pre-set and require no adjustment. Later models have the helical spring spacer do not need this modification. Don't try to use the BeCu washer and spacer, it won't work on the later type.
B)Replace the woodruff keys on '67 and earlier pinion and main shafts, use special hardened ones available from most H. P. outfits.
C)The synchro rings that drive third and fourth gear on the main snaft are only pressed on. Do one of two things here- either use loctite when pressing into place or have these assemblies tacked in 3 or 4 places with a heliarc weld, then resurface excess weld. (The loctite is the easiest and is stronger than you might think.) To keep the pressed on synchro rings in place, press them on using red loctite - remember, (especially, if you're using close ratio gear sets that cost you an arm and a leg) a weld can break and if a synchro ring goes bad on you - the gear will have to be replaced. The gear and synchro pressed on with loctite has

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