Bear­ing up

NZ4WD - - TORQUE TALK -

It was ser­vice time on the Dis­cov­ery V8 once again and a check of the front wheel bear­ings re­vealed a lit tle too much play in the front left and needed to be reme­died. Wheel bear­ings are one those things we tend to ig­nore un­til the wheel col­lapses or we jack up the ve­hi­cle to phys­i­cally check them as they do at WoF time. At the time I had just re­turned from a week­end out­ing where the ve­hi­cle had been sub­jected to some deep wad­ing and wa­ter holes which is one sure way to con­tam­i­nate wheel bear­ings. Wheel bear­ings gen­er­ate heat and wad­ing into deep cold rivers and streams gives that sud­den cool­ing as­pect of the hubs and cre­ates a vac­uum be­hind the hub seal and can suck wa­ter into the hubs and bear­ings. An­other fac­tor to im­pact on the wear of wheel bear­ings are the large tyres we fit to ve­hi­cles, es­pe­cially when we use in­creased off­set rims to ac­com­mo­date th­ese tyres which in­creases the side load­ing on the wheel bear­ings.

Handy hint #1

Over­tight­en­ing or loose ( un­der tight­en­ing) wheel bear­ings will lead to the ul­ti­mate fail­ure of the bear­ings so it is im­por­tant to know how to set them up cor­rectly. Rather than knock at the bear­ing nuts with a ham­mer and chisel or screw­driver, in­vest in the proper sized tube socket for your ve­hi­cle. For Land Rover the nut is 52mm which is the same size as the hot wa­ter cylin­der el­e­ment, and sock­ets for th­ese are read­ily avail­able in the plumb­ing depart­ment at your lo­cal hard­ware store such as Bun­nings, Mitre 10, etc. On re­mov­ing the hub, I had in­deed had wa­ter con­tam­i­na­tion in­side the hub so it was go­ing to need closer in­spec­tion of the bear­ings rather than a sim­ple ad­just­ment – so the brake caliper had to be re­moved and tied up out of the way. The lock wash­ers are then un­done to al­low the first of the nuts to be re­moved, fol­lowed by the lock tab and sec­ond nut. Once the hub was re­moved the other bear­ing was show­ing signs of cor­ro­sion so it wasn’t just from this lat­est dunk­ing, and new bear­ings and hub seals were go­ing to be re­quired. The stub axle was show­ing the first signs of wear but time spent ‘pol­ish­ing’ it with very fine wet and dry sand­pa­per had it suit­able for con­tin­ued ser­vice. When it comes to re­place­ment bear­ings the ad­vice is don’t buy cheap, ever! If you have to save money, do so by fit­ting a cheaper sound sys­tem, as wheel bear­ings play an im­por­tant role by en­sur­ing your wheel doesn’t fall off; sort of im­por­tant if you think about it! With cheap bear­ings, any bear­ing in fact, it’s all about the met­al­lurgy and the man­u­fac­tur­ing process and ma­te­ri­als used to make the bear­ing, and cheap bear­ings do not last. It is best to buy good qual­ity Ja­panese or Euro­pean bear­ings such as Timken, SKF, etc. I for­tu­nately had a SKF bear­ing kit in stock which comes com­plete with new hub seal ( gen­uine Land Rover in this case), drive flange gas­ket and new lock­ing tab. The hub was thor­oughly cleaned and the bear­ing shells knocked out and the new ones fit­ted. It is ex­tremely im­por­tant to prop­erly pack grease into the bear­ing and if you don’t have ac­cess to a pack­ing tool it is best done by putting grease into the palm of your hand ( prefer­ably with gloves on) and push­ing the bear­ing into the grease, forc­ing the grease into the bear­ing. Work around the bear­ing and keep adding grease un­til it is com­ing out the other side.

Handy hint #2

Fit­ting the hub back onto the ve­hi­cle it is im­por­tant to get the bear­ing tight­ened cor­rectly. A tip I was taught was to tem­po­rar­ily fit the wheel back on and spin the wheel giv­ing it a cou­ple of ‘ thumps’ to set­tle the bear­ings into place. This is best done with a steel rim or at least one that you can torque up the nut with your tube span­ner through the cen­tre of the rim. Once done, fit the lock tab and sec­ond lock­ing nut or a re­place­ment stake nut if you have a later type ve­hi­cle hub and don’t for­get to fold over the lock­ing tab. All I need to do now is check the other side as chances are that it too will be con­tam­i­nated, even though at this stage there is no ex­ces­sive wear or play in the wheel.

Hub off and bear­ing out.

A bear­ing in the hand...

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