GQ Front Wheel Bearings and Grease follow-up

Submitted: Monday, Jan 21, 2008 at 14:45
ThreadID: 53739 Views:4749 Replies:9 FollowUps:18
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Well, last Friday the mechanic fitted Nissan front wheel bearings and seals and greased them with Castrol APX as suggested on the forum. This is after two sets of SKF bearings were running too hot and melting the grease.

Today I took the GQ for a 20km quick run and stopped out of town to feel the hubs and they were only warm. Then I drove home 2 kilometres and when parked in the garage I felt them again and they were HOT!!!

I had asked the mechanic to tighten the bearings to specifications and provided the Manual but I didn't see any dirty fingerprints in the book so I guess he has done his own thing again. I will now have to have another look myself and maybe slacken the bearing nut off. Trouble is I don't have the right tools so might have to use a hammer and screwdriver like in the days gone by.

I will only be able to tell if the bearing if the grease is not melting after about 500km.

This whole bearing caper has been most annoying, making me even grumpier than I usually am.


Cheers

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Reply By: Member No 1- Monday, Jan 21, 2008 at 14:53

Monday, Jan 21, 2008 at 14:53
are you sure you havent got sticking disc pad/s?

i would have thought that 20klm would have been ample time for the bearings to heat up if adjustment wrong
AnswerID: 282893

Follow Up By: Willem - Monday, Jan 21, 2008 at 19:15

Monday, Jan 21, 2008 at 19:15
Yer right. Definitely brakes, methinks
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FollowupID: 547475

Follow Up By: Member No 1- Tuesday, Jan 22, 2008 at 06:29

Tuesday, Jan 22, 2008 at 06:29
if it aint, I have know idea what it could be if bearing adjustment isnt wrong.

hope you sort it out soon
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FollowupID: 547621

Reply By: Moose - Monday, Jan 21, 2008 at 14:58

Monday, Jan 21, 2008 at 14:58
G'day Willem
They must be bloody tight to get hot after that distance! Might be something else - brakes?
Good luck with resolving the problem.
Cheers from the Moose
AnswerID: 282895

Follow Up By: Willem - Monday, Jan 21, 2008 at 19:15

Monday, Jan 21, 2008 at 19:15
Always something else....lol


Cheers
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FollowupID: 547476

Reply By: Peter 2 - Monday, Jan 21, 2008 at 15:35

Monday, Jan 21, 2008 at 15:35
Willem
How long since the master cylinder has been touched, if ever ;-))
When they get old and tired the rubber components can stick and swell which prevents the fluid completely returning to the reservoir but at the same time keeps a small amount of pressure in the brake system.
There is never enough fluid retained to notice a drop in the reservoir.
This might explain why your initial 20 k run failed to increase the hub temp but after a few more brake applications and also the engine bay heat rising as the engine and fan pull more hot air into it warm the master cylinder up to the point where it plays up.
Could also explain a lack of grunt (brakes dragging) and increased fuel consumption if this is the case.
Just a thought as I've had this exact same problem on both the old Volvo's. The first one took ages to sort out but the second car I knew and went straight to the master cylinder. Both were around 20 years old when it happened too.
Peter
Peter
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AnswerID: 282899

Follow Up By: Willem - Monday, Jan 21, 2008 at 19:10

Monday, Jan 21, 2008 at 19:10
Hi Peter

'If ever' is the operative word here.

Your explanation has merit as I think that this problem is a multi-faceted one. Even this 'old' 1994 vehicle seems to be finnicky.

I think should flog it and go and buy another very old FJ55 or H series Troopy if I can find one without any rust in it....lol

Bloody cars!!!!!!!


Cheers
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FollowupID: 547469

Reply By: Member - Lionel A (WA) - Monday, Jan 21, 2008 at 15:38

Monday, Jan 21, 2008 at 15:38
Hi Willem....If Im telling you how to suck eggs, please accept my appologies.
My dad was a mechanic for many many years so I grew up helping him work on a wide array of vehicles. Austin 7s through to Heavy haulage trucks.
The trick with wheel bearings, in those days, was to tighten the retaining nut then back it off until you got a very slight amount of play in the hub [wheel on] then lock it in.
Never had any problems or returns using this method.

Last week I replaced the front bearings in the MK. Everytime I set up the correct amount of play, when I ran up the outer lock nut, the clearance would disappear. What was happening in the end was I reused the locking washer which, in effect, when tightening the outer nut would lock onto the washer then force the inner nut to over tighten.

Solved the problem with new lock washers from Nissan.


Hope this is of some help mate....Lionel.
AnswerID: 282900

Follow Up By: Willem - Monday, Jan 21, 2008 at 19:13

Monday, Jan 21, 2008 at 19:13
Thanks Lionel....thats what we used to do way back!!!!

These days I detest working on the vehicles especially if I have to crouch or bend to get to the affected parts.

Maybe I will summon up my energy tomorrow and jack the wheels up an go from there.


Cheers

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FollowupID: 547473

Follow Up By: Member - Lionel A (WA) - Monday, Jan 21, 2008 at 19:33

Monday, Jan 21, 2008 at 19:33
Hey Willem,
I cant stand bending or crouching myself, too much belly in the way. What I do is put a milk crate upside down, place an old folded towel over it and kneel down,flopping over it.
Very comfy, allowing you to work at hub height all day.

Even been known to nod off with a brake pad in my hand...hahaha.

Cheers.....Lionel.

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FollowupID: 547486

Reply By: Louie the fly - Monday, Jan 21, 2008 at 18:22

Monday, Jan 21, 2008 at 18:22
Willem, try jacking up the front and checking for "wobble' in the bearings when cold. There should be a slight amount of play as when in service bearings heat up, and quick. The go for a burn and jack it up again. Check for the same feeling and if the wheel is harder to turn. If they are that hot now they are probably rooted again.

I'm trying to find my bearing course notes and a book that has all that info in it but my place is a bit of a pig sty at the mo.

if I find it I will send you some info. Good luck
AnswerID: 282928

Follow Up By: Willem - Monday, Jan 21, 2008 at 19:14

Monday, Jan 21, 2008 at 19:14
Thanks Louie....I think that it might be a braking problem but I will go have a play tomorrow.


Cheers
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FollowupID: 547474

Reply By: Member - Axle - Monday, Jan 21, 2008 at 20:29

Monday, Jan 21, 2008 at 20:29
Hi Willem!, iknow where you can buy a landrover that is not having problems with wheel bearings, HAHAHAHA, (Just everything elsel...lol) SKF have been around a long time their product is not chit, I think Peter is on the money , or the problem a bit further towards the brake caliper area? ( piston seals ). Although any brake drag would be very noticeable in vehicle performance. Have you tried jacking it up all fours,have someone put the brakes on then check each one individually on release??

Everyones a know all,..lol, Bloody frustrating!!, like landrovers and their electrical caper, can't solve a intermitent blinker problem at the moment.

Cheers Axle.


AnswerID: 282961

Follow Up By: Willem - Tuesday, Jan 22, 2008 at 07:36

Tuesday, Jan 22, 2008 at 07:36
Thanks Axle.....but I have had my fair share of Laqndrovers....:-)))


Cheers
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FollowupID: 547627

Reply By: splits - Monday, Jan 21, 2008 at 21:13

Monday, Jan 21, 2008 at 21:13
Willem

I have to agree with those who suggested brakes. An over heated hub will be caused by dragging brakes, not a wheel bearing, in about 99.9% of cases. I spent 19 years working in the motor industry in my younger days and I am buggered if I can ever remember a wheel bearing causing a hub to overheat, particularly a hub the size of those on a GQ. A bearing would have to be worn so badly that it is almost red hot to do that and if that happened you would hear it a mile away.

Dragging brakes can be caused by a master cylinder but that is not common. Your problem is most likely a partially seized caliper piston. Hydraulic pressure applies the brakes but the pistons are only pulled back by the distortion of the rubber seal around them and the run out, if any, in the disc. There are no springs in there to do it so they stick easily when corrosion and dirt starts to build up.

One sure sign of it is one brake pad worn more than the other. If you see this on yours then the pad with the most wear will be the one with the stuck piston.

Whatever you do don't start experimenting with wheel bearing tension. I am assuming they are the tapered roller type and if that is the case they must be set with the correct amount of pre-load and no more or no less.

Brian
AnswerID: 282979

Follow Up By: Willem - Monday, Jan 21, 2008 at 23:27

Monday, Jan 21, 2008 at 23:27
Brian

The trouble began in December when I had the brake pads, rotors and bearings replaced. Workshop fitted SKF bearings and seals.

The grease started leaking out behind the seal and dripping down the backing plate and onto the brake calipers.

First pull down established that the grease Castrol HTB had turned to oil. Replaced seals with genuine Nissan ones. A few days later, when going to lock hubs for creek crossing I discovered hubs were red hot after driving 70km.

Second pull down and inner bearing cones were discoloured and grease melted again. Replaced SKF bearings and seals and went on holiday. Grease started leaking out after about 500km.

3rd pull down(last Friday) and fitted with Nissan bearings and seals and Castrol APX grease used. After a 20km run today hubs running cool. 2km later hubs running hot. So it has to be a brake issue this time.

Mechanic has not discovered any fault with brakes but then again he has not been asked to look at this area. Garage operates as a repair business and mechanic is qualified but I doubt whether any serious thought goes into problem solving. I live in a small country town some mechanics are few and far between. INternet throws up more ideas....lol

Cheers

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FollowupID: 547602

Follow Up By: splits - Tuesday, Jan 22, 2008 at 00:34

Tuesday, Jan 22, 2008 at 00:34
Willem

I think it has been a brake issue all along. A piston may be in the early stages of seizing and is releasing sometimes then sticking and leaving the pad dragging at other times. It will eventually stay permanently stuck. This is a very common problem.

I still find it hard to believe that a bearing could be so tight that it could cause that much heat. The mechanic would have to fit a length of pipe to the spanner and swing on it to over-tighten it sufficiently to even come close to doing that.


You may be able to check the calipers yourself even if you are not sure how to fix them. Undo the two retaining bolts, take the caliper off and try and push the pistons back with your fingers. Even freely moving ones will be fairly firm but they should move. If they won't move then try pushing them with a G clamp. If they still won't go back then they are definately stuck.

This is the type of thing a good mechanic should be on the look out for. If a car is getting on in years and he does not know its history, then he should suggest a complete overhaul of the hydraulic system. Brake fluid absorbs moisture and should be changed regularly in accordance with the car manufacturer's instructions. The rubber components of brake systems also deteriorate with age. Neglecting the system will eventually lead to corrosion and leaks. When you dismantle parts to fit new seals, it is common to find so much corrosion in parts like the master cylinder for example that it is beyond repair. New ones are often very expensive.

Mechanics should never do work that is not necessary but on the other hand they can not afford to miss work that is necessary. That does not do their buisness or the customer any good at all.

I am beginning to wonder about your mechanic though. Nobody fits three sets of wheel bearings without trying to find out what the problem is.

Brian
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FollowupID: 547611

Follow Up By: Willem - Tuesday, Jan 22, 2008 at 07:43

Tuesday, Jan 22, 2008 at 07:43
Thanks for the info Brian

The isuue has been with both wheels not just one.

I had the brakefluid replaced about 50,000km ago

I will start to look at the brakes in earnest now and look at all components for excessive wear.

The new brake pads have been in for around 5000km. Could it possibly be something to do with their manufacture? I think that the garage sourced them from Repco and I recall that they may be the Ferodo Brand.


Cheers
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FollowupID: 547629

Follow Up By: splits - Tuesday, Jan 22, 2008 at 09:56

Tuesday, Jan 22, 2008 at 09:56
Willem

The type of pads will not cause this problem. As long as you use a recognised brand like Ferodo,.Bendix or genuine Nissan, you should be ok.

Having the problem on both could still be brakes. Seized pistons on both sides is common. They have all done the same ks, are the same age and share the same brake fluid so they are usually in the same condition.

The fluid in my Hilux should be changed every 40,000 ks or 24 months according to the service book. It was more often than that years ago. I change mine every six months. It only involves an $8 1/2 litre bottle of fluid and a few minutes work for my wife and I.

I just had another thought about your grease turning to oil. Is diff oil getting into it? There should be an oil seal around the axle inside the outer end of the diff housing. It stops diff oil from entering the swivel hub where the CV joint is. It is so long since I have worked on a live axle 4WD of any make that I can not remember if it is possible for oil that has leaked into the swivel hub to work its way into the wheel bearings.

I could be worth checking this. If the seals in your car are the originals and they are not leaking then they most likely soon will be.

Try checking the oil level in the diff. If it is way down then it is most likely going into the swivel hub and maybe even further.

If you find this is happening then that raises the question of the hub temperature. Every hub gets fairly hot but is it too hot? That is something I can not work out from here.

There is then the issue of the new bearings discolouring. They all do that to a certain extent but once again there is normal and excessive. Yoiur mechanic should be able to decide what the situation is.

Brian
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FollowupID: 547664

Follow Up By: Willem - Tuesday, Jan 22, 2008 at 14:12

Tuesday, Jan 22, 2008 at 14:12
Brian

Thanks for all your interest

Axle seals are good.

I removed the front brake calipers and checked the pistons this morning and they work well and smoothly.

I took the truck for another 25km run and the hubs were hot when I came home. I did not use the brakes, just geared down to slow down.

It would seem that the freewheeling hubs are hotter than the wheel hub itself.

There are scuff marks on the rotors but that may be normal. Both brake pads and rotorr are new.

Maybe the whole shebang is meant to run hot.....lol


Cheers
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FollowupID: 547707

Follow Up By: Member - Luke (SA) - Tuesday, Jan 22, 2008 at 20:27

Tuesday, Jan 22, 2008 at 20:27
Willem,

Next time you take your Nissan for a drive test to see how hot the rear hub or disk is (presuming it has disks).

IMO if your master cylinder is sticking on it might be doing the same to the rear.

If the master cylinder has two reservoirs it might not make a difference as (as far s I know) one reservoir does the front brakes and the other does the rear.

But from memory the GQ has only one reservoir.

I have done the wheel bearings on GQ's and my current GU and have never had a problem. I do them the same way as many others on here have said, tighten them up till it wont tighten no more, back off until there is wheel bearing play, tighten back up slowly until there is no play, (spinning the disk while tightening) then back off slightly until you can find a happy medium for the split pin or however else it is locked on with. Works for me

Cheers Luke
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FollowupID: 547777

Follow Up By: splits - Tuesday, Jan 22, 2008 at 21:24

Tuesday, Jan 22, 2008 at 21:24
Willem

They do get hot because there is a lot of heat generated in the brake disc and not all of it goes straight into the atmosphere but it is hard to say what is normal without seeing it.

The grease running out like oil has got me curious. That could only be heat or oil mixing with the grease. In order to possibly eliminate the heat theory I would ring the manufacturer of the grease and see what they say. These greases are supposed to be "high temperature" so I would ask them if it is possible for a combination of bearings and brakes to generate enough heat to turn the grease to oil. If they say no, not even if the disc was red hot as you often see on racing cars, then you will have to have a closer look at the axle seal.

If you do check the seals then make sure the axle has not been running off centre in them. This can happen if the swivel hub bearings are worn or someone who did not know how to centre the hub has assembled them.

Another thing you could try is comparing it with another car. If it feels the same then yours is normal.

If you dismantle the bearings again then I suggest you find a Nisasan book and see what it says about adjusting them. Luke just mentioned one way but every 4wd with a full floating hub on a live axle that I have ever worked on has been done the same way as my Hilux. The same procedure applies to full floating rear hubs.The instructions in the Hilux manual are as follows.

Tighten the adjusting nut to 59 Nm.
Rotate hub in both directions to seat bearings.
Back nut off 1/16 of a turn.
Fit spring gauge to wheel stud, pull it to rotate hub and note force required to move it.
Tighten nut to 25 Nm.
Fit new lockwasher and the locknut.
Tighten locknut to 47 Nm
Check hub rotates freely and there is NO freeplay in bearings.
Check again with spring gauge.
Hubs should start rotating between 10 - 38 Nm PLUS the first measurement recorded.
Re-adjust if outside those figures.

The GQ may have different torque figures but it will most likely be adjusted the same way. Those type of bearings do not have freeplay and must be under slight pressure or preload as it is usually called.

Brian
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FollowupID: 547794

Follow Up By: Willem - Tuesday, Jan 22, 2008 at 22:50

Tuesday, Jan 22, 2008 at 22:50
Thanks Luke and thanks again Brian

You have gone into a lot of detail

I have a Gregorys Manual, Yes nm is 59 to 67

I checked the axle seals personally...no leaks

Swivel hub bearings are good and birfield joint good as well. GQ did not do a lot of offroad until I got hold of it...lol

Whe IO had the front wheels jacked up they turned slower than I would have expected giving the impression that the brake pads may be dragging on the rotor. Still there was no audible noise

This time around I used Castrol APX as suggested by a few on this forum instead of Castrol HTB.

GQ has done a lot of offroad work and and had no front end problems until I had the brake pads, rotors and bearings replaced.


Cheers


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FollowupID: 547827

Reply By: That Troopy Bloke (SA) - Wednesday, Jan 23, 2008 at 00:03

Wednesday, Jan 23, 2008 at 00:03
G'day Willem
Surely no mechanic, no matter how incompetent, could stuff up the wheel bearing adjustment 3 times.
My money would be on the caliper seals. These seals are like a square section 'O' ring. When you apply the brakes, the fluid pushes the piston out, and the seal actually 'grips' the piston slightly, deforming it's shape towards the rotor. When the pressure is released, the seals relax and return to their original shape and position, and pull the piston back slightly to give the running clearance required for the pads.

When these seals are worn beyond their 'use by date', they won't draw the pistons back from the rotor, the pads will rub, and generate heat.

A better explanationhere

Cheers
Glenn
AnswerID: 283229

Follow Up By: Willem - Wednesday, Jan 23, 2008 at 07:23

Wednesday, Jan 23, 2008 at 07:23
Thanks for your reply Glenn

I have saved the drawings and will discuss this with the mechanic.

The interesting thing though is that the FWHubs seem to be hotter that the hub itself on touching.


Cheers
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FollowupID: 547852

Reply By: splits - Wednesday, Jan 23, 2008 at 11:57

Wednesday, Jan 23, 2008 at 11:57
Willem

Glenn is right about the piston seals. I would have replaced them immediately this problem started if for no other reason than age.

My Hilux is a 6/03 model with 53,000 ks and it will have new genuine seals in the calipers before the end of this year.

The thing that I am still concerned about is the grease turning to oil. Dragging brakes will certainly cause excessive heat but you said your pistons are moving. They could still be causing slight dragging but the heat build up should be minor. I have repaired countless seized calipers where one pad is almost worn out and the other looks like new. The pistons were being pushed on by the extremly high hydraulic pressure but were so tight they would not back off at all. This would have caused a lot more heat than a piston that may be a little tight but could still be moved by fingers. I can not remember ever seeing liquified grease comming out of the hubs on those cars.

Brian
AnswerID: 283294

Follow Up By: Willem - Wednesday, Jan 23, 2008 at 13:27

Wednesday, Jan 23, 2008 at 13:27
Thanks Brian.

This is probably the way I will go. The garage have replaced all of the bearings at no cost to me so far. I am just a tad disappointed that the mechanic does not have an enquiring mind(the mechanic is a complicated person and we wont go down that road).

Just as well I don't have a really modern 4by. Although the GQ is an older vehicle now, it is still more complicated than the 4bies I used to drive in the 1970's. Those I could repair myself. They were however a tad utilitarian and these days we clamour for comfort and air-conditiong and power steering and so we pay the price.



Cheers
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FollowupID: 547927

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