GQ Front Wheel Bearings and Grease follow-up

Yer right. Definitely brakes, methinks

if it aint, I have know idea what it could be if bearing adjustment isnt wrong.

hope you sort it out soon

Always something else....lol


Cheers

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

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

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.

Thanks Louie....I think that it might be a braking problem but I will go have a play tomorrow.


Cheers

Thanks Axle.....but I have had my fair share of Laqndrovers....:-)))


Cheers

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

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

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

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

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

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

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

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

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

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