Strange front head howl on the road

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audiocontr
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Joined: Sat Jul 09, 2016 1:22 am

Strange front head howl on the road

Post by audiocontr »

Hello all,

I have a couple of ex military haffies, and the better of the two started a front end howl that varies with the speed of rotation. It comes and goes, and goes up and down in pitch like the sound of an out of balance drive axle.

I noticed the sound goes away if i pull it into 4wd. Turning while in 4wd brings the noise back again. The sound is not present while running all 4 wheels up in the air, so it appears it needs a load

Any suggestions of what to look for?
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heinkeljb
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Location: Lewes, East Sussex - UK

Re: Strange front head howl on the road

Post by heinkeljb »

Howl is usually bearings, so could be anything from wheel hub shaft bearings, to the bearing for the little cog in the hub, to the Revepa (CV) joint to the bearings in the diff.

Your comment about it coming back whilst turning suggest it could be the CV joint. When was the last time to had that cleaned and re-lubricated?

Something you could try would be to have all the wheels in the air, but to then use ratchet straps to lift the front axles up so they are more in the position they would be in whilst driving (i.e. not hanging down) and then apply a load by putting your foot on the brake. The only problem with this is that to get the howl you will need to have the wheels turning at road speeds and not just tick over speeds!

John
Haflinger 703AP LWB 1973 - (Once owned by Lady Sutherland & Sons.) Now called "Lurch" !

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audiocontr
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Re: Strange front head howl on the road

Post by audiocontr »

Thank you for the info. Not what i was hoping to hear, but understood.

I have not removed, nor cleaned/lubed the CV Joints. Looks like that will be first. Will i have a chance to visually see bearing issues in the CV? Feel for a click like i would in a conventional CV?

Spring removal - special tool needed equivalent to the fun of a pinzgauer?
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heinkeljb
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Re: Strange front head howl on the road

Post by heinkeljb »

There is a another thread on here relating to taking the front hubs off which list various things you have to undo etc.

Wheel off.
Disconnect brake line
Disconnect Steering track rod end
Drain the hub of oil
Remove locking pin from top swivel joint (king pin)
Remove cover from bottom of bottom swivel joint (king pin) - watch out for the shim and the ball bearing
Remove the spit pin from the bottom swivel pin
Undo the nut - make yourself a proper tool to do the job! Ring spanner of the correct size (24mm if I remember correctly) and use an angle grinder or bench grinder and shave a bit off the sides/ bottom angle of the ring so it fits on the nut properly
Take the top swivel pin out using either 7mm or 8mm threaded studding and a socket and nuts / washers. Top pin can be a pig if it has developed a lip due to the limited arc that it moves through over time. You can use a Dremel type tool and cut a slot in the top of the pin so you can get a punch / chisel on it to turn it then try again to pull it out. Applying heat can also help
Pull bottom swivel pin out
Pull the whole hub from the drive shaft - be careful with the last few cms as the splines can cut the oil seal (which is expensive)

Now you can split the hub if you want to check the bearing in it

The ring on the Rezepa joint unscrews and you can then remove the rubber seal.
Cleaning at this point if you haven't taken the shaft out of the hub can be a bit pig, but can be done. One you have washed out all the old dried up grease / rubbish you will probably find that the joint graunches a bit - pitted balls inside. Not designed to be taken apart any further.
Fill it back up again with new grease - approx 250gm
Put it all back together again and see what difference it makes to your howl! If nothing, then you know it is another bearing at fault and if you checked the bearings in the hub whilst you had it all apart, you can now say "it must be the other side" or "it must be the front diff"......

John
Haflinger 703AP LWB 1973 - (Once owned by Lady Sutherland & Sons.) Now called "Lurch" !

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AustHaflinger
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Location: Canberra Australia

Re: Strange front head howl on the road

Post by AustHaflinger »

Also what you do not want to hear - I had similar symptoms and it was the bearing in the front diff - took the diff out and replaced the bearings - fixed the issue. Changes when in 4wd compared to 2wd are often diff as the load comes from a different source - the drive in 4wd and from the front wheels in 2wd.

Garry
Haflinger 700AP (73)
Range Rover Sport TDV6 (07)
Landrover FC 101 (77)
Landrover Series 1 SWB Station Wagon (57)
Landrover Series 1 SWB (57)
Jaguar E-type Roadster V12 (71)
Jaguar XJ12C (76)
audiocontr
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Re: Strange front head howl on the road

Post by audiocontr »

Gary, do i have to pull the body off to pull the front dif?
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AustHaflinger
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Location: Canberra Australia

Re: Strange front head howl on the road

Post by AustHaflinger »

Not at all - it unbolts from the front of the centre tube and other mounts where the 4wd activating mechanism is located.

Here is a link to one of my posts that may be of interest. viewtopic.php?f=5&t=2927

Garry
Haflinger 700AP (73)
Range Rover Sport TDV6 (07)
Landrover FC 101 (77)
Landrover Series 1 SWB Station Wagon (57)
Landrover Series 1 SWB (57)
Jaguar E-type Roadster V12 (71)
Jaguar XJ12C (76)
kerry460
Posts: 211
Joined: Wed Oct 22, 2014 3:19 am
Location: Launceston Tasmania AUS,

Re: Strange front head howl on the road

Post by kerry460 »

G,,day . this may not help but it is worth knowing .
i once had a severe bearing noise . got ready to pull the front end out .
i removed the front diff bash plate , then i needed to move the haffy .
the noise was gone , the bash plate was touching the diff housing and acting like an amplifier .

worth knowing

kerry
ex Tasmanian Haflinger agent .
1984 G Wagen 300GD auto
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robw
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Location: Halifax, UK

Re: Strange front head howl on the road

Post by robw »

I had similar - mine was bearings in the centre tube which was fun !
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