Drive line shudder from front

[Red Oktober]

Hi folks.
I have developed a very concerning drive line shudder from the front end from 20mph onwards.

I replaced the old stub axles with new ones and the needle bearings from Milners last week ... but they haven't sorted it out.
I've spoken to milners on the phone but they say they haven't heard of that before . ..

there's no play at all from the king pin bearings or in the wheel bearings. ..


Help!!

 

[IRLGW]

Sunds like a number of possibilities and really a bit of elimination. I have had this problem on different trucks with different causes each time. Worst case was a loose steering box on a defender. Do you offroad the truck? WHen you did your axles etc did you top up the Diff oil?

Warped Brake Disc
Buckled wheel
Damaged Tyre
Play in Steering system (Loose or worn component)
HardySpicer/Other Drive Train

 

[clivehorridge]

Play or just dryness in the front prop UJs would be my first thing to check Carl.

It could also be the syndrome Chris had with front prop shaft alignment and UJ "phasing". I tried to follow his thread but being a simpleton, I lost it towards the end and couldn't identify a conclusion on the "phasing" issue.

Chris won't be at all surprised to hear that I couldn't keep up with the thread! .

 

[Red Oktober]

Right ..... just had one wheel lifted off the deck while it was put into "Drive" so only one wheel rotated. (no VC in mine)
and there is a very small amount of play in the axle end of the front prop (1mm or so) but can clearly been seen as the free wheel is spinning. ... have a video to upload if it would help.

 

[Red Oktober]

Little video ...

https://www.youtube.com/watch?v=P44z57__jfc

 

[clivehorridge]

A nice little video Carl, but not really helpful in respect of play or dryness in the prop UJs.

You need to check for rotational play between one half of each UJ (the flange side) and the other half (prop shaft side). As I said, even without any visible or "feelable" play, dryness in the UJs can set up shudder through the drive-chain.

I felt it on mine last summer on the motorway, fine when I set off, but after 300kms, the track took on quite a shaky behavior.

Chris advised this too on another thread, so once home, out came the grease gun. I pumped the joint with grease, and it took some time (and spilled grease) before I got it to come out of all 4 UJ bearings.

It's very important, to get grease showing on all 4 needle bearings (one on each of the 4 points of the UJ "cross").

After this, the truck was back to normal, even though there was no play at all in that (front) UJ.

Give it a try, because if/when they let go, it can be an even bigger mess.

 

[Red Oktober]

There is about a 1mm or so of play in the UJ at the axle end. .. and although it's not obvious in the video the car was "bouncing" slightly as the wheel was spinning

 

[clivehorridge]

There is about a 1mm or so of play in the UJ at the axle end. .. and although it's not obvious in the video the car was "bouncing" slightly as the wheel was spinning

I would be inclined to get that UJ changed before looking elsewhere for other problems. There's a good chance that 1mm will cause your shudder, 1mm is quite a lot of play on those small needle bearings IMO. A good greasing will reduce play but I can't see it taking up so much slack.

As I said, better safe than sorry, because when they let go, it can damage the yolks and you'll end up having to replace the shaft or a flange, let alone other damage that a free-end of a prop shaft may cause, slamming around under the truck at speed. The transfer box casing for one can be smashed by a free prop end, and that would be a nice little earner for Karl

 

[Red Oktober]

got the front prop issue being sorted.

 

[clivehorridge]

got the front prop issue being sorted.

That's the way, good luck in it curing the problem...

 

[Dave2000]

Always a test on any forum trying to find vibes and noises. Dry UJ's 'normally' make a squealing noise when rolling slowly forward or backwards. I have also seen a bad vibe caused by OVER greasing the sliding joint on the propshafts, this prevents the propshaft lengthening and shortening between the flanges. Is there any shudder when braking gently? Try this at very slow speed with your hands off the steering wheel, you are looking for the steering wheeling rocking gently left hand right as the buckled wheel/damaged tyre/warped brake disc/sticking brake calliper/loose wheel bearing/worn TRE/worn ball joint and so forth pull the steering gear back and forth...........sorry there are so many possibilities. Also worth checking the damper across the steering, assembly, this shudder you have is often called the 'death wobble'. Often cause by the upper and lower swivels. As wear only take place over a small radius of the bearing there is often smooth and tight spots on the bearing races. The only way to correctly check the upper and lower swivels is to remove the road wheel and disconnect the steering joints and check the movement is smooth and not 'loose', you need to check with a spring gauge how much effort it takes to move the hub.

Lots to go through I am afraid, just try and be methodical, the propshaft is a good start though IMO.

regards

Dave

 

[Red Oktober]

Always a test on any forum trying to find vibes and noises. Dry UJ's 'normally' make a squealing noise when rolling slowly forward or backwards. I have also seen a bad vibe caused by OVER greasing the sliding joint on the propshafts, this prevents the propshaft lengthening and shortening between the flanges. Is there any shudder when braking gently? Try this at very slow speed with your hands off the steering wheel, you are looking for the steering wheeling rocking gently left hand right as the buckled wheel/damaged tyre/warped brake disc/sticking brake calliper/loose wheel bearing/worn TRE/worn ball joint and so forth pull the steering gear back and forth...........sorry there are so many possibilities. Also worth checking the damper across the steering, assembly, this shudder you have is often called the 'death wobble'. Often cause by the upper and lower swivels. As wear only take place over a small radius of the bearing there is often smooth and tight spots on the bearing races. The only way to correctly check the upper and lower swivels is to remove the road wheel and disconnect the steering joints and check the movement is smooth and not 'loose', you need to check with a spring gauge how much effort it takes to move the hub.

Lots to go through I am afraid, just try and be methodical, the propshaft is a good start though IMO.

regards

Dave

No wandering/shaking under braking.
No missing/moved wheel weights.
All the steering joints are sound.
the shuddering only happens when under acceleration.

 

[Dave2000]

Might be worth checking the gearbox mount as the tail tries to shake the dog? Mine looked ok but when it was taken out to replace GB/TB I found it was starting to fall apart.

Still throwing out thoughts and ideas.

regards

Dave

 

[clivehorridge]

Might be worth checking the gearbox mount as the tail tries to shake the dog? Mine looked ok but when it was taken out to replace GB/TB I found it was starting to fall apart. Still throwing out thoughts and ideas. regards Dave

I had that too Dave, and an expensive bit of rubber it is too IIRC

 

[Dave2000]

I had that too Dave, and an expensive bit of rubber it is too IIRC

IIRC about 50 euros with trade discount, not too bad as long as it lasts like the OE part, perhaps another 20 years..............
yeh right.

regards

Dave

 

[chapel gate]

Have you done any jobs on the truck of late? I had a vibration at 60 when I decelerated. Front prop re balance sorted it.

 

[Red Oktober]

Fixed ......

was a knackered Uj. ....

 

[clivehorridge]

Fixed ......

was a knackered Uj. ....

 

[Dave2000]

Great stuff, not an arm and a leg like many have found out whilst trying to trace problems like that.

regards

Dave