High speed vibration
High speed vibration
Hi All,
Ok, 55 to 60 mph a small but noticeable pulsing high speed vibration from drivetrain
Clutch in and it’s still there
Diagnostics time
I’m thinking order of priority based on likelihood and effort
Fast moving bits first
1 check replace Uni joints move free and not worn and check alignment to clips
2 check tail shaft for damage (balance check?) haven’t hit anything I recall
3 Check pinion bearing play
4 check replace gearbox rear bearing
5 check gearbox rear bronze bush (has anyone ever replaced or checked one if these? I haven’t heard or seen a replacement If so any info pls)
Slower moving bits
6 check replace rear wheel bearings
7 check diff carrier bearings
Not moving bits
8 check engine mounts, gear box mounts and exhaust mounts for rubbing and condition (do this up the list as it’s easier to check )
So what have I missed?
Any info on the rear bronze bush appreciated
Has anyone had to re balance a tail shaft recently in the west?
Keen to hear your experiences
Don’t say drive 5 mph slower!!
Ta
Blackdog.
Ok, 55 to 60 mph a small but noticeable pulsing high speed vibration from drivetrain
Clutch in and it’s still there
Diagnostics time
I’m thinking order of priority based on likelihood and effort
Fast moving bits first
1 check replace Uni joints move free and not worn and check alignment to clips
2 check tail shaft for damage (balance check?) haven’t hit anything I recall
3 Check pinion bearing play
4 check replace gearbox rear bearing
5 check gearbox rear bronze bush (has anyone ever replaced or checked one if these? I haven’t heard or seen a replacement If so any info pls)
Slower moving bits
6 check replace rear wheel bearings
7 check diff carrier bearings
Not moving bits
8 check engine mounts, gear box mounts and exhaust mounts for rubbing and condition (do this up the list as it’s easier to check )
So what have I missed?
Any info on the rear bronze bush appreciated
Has anyone had to re balance a tail shaft recently in the west?
Keen to hear your experiences
Don’t say drive 5 mph slower!!
Ta
Blackdog.
Nostalgia isn’t what it used to be.
Re: High speed vibration
I had a fair bit of movement in that gearbox extension bush when I got the ute. Lying underneath I could jiggle the tailshaft slip yoke in all directions a fair bit (but only as much as the output shaft allows of course).
I read that the bushes can't be replaced (but everything is possible)...I found/bought another extension with a better bush (pretty much going on the thickness of what was left.
I also got a second gearbox (which I put a kit through) and that's now in the ute. That one also had a better bush in it even though the output shaft bearing was stuffed.
I'd expect some wear in all of them but I think my original one was chewed out because the front uni was stiff.
I read that the bushes can't be replaced (but everything is possible)...I found/bought another extension with a better bush (pretty much going on the thickness of what was left.
I also got a second gearbox (which I put a kit through) and that's now in the ute. That one also had a better bush in it even though the output shaft bearing was stuffed.
I'd expect some wear in all of them but I think my original one was chewed out because the front uni was stiff.
Re: High speed vibration
I would check wheel balance first.
Then unis, I once had the cups indented by the needle rollers and it took me months to find it,
Jack up the rear and run it on stands, that will eliminate the front.
Trial and error, good luck.
Greg
Then unis, I once had the cups indented by the needle rollers and it took me months to find it,
Jack up the rear and run it on stands, that will eliminate the front.
Trial and error, good luck.
Greg
So many cars so little time!
Re: High speed vibration
My two cents' worth:
If the vibration is worst at no or little load, and gets slightly better under acceleration or deceleration, then your driveshaft is out of balance. Replacing the front yoke, the rear extension housing bushing, and the universal joints with new items will help, but possibly not cure, the condition.
Holden driveshafts from late FJ onwards have cardboard tubes in them to mute the sound of stone impacts on dirt roads. The tubes move around inside the shaft and cause it to go out of balance (if it ever was to start with). The cure in this case is to go to a driveshaft place and ask them to open the driveshaft, remove the cardboard, and re-balance the shaft.
GM-H was aware of driveshaft imbalance in Holdens, but never really did anything about it until the 327 Monaros, when driveshaft failures happened during high-speed testing at Lang Lang . . .
Oh, and - check the drivetrain geometry. The gearbox mainshaft should point straight at the diff pinion, and vice-versa. If the car has been raised at the rear, it'll be more prone to drivetrain vibrations.
Rob
If the vibration is worst at no or little load, and gets slightly better under acceleration or deceleration, then your driveshaft is out of balance. Replacing the front yoke, the rear extension housing bushing, and the universal joints with new items will help, but possibly not cure, the condition.
Holden driveshafts from late FJ onwards have cardboard tubes in them to mute the sound of stone impacts on dirt roads. The tubes move around inside the shaft and cause it to go out of balance (if it ever was to start with). The cure in this case is to go to a driveshaft place and ask them to open the driveshaft, remove the cardboard, and re-balance the shaft.
GM-H was aware of driveshaft imbalance in Holdens, but never really did anything about it until the 327 Monaros, when driveshaft failures happened during high-speed testing at Lang Lang . . .
Oh, and - check the drivetrain geometry. The gearbox mainshaft should point straight at the diff pinion, and vice-versa. If the car has been raised at the rear, it'll be more prone to drivetrain vibrations.
Rob
Re: High speed vibration
I use Hardie Spicer in Welshpool for driveshaft stuff , and I have a spare extension housing or 6 at home
When you're faced with an unpleasant task that you really don't want to do, sometimes you just have to dig deep down inside and somehow find the patience to wait for someone else to do it for you.
Foundation member #61 of FB/EK Holden club of W.A.
Foundation member #61 of FB/EK Holden club of W.A.
Re: High speed vibration
Old Dudley told me a bush mechanic way to balance your tailshaft. Put a hose clamp on at the front and rotate incrementally between road tests. I e got a minor vibration around 100kmh. It’s where they seem to happen.
FB ute fixer upper, EK van on rotisserie
FB ute fixer upper, EK van on rotisserie
getting my FB ute on the road
EK van on rotisserie
EK van on rotisserie
Re: High speed vibration
Very interesting thread, looking forward to learning something here. I have an FC sedan and an FB ute and both have a vibration which comes in at close to 60mph / 100kmh. The FB gearbox has recently been recoed, both tailshafts have been balanced (the FC was retubed), wheel balance checked and rechecked, wheel bearings new, new tyres, new engine mounts and so on. Both cars have 3.55 diffs with "red motor" uni's. The vibration really feels like drive train. At this stage I just avoid the vibration period, it disappears at higher speeds, but it would be nice to have it gone. Cheers, Fraze
Re: High speed vibration
I had this bad on my first car, a HK wagon. Just above 60 mph would vibrate like hell. Was the output yoke in the end. I kept my speed down or broke through occasionally (down Sellicks Hill). Eventually fixed it and time to sell as I was now driving too fast in the old crate.
FB ute fixer upper, EK van on rotisserie
FB ute fixer upper, EK van on rotisserie
getting my FB ute on the road
EK van on rotisserie
EK van on rotisserie
Re: High speed vibration
Thanks all for your input
Greg good idea. Though growing up watching Ferris Beuller’s Day Off makes me not keen on running cars on jack stands! But will give it a shot.
Rob that description of goldilocks speed is spot on. Drivetrain. Thanks for the history facts too! Drivetrain alignment, I’ll check the diff and gearbox output shaft are looking at each other on top of what else is listed. We forget these cars had a higher gravel to tar ratio then they see now. Cardboard to quiet.
Blacky I’ll text you on the output shaft. Ta.
Clay that’s a great tip. Front end, got it.
Fraze I’ll let you know how it goes
Blackdog
Greg good idea. Though growing up watching Ferris Beuller’s Day Off makes me not keen on running cars on jack stands! But will give it a shot.
Rob that description of goldilocks speed is spot on. Drivetrain. Thanks for the history facts too! Drivetrain alignment, I’ll check the diff and gearbox output shaft are looking at each other on top of what else is listed. We forget these cars had a higher gravel to tar ratio then they see now. Cardboard to quiet.
Blacky I’ll text you on the output shaft. Ta.
Clay that’s a great tip. Front end, got it.
Fraze I’ll let you know how it goes
Blackdog
Nostalgia isn’t what it used to be.
-
- Posts: 790
- Joined: Thu Jul 02, 2020 3:04 am
- State: SA
Re: High speed vibration
Was painting the old drums today and seen they had balancing weights on them.
I guess this is another small piece to the puzzle?
I guess this is another small piece to the puzzle?
- Attachments
-
- EA06FE05-5357-4EDE-B4AF-A55C51C1B7A0.jpeg (98.38 KiB) Viewed 728 times
Drew
Re: High speed vibration
You wouldn’t be short of any brake bits. If you are let me know.
FB ute fixer upper, EK van on rotisserie
FB ute fixer upper, EK van on rotisserie
getting my FB ute on the road
EK van on rotisserie
EK van on rotisserie
-
- Posts: 790
- Joined: Thu Jul 02, 2020 3:04 am
- State: SA
Re: High speed vibration
If you are talking to me Clay yep I’ve got everything new and ready to bolt on.
Drew
Re: High speed vibration
Sorry, thread hike. Thought so Drew.
FB ute fixer upper, EK van on rotisserie
FB ute fixer upper, EK van on rotisserie
getting my FB ute on the road
EK van on rotisserie
EK van on rotisserie
-
- Posts: 790
- Joined: Thu Jul 02, 2020 3:04 am
- State: SA
Re: High speed vibration
Hey Blackdog how did you chasing the vibration?
Just in the topic of the brake drums with balance weights in them…
Been doing some research and apparently on the older cars a lot of the rear drums for balanced in the factory, I’m unsure how true this is…
I have 4 original drums and 2 have been balanced so I’m guessing the balanced drums were off the rear of the car.
Maybe check your drums and see if the rear ones have balance weights, off not see if you can dig some drums up that have the weights.
I have no idea if this will work but it certainly has got me thinking about why the balance weights are on the drums…
I originally would not have thought it would have been an issue but it’s worth a check.
Just in the topic of the brake drums with balance weights in them…
Been doing some research and apparently on the older cars a lot of the rear drums for balanced in the factory, I’m unsure how true this is…
I have 4 original drums and 2 have been balanced so I’m guessing the balanced drums were off the rear of the car.
Maybe check your drums and see if the rear ones have balance weights, off not see if you can dig some drums up that have the weights.
I have no idea if this will work but it certainly has got me thinking about why the balance weights are on the drums…
I originally would not have thought it would have been an issue but it’s worth a check.
Drew
Re: High speed vibration
Hi Drew,
In the ‘collecting few parts’ phase
Uni joints sourced and alternate rear housing (thanks Blacky)
Drum weights, I have new drums on the Ute and they don’t have weights on them. Guess they back their machining skills.
New rims and tyres also and balanced. Will be checking weights missing on the wheels even they only had 10g on them.
Interesting development also, I took a note from Clays post and checked the speedo with phone gps.
55 mph is about 115 kph. The old girl loves a country road!
Be a few more weeks before I get to it.
Blackdog.
In the ‘collecting few parts’ phase
Uni joints sourced and alternate rear housing (thanks Blacky)
Drum weights, I have new drums on the Ute and they don’t have weights on them. Guess they back their machining skills.
New rims and tyres also and balanced. Will be checking weights missing on the wheels even they only had 10g on them.
Interesting development also, I took a note from Clays post and checked the speedo with phone gps.
55 mph is about 115 kph. The old girl loves a country road!
Be a few more weeks before I get to it.
Blackdog.
Nostalgia isn’t what it used to be.