Universal joint questions??? Am I on the right track???

[SavVYute]

Hi everyone,

I’ve decided to try and cure a noise that I’ve pinpointed is coming from under the front seats of my VY Ute (V6) SeriesII.
The noise is probably described as a ‘resonant hum’. It is most noticeable from about 60kph and up. Mostly with a slight load on the drive train, but goes away as soon as you release the accelerator or shift to neutral (while cruising along).
I’ve done some research and think it is the uni joint just behind the centre bearing in the tail shaft that’s the problem. It looks in good condition, but there’s a trail of dried grease sprayed in a semi-circle over the transmission tunnel surrounding the joint. This makes me think it might be this joint going dry that is making the noise.
My questions are:
(1) How do you remove these uni joints from the tail shaft yolk? They don’t have any circlips that I can see. They look like they’re held in place with centre punch marks.
(2) Do you think my reasoning is on track or could something else be making the noise?


Thanks.

 

[SavVYute]

Wow ... nearly 100 views of this post so far and nobody knows the trick to removing this type of uni joint once I've dropped the tailshaft?

Just looking at it I'd guess you could just press it out over the tops of the staked up metal tabs with a bit of force?
I've done a few uni joint replacements over the years, but never one held in place like this before.

Anyone???...

 

[monkeys437]

Wow ... nearly 100 views of this post so far and nobody knows the trick to removing this type of uni joint once I've dropped the tailshaft?

Just looking at it I'd guess you could just press it out over the tops of the staked up metal tabs with a bit of force?
I've done a few uni joint replacements over the years, but never one held in place like this before.

Anyone???...

Yes you can press it out but putting a new one in is a different story. Most tailshaft places should be able to do it but its not really a DIY job. Even if you find a way of re-staking it if the uni joint isn't centred properly It will be out of balance and vibrate. Id be checking condition of the centre bearing and the rubber doughnuts too if you haven't already

 

[Not_An_Abba_Fan]

A uni joint won't hum, when it's worn it will have freeplay in it when you grab either side of the joint and twist them in opposite directions back and forth.

If it's humming, it will most likely be the centre bearing itself.

 

[SavVYute]

A uni joint won't hum, when it's worn it will have freeplay in it when you grab either side of the joint and twist them in opposite directions back and forth.

If it's humming, it will most likely be the centre bearing itself.

Thanks for that info Not_An_Abba_Fan.
I was under the impression uni joints were the weak link in the chain and usually the first thing to fail in the driveline. (and the cheapest component to replace) I didn't think centre bearings gave much trouble until you got to taxi type kms?
My ute's only just hit 60,000km so I kinda ruled that possibility out.

 

[Not_An_Abba_Fan]

The centre bearing usually goes before the uni's, especially if in a wetter climate as it is constantly hammered by water. Uni's are surprisingly strong.

 

[DevilDRake]

Mine was vibrating but it felt like an axle hop vibrate if i gave it alot. Mine was just the Rubber coupling, check yours haven't only slightly cracked. Better to check before pulling it all apart, i got quoted like $400+ to do the tailshaft bearing -.-

 

[SavVYute]

The centre bearing usually goes before the uni's, especially if in a wetter climate as it is constantly hammered by water. Uni's are surprisingly strong.

OK. Thanks again Not_An_Abba_Fan. Next time after I've driven the the ute for a bit I'll get under it after and feel the centre bearing and see if it's hot.
That might be a clue if it's on it's way out if it feels hotter than everything around it.

I looked up the Hardy Spicer online catalogue a minute ago and it says you can't replace VX onward Commodore uni joints without special tooling and directs you to full shaft replacement options...
"Special tooling" is probably a bench vice and a couple of old sockets so you can press it out.

Yes you can press it out but putting a new one in is a different story. Most tailshaft places should be able to do it but its not really a DIY job. Even if you find a way of re-staking it if the uni joint isn't centred properly It will be out of balance and vibrate. Id be checking condition of the centre bearing and the rubber doughnuts too if you haven't already

Thanks Monkeys 437 for the advice too. I'll check the rubber doughnuts as well.

 

[SavVYute]

Took ute for a decent run yesterday then crawled under it straight after and felt the bearings.
Diff, pinion area and everything in and around the back axles felt normal (warm).
Rear tailshaft was warm - until you got to the centre uni joint and the centre bearing area - that was hot, almost too hot to keep your hand on.
Trouble was further forward the front section of tailshaft was pretty hot as well....so I think the heat was just transferred back from the hot engine, exhaust and transmission.

Everything looks good as far as the rubber goes on the doughnuts and around the centre bearing as well.
I could end up replacing parts all over the place and still not sort this out.
So I've booked the ute into a transmission specialist next week.
They took it for a test run today and agreed there’s something wrong, but couldn’t really pinpoint where the noise was coming from.
“Could be auto... could be diff… we’ll have to do a full service on the auto first…”
Quoted about $280.

Sounds to me like a fair call. I’ll keep you posted.

 

[itsaholdennotachevymate]

as far as i know with uni joints they dont make a humming noise when you drive but they make a nice metalic clang or a thud when you change gear when its ####ed or when you first put it into gear