Hi folks
Got another question on my '73 Triumph Stag, but it's relevant to any rear-wheel-drive car:
I'm hearing a wub-wub sound from the rear most of the time now - can almost feel it too, but that might be anecdotal. The diff is nicely filled with oil and the car is usually otherwise smooth and quiet.
Is that the rear wheel-bearings on the way out ?
Thanks
Frank
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Work back along the drivetrain, could be a propshaft bearing or U joint, differential bearings or a wheel bearing.
My experience is from an early rwd Escort, but does the Stag have any known weaknesses in any of these areas?
Stargazer
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I had a tyre cause this. It was a Firestone with the tread in 'blocks'. The noise got quite severe but the garage couldn't find anything wrong. I changed the tyre as it wore out and the noise ceased.
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For checking the diff, propshaft, etc is it acceptable to raise the rear of the car on axle stands and run it in first gear like that to see/hear if there's anything wrong in the movements ?
Or do unloaded suspension and bearings not create the circumstances needed to troubleshoot these components ?
What would the test be for bearings ? Any way to lever the wheel from side-to-side etc to check for play, or anything like that.
Thanks again
F
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I used to have a Triumph 2.5PU - same (carp) rear suspension design. You could try raising it on axle stands and running to test but as the ladings will be very light you may not be able to replicate them. (and you have to ensure it's VERY secure as any accident could be horrendous)
I would suggest a series of simple and systematic tests to remove potential causes:
swap rear tyres to front and vice versa and see if the sound still exists.
Jack up each rear wheel separately and test bearings by holding each wheel at top and bottom and try to rock it vertically : if it moves you may have worn bearings.
The rear splined halfshafts often bind .. have these been well greased and are the rubber dustcovers ok? If not cornering can be fun when they bind and release ..
Iirc the propshaft joints require lubrication. You have to screw a grease nipple in before greasing and remove it after. (some models may have been fitted with greased for life?) Have you greased them?
Are you sure the noise is definitely from the rear? Sometimes noise travels strangely inside a car.
madf
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hey madf - I'll definitely try that (swap wheels and try the vertical-movement test).
About the half-shafts: there's not much mention of them in my manual other than "grease them"; doesn't say how or where. Is it a matter of filling the rubber bellows with grease ? Same with the propshaft - just says to grease them, no idea where.
I have a grease gun, just need to buy the nipples for it.
Thanks for the ideas - I think the manual assumes a lot of knowledge which everyone knew from that era, especially as regards greasing the various components.
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Yup bellows should be pulled back & greased as A. it stops the splines wearing & B. stops them locking up which gives interesting handling.
I've had this strange noise on various cars all independant rear. Mine have been odd tyres on rear, can even be odd tyre wear. A knackered CV joint on the Grananda whih sounded like a diff problem. A gearbox mount & a problem on the Alfa 75 which turned out to be tyres themselves looked OK but on replacing both the noise completely went away. This was after replacing wheel bearings both sides! Not cheap but luckily the warranty paid.
Jim
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rear drive shafts as with prop shaft are unlikely to make any noise,But will cause vibration as joints wear, throwing them out of round.wheel bearings or diff is more likely the culprits as they make a noise when bad enough and cause car to vibrate when bearings are bad.check for excess play or side to side motion on drive shafts/prop/shaft connection to diff
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Steve
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When the rear gearbox mounting failed on my P4 the symptons were of a worn UJ joint, i.e. noise & vibration; worn mountings can allow engine/gearbox to move backwards slightly causing all sorts of problems.
Does the stag have a support bearing halfway along the propshaft which may have worn?
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/>Frank
I still have a set of grease nipples I used.. may take a day to find..(you need long thin ones). If you are interested I'll dig them out.
madf
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I once had what could be a similar noise with a Capri,turned out to be a bulge in the tread of a tyre.I would expect a bearing to give a steady sound,yours seems more like something catching,brakes possibly?
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Thanks for the ideas, folks ! I haven't put the car up in the air yet to check it out but will do so on Friday or at the weekend.
There's no real vibration from the thing yet, but it could just be at the early stages.
I'll post back once I find out what's up with: prop-shaft, half-shafts, diff, U-joints and the bearing/movement test. If the worst comes to the worst, there's a workshop near where I work where the main guy does a lot of work on local Stags. I'd need to start saving before going near them though ;-)
madf: that's a very fine offer, thanks very much. If you do happen to find them, I'd be very interested - or even if you know what sizes I would need to buy. Halfords don't tend to sell this sort of stuff but I can probably find same from a Caterpiller dealer or whoever makes/repairs hydraulic pipes etc. Email me on franksm@gmail.com if you will. Thanks again !
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Hello Frank.
Interested to know where you are, as I have a Stag and it it useful to know where the specialists are in time of deep trouble.
Thanks
John
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I'll post back once I find out what's up with: prop-shaft, half-shafts, diff, U-joints and the bearing/movement test.
If you don't find anything wrong at the back check the front wheel bearings.
Noise from here can travel down chassis members, and resonate in the back (certainly does on a GT6).
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