Popping and vibrating...

[MarshallandMia]

Good morning Gugus,

I have two separate issues that I'm trying to chase down in my Mk3 Spitfire, so I'll describe each individually.  First though, let me say that the PO had this car completely apart and did sort of a half-a$$ job 'restoring' it.  Second, the car has ALL new suspension and steering bushings, shocks, springs, and Ujoints were checked a/o replaced.

Problem 1: popping.  A loud pop or creak, often repeated in rapid succession when cornering and over bumps. It sounds like metal binding and moving against another part; something flexing.  It's alarmingly loud.  It appears to be coming from the dash/firewall area, under the windscreen, but I've tightened every bolt I can find as I test the limits of my contortionist abilities.  If anything, it might actually be worse now.  

Problem 2 (&3): vibration (and occasional clunk).  I've reviewed forum posts here and on triumphexp.  At higher speeds (above about 50) I'm getting a vibration all over the car and steering wheel.  I also get a bit of a clunk at low rpms, particularly when pressing the accelerator after coasting in gear.  I'm trying the process of elimination.  I have wire wheels, so perhaps balance could be an issue.  I have not tried pushing in the clutch at highway speeds, and I can't be sure but it's possible that it's worse in OD.   I can definitely hear the OD unit spinning when it's engaged (like a washing machine in spin cycle, or perhaps my scroll saw motor turning).  I jacked up the rear of the car and have found that I can turn the propshaft a bit back and forth (see video).  I apologize for my ignorance, but is this normal?  It shouldn't be universals as these should all be new or checked.

 

 

 

[yorkshire_spam]

For an older worn diff a bit of back-lash is to be expected, I assume the video is with hand-brake applied? I wouldn't expect backlash to come to such a "hard stop" unless the wheels are prevented from turning. 

Problem #1 sounds really worrying, I'd be reluctant to drive it until you find the source of that.

Problem #2 the favourite would be something out of balance to start with. If you can, get the wheels checked and go from there, if they are ok then maybe a propshaft WAY out of balance? 

 

Might be worth making contact with your closest club group and seeing if somebody will pop round and give you a second set of eyes/ears on the problems?

 

[Clive]

Have you any local spitfire (etc) owners who owe you a favor? If so, borrow a known good/balanced set of wheels.

2 things could be down to the wheels. The balance (they need somebody who knows how to properly balance wire wheels, easy to get wrong) and also the wheel to hub splines can wear, which can cause clunks. Thinking about it, the sharp crack sound could even be wire wheel related, they can flex alarmingly. 

Propshafts are notorious for balance. Changing the UJs (U joints) can/will put them out of balance. And prop balance gets really obvious at 50-60mph

They would be my starting suggestions

[glang]

The first does sound like body flexing and I get something between the roof and body of my fixed head Vitesse. This is probably because I removed the roof during resoration and then didnt use sealant/adhesive putty, as it had originally, to replace it. I tighten the fixings periodically and also use silicone spray which quietens it down...

The propshaft rotation you have looks normal and due to slight backlash in the diff gears. However sometimes it can mask play in the universal joints and its necessary to 'lock' the uj with a screwdriver to check. Clunks can also come from worn suspension bushes which allow movement when changing from coasting to acceleration and again can be difficult to find due to the tension of the spring holding things in place. Propshaft balance/straightness is a common source of the vibration you describe....

[Tim Hunt]

As to the clunks as Clive says it could be wear on the splines. Another possibility is that one or more wheels is/are not correctly tightened. Jack up the car and lock the brake on each wheel in turn. Then grasp each wheel at 3 and 9 o'clock and try rotating the wheel both ways. If you detect any any movement at all then fully tighten the wheel in question. This may not solve your clunking problem since, as you have read, play can develop in many places in the drive train of these cars

[TRTOM2498]

If you have vibration at the steering wheel, & you have isolated the actual wheels (rims), with tyres removed, to check for flat spots, and tyres are similarly OK, you could have wear ('lift') at the track rod.  Jack the car up and pull (lift) each front wheel and check for movement in the rack.

How old are your tyres ? They should be dated on the sidewalls. 

[MarshallandMia]

Thank you all so much for the responses and advice thus far. I don't really have any good contacts to try different wheels, but I'll stay on that as situations allow.  Mia is going into the shop Friday for carb needles and maybe I can have them take a look at it.  I'll certainly have them look at the propshaft since Ujoints have been replaced and, as has been pointed out, this can affect balance.  

As it's the easiest job for me at home, I've been continuing the search for the 'pop'.  While I'm not sure I found it, I did discover that the front far side body bolt is stripped (the firewall to chassis mount)...and that could definitely be it!  😬Yikes.

Let me just say, that of all the people in the world, the man I bought this from is likely the most deceitful person I've ever known.  May he be judged for what he's done.  He's probably somewhere on these Triumph forums.  I've discovered SO many lies that he told me about this car, and there's not a thing I can do about it, except perhaps warn others (as he likes to 'fix and sell').  I'm not sure it's ethical to name names, however, even though what he did was criminal.  

[thescrapman]

One thing to check with the wire wheels is that the correct "wire wheel nuts and studs" are fitted.

Having the splined adaptors held on with normal ones gives some really scary noises from the wheels.

[MarshallandMia]

Good morning all.  I sincerely appreciate all the suggestions and information.  I'm still on the hunt for the popping, but I'm almost certain after the process of elimination that the vibration is either the propshaft or the wire wheels.  Soon enough I'll have the answer to that.

The popping is as nervewracking as it is mysterious.  I double-checked the H plate and saw something funny about the way it was joined to the lower dash.  So, I compared it to one I pulled off another car and, lo and behold, it's 3/4" too short.  Looks like the PO strikes again, as the plate was only 'sandwich bolted' to the lip of the lower dash.  I swapped it out for the correct plate and I'm sure everything will be much more stable.  However it did not address the popping issue.   

[MarshallandMia]

Alright, I have more symptoms for the forum...

The popping MOVES across the car likely due to flexing, the sound changing slightly at each location.  It almost sounds like two long metal pieces that are flexing along their length from left to right as the car changes direction, but it also does it while going straight and I hit a bump on one side or the other. It can be felt slightly in the tunnel when my leg rests against it, but the source is almost certainly higher up near the bottom of the windscreen/bulkhead (very loud from that location).  

On another related note:  I'm getting an occasional pop from behind me when pulling out from a stop, forward or reverse.  But all the Ujoints have been done, bushes done, and shafts checked.  And I showed you the video of the propshaft (above).  I don't remember hearing it a couple months ago, maybe since before we put the shims in the radius arm (which I know are tight).  I was recently talking with a Triumph guy who claimed that with the swing spring coversion (from Rimmer, w/1/2" block) you have to use longer driveshafts.  I don't recall reading that ahead of time.  Is this true?  

Edited March 31, 2022 by MarshallandMia
addition

[glang]

I cant see a swing spring kit from Rimmers but the one from Canley does not need a change of driveshafts. However of course the new spring supplied might not be the same as the original used by Triumph on the later cars...

[PeteStupps]

On 31/03/2022 at 09:15, MarshallandMia said:

I was recently talking with a Triumph guy who claimed that with the swing spring coversion (from Rimmer, w/1/2" block) you have to use longer driveshafts.  I don't recall reading that ahead of time.  Is this true?

No this isn't true. Later Spitfires had longer driveshafts but the swing-spring conversion sets are for use with short driveshafts. I guess if you had a long spring fitted to short driveshafts, the rear wheels would have positive camber sort of like this \---/  although it might not be noticeable. 

On the other popping noise, what happened about the stripped body-to-chassis bolt mentioned further up? Can you see whether there is a spacer shim at each body fixing point? Can you recreate the noise if the car is stationary, by stepping quickly up onto the suspension turrets or passenger footwell?

Other possibility: could it be the bonnet? Is that secured firmly (but not so tight it distorts) when the catches are closed? If not, try adjusting those rubber locating cones. When mine was slightly lose it made a right racket, being such a large expanse of wobbly metal. 

Have to say I'm curious about the bloke who sold you the car! Whereabouts in the country did you purchase it, out of interest? 

[glang]

14 hours ago, PeteStupps said:

No this isn't true. Later Spitfires had longer driveshafts but the swing-spring conversion sets are for use with short driveshafts. I guess if you had a long spring fitted to short driveshafts, the rear wheels would have positive camber sort of like this \---/  although it might not be noticeable.  

Thats what I wonder: is the swing spring supplied in a conversion the same as the unit sold as a replacement for an original? I would have thought so as its unlikely two types have been remanufactured but of course that will change the set up in the first case and it could be why Canley strongly recommend using a height correcting spacer block....

[drofgum]

The length of the spring has nothing to do with the camber of the wheels. That is solely determined by the ride height. Long axles don't affect the camber directly they merely push the hub bearing carriers out. The vertical links just take a different angle to the axles. Similarly a longer spring would just push the top of the vertical links out without changing the camber. The longer axles do give slightly more leverage on the ends of the spring, so there may be a slight decrease in ride height, and consequently camber. There was no part number change between the short axle spring and the long axle spring.

The most likely reason for Canley Classics' recommendation is that the new springs on the market are stiffer than the originals and lead to greater ride height. That gives positive camber which is undesirable.

Cheers,

Paul

[PeteStupps]

16 minutes ago, drofgum said:

The length of the spring has nothing to do with the camber of the wheels. That is solely determined by the ride height.

I had heard that before but wasn't sure it was accurate. Trying to picture the geometry in my head, it seemed like a longer spring would push the wheels into positive camber. But of course you're right, the only relevant pivot point is the UJ on the half-shaft, which ties camber directly to ride height.

[glang]

3 hours ago, drofgum said:

The length of the spring has nothing to do with the camber of the wheels.

Not sure I agree with that as it comes down to leverage the same as you say with the axle length. If you apply a force to the spring a certain distance from the its differential fixing point the further out the more deflection for the same force. Therefore with two equal strength springs the wider one will deflect more when supporting the same car weight and if theres more deflection the car will sit lower with more wheel camber....

[MarshallandMia]

On 04/04/2022 at 17:58, PeteStupps said:

No this isn't true. Later Spitfires had longer driveshafts but the swing-spring conversion sets are for use with short driveshafts. I guess if you had a long spring fitted to short driveshafts, the rear wheels would have positive camber sort of like this \---/  although it might not be noticeable. 

On the other popping noise, what happened about the stripped body-to-chassis bolt mentioned further up? Can you see whether there is a spacer shim at each body fixing point? Can you recreate the noise if the car is stationary, by stepping quickly up onto the suspension turrets or passenger footwell?

Other possibility: could it be the bonnet? Is that secured firmly (but not so tight it distorts) when the catches are closed? If not, try adjusting those rubber locating cones. When mine was slightly lose it made a right racket, being such a large expanse of wobbly metal. 

Have to say I'm curious about the bloke who sold you the car! Whereabouts in the country did you purchase it, out of interest? 

When we installed spring conversion there was some positive camber, which was then about 90% corrected with a 1/2" block on the diff (I now only have a few degrees positive).  We then corrected the toe-in with shims on the radius arms.  

I can't do anything about the stripped body bolt without lifting the body up; there's no way to get a tap in there as it sits, I don't think.  I admit that I did consider (as a temporary measure) coming in from the bottom of the chassis wing and putting in a through bolt using a plate on the bottom to spread the load.  Ultimately decided not to do that.  The others bolts are solid, and all have spacers, and I just drive it while being mindful.  It doesn't seem inclined to pull out.  

The popping (could also be described as rattling) is most definitely coming from the top of the bulkhead somewhere but does seem like it 'moves' across the car as she is taken through corners and over bumps.  It cannot be recreated when parked.  I also considered the bonnet and have tried making adjustments.  But short of taking it completely off and giving it a try, any adjustments don't seem to make it better or worse.  Maybe I'll just take it down the road unbuckled.  

Regarding the PO...sigh...(I actually did sigh there, as I sit thinking about what to write here).  I'm torn by my morality and am reluctant about any disclosure.  Silly, really.  He would deserve any kind of whistleblowing or even a good old-fashioned pub alley a$$ kicking.  But it's my fault, too.  I should have dug deeper into the car but he earned my trust.  The fact that when I tried to contact him a couple days after purchase and found that he'd blocked my phone and email speaks volumes...after he had wooed me with lots of prepurchase correspondence, over an hour spent going over the car via video chat and tea and cakes when I arrived.  He knew what he did.  

[drofgum]

Glang,

See the rear spring chart in this link: http://auskellian.com/paul/links_files/springs.htm The spring length doesn't change.The two springs used in the MkIV for short and long axles are listed in the chart. Same length when fitted.

 Cheers,

Paul

[glang]

Thanks, thats interesting. As the same spring is used on both MkIV the early ones with short axles must sit a bit higher as indicated by the difference in wheel rates for the two.

Then if its also used in the conversion kits for the Mk1/2/3 Spitfires they must sit considerably higher...

[Tim Bancroft]

With regards to the popping noise, it sounds like you need to a passenger whilst someone else drives the car, you have a good listen then...where are you based, if local to someone on here, you could drive and they listen?

[MarshallandMia]

17 hours ago, Tim Bancroft said:

With regards to the popping noise, it sounds like you need to a passenger whilst someone else drives the car, you have a good listen then...where are you based, if local to someone on here, you could drive and they listen?

Thanks Tim,

That's exactly what I need.  I did reach out to the only person I know of locally but it hasn't happened as of yet.  I'm near Sudbury, Suffolk.  I just don't get it; there aren't that many places for a noise this loud to hide!

[mpbarrett]

16 hours ago, MarshallandMia said:

Thanks Tim,

That's exactly what I need.  I did reach out to the only person I know of locally but it hasn't happened as of yet.  I'm near Sudbury, Suffolk.  I just don't get it; there aren't that many places for a noise this loud to hide!

very active TSSC group in Norfolk that might be able to help, try there forum or if you do facebook they have a group there. (2) TSSC Norfolk | Facebook
I think there next meeting is on monday at The Ringland Swan | Places to eat in Norfolk | Pub Restaurant. 

mike

[Velocita Rosso]

The one thing that has not been mentioned ....on a MK3 the windscreen is held to the scuttle by:

three nuts and bolts on the top of the dash

two nuts and washers that hold the pillars of the screen to the mounting bracket

and....two bolts each side of the scuttle, holding the mounting bracket to the scuttle(bulkhead) 

If they are not tightened or the bracket has snapped...which is common...and is not tightening up to hold the windscreen to the scuttle,then that could give those symptoms  

Try each area for breakages/snapped brackets

If there is movement before examination,then just try tightening first...........so you have three, on top, two each side and the two nuts on the screen pillars

I have had problems before a total restoration, on the four bolts holding the screen pillars in place. 

 

[MarshallandMia]

Right, so I've been to a Triumph specialist in Potter's Bar to have my carbs tuned a bit.  He says the sound is 'scuttle shake'.  The only thing he suggested was to check the braces behind the dash.  I guess I'll check them again, haha!  He also said the propshaft (a belt type, or something) was in backwards and that's probably where a lot of vibration is coming from, and potentially the wheels.  I don't know if I have the PO to thank for that, or the first guys that replaced the universals.  I've had some really awful luck with this little car. 😂

Edited April 20, 2022 by MarshallandMia