Strange driveshaft? noise?

[KiwiTom]

Hi there. I am a new guy to this site but owned hearalds for many years in my youth. It is a long story I am trying to get a 1967 1200 herald in a state where someone might want to but it. It has been shed stored for about 10 years that meant i had to replace most of the slave cylinders but at last I have got everything sorted and it is running beautifully except....there is a distressing loud vibration noise that sounds like the prop shaft (or perhaps the exhaust) that only occurs when there is no load on the engine. Under acceleration, nice and quiet. Slowing down, nice and quiet. That sweet spot when you are at the speed you want to cruise at with no loading on any of the shafts...horrible loud noise that sounds like something is in the process of falling apart.

I was just wondering if anyone had experienced this before and if you had any ideas as to where to start.

[Pete Lewis]

Most shafts grumble rumble vibrate or knock

a loud  noise in the body seems more like exhaust or elsewhere is fouling somewhere when off load ,  also check the engine mounts for seperation.

[KiwiTom]

Quoted from Pete Lewis

Most shafts grumble rumble vibrate or knock

a loud  noise in the body seems more like exhaust or elsewhere is fouling somewhere when off load ,  also check the engine mounts for seperation.

Thanks for that Pete I will check the engine mounts. My next plan is to put it on blocks and see if I can get it to make the noise off the road so I can better pinpoint it.

I was given this car by a friend who died of cancer so that I could sell it to assist my daughter who now has stage 4 breast cancer with her treatment, so it will be great to sort this issue out.

[Nick Jones]

Sounds like propshaft to me.  If it's one of those horrible strap-drive things then it's pretty much a dead certainly but a slightly slack UJ could do it, as could a worn sliding spline although, I don't think you'll find one of those on a Herald.

Engine mounts are worth checking carefully as already suggested as are the gearbox mounts.

Even cars that run sweetly on the road can make horrible noises on blocks.  I'd suggest removing the rear wheels and brake drums.  Also make sure the driveshafts are not rubbing on the chassis as they sometimes do on full droop.

Good luck!

Nick

PS. is the car in UK or NZ?  Have a son who thinks he wants a Herald..... (in UK)

[Casper]

Quoted Text

sliding spline although, I don't think you'll find one of those on a Herald.

12/50s had them, I believe

C.

[Bitumen Boy]

Quoted from Casper

12/50s had them, I believe

C.

My 1200 had one when it first came to live at my expense - probably a PO's scrapyard bargain. It was knackered and I was lucky to get hold of a solid type replacement. Things get swapped around on old cars, just because something wouldn't be fitted by the factory doesn't mean you won't see it now.

[Mark Hammond]

Late 13/60's had 'em too..........

M.

[Nick Jones]

Whatever.  My 1200 had a solid one when I got it (with fore/aft stay bar on the gearbox) and a succession of sliding spline ones thereafter to suit the transmission of the day.  Definitely a potential source of off-load rumble if the splines are worn and small chassis Triumphs are very fussy about propshafts in my experience.

Nick

[heraldcoupe]

Quoted from Nick Jones

a worn sliding spline although, I don't think you'll find one of those on a Herald.

They were fitted at the factory pretty much throughout Herald production, but only to occasional cars. They were supposedly substituted where vibrations couldn't be eliminated with the regular solid (or later, strap) propshaft.
I've had about 2-3 cars with them out of roughly 100 Heralds I've owned,

Cheers,
Bill.