Jolting - where to start?

[Tea]

I got in to our traveller (for the first time in a few weeks) instead of a modern car to go to work and found it has a bizarre jolting. It is a consistent jolt that increases in repetitions at the same rate as the car increases with speed. The only other times that I have experienced a similar feeling is when I had a lump of tar on a tyre and once when I got out of the car to find a 3" screw stuck in the tyre. It feels like it's coming from the rear passenger wheel, but that may be because the window latch is a little loose that side and so that's where you hear the squeak/ rumble drawing your attention.

I've checked all the tyres and they're all in good shape. No punctures, difference in pressures, flat spots, bald patches. The suspension looks and feels good and greasing was done 300 +/- miles ago. Engine mounts are fine, steady bar in place as is the gearbox steady wire.

The car has been used once or twice since I last drove it, including a 4 hour round trip, with no reported issue.

What should be the first places to check outside of the ones listed above?

Thank you in advance for suggestions.

[Sleeper]

"(for the first time in a few weeks)"

Flat spot on one of the tyres?

John

[kennatt]

jack the rear up,well supported on axle stands,start it and put it into gear let clutch out so back wheels are turning get out and watch the rear wheels,if you have a flat spot or distorted tread,or any thing else amiss on the rear you will see the wobble.

[oliver90owner]

There was no mention of checkng for bulges in the ture wall or tread. Likely noticeable as per Kennet's advice. But off to a tyre specialist is my advice if you don't find anything. Exploding tyres are not something to look forward to!

[palacebear]

Not wishing to ask the obvious ... are the wheel nuts all tight? No prop-shaft nuts/bolts lose or missing?

Alternatively (experienced this with a Marina years ago) but probably unlikely ... broken or chipped crownwheel tooth may cause these symptoms initially but complete failure will quickly follow unless any stray fragments sink straight to the bottom of the axle casing.

[geoberni]

Must admit my thoughts were same as Palacebear. Check wheel nuts. I had something similar on a car many years ago, but it was the nearside front so showed itself on cornering.

[Trickydicky]

check the brakes are not sticking as the car has been sat for a while.

[Tea]

No flat spots - as mentioned in original post, the car has been driven since I last drove it a few weeks back.

Will start with jack up the rear and checking again for bulges, loose nuts etc.

Thanks for the suggestions so far.

[moggiethouable]

After a run perhaps check the temperature at the hub caps, hot might indicate a rogue brake shoe or seized hydraulic brake cylinder?
Perhaps a loose spring on a brake shoe?
Jack the car as suggested on a previous post and check by hand the wheels are spinning freely.

[Tea]

oooohhhhhhhh the humiliation - it was a flat spot. I jacked up the back, like suggested, but still couldn't see anything. I then decided to change the rear passenger side wheel and tyre for the spare and all was fine.
With the wheel off I took it inside to a day glow lamp and found a flat spot on the inner edge about the size of a matchbox lid which will have been causing it.

Thank you as always for the suggestions!

[moggiethouable]

I do like happy endings.
I attended a course with work once, the instructor suggested we should all make a fool of ourselves at least once a day, I remember thinking if only I could limit it to once a day

[firedrake1942]

I had a boss like that! Trouble is, he thought he was perfect.

[geoberni]

Way back in 1977, when I was serving in the RAF in Germany, the done thing was, naturally, to buy a new tax free Forces Discount car.
One of my friends at the time brought a Hillman/Crysler Avenger. He got an extra discount for having one of the older Hillman badged ones with the Hockystick rear lights.
He found he had a rumble at about 60mph and higher, so reported it to the Dealer, who proceeded to blame all manner of owner problems, like 'You must have distorted the brake drums by getting them hot and putting the handbrake on too hard'.
However, changing the brake drums had no effect.
Eventually, they changed all 4 tyres on spec, because it seemed the car had been stored in one place for some 9-10 months and all had a small flat spot.

So how you've managed to get one in 'a few weeks', and only on one tyre is quite puzzling.

[Tea]

The reason it's only on one tyre is that I have 3 new tyres and one older tyre. Although the older tyre has barely been used it must be 'softer'. I've been meaning to change it for awhile now, but procrastination and lack of funds have meant it's been put off until I have no choice.

[JOWETTJAVELIN]

In the meantime you could inflate the tyres to their maximum when its stored, and push the car a few inches every so often to change the contact area. Also worth noting, is radial tyres can be inflated much higher than the book figures (for crossply).

[irmscher]

Long time no hear Josh have you still got a Minor ??