Rumbling noise after long run...

[pwd95]

Hi all, strange little issue I'd like some opinions on if you will.
The Chim drives great now after the body off partial resto last year. I can drive it for an hour or 2 & all is well but if I go over the 3 hour mark...
When I pull away from junctions or any occasion from standstill I get a rumbling sound from the rear of the car.
1st hour or 2 nothing...
Just come back from the TVRCC Braveheart tour which is the 1st time I've driven that long really.

[Belle427]

Try an oil change with the correct stuff first and go from there, when was it changed last?

[pwd95]

Changed it just before the trip but have ordered the 80/140 stuff now to see how that goes.

[PabloGee]

Definitely worth doing that first - saw you’d posted on FB too