Hi Everyone,
My 1979 S1 Eclat vibrates at speed (70+), it's been the case since I got it 2 yrs ago. I've changed a bunch of things (tires,alignment, bearings, u/j, engine & gearbox mountings, bushes ..) without success.
I was so far leaning towards an incorrectly balanced propshaft, as the vibrations were clearly vehicle-speed related.
After changing the engine and gearbox mountings, the car now makes a loud (bearing?) noise coming from the back when I lift the throttle. Vibrations are worse.
I got my mechanic to lift the car, and I saw that the propshaft has a lot of play towards the differential end. 3 sec video here :
https://youtube.com/shorts/PU7DujiBpNU?feature=share
So...clearly something's not right with the diff, but I don't know if:
- a poorly balanced propshaft could have destroyed the differential
- or the diff was just progressively deteriorating.
With this long intro, I have 2 questions:
- can this great group advise on the most likely cause, what parts are most likely to fail?
- can the propshaft be removed without taking the engine+gearbox out, once the diff is removed?
I'm hesitating between:
- buying a bunch of internal diff parts (input bearings,seals, etc) and hoping that the damage doesn't extend to pinions and other internals...(cheap on parts, likely more expensive on labour)
- sourcing an entire diff (lotusbits has a newly rebuilt one, but it's not cheap, and I have to ship it to Singapore. But labour would probably be higher than with the first option)
To add some context, I'm not equipped nor qualified to takeout the diff and investigate, I would need to book time with the shop.
Happy to listen to your advice.
Thanks a lot!
Bernard