Rockie51 Posted October 15, 2018 Report Share Posted October 15, 2018 A couple of years ago, a vibration in the 4A was traced to a failed propshaft. It had been rebuilt by Hardy Spicer here in Oz and had probably only done about 25k miles and had been regularly greased. I had it rebuilt again by a different driveshaft specialist. At the same time I purchased a new gearbox cover from Rimmer to replace the old one which was disintegrating. The first trip around the block after putting everything back together revealed a horrible noise from the front UJ hitting the new cover. Initially I blamed the new cover but further investigation showed that the new front UJ was much larger than the original. As we were about to go on a long trip, I allowed the UJ to "machine" some clearance on the cover and after a short time it only contacted the cover when the car hit a bump. I have just put the gearbox back after having some seals replaced. While the box was out, I took the propshaft back to the rebuilder and explained the problem. We are going on the Triumph National Rally in a couple of weeks and I have to get the car back on the road this week to get other work done. The rebuilder suggested that I simply reverse the shaft as the back UJ is still the original smaller size. This means that the splined section will be at the back instead of the front. I intend either buying a new propshaft or getting mine rebuilt with the correct UJ when we get back. My question is whether running the shaft this way for about 5000km will cause any issues. Rockie Quote Link to post Share on other sites
RdeJ Posted October 15, 2018 Report Share Posted October 15, 2018 Hello Rockie Having the long end of the propshaft mounted at the gearbox side will enlarge the chance of introducing a vibration at higher speeds ( > 50 mph) Had this issue years ago on a Spitfire. Reversing the shaft such the splined end was at the gearbox side cured the vibration. Would not take the risk with such a long trip on schedule. Robert Quote Link to post Share on other sites
RogerH Posted October 16, 2018 Report Share Posted October 16, 2018 Hi Rockie, having the larger UJ at the back may also cause worse issues. On my dodgy diff thread - posters replied that it may be the UJ hitting the tunnel (at the back) when cornering may give the clonk - and that is with the correct standard UJ. Get your prop sorted with the correct UJ. Roger Quote Link to post Share on other sites
Rockie51 Posted October 17, 2018 Author Report Share Posted October 17, 2018 I have decided to re-install it with the spline at the front. I went to a local rubber supplier yesterday and bought some new sealing rubber. I will pack the back of the tunnel up to give a bit more clearance and fix the problem after the trip. No links to the Vaseline thread please. Rockie Quote Link to post Share on other sites
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