Have you checked the torque on the rears...?
It's possible they were not pressed fully home and so the play your feeling is the driveshaft in the drive flange on the spline.
I strongly suspect these will torque up with no play afterwards.
The mechanic who did the MoT showed me the play on both sides. He tried tightening the nut and though it moved a wee bit the play remained.
The mechanic showed me the issue and I have rechecked it back at home.
I had problems with my 2019 kit's rear bearing fit on the driveshaft, and ended up with both rear bearings and driveshafts being replaced under warranty. In short the shaft seemed to be undersized, resulting in bearing fretting, damaging both the bearing and the shaft.
Would be interesting to see yours one taken apart.
My detailed build blog
That`s why I bought a 7 in the first place....so I could spend the rest of my life taking it apart and fixing it!
JonPivo - Is your car post 2016 ? If so it will already have the uprated rear hubs & bearings fitted.
You do state that 'both bearings' have failed indicating the old set up of two bearings per side ? Or do you mean both near side & off side. If this is the case it must be very rare for 'sealed for life' uprated bearings to fail so early. All I can think of is that the rear hub nuts were not torqued correctly. It pays to check the rear hub nut torque from time to time as a JIC precaution.
The old two bearings per side system was OK if lubricated IAW with the Caterham service schedule recommended every four years. In fact if serviced properly they were one of the most reliable items on a Seven !! The only problem was that over greasing on re assembly created a positive loss system issuing grease passed the seals which caked the inner side of the hub & disc.
I upgraded my car (2012 R400) when the diff was pulled to replace the chocolate fire guard Titan LS unit.
I wrote a piece for LF & published in the July 2021 edition highlighting the benefits of upgrading. Unfortunately not available in the LF archive as yet.
It's interesting what was said about driveshafts. We had some issue with racing Minis where the bearings kept failing. It turned out to be a badly machined driveshaft that was not seating properly/squarely and seemed to be stressing the bearing. If the problem persist with new bearings, I'd look at the driveshafts.
#17 Geoff, mine is a 2016 factory built car. Is there an easy way (without dismantling too much) to know which hubs and bearings are fitted?
StevehS3 - If you jack & axle stand the back end high enough to get under then with a bright light you should be able to see the inner side of the hub. This is a difficult process !!
If you have the standard hubs & bearings then you should be able to see the black grease seal around the hub lip. Also there should be some grease splatter.
If you have the 2016 > hubs & bearings you should be able to see the face of the bearing without grease seal & of course no grease splatter.
Thanks Geoff. I will take a look. Should have inspected whilst changing the chocolate Titan.