24-05-2019, 05:25 AM
Compared with many other older makes the synchro box is well made and reliable. Many other common makes utilised plain splined washers to separate the mainshft gears and these disastrously fail. Many other makes strip gears (Morris 1000) and/or pit early. Mile for mile, and esp considering use, Sevens last very well. I have replaced utterly failed bearings in 1970s cars at a fraction of Seven mileage. Even when heavily pitted 1st gear remains robust.
Main problem seems to be ridged 1st/3rd shaft bearing surfaces and loose synchro cones, neither of which commonly strand.
The drive shaft is not original. It may have been fabricated. Is there travel in the splined part? Yolks phased?
Even poor synchro is a huge convenience as double declutching does not have to be super precise.
Significant serious problems often produce metal dust in the oil (as does unimportant pitting).
I am not sure if it is possible with Sevens but if poking about in gearbox with lid off and interlock removed, beware to not release the synchro balls.
Main problem seems to be ridged 1st/3rd shaft bearing surfaces and loose synchro cones, neither of which commonly strand.
The drive shaft is not original. It may have been fabricated. Is there travel in the splined part? Yolks phased?
Even poor synchro is a huge convenience as double declutching does not have to be super precise.
Significant serious problems often produce metal dust in the oil (as does unimportant pitting).
I am not sure if it is possible with Sevens but if poking about in gearbox with lid off and interlock removed, beware to not release the synchro balls.