The gearbox and overdrive were working fine. However, shifting down requested double clutching indicating worn synchros, which lead to a rebuild.
This gearbox is really easy to work on. If you are strong enough that is, because with its cast iron case and Laycock overdrive, it is amazingly heavy. You just unbolt the bellhousing and the overdrive and you pull! What looks like 1000’s of parts on the exploded view of the parts list make a compact and meaningful ensemble when you have it in you hands.
Synchromesh for the BJ7 were still bronze and that is the material of the new ones also. While open, the layshaft and roller bearing were changed because that is supposedly a high wear item. Mine however had hardly any trace of use…All new gaskets and lip seals as matter of course.
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cleaned empty case |
guts |
2-3-4 on mainshaft |
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new layshaft and bearings |
assembled |
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The overdrive did not need a rebuild and was only cleaned, painted and outfitted with new seals and gaskets. The solenoid looks as new.
Mating the OD to the tranny was done using copious amounts of Hylomar gasket sealant and the ‘wire trick’ from Mr. Finnespanner to help get past the oil pump roller. Between aligning the OD splines and gettingpast the roller, the mating took the best part of 2 evenings.
At the end the transmission shifted up and down smooth like silk and you barely had to look at the switch to have the OD kick in.