Gearbox Condition Check

Gearbox Condition Check

Author
Discussion

JTBUSH

Original Poster:

625 posts

215 months

Friday 22nd January 2010
quotequote all
I bought an engine in bits a while back, and have got all the engine components machined, ground, bearings matched etc etc etc.

The only unknown quantity is the gearbox. The guy I bought the box of bits off didnt know the history of the engine or box.

The gearbox looks clean and in decent nick. All the gears look ok with no marks or chunks out of teeth. The selector works ok on the bench and overall, it appears to be a good box.

Are there any other checks I can do without stripping the box down to make an assessment of the gearboxes condition. The engine Im building will be knocking out somewhere around 80-90bhp hopefully, so any weakness in the gearbox will soon be exposed.

Equally, Im short on time at the moment so rebuilding the box is something I would like to skip if possible.

guru_1071

2,768 posts

241 months

Friday 22nd January 2010
quotequote all
the quickest thing you can do is inspect the tiny syncro teeth on second (compare them with the ones on forth), then waggle the 1st/2nd synco hub to see how worn the fork is, if there is a lot of 'waggle' then its worth rebuilding.

the only other you can do is see if there is any ip and down, or fore and aft movement in the mainshaft - excessive movemnet will point to knackered bearings

oh, and check the sump plug thread to make sure its not stripped!