Technical 4x4 jumping out of 5th gear

[mortonad]

My 58 reg 4x4, 36k miles, has just started jumping out of 5th gear. At its very recent service an oil leak was found from the gearbox rear oil seal which is about to be replaced. Is there likely to be any link ? It seems doubtful to me. But if not what is the likely problem/solution ? Could it just be a linkage problem, or a clutch problem ? I find it hard to believe that it's a gearbox internal issue, there seems to be no history of such problems. Any comments gratefully received.

 

[varesecrazy]

hi, try and check / lubricate the selector mechanism,

as you say they are not troublesome boxes..,
however if all appears o.k. outside AND it only "jumps-out" under deceleration, it may well be a worn box,
Charlie

 

[mortonad]

Thanks. Having replaced the oil seal and refilled the gearbox with oil the garage reckon they have cured the problem. We shall see. If not I'll follow your suggestion.
Thanks again, Alastair