Integra gearshift problems

[possumscratcher]

'89 integra SX16......
....jumps out of 5th gear AND very hard to select reverse (baulky/crunching)
....some history here maybe theres a connection.

The alternator died, and what a pig of a thing to access!
I got it rebuilt OK, but removing and refitting meant undoing the top engine mounting in front of the power steering pump and jacking up the sump as far as I could, to get the alternator out from under the manifold (there didn't seem to be any way to get it out underneath!). All fixed, but a few days later I found it was jumping out of 5th gear at about 100 kmh, and very hard to select reverse.
My first thought was that the gear shift linkage had been distorted by lifting the engine, but it looks ok.....any ideas anyone?

[xtat1k]

Synchros.

[possumscratcher]

Ok thanks for quick reply.
I forgot to mention that I lost a bit of gearbox oil when I pulled one of the driveshafts to try to give room to get the alternator out (maybe 1/2 litre) which I haven't topped up yet - its not noisy or anything, seems odd that its only 5th gear. Is there synchro on reverse on these things?
Are Hondas particularly sensitive to gearbox oil levels?

[xtat1k]

try flush ur gbox oil and put new one in.
see if you still have the same problem.
if yes, im guess its ur synchros if no more issue guess it was just the oil.

[teh_mechanic]

there is no synchro on reverse.
usually, being hard to get into reverse is either a fault in the clutch system or an oil or internal gearbox problem.

since your oil is low,try topping that back up first,hondas and other fwd's are quiet sensitive as the relatively small amount of oil that goes into them has to lubricate the entire transaxle (gearbox and diff)

and as claymore said,after topping up,it could be something to do with alignment of shifter

[possumscratcher]

What a helpful crew!
This car has a rod linkage not cable shift, so its fairly straightforward. Theres no obvious binding anywhere.
I actually put a litre of oil in it this afternoon (must have lost more than I thought), and it appears to be OK! Indeed these boxes must be ultra sensitive to oil environment, not really sure what difference it could make but there you go.
Next Q - do I top it up right to the level of the filler plug? (its in the top under the battery tray). At the moment its about 2 cm below the top...