old school F10 boxes

[mayhem]

my mk1 astra is a 1200 S OHV engine with a F10 4 speed gearbox.
i'm picking up a F10 5speed from a mk2 astra 1300 next week..

now there's this story:

a OHV engine has a different bolt pattern, and the OHC engine's use m10 bolts, while a ovh engine uses m8 bolts..

anybody ever tried this? or has a ohv and ohc box laying around and willing to check for me?

[mowgli]

the casting is different, but you can fit all the bits from the 5 speed into the ohv box. including the diff. then you can sell the 4.53 diff over here for loads of money to a rally boy

[garyc]

The cluster will probably be worth more :-) if its a 2.21 or 2.18 2nd gear that is!

[youngcorsakeenan]

does the 4.53 diff come in all the 1.0 ohvs? is it the best of the standard diffs without going for quafie or the like.

[garyc]

I think the 4.53 diff comes on combo vans too, well according to EPC. there are loads of f10 FD's from 3.5-4.5 I guess you will need to test to see which is best for your application.

[MattBrown]

I have 5 f10 boxs and not one is 4.53fd

[nova 2L 16V]

I have a 1.0l nova engine out of a J reg its a 4 speed what gearbox will this be then?

[mayhem]

f10.

@garyc: kadett D F10/4 is always a 2.21 2nd gear. all other models are a 1.97 2nd gear.

there are 3 different diff ratios for a kadett D 1.2s ohv engine.

3.94
4.18
4.29

the 4.53 diff is only on the kadett D 1.0N, 1.0S, 1.2N


@mattbrown: corsa A/nova is always a 3.74 or 3.94 diff.

[mowgli]

i thought your car did some crazy low maximum speed in top gear.......

some of the 1.2 astras/kadetts had the 4.53 and i think there was a 4.4(ish) diff on early estate models. yours could have been swapped at some point in its life.

the corsa A/nova had 3.74, 3.94 & 4.18 diffs, the 4.18 only on the sr model with a f10/5wr

[mayhem]

i only checked the f10/4 boxes for the ratios :) but as i said mowgli, the 1.2N has a 4.53 diff (F10/4 speed)

i can go over 90mp/h, but then i'm really far into the red zone (6500ish rpm)
at 75mph (the legal speed here on a dual carriageway) it's about 5700 rpm iirc.

swapping the whole diff and casette thing, is that difficult? i never turned a gearbox inside out.

[mowgli]

it is really easy. you just undo take the shift box off the top, and the end off the box... then pull. the hard bit is getting the diff out & putting the new one back in. if you mark the big threaded bearing carrier with some paint, and unwind it & you keep the old diff & swap the gear over, then it should go back in to the same mark with no trouble.

loads of people are frightened of doing a gearbox, but it really is easy compared to doing an engine, it is just a bit different.

oh, and 75mph should be about 3500rpm with an f10/5

[mayhem]

thanks mowgli.
i assume the torque settings etc. can be found in the haynes manual?
(never looked at the gearbox thing lol, only had a quick browse when doing the ignitoin)

[mowgli]

yes, the haynes book is very good with the gearbox rebuild stuff

[mayhem]

cheers, rep added.