1.6 to redtop conversion problems!!!!please help

[btcctroy]

i know , too hard to get here though . Wen the engine was in the other car with the other F16 box it was fine , i should hav changed the whole lot at the time .

Is there much work changing a gearbox on a cav?

yep!

[Robsey]

Just the most obvious of questions, but have you set up the gear linkages properly...as per the haynes manual?

And if gears are not meshing but you have set the linkages as stated, then this could be either a knackered box, or clutch incorrectly set.

I think there are indeed 2 x F16 boxes... wide ratio and close ratio or (touring box and sport box), but I am open to correction on this

I am also making the assumption that all F16's are 5 speed units.

There are 4 and 5 speed versions of the F10 and F13 boxes, but this is not relevant for the Mk3 Cav, just a point of interest.

Regarding swapping a box, it would be no harder than what you have done already.

Mainly disconnecting your drive shafts, gear linkages, and engine / gearbox mounts..oh and your reverse light wiring.

Drop gearbox out underneath car...

The swap around by raising gearbox up into position, loosely bolt into place - until they are all in, then torque up, remembering than one bolt also holds the earth tag.

Then its a matter of bolting up engine mounts - not too tight.
Fit drive shafts, gearlinkages and fit wiring.

gentley run the engine to settle the mounts....stop the engine, and torque mounts up fully.

Recheck linkage adjustment...

[Envoy CDX]

Unless it was a c16nz2 then it will be an F13 box. if its the e16 series engine it will be an F15 box.

[cav16]

alot of work then , will the gearbox come out without havin to remove the crossmember i? Think i'll get sum1 to change the gearbox cos if i do it sumtin will go wrong haha


My car is a 1995 opel vectra 1.6 GL 8v , how wud i tell which gearbox it is?? , shud it say on the top of gearbox , F16 etc>?
I just assumed my own gearbox was F16 but i'll hav to double check wen i get home later. The 2 gearboxes are different to look at so the 1 in my car now must be the F13

[Squig]

the gearboxes usually have a plate with the gearbox code printed on it.

Robsey you are right re the 2 boxes not sure what had what though

[cav16]

i never disconnected my gear linkage , the gears all work but its just the gearbox is not engaged with the engine sumhow , cud be the trust bearin that slipped out of place . If i am swapping the gearboxes will i hav to drop the crossmember or 1 saide of it or??

[btcctroy]

Take the cover of the rear gearbox cover see it the input shaft has engaged properly. Your see the cover in passenger wheelarch. Your need a new gasket

[cav16]

do u mean the inspection plate?? need to wait till i get home , i must check to see does the clutch on my 1.6 engine fit the F16that was in the other cr that had the redtop in it , if it doesnt fit then my gearbox will defo need to come out

[cav16]

checked 2day and gearboxes are definitly different cos theres a smaller main shaft in my original gearbox . So 2moro iafternoon im gonna start and hopefully get it changed , any more info i shud know b i start??

[Robsey]

From reading threads on various forums, it appears that the number after the F is the amount of force that the gearbox can handle

F16 = 160 lb/ft

F20 = 200 lb/ft

I also believe that the innards of the F20 is just an unprated but identical version of the F16.

There are also 3 versions of the F16,
Standard wide ratio, SRi version with close ratio, and you can also get an Astra GTE (mk2) super close ratio.

On some gearboxes, there is a plate with the following details..

Four digits - box ratio type - box ratio value..... eg

1234W412 = box number 1234- wide ratio box and ratio = 4.12 : 1
****Cxxx = box number **** - close ratio box and ratio = x.xx : 1

Note though that not all boxes have this coding on the end plate.

[cav16]

thanks , must check to see if the box im puttin in is close ratio or other .

Another problem that i cud hav now is that wen i put in the Driveshafts from the other car into mine after i change the gearbox , is ther a chance that they wont fit??

[Squig]

should fit...

[btcctroy]

which cover did you remove you can change the clutch without removing the gearbox on these.

[Robsey]

Depends upon your fly-wheel...
From 1992 onward, the Pot-Style flywheel was phased in across the vehicle range.

If you have a pot-flywheel, then the inspection hatch will be insufficient in size to allow swapping / removal of clutch components.
The gearbox will have to be removed to change clutch mechanisms.

Non-pot type(relatively flat profile) flywheels, can be swapped without removing the gearbox

The inspection hatch is underneath upagainst the engine adapter plate.

The input shaft inspection plate is at the end of the gearbox, and should have a 36mm heaxagon pressed into it, which is removed using a 36mm socket.

The only way the box won't fit, is if you have a Mk2 Cavalier / Astra gearbox.
I understand some of the mounting lugs for the mounts on these may be different.

[btcctroy]

Depends upon your fly-wheel...
From 1992 onward, the Pot-Style flywheel was phased in across the vehicle range.

If you have a pot-flywheel, then the inspection hatch will be insufficient in size to allow swapping / removal of clutch components.
The gearbox will have to be removed to change clutch mechanisms.

Non-pot type(relatively flat profile) flywheels, can be swapped without removing the gearbox

The inspection hatch is underneath upagainst the engine adapter plate.

The input shaft inspection plate is at the end of the gearbox, and should have a 36mm heaxagon pressed into it, which is removed using a 36mm socket.

The only way the box won't fit, is if you have a Mk2 Cavalier / Astra gearbox.
I understand some of the mounting lugs for the mounts on these may be different.

outstanding info

[Robsey]

Thanks, I try my best,

I had a long trawl round various sites to try to ensure that I gave the best info I could...
Obviously I am reliant upon the info that I looked at being correct in the first place.

[Squig]

Worth also mentioning the flat type is lighter than pot type....

[cav16]

Very good info .

Strarted to change the gearbox , dropped crossmember n everythin , gearbox ready to come out , check to see will my dirives from F16 fit my hubs and they wont , fudgery balls . So i hav to change the struts from the donor car that had the redtop in to my own car , hav them off and i noticed the ABS things that bolts to each hub are damaged , the 2 of them hav snapped bolts stuck in them , problem is my car has the abs and in wonderin wat can i do about this?

[cav16]

will it be safe if i hav the 2 ABS things at front disconnected , there is no place for them on the other hubs .
Mite get the gearbox changed later , crossmember is off so everythin shud be straightforward .

[btcctroy]

will it be safe if i hav the 2 ABS things at front disconnected , there is no place for them on the other hubs .
Mite get the gearbox changed later , crossmember is off so everythin shud be straightforward .

your car will fail the mot as the light will come on. they'll check to see that the abs warning light comes on and goes off when the ignition is turned

the abs is a safety feature which should work

[cav16]

i suppose i'll hav to drill out and make new threads for the abs boxes . On the hubs i fitted the bolts were snapped , looked like sum1 just hit off the abs boxes with a hammer .

Anyway yesterday i got the F16 gearbox in , cudnt get any gears though , adjusted the linkage at the bottom and hav all gears now , mite need more adjusting wen i hav the car for a drive.

Waitin on a new thermostat later this evenin , so hopefully i can hav the engine runnin anyway , still need a driverside driveshaft tho .

[cav16]

got the driveshaft yesterday .

Also the man came with the termostat thing , but he had the wrong part , he had a new termostat but i need the bit that the termostat bolts to. Wat is this part called? And are they hard to get?

[cav16]

still waiting on new termostat part , But i hav a new problem

The gearbox is in a few days , 2day i just put it into gear and tried to turn the hubs , they turn no matter what , dont think they shud do this , wat wud be wrong?? If i turn over the engine whilst it bein in gear , the hubs dont turn ,

Wat wud be the problem here?

[Gaz]

in what gear?

[cav16]

every gear , but a friend said its suposed to be like that , i'll know wen i get the hair off the jacks . Wen i fitted the driveshaft i got i went to put on the nut thats goes at the end of drive and it would not thread , think i'll take the drive to a garage and get the boots renewed too .

I think the thermostat housing part will be here on wednesday