changing crownwheel in gearbox

**Austin_Nova16** · 13-01-2003 14:02

I am wanting to change the crownwheel in my F16 to one from an old F16cr box.

How do I go about doing this?
Is it simply a case of swapping the diff units?

cheers in advance

**Austin_Nova16** · 13-01-2003 17:24

^bump^

**DarrenH** · 13-01-2003 17:30

Originally posted by Austin_Nova16
Is it simply a case of swapping the diff units?

the final drive is made up of two parts, the diff crown wheel and the mainshaft pinion. you cannot just change the crownwheel, it will be too big or too small to match the pinion.

I dont know if your doing this to get different final drive or just replacement due to failure, either way you need both parts.

The crown wheel unbolts from the diff, just for reference, but you need to take the diff out to do that so straight swap the whole diff is easier.

**muppet** · 13-01-2003 17:49

How easy is it to change the pinion. I want to change the final drive on mine but will probably wait until I blow the gearbox.

thanks muppet

**DarrenH** · 13-01-2003 17:52

dont know.

**DarrenH** · 13-01-2003 18:00

-

**DarrenH** · 13-01-2003 18:01

if we take the F20. there are 2 types for FWD.

1) 65 teeth crownwheel, 19 teeth on mainshaft pinion
2) 71 teeth crownwheel, 20 teeth on mainshaft pinion

1) 65 divided by 19 = 3.42 final drive
2) 71 divided by 20 = 3.55 final drive

**muppet** · 13-01-2003 18:21

What models did the 3.42 come on then. I think this is the ratio I am after. Are there any 3.1's as I think that would be even better suited to my mini.

oh and what do you mean don't know. What happened to the fountain of knowledge we expect from you.

another question are the crown wheel and pinions the same as on the F20.

thanks muppet

**DarrenH** · 13-01-2003 18:25

Originally posted by muppet
another question are the crown wheel and pinions the same as on the F20.

compared to what ?

**muppet** · 13-01-2003 18:28

Sorry I meant are the crown wheel and pinions the same on the F20 as the F16. doh.

thanks muppet

**DarrenH** · 13-01-2003 18:31

F16 come in

71/19 (3.73)
71/18 (3.91)
71/20 (3.55)
67/16 (4.19)
67/17 (3.94)
67/18 (3.72)

**DarrenH** · 13-01-2003 18:33

the 71/20 (3.55) for F20 and F16 are the same part number, so that suggest F16/F20 sets are interchangeable.

**muppet** · 13-01-2003 18:47

What gearbox do the turbo diesels use and can the crown wheel and pinion be used in the F20.

thanks muppet.

**DarrenH** · 13-01-2003 19:14

despite what people say, i dont think there some wonderfull beefy special diesel box thats strong enough for sherman tanks. nova/corsa TD use the F15, think mk3 astra TD used F18. mk2 astra, same.

**muppet** · 13-01-2003 19:17

I am not on about the strengths but just want to change my ratio's. Oh sorry for hijacking the thread as well.

thanks muppet

**DarrenH** · 13-01-2003 19:29

from what i can tell mk2 diesel used 3.94 FD, mk3 TD used 3.55 or 3.74

next idea lmao

**MARK BEESON** · 13-01-2003 19:32

I had a broken box and planed to change just the gears set.This can be done in 1/2 hour.Although the new box that i bought had 19 teeth the old one had 20 teeth.So i changed all of the box .The crown an pinion have to match regardless.If you wanted to change the final drive you would have to change the main shaft which isnt an easy task

**novarallycar** · 13-01-2003 20:30

on the f10/13 you can change the cwp on its own but on the 15/16/20 the pinion gear is a machined part of the output shaft meaning an entire gearset would have to be changed to achieve a lower cwp, iirc.

Hope this helps...

**Johnny A** · 13-01-2003 21:08

Was gearboxes came with the 3.42???

I have an Gearbox off a 2.0 8v Calibra. Would that have one??

**Austin_Nova16** · 13-01-2003 22:10

my old gearbox was a very close box, so i'm gessing that it has the 4.19 crownwheel. My new F 16 is way too long.

The old gearbox has a buggered 3rd gear, so i cannot use the gears.

How do i take the pinion gear out? Does it involve swapping the output shaft?

cheers

**MARK BEESON** · 13-01-2003 22:14

The pinion gear is on the end of the main shaft.A lot of stripping down and im not sure if you need a press

**Johnny A** · 13-01-2003 22:21

Wanna swop boxes austin, I have an F16CR, with I am guessing around a 3.8 diff

If u have a 3.55 I will gladly swop

**MARK BEESON** · 13-01-2003 23:51

Any ideas on 1st through 5th ratios on a f20?/f28?Quaife

**DarrenH** · 13-01-2003 23:56

Originally posted by Nova16v
Wanna swop boxes austin, I have an F16CR, with I am guessing around a 3.8 diff

If u have a 3.55 I will gladly swop

strange as it may seem, long ratio gearboxes have a very short ratio final drive. and short ratio gearboxes have a fairly long final drive. kind of a compensator if you like.

example

F20 (only close ratio made), final drive 3.55
F16 wide ratio, final drive 3.94

**DarrenH** · 14-01-2003 00:03

In an ideal world you would want a short ratio box, with short ratio final drive, perfect example is mr stickland, purchased a reconditioned F16 close, with 3.9 final drive. Hefty increase in acceleration to boot.

Thread: changing crownwheel in gearbox

LinkBack

Thread Tools

changing crownwheel in gearbox

Re: changing crownwheel in gearbox

Posting Permissions