Can the Gearbox on Mk3 Cav be removed from the top?

[Makis22]

I decided to swap out my gearbox. I looked in the Haynes manual and they say I have to remove the subframe to do that. Is there anyway I can avoid this and try to remove it from the TOP? Has anyone done this? You expert ansers will be appreciated.

[Mark T]

The gearbox sticks out into the arch a bit, there is metal work above it, so no way it will come out of the top.

[mavvmad]

Yeah it will come out the top.....



























































if you take the engine out lmao lmao lmao

[DarrenH]

do chickens have lips ?

[Mark T]

Originally posted by 0ddball
do chickens have lips ?

Which end?

[Makis22]

You guys are right. No way from the top.
I managed to get it out from the bottom, but had to lower the subframe. I should be able to fit now the other one tomorrow.
It looks like indeed my old box was on its last legs. Just spinning the input shaft you can hear some grinding noise in the box. The one I picked from the scrapyard seems to be quite so when fitted it should improve matters for me.

[Makis22]

Managed to put gear box back in. It has fixed my problem so I am happy. I even more happy becaust the box although a F16 WR must have come from a 1.8 Cav. There is no markings on the box to tell you, so I checked it out before fitting by spinning the input shaft in a given gear and see how many turns the drive shaft does. It turned out according to my calculations that the new box has a 3.9:1 instead of the 3.55 of my old box. The other thing that gave it away it might be a 1.8 F16 box was the slightly smaller clutch release bearing.
I took it for a spin and here are my finding.
1. First gear is a bit wild. Wheels spins easily on dry tarmac without droping any clutch.
2. Second gear now cuts out on 61 mph indicated instead of 66 indicated. So there is definetelly more urgency there.
3. 4th gear makes acceleration between 95-115 indicated something that it was impossible to have with the old box.
4. 5th gear although more noisy now then before, gives real acceleration at normal motorway speeds without having to drop a gear. It seems also capable of getting the car to 130 and beyond. Expect top speed to actually being improved with this gearbox swap.

No I need to fix some of the rattles, and get that exhaust note improved.

[Mark T]

The F16W has a final drive of 3.94

2nd gear top end should be the same on Wide and Close ratio boxes due to the different gear ratios and Final drive ratios.



the F16 CR will top out at 150mph, the F16 WR at 170 mph.

If you could ever get to 6800 rpm in top.

[Makis22]

I think 6800 for an 8V in 5th is academic. A more realistic figure would be to give the speed at 5500. According to my calculator
F16 CR - 120 mph
F16 WR, 2.0 engine (3.55 final drive) 150 mph
F16 WR, 1.8 engine (3.94 final drive) 135 mph

This makes the F16 WRb (with 3.94 final drive) slightly overdrive in 5th compared to the CR box and overall could be a good alernative to a CR box. I used to have a CR on my old Mk2 SRI130 and it fitted that car well. I think the Mk3 Cav has better aerodynamics then the Mk2 Cav so I think it will benefit from the slightly wider fifth to get a slightly better top speed and also more relaxed high speed motorway driving.