BXProject

So the valver isn't the most pleasant beast when it comes to cruising on UK roads, 70mph becomes too hurried and too noisy. After the first hour i normally find it want to leave the motorway by any means necessary!

It's known by most valver owners that fitting a TD 5th gear can make crusing considerably more pleasant. While i can find a number of people who've done the change and sing its praises, i've never seen a decent write up.

Well i've managed to get a TD box, so i figure it's about time i try the mod myself, and write it up as i go.

Well the first steps are to get the 5th gear set from the donor parts. Doing it on the bench gives a chance to practise!

The box came with a vague recollection that it might have been from a 309 TD. It certainly didn't come with the mounts for the FDV like a BX box might have. The bell housing will be used with the GTi6 gearbox all being well!

First job, take the gear set end cap off.



What you can see is the 5th gear selector, 5th gear synchro and half of the 5th gear set.



On the vehicle you need to keep the gearbox locked in a specific gear, i forget what gear, but the grey haynes manual does specify it.

To get the gear set off you need to undo both main shaft nuts. These require 12pt 28mm, if the nuts have been fitted correctly then they should be stake locked which will need undoing. In my case the nuts where very easy to undo. It might take a rattle gun.



With the nut removed, you need to remove the gudgeon pin holding in the selector shaft as arrowed. I think there was something else that needed undoing, refer to the haynes until i update this thread



Next remove the centre of the synchromesh



Then remove the synchromesh and selector fork. The shaft with the slot on the end is retained by a sprung ball in the selector fork and will need a gentle tap to remove it.

It is at this point that if you don't have the correct gear engaged, then the selector shaft will vanish off into the gearbox causing huge amounts of grief!



Selector and synchro removed



And the bigger gear of the two 5th gear set removed



That's as far as I've got so far , and these are the things that have been removed.



As they work as a set, you'll need to remove the other visible gear as well.

You'll also notice there isn't a paper gasket on the cover, only a bit of instant gasket.

So obvious question to those in the know, is that it? Is it just a case of swap these over on the valver?

I've heard something about having to grind something off, though i'm not too sure what or where.

More to follow i guess.

It's my understanding that 1mm has to be removed from either the shaft or cog as they're not directly interchangeable. Personally, i'd have thought they would be a simple swap but i think that came from Mike E...

That sounds like a bit of a pain TBH though i didnt think BE3 boxes had any real internal differences other than the gear sets, it would seem mad to have to a different shaft size for the valver than for the TD.

I wonder if Mike got his donor gear set from a BE1 cog box?

I shall have to ask!

I cant remember which way round this goes but yeah, you need a cam grinder to take 1MM out of the shaft if you've used the TD set form an early box, I think, or, it might be the later box, actually, later makes more sense...
I'll have to check the 2 boxes I have in bits to tell you!

Well both boxes are BE3 if that helps?

Need to finish painting the valver then i can get at the gear box and find out.

yarp, but there is an early BE3 and a later BE3 with different thickness shafts! ooh err missus!
I wish I could remember which is which, but I cant. I'll have a look at the box in bits at the weekend and let you know. Either way, I have another spare set you can have!

As far as I can remember the later BE3 box is compatible without any mods and the earlier one is different.

However, when I converted the Meteor to D, I checked out all the gear ratios and decided to keep the petrol box (as the D engine came with an earlier box) as there was hardly any difference in any of the ratios, at least not worth stripping and changing the gears to use the later change mechanism.
This discussion has come up before so I wondered what the overall difference to the performance would be if you just fitted the complete T/D box as it also has the heavy duty clutch.
May be a change of final drive crownwheel could be an option for longer legs but that would compromise acceleration, but a much easier job as it's a bolt in item.

Assuming that the gears are hot swappable, then changing a box is going to be considerably more hassle. Not to mention having to find a new box! The donor box i have, while complete, is shot to shit (bearings have mostly failed.

I'm sure when i've looked at the ratios before, changing for a TD box on a valver will simply kill it flat, but might be worth reviewing i guess.

When the first box failed on my valver i had a 19 n/a D box on it for several months and really couldn't tell a lot of difference. Not sure what the ratios were in comparison but it was all i had available.

you are right jay the differences in ratio are mathematically miniscule and as far as i'm aware there were/are 4 different crown wheels, more if the 4x4's are different too.
Never checked out what the resulting final drives would be ie do the sum of crown wheel teeth and top gear ratio but given the closeness of those ratios it should be easy enough to calculate the best compromise.

Where's me slide rule!!

Philhod wrote: Where's me slide rule!!

Real Retro!

(I've got two! )

Haven't used one since Sinclair brought out the first pocket memory calculator (Polish Logic) and I bought it for £19.99 and that was a discount price believe it or not.

I've got 2 indeed!!
I only have my 6" one left it's a Pic, I've no idea what happened to my full size one I used daily.

The £20 you paid was about a weeks wages back then for fucks sake..

They also had a distinct advantage over calculators. Because you choose which indices to use for each calculation, you immediately know if you made an error, unlike a calculator where only when you got the answer did you realise there was something wrong and only then if your maths was good enough to know roughly what the answer should be.

Philhod wrote:This discussion has come up before so I wondered what the overall difference to the performance would be if you just fitted the complete T/D box as it also has the heavy duty clutch.
May be a change of final drive crownwheel could be an option for longer legs but that would compromise acceleration, but a much easier job as it's a bolt in item.

the TD and valver clutch is exactly the same unit.

There is a P1 running with a TD box, and whilst it's more economical and less noisy at speed, it wont accelerate like a valver should.

Yeah, that's what I meant Doc. You pays your money and you takes your choice.

I just wonder though, if you put 2 correctly set up valvers side by side one with standard box and one with TD box. What actual difference would there be????

only one way to find out! I imagine the shorter geared standard car would pull away fromt he TD boxed car to 135MPH!

Ahhh, but if you crammed an extra 20-30 pony's under the bonnet i imagine that would be overcome and you'd be looking at a 150mph supercar

true, but then I've driven and been told of more that cant pull the limiter in 5th in standard guise. Mine will, without flooring the throttle, so I reckon mine could push 145 / 150 as is with the gearing, or a raised limiter. Gearing it up would be my preference really, once you get into 8K + territory you'd be looking at ditching the hydraulic tappets, and that just becomes more of a faff..
All that said, I might have a play about anyway, I have a better valver box for mine, and a stripped TD box kicking about..

Kool I wish I had time to come down and try them out.
When I get some time I will look at the exact ratios of each box and calculate some theoretical speeds using the different final drives.
OK so longer legs will always drop your acceleration by seconds but given the right combination to final drive including road wheel size would not drag you back too noticeably and give you true 150 mph+ with less extra horses and keep you under 8K. It's all in the maths.