Tech. questions: LT77 and disk brake conversion.

Hi again,
Flushed with the success of my tax-exemption thread, I have a couple of
technical questions for you guys which I'm sure you can answer quickly.
Once again if there's an FAQ I should refer to please point me there
(have checked the one for this group).

1) If I understand correctly an "LT77" is the 5-spd. gearbox with
full-time 4WD from 90 & 110 type onwards (variously superseded in
1990s). Will this box work OK with series-type axles? Or can I expect
worse fuel consumption compared to an old-style box and free-wheeling
hubs? (due to front drivetrain drag etc.)

2) Is it possible to convert a series-type front axle to disk brakes?
If so is it just a matter of swapping everything from the swivel ball
outwards? I've seen some references to aftermarket kits, but I'm
talking about using standard parts, assuming I had a whole axle as a
donor.

Thanks in advance,
Ruaridh.

Ruaridh wrote:

> Hi again,
> Flushed with the success of my tax-exemption thread, I have a couple of
> technical questions for you guys which I'm sure you can answer quickly.
> Once again if there's an FAQ I should refer to please point me there
> (have checked the one for this group).
>
> 1) If I understand correctly an "LT77" is the 5-spd. gearbox with
> full-time 4WD from 90 & 110 type onwards (variously superseded in
> 1990s). Will this box work OK with series-type axles? Or can I expect
> worse fuel consumption compared to an old-style box and free-wheeling
> hubs? (due to front drivetrain drag etc.)

It is possible, but you need to either convert the front axle to full time
four wheel drive or the transfer case to part time four wheel drive. Either
is expensive. Fuel consumption for the part time four wheel drive would not
be significantly different, higher for full time four wheel drive, but
probably not a major change.
Why would you want to do it? seems like a lot of trouble for little gain
unless you are fitting an engine that develops too much power for the
Series gearbox.
>
> 2) Is it possible to convert a series-type front axle to disk brakes?
> If so is it just a matter of swapping everything from the swivel ball
> outwards? I've seen some references to aftermarket kits, but I'm
> talking about using standard parts, assuming I had a whole axle as a
> donor.
>
> Thanks in advance,
> Ruaridh.

I believe Zeus do a disc brake kit. There are no standard parts you can use.
It is possible to fit a Rangerover or Disco axle, but there are serious
problems, the main one being that the track rod behind the axle goes
through the springs. There are ways round this but none strike me as very
satisfactory. It is not feasible to change from the balls out, although it
is probably possible if you have a good engineering shop available - apart
from the fact that nothing quite fits, you still have the problem that the
track rod is at the back on all disc brake Landrovers, but at the front on
Series Landrovers. If you just want to improve the brakes, consider
upgrading to Stage 1 drums, or at least to lwb 11" drums if it is an 88.
JD

In message <[email protected]>
"Ruaridh" <[email protected]> wrote:

> Hi again,
> Flushed with the success of my tax-exemption thread, I have a couple of
> technical questions for you guys which I'm sure you can answer quickly.
> Once again if there's an FAQ I should refer to please point me there
> (have checked the one for this group).
>
> 1) If I understand correctly an "LT77" is the 5-spd. gearbox with
> full-time 4WD from 90 & 110 type onwards (variously superseded in
> 1990s). Will this box work OK with series-type axles? Or can I expect
> worse fuel consumption compared to an old-style box and free-wheeling
> hubs? (due to front drivetrain drag etc.)
>

No. Unless you find a Stage I V8 font axle, which has CV joins rather
then UJ's.

> 2) Is it possible to convert a series-type front axle to disk brakes?
> If so is it just a matter of swapping everything from the swivel ball
> outwards? I've seen some references to aftermarket kits, but I'm
> talking about using standard parts, assuming I had a whole axle as a
> donor.

There is/was a kit available from Chris Perfect. Just swapping bits
won't work without a lot of work. The fact the eveyone's not doing
it tells you all you need to know! Or you could look for a Santana
front axle/swivels - very rare in the UK though.

>
> Thanks in advance,
> Ruaridh.
>

Richard

--
www.beamends-lrspares.co.uk [email protected]
RISC-OS - Where have all the good guys gone?
Lib Dems - Townies keeping comedy alive

Great - thanks.
Re. disks:- understood.
Re. g/box:- I would want to do it just to get the 5th gear / higher
cruising speed. I may have misunderstood - perhaps when people fit 5
speed boxes to older Landrovers they use the old transfer box
arrangement. Is this possible?
Of course I'm aware I could use Fairey overdrive with the old box, but
I'm unclear on how good that is.
Cheers,
Ruaridh.

Ruaridh wrote:

> Great - thanks.
> Re. disks:- understood.
> Re. g/box:- I would want to do it just to get the 5th gear / higher
> cruising speed. I may have misunderstood - perhaps when people fit 5
> speed boxes to older Landrovers they use the old transfer box
> arrangement. Is this possible?
> Of course I'm aware I could use Fairey overdrive with the old box, but
> I'm unclear on how good that is.
> Cheers,
> Ruaridh.

It is probably easier to fit the five speed box to the Series transfer case,
but still may involve engineering work including replacing prop shafts and
moving gearbox mounts due to different length of box.

The Fairey overdrive is effective but is a bit fragile although it performs
well if looked after. The much rarer Toro overdrive is said to be better,
but I have no experience with it.
JD