Borg Warner model 35 automatic gearbox

[...---...]

Would I be able to replace the BW model 35 gearbox in my mk2 Humber Sceptre
with a BW model 35 box out of a Rover P6 or Hillman Hunter?

[Andy Dingley]

"...---..." <ga...@gfelce.freeserve.co.uk> a écrit :

>Would I be able to replace the BW model 35 gearbox in my mk2 Humber Sceptre
>with a BW model 35 box out of a Rover P6 or Hillman Hunter?

I'm no expert on this but _yes_, subject to a couple of fixes.

The bellhousing needs to match the engine backplate. Should swap from
the old box. Similarly for the propshaft flange and any mounts

The big flat bit underneath an auto box is a hydraulic computer.
You'll need to have some calibrated orifices swapped around so that
the change points are correct for your car / engine / back axle. This
isn't hard for an auto specilist to do, as they have the magic book
and the parts. If you don't do this, it might work reasonably well,
or very badly, depending on how much difference the box's new home is
from the old one (a Hunter - > Humber swap might not even notice, if
the engines and axle ratios were similar).

Putting a Granada engine and box into a motorcycle trike, unchanged,
gives some very odd shifting !

--
Smert' Spamionam

[Tony Simons]

Basically all BW35 are very similar, I fitted an A60 one to my P6, the tail
casing needs swapping as does the bell housing, the valve body should
ideally be changed to the one from your vehicle to enable shifting to take
place at the correct speed etc. This is where things can go wrong, there are
two types, one has both front and rear pumps and one has only a front pump,
the valve bodies are not directly interchangeable from one to the other as
there are non return valves in the valve body to prevent the pumps fighting
each other.

--
Tony Simons - NECPWA
North East Club for Pre-War Austins or the
Nearly Everywhere Club for Pretty Well Anything

"Andy Dingley" <din...@codesmiths.com> wrote in message
news:iikrbt43h9bn5ailb...@4ax.com...

[Dave Plowman]

In article <iikrbt43h9bn5ailb...@4ax.com>,

Andy Dingley <din...@codesmiths.com> wrote:
> The big flat bit underneath an auto box is a hydraulic computer.
> You'll need to have some calibrated orifices swapped around so that
> the change points are correct for your car / engine / back axle. This
> isn't hard for an auto specilist to do, as they have the magic book
> and the parts. If you don't do this, it might work reasonably well,
> or very badly, depending on how much difference the box's new home is
> from the old one

Hmm. Correct in theory, but 99% of all 35s I've come across have had their
downshift cable incorrectly set - or wear in the throttle mechanism which
amounts to much the same. So as long as the box came from a more powerful
car and not the other way around (Rover P6 2000 and 3500 for example) I
doubt few would notice -it's a fairly crap box anyway.

--
* Did you ever notice when you blow in a dog's face he gets mad at you? *

Dave Plowman dave....@argonet.co.uk London SW 12
RIP Acorn

[Tris Foulds]

Dave Plowman <dave....@argonet.co.uk> wrote in message
news:4a60cc5890...@argonet.co.uk...
Snip

-it's a fairly crap box anyway.
>

Yep. I had a Daimler 2.5 V8, Lovely engine, shame about the deranged shift
pattern Jaguar foisted on its gearbox (a BW35...).

A BIG improvement can be made by getting and fitting the valve block from a
S1 2.8 litre XJ6, you'll actually get downshifts at sensible speeds, as the
Daimlers standard valveblock won't change down 'cept at virtually a walking
pace!

The kickdown cable is a pain to adjust, either you get NO kickdown, but
smooth changes or kickdown working, but pretty abrupt changes!

[John Redman]

I used to have a Stag with a BW65. Same size, fits OK, you just need
different shafts because they're not the same length. A lot less clunky than
the 35 too.

[Jim Warren]

Tris Foulds <trisf...@netscapeonline.co.uk> wrote in message
news:3abdf...@plato.netscapeonline.co.uk...

<snip>

> The kickdown cable is a pain to adjust, either you get NO kickdown, but
> smooth changes or kickdown working, but pretty abrupt changes!
>

Or in the case of the BW35 on my Triumph, when I kick down it stays on full
throttle until I poke the linkage under the bonnet! I must get underneath
and have a look...
Any suggestions on what might be causing it, to save me checking everything
systematically?

[Dave Plowman]

In article <_5Bv6.58171$HR6.6...@nnrp4.clara.net>,

Jim Warren <jimw...@freeuk.com> wrote:
> Or in the case of the BW35 on my Triumph, when I kick down it stays on
> full throttle until I poke the linkage under the bonnet! I must get
> underneath and have a look... Any suggestions on what might be causing
> it, to save me checking everything systematically?

The 'kickdown' cable - wrongly called on a 35 as it controls more than
this - pulls on a spring loaded cam. This cam operates the pressure
modulator valve - spring loaded onto the cam. These valves have a habit of
sticking, and can only be rectified by stripping the valve body.

But disconnect the cable inner at the throttle end and make sure it pulls
out easily and smoothly. If not it might be 'snagging' on the inner and
should be replaced. Check also that the run of the cable is smooth with no
sharp bends.

--
* Virtual reality is its own reward *

[Andy Dingley]

"Tris Foulds" <trisf...@netscapeonline.co.uk> a écrit :

>Yep. I had a Daimler 2.5 V8, Lovely engine, shame about the deranged shift
>pattern Jaguar foisted on its gearbox (a BW35...).

Ooh, I had one of those too (in a Moggy Minor !). Stuck a manual
shift valve on it in the end.