ZF-4 Stage Automatic Transmission Refrofit to P5B?

[1969coupe]

Greetings,
I have purchased a 1995 Rover 3.5 litre V8 motor &
ZF 4-speed automatic transmission.I intend to fit these items to our 1969 P5B Coupe.Motor & auto are ex a DAF 400 series ambulance.(this chassis once was
known as a Leyland Sherpa van)Both items will need
stripping,inspection and possible rebuild.I guess they have been thrashed but at least well seviced.
Question:-the ZF 4-speed auto appears to have a
mechanical speedo drive orifice.Also no obvious dipstick/filler tube.It appears to be only slightly longer than the original BW 35 auto.
Has anyone out in Rover P5 land done this conversion?
Are there any problems to be avoided ?
Regards,
Nick Rogers
Auckland,New Zealand.

[Phil Nottingham]

Yes it has been successfully done by a club member - go into the old forum to read more about it. Hope you can join the club

[jlalexander]

the only add I would suggest to what's in the old forum, is that the ZF box selector is cable operated; that makes life quite easier. The ideal cable, to use if you can get one, is the late P6 V8 BW65 cable. That will avoid you to fiddle with the awkward P5B linkage, and it will connect directly onto the existing gear-lever. The speedo can be accurately calibrated by speedy cables (http://www.speedycables.com/calibration.htm) if you want to keep a clean driving license.If you have the 4HP22 reconditioned, make sure that the engineer that will carry the rebuilt is aware of the most common failure on these boxes which is the rings behind the pump that wear out the bush on which they bed, leading the "A" clutch to be permanently lightly applied and wear out quite quickly.That bush MUST be renewed during an overhaul.

[stusax]

Hi Nick. I'm looking at putting a ZFHP22 into my P5B as well. I agree with the last post that you need to attend to the box's weekness of having a tendency to burn out the front clutch pack.

I'm looking at using a Range Rover bell housing and box, with a BMW extenxion housing, but would welcome any advise to the contrary.

Phil... how do I get into the old forum to read more about this??? Thanks.

Nick... I'd love to hear how you go!

Stuart

[Keith - Portsmouth]

Stuart, the old forum is here ===>>>

boardserver.superstats.com/list.html?u=P5Club&f=1

Keith

[stusax]

Thanks Keith. I'll go and have a look!

Stuart

[poodumrover1]

Hey Guys I am based in Ireland and here is some information with regard to doing the conversion I found a while ago. I am proposing a similar conversion to one P5B I am restoring.

Best regards,
Stephen


Gentlemen,
As promissed (a LONG time ago...) the instruction Richard Stennet sent me (through David Green)
concerning the fitting of a ZF 4 speed gearbox.

I must add that I found the original starter motor sufficient for the new box.


Hi Guus, You've certainly taken on a task there.......four-speed ZF instead of three-speed BW35.
The end result is very good, but it will take a bit of doing! I found a website, which doesn't
seem to exist anymore, and typed in my requirements for the gearbox and shortly I received a telephone
call from a breakers yard that had the one I wanted. The place was WESTBURY BREAKERS in Wiltshire.

I bought the gearbox and bell housing, and later, when I found out what else I needed, the flywheel,
drive plate and starter motor from them. I've no idea whether they're likely to have another LDV Sherpa
in the yard, but their telephone number is 01373 822328.
Even later, when I discovered that I needed more parts from the donor vehicle, I rang them to find out
that they had disposed of the vehicle.
Eventually I found another breakers yard in East London that scrapped and broke up Sherpas and Ford Transits.

I drove there (more than two hours each way) and bought the gearbox oil cooler, the speedometer cable, the
plate that closes off the bellhousing at the bottom and the connection attached to the wiring loom that plugs
into the gearbox four-pin plug for the reversing light and inhibitor switch.
Their telephone number is 020 8293 1892.

You will need the lower half of the Sherpas speedometer cable and the P5B's speedo cable to have one made up
that will fit between the ZF 'box and the Rover's speedometer.

Regards,
Richard

Dear David,
Received queries and snapshots regarding the ZF auto 'box from Guus.
I can't claim that the way I went about fitting one to my car was the right way, but it's all in and seems to work OK.
The big advantage with the swop is that the fourth gear is an overdrive reducing the engine through to back axle
ratio from one to one to 0.728 to one. On the road this means that at 70mph, instead of the engine spinning at 3550rpm,
it's only turning at 2600rpm. Even with my 4.9 litre, it is more economical on long journeys. The 'box won't change
from 3rd to 4th until I'm doing about 45mph, so increased economy may not be evident if the recipient car is used mainly in town.

To fit the gearbox with its bell housing to the P5B V8 you'll need the LDV's flywheel (which has four big holes in it so
that the bolts holding the torque convertor to the adaptor plate can be inserted through the flywheel), the adaptor plate
and boss, and the ZF's torque convertor (which is slid on to the front of the gearbox's input shaft and centralised, before
the bell housing is offered up to the back of the engine). The LDV's starter motor is also required; the P5B's, or an SD!'s,
is no good.

The BW35's kick-down cable has to be modified and fitted to the ZF 'box.
I had the speedometer cable drive gears within the gearbox changed so that the unaltered P5B speedometer would read correctly
(well almost; instead of the P5Bs 20:1 gearing, the drive in the ZF is now 21:1)

I had 88mm chopped out of the front portion of the prop-shaft, re-welded and balanced.

The BW35's mounting bracket welded to the sub-frame rear cross-member fouled the ZF and had to be cut off. I made/had made
from quarter inch plate a new mounting for the gearbox using bits of the original mounting and rubber.

I bought and slightly modified a V8 Range Rover's dip-stick and filler tube for the gearbox.
I used the LDV (Sherpa)'s oil cooler. A wide, tubular affair which, after moving the horns, I mounted on new brackets fixed
to the nuts and bolts that hold the bottoms of the front wings to the front valance. I then cut much larger, eliptical holes
through the valance (below the bumper) to allow cooling air in.
I ran steel reinforced rubber pipes between the ATF cooler and gearbox.
The wiring to the gearbox's inhibitor switch (which is inside the 'box) and reversing light switch was a little fiddly and
time-consuming, but reasonably straightforward.
The transmission tunnel doesn't need modifying to accomodate the gearbox, unless you decide to use, for example, a Range Rover's
gear selector quadrant and its Bowden cable.
I chose to use the original P5B selector (which means I can't select 1st gear) and made up a system of rods, levers and a counter-shaft
from threaded stud onto which I fitted the BW35's nylon joints (like tiny track rod ends).
The front, lower cover on the bell housing (cast aluminium) fouled the bar that goes across between the two rearmost sump to crankcase bolts.
A lot of filing is required to gain the necessary clearance.

I think that's about the extent of the job. Bear in mind though that the cost of the job is unlikely to be reflected in an increase in value of the car!
The advantages are increased economy and very quiet, leisurely motorway cruising.
There may be just one downside worth considering: If you begin a long ascent and start at the bottom of the hill fairly slowly, say
50mph, the engine will be turning so slowly that it may be generating insufficient power to carry that speed up the hill. Even if the
speed is maintained, it would be almost impossible to accelerate without kicking down or changing down a gear.
Good luck!

Richard

David,
One more thing necessary in the BW35 to ZF 'box swop is the need to have a new speedometer cable made up.
I used 'Speedy Cables', they're in Hertfordshire. I think it cost around £65-. I sent them the lower half of the LDV Sherpa cable and a
P5B cable. They made a new one up to the length I requested using the P5B speedometer fitting and the LDV gearbox fitting. It's a very thick cable,
about the diameter of a fat finger, and it's a tight fir coming from out of the side of the 'box to clearing the inside of the transmission tunnel.
The cable is held to the 'box with a very difficult to get hold of (i.e. find a replacement for) 7mm bolt.
Richard

PS There's been a lot of chatting about the ZF swop on the Club's website Chatline; much of it incorrect speculation as to what and
what not should to be done. I would have typed up this description of the job and posted it on the Chatline, but I can't go off-line
whilst tapping away with my two indexes! If you know of any way that this info. can be posted, please feel free.

David,
And another final thing.
The front P5B prop-shaft flange and the rear ZF gearbox flange mate up exactly without modification.
Richard


Guus,
The original P5B or SD1 starter motor will bolt to the front of the Sherpa's bellhousing OK, but as far as I could make out, the gear on
the starter's shaft would not 'throw' backwards far enough to engage with the ring gear on the LDV's flywheel. For that reason I bought
and fitted a Sherpa starter motor.
Later on, when you come to sorting out a gear selector mechanism, you can manufacture your own linkage using rods and bits of the original P
5B's ball joints (as I did) or modify the selector from a Range Rover fitted with the ZF 'box. Use a Range Rover's gearbox dipstick tube/filler
and the right dipstick. The Sherpa's dipstick comes out at the FRONT of the nearside (UK) rocker cover whereas the Range Rover's comes out in the
same place as the P5B's (Rear of off-side rocker cover).
Richard

Guus, The LDV's torque convertor will not fit on the back of an SD1 or P5B flywheel. You need the one off the LDV. I have a couple of pages copied
from an LDV Sherpa Workshop Manual. If you let me have your postal address I'll run off some photocopies and send them to you.
Fourth gear with the ZF runs at 1 : 0.728, a sort of overdrive (1 : 1 in third, like the BW35's top or third gear).
The engine in a P5B with 185 radials on it will be doing 3,550rpm at 70mph. With the ZF 'box, at 70mph, the engine will be doing just 2,600rpm......
very leisurely!
In May (?) 2001 we came over to the Netherlands for the 30th Anniversary of the Rover Owners Club Holland. Geoff Moorshead (our Membership Secretary)
in his 3.5 litre, 3-speed Saloon got about 22.7mpg. I got three miles to the gallon more (bear in mind that mine has a four litre engine).
Regards,
Richard

[harvey]

Anyone considering this conversion would do well to look at ebay item 150171244726.
It's the correct 2wd sherpa V8 ZF box with all the right bits to get you on your way.

If it was closer to me I'd have a punt myself.

[jimjam]

Does anyone know a reason not to just pick up a Range Rover version of this gearbox?

Given that my big motor is based upon a 4.0litre Disco engine surely this would be the easiest route for me to take? I realise I'll need to replace the transfer case with a different tail housing but wouldn't one from a BMW or Jag do the trick? I'm going to have to modify the prop/driveshaft anyway.

Also, I suspect there are electronic and manual versions (valve body) of the box - anyone know serial or part numbers of the manual boxes and which cars used them? (apart from the Sherpa that is - they're rare as hens teeth in NZ).

[harvey]

You would need the tailshaft and the housing, and one with a cable drive speedo, which AFAIK are not on those (Jag/ BMW) boxes. Changing the tailshaft would also involve completely stripping the box.

Like it or not, the Sherpa box is the one to have.

[jimjam]

Just discovered the torque limits of these boxes and even when upgraded with 4HP24 parts it's rated way below the amount my motor will be putting out (350-400lb/ft before the supercharger ).

So, looks like I may be forced into the 'American' route with either a TH350 (which is only a 3 speed and I really want an overdriven top) or T700R/TH400. The 700R when built properly is a nice 'box and can be made to handle huge power/torque but the TH400 is bullet-proof and also available as a 4-speed (4L80E) with electronic control. Of course my mechanic mate wants me to use a TH350 as they are strong, small and easily obtained but also because he wants me to get a Gear Vendors overdrive/underdrive for it. This unit effectively gives you 6 forward gears with top being overdriven so you get better accelleration plus more relaxed cruising. Expensive though at between 2-3k USD.

I'm actually thinking that an electronic gearbox could be better as there is lots of development amongst the megasquirt guys to incorporate gearbox control in add-ons to the megasquirt ECU which I'll be using anyway.

From my queries so far I'd say there are more people with knowledge of the American 'boxes here in NZ than the German so perhaps that'll be the deciding factor. I'll let you know what I choose!

[Guus]

Had a conversion done myself. Found a ZF-4 in London. Purchase was cheap, conversion itself very costly however! New studs had to be welded. But now I'm very pleased with the result!
Guus