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[2286]

As I have an overdrive fitted I am unable to fit the cheaper and more readily available rear mounted pto.

As such I have and continue to desire a bottom mounted.

The cost if you can find one is frightening and prohibitive.

Does anyone have a workshop manual, dimensions and parts list for one.

Aside from the case itself are the internals raided from the land rover store cupboard or are they specific to the unit.

Has anyone dare try and make one.

I assume the intermediate gear is in permanent mesh and its tooth engagement shim governed.

Then a sliding collar as per rear driven unit.

Are they only suitable for hydraulic pump due do location and output?

[Davidss]

You are asking for a hell of a lot of information there.

Your Forum profile does not show you as a S2C member. If the profile is incorrect (I.E. You are a member) then you need to sort the profile status out with the Webmaster (Wittsend).

If the profile is correct then I suggest you need to pay to join the club, which will then enable you to access a lot of technical information, like manuals, Parts Lists, Fitting instructions, etc, which will help in your research.

Regards.

[autorover1]

I did exactly what you are suggesting, fitted a bottom PTO for a hydraulic winch.  Had to make up my own linkage for the  operation of it, as the Overdrive was in the way. Its some time ago and I think I ended up using a heavy Bowden cable  off a gear shifter . The PTO runs opposite way to the normal centre PTO due to the idler so I had to rebuild the hydraulic pump to account for that  . Many bits are from the standard PTO  .  One can fit a hydraulic or Mechanical PTO to the unit. Its in the  1965 Optional parts catalogue I have. . 

[Chris Mortimer]

Like you I have an overdrive fitted, I was lucky enough to buy a bottom PTO at a very reasonable price, it now drives a rear PTO via a jointed prop shaft.  Works perfectly as long as you don't mind driving the rear PTO in reverse.  If you bolt on the rear drum to the rear PTO then you can simply twist the flat belt into a figure of 8 to reverse the reversing the bottom PTO does (does that make sense, not sure, in my head it does ). 

In answer to your question about the intermediate gear, you are correct, permanent mesh and shim governed.

[Peter Holden]

Twisting a flat belt to change the direction of rotation of the driven equipment was common on farms when machinery was driven by a flat belt as was reversing the tractor to tension the belt.

[Moogling]

If you have the skills to make a PTO,  why not consider one off the back of the overdrive?

[2286]

autorover1 is the equipment fitted to the forward control pictured, if so then ground clearance will not be such an issue for yourself as it would for me with an 88 even if it is on 750's.

I have standard series wsm and optional parts brochures.  The latter tends to be more of a sales aid as opposed to technical.

Chris interesting and shows it is possible, I had not even considered the direction change due to idler.  Some pto driven implements requiring clockwise only input.

I appreciate the pulley and belt fix is an option for a table saw or similar.

The shim governed mesh are they around the entire outer edge of the pan where you expect a gasket to be on a standard transfer cover.

Does anyone know if the bottom pto was an in house land rover product or an approved endorsed item made by fairey or similar due to the precision required.

Romahome re agri belts canvas or leather I can never understand how the join does not cause it to come off the pulleys.  I realise some pulleys have a camber that walks the belt to the centre but is that sufficient to counter the lump of the join.

Also they run very loosely to my eye and there must be a lost of power transfer loss.


Moogling I had wondered if drive through the overdrive was possible but backed away from the idea due to the reported fragility of the overdrive. 

That is a work of art and certainly makes the most of the space on offer.  Inside the casing is there an additional bearing, a dog clutch then another bearing.  Then pulley to micro v belt tensioner and face mount pillow block.

Output through chassis to the rear pto unit?

[Clifford Pope]

I have read that it is a common mistake to assume that a belt must slip if it is not very tight. In fact a belt is always tight when transmitting power, because the drive pulley pulls it so.
It's like a winch - it only needs half a belt to work. The return half is just a handy way of feeding in more belt so that it doesn't run out.

[autorover1]

The PTO was I  understand made for Rover, who specified it , by Aeroparts in Hereford . The same company who made the winches & other PTO parts. Lots of the parts are standard Rover. For instance the idler is made from the same steel blank as the idler in the transfer box, but only machined for one gear . Regarding shimming, the parts book lists 6 gaskets, presumably you use as many as required for correct mesh.  I fitted the bottom PTO to an 88" S3 back in 1980, so some time ago . I made a bash plate for under the bottom parts on the PTO  as the pump fittings were  very near or slightly below the bottom chassis rail . For info it wont fit on a standard FC as the transfer gears are in a different position, having constant mesh gears on both High & Low box.  When I worked at LR I was able to view all these parts  drawing at the Rover drawing office store
See attached extract from parts book

[Moogling]

Moogling I had wondered if drive through the overdrive was possible but backed away from the idea due to the reported fragility of the overdrive. 

That is a work of art and certainly makes the most of the space on offer.  Inside the casing is there an additional bearing, a dog clutch then another bearing.  Then pulley to micro v belt tensioner and face mount pillow block.

Output through chassis to the rear pto unit?

Inside the casing is pretty much the crux of it, yes, but the output goes to a toothed timing gear which passes the power sideways to a smaller  gear, tensioned off a plate and timing belt tensioner -  The power is passed forward by a shaft to an alternator that provides power for a stick welder.  The engine speed is operated by a pneumatic actuator that's triggered by a switch on the welding torch.  It's a beautifully engineered set-up that's unfortunately not mine!

[22900013A]

Whilst the standard BPTO will not fit an FC/1 Ton transfer box (nor indeed will any standard PTO) a special version was produced that will, however it is of course extremely rare.

[2286]

Clifford re belts so it may be consider like a chain with a taught driving side and a slack return side.

autorover 1 thank you for posting the diagram and parts list.  The one I had until yesterday came from a british leyland optional parts book that I suspect dates from the 1970's.

I did a little further research and found what you have explained that it was an Aeroparts manufactured item.  Looking at the internals I could not decide if the intermediate was a regular part with the surplus gear machines off.  I could not believe that mesh depth was controlled solely by stacking gasket paper, quite crude given my perceived precision of the rest of the assembly.

What no parts book can tell you is the real world insights as you go on to explain with regard to the 88 inch fitment and belt and braces bash plate protection.  Can you recall if the 88 was on 6.00x16s or larger wheels and what the owner intended to use it for, private or utility?

I too found the FC has a different non interchangeable bpto due to helical and straight cut gears.

Whilst in the DO did you have access and do you have the technical drawings giving critical shaft centre positions.

I found a warning to ensure that you have the correct dowty pump for the bpto due to the direction of rotation.  They must be stamped A for anticlockwise, later pumps were able to be used in both directions.

Moogling I had not expected an alternator to be on the output!  I did see the pipes that looked like airlines but incorrectly assumed that they were breather pipes.  Did the person who made it all go this route to get higher rpm and greater input variation rather than tap directly from the engine crank for example.

22900013A The reason they do not fit each other is due to the gear type as mentioned above?  autorover mentions a difference in gear position too.



 

[autorover1]

Although it was an Aeroparts manufactured,  I believe its a  Rover designed part . The PTO idler has the teeth machined to fit the TB idler and are the opposite angle  so cannot be made from an existing finished part. I had 7.50 x 16 tyres on my S3 88"  so I had a bit of extra ground clearance as I used to carry out vehicle recovery  at Car Rallies and that's why I had the bottom PTO pump to drive my Hydraulic winch.

[Moogling]

Moogling I had not expected an alternator to be on the output!  I did see the pipes that looked like airlines but incorrectly assumed that they were breather pipes.  Did the person who made it all go this route to get higher rpm and greater input variation rather than tap directly from the engine crank for example.

They are breathers - or supply lines.  The setup isn't complete in the image I posted - I don't have a finished image but the following may help.

Primarily it was a project just for the sake of it, but it's a standard 2.25d with a massive compressor, and an oversize alternator already - the engine bay is cramped.

[22900013A]

22900013A The reason they do not fit each other is due to the gear type as mentioned above?  autorover mentions a difference in gear position too.

Yes, different transfter box gearing and gear positions to a normal transfer box. They have a longer mainshaft on the 1-Ton/FC variant, hence the domed rear cover when no PTO is fitted.