Trivia,Jaguar bought out Henry Meadows,the gearbox and engine manufacturers,it seems its the same gear box that TMP still manufactures?
Henry Meadows
In December 1964 Jaguar acquired Henry Meadows Ltd, a company that specialised in producing both engines and transmissions, and whose factory was conveniently located next to that of Guy Motors – of which full advantage was taken by Jaguar as one of Meadows activities was the build-up of engine/gearbox assemblies for the ‘Big J’ trucks produced by Guy Motors. It was the marine aspect of Henry Meadows Ltd that was largely concentrated on by Jaguar, although the company continued to undertake machining and assembly work for other firms – both within the Jaguar group and on “outside contract"
Does your TMP / Henry Meadows gear box leak oil?
The alloy facings of the various casings are mated using only a sealant,no gaskets,after a rebuild about seven years back mine always leaked a little oil,nothing so bad you would worry but it was there.Recently the leak has got worse,again,not so bad you would remove the box but a drip tray was requirecd to contain the oil.Yesteday I fitted a new spin on oil filter,GUD Z93 type,ran the engine in gear for around 3/4 of an hour,the leak has stopped! I can only assume that as the filter became blocked,it was causing a back pressure and the oil gallery passes through a casing joint,the 90 to 100 pounds pressure was enough to cause the leak,with a new filter and I assume no back pressure,the oil runs free and has no need to find a route that in my case was a leak,its at the bottom of the casing by the way.
Note,I have felt under the bottom of the gear box casing,there is an external section that feels like a half section of a tube,about 50mm long and 10mm diameter, it has a fitting on the engine side,it feels like a sump or drain plug,has anyone ever removed this? I assume this is an oil gallery in the alloy casing?
reply to roy@comlumber.com
Bronze nipple with a B SP 3/4" thread (British standard pipe thread)
The cause of the problem?
TMP gearbox,the engine is running,the shaft is in gear,left click the picture for a larger size and more detail.
This TMP box is mounted on the back of a Perkins 4108 diesel,with less than 2000 hours on the clock,its in good condition still,even better as we stripped and refitted it with new bearings and seals around five years back,I have some notes to consider with a TMP gear box though,the box was also branded as a Henry Meadows box too.
Thames Marine Products are in Weybridge,Surrey,England,new boxes are still made and repairs to old ones undertaken,a very good webb site with lots of info can be found at http://www.thameswaymarineproducts.co.uk/ the address is below,ask for Kevin,the owner.
Thamesway Marine Products
96 Thames St Weybridge, Surrey,KT13 8NH.
Tel & Fax No 01932-843072
The picture shows the gearbox fitted with a reduction gear,thats it at the back of the main box and hanging lower than the main box,beware! the reduction box has its own oil gallery,checking the main box with its provided dip stick does not check the oil in the reduction box,for which no dip stick is given,to check the oil level you must remove the bronze plug that is visible low down on the side (it may be on the other side too) then fill with a 20 grade oil (20/50 grade is ok) untill the oil comes out of the hole,then its full,replace the plug and close off the top filler plug,which has a breather hole,make sure its open,over filling will cause leaks.
There can be a problem with corrosion of the main housing due to the raw water (sea) cooling system,this is compounded by the factory originally using large bronze nipples where you see the pipes fit to the back of the gearbox,the box being alloy,mixed with bronze and sea water basically makes a battery solution,the result is corrosion,in our case bad enough to have a leak on the top of the casings where they are joned together.
TMPs web site suggests on some boxes you can run with no water cooling as long as you use no more than 2000 rpm,this was tried but we nearly cooked the box,so in our case we had to revert to water cooling.The leak area was opened out,mechanically cleaned, dried 100%, then sealed and closed with our 816 epoxy and 205 (thin) cure agent,when dried it repaired the box as you can see,Hammerite paint to the correct Perkins colour was used as the finish,the bronze nipples were removed and a pair of nylon ones (3/4"BSP threads)fitted instead,the box now runs at a normal temprature and is repaired without a very dificult removal,as the box and reduction gear weigh 50kgs!
How does it work? (There really is no easy way of explaining this)
The gearbox incorporates an epicyclic gear train for ‘Astern’ running and the input and output shafts are locked together in ahead to
give a direct through drive. There is a small reduction in output speed in ‘Astern gear’. In ‘Neutral’, when the engine is running, the
output shaft is prevented from rotating by a hydraulically-actuated automatic brake. When the engine is stopped, the brake retracts,
so that the propeller shaft is free to rotate. Gear selection is achieved hydraulically by moving the control lever located on top of the
main box. The gearbox contains its own oil pump and oil reservoir. All bearings in the direct drive version are force lubricated and a
renewable element filter is fitted. In the case of the ‘Reduction’ model the bearings are bath lubricated although bearings in the main
box are force lubricated as in the case of the ‘Direct Drive’ version.
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