Another Another newbie question

[darren620]

Hello all. ive trawled through a good number of posts about the J2 gearbox and note that some of the gearboxes have dip sticks. the one i am working on has no such luxury. 

ive looked all around and want need to check the actual level. i'm pretty certain it hasnt been checked for quite some time. on the top is a lozenge shaped plate with 2 bolts securing. but the cream ( yes cream ) paint is utterly untouched in the areas of the bolts. and it seems a high point. 

coming down the casting. it seems theres a round brass plate that i would describe is the cover plate for a bearing thats definately for the chain wheel for selecting gear. 

then lower, on the rear another round brass plate. this does, to me, look like a place to put an inspection plate. perhaps a filling point. it has a bolt and 2 screws holding it in. ive removed those but it seems happy in its place and i didnt want to get too brave in changing its mind until i could be more sure it was the plate. 

 

the owner is complaining about gears now being difficult to get/undo. etc. other posts on here i have read all pointing towards the oil...

 

 

thanks in advance. and thanks for my first post hopefully being approved by admin soon. 

[BEngo]

Without a dipstick there is no way to actually check the gearbox oil level. The best thing is to put the right amount of oil into an empty box and make sure it does not leak out.

 

The lower  brass thing with a bolt and two screws is a bearing cover plate for the lay shaft. The one above it is for the starting handle shaft.  Leave both well alone unless you want to dismantle the box. 

 

Right at the bottom of the gearbox, on the back, well hidden under the output shaft and the clutch thrust box is an oval plate, held by two studs or bolts. It is much like the one on the top.  This is the gearbox drain.  Remove it and allow the oil to flow out.  Once all the oil is out replace the plate and remove the top oval / lozenge shape plate with two screws.  Pour in one Scotch bottle's  worth  of SAE 30 engine  oil ( 26 2/3 fl oz, 1/6 imperial gallon or 750ml. ) Refit plate.   Repeat every 200-250 hours.

 

There is (should be) a grease nipple on the clutch thrust box.  The grease lubricates the bronze lump driven by the gear change chain that pushes and pulls the cone clutch inside into gear.  It also  doubles as an oil seal! Give it a good greasing with a general purpose grease. 

 

There were two sorts of gearbox.  One has metal to metal clutches and the other has friction lined clutches.  The metal to metal ones are renowned for being hard to get  out of gear.  The clutch thrust box will bear the scars where it has been thumped with a nammer to get gear change. 

 

N

[darren620]

many thanks for this info. we'll do a full box oil change when we get back from this eventful trip. 

[BEngo]

From what you describe an oil shortage is quite possible.

I should put a half-pint of oil in the top now.  That is not enough to cause overheating but will ensure that the expensive and fairly hard to find imperial ball bearings do not get run dry.

 

N

[darren620]

OK. 

 

just to be sure ive taken a pik of the top and bottom of the gearbox. from the paint on the top. if indeed its the actual fill point. we can all be totally rest assured that this has never been filled. 

i'll make sure to put half a pint in before we start up tomorrow. 

[MtB]

Yes those two oval plates are the fill and drain holes, and the paint looks undisturbed. 

 

One problem I've spotted is that Kelvins need to be green or blue, and no-one knows if they'll work properly painted white. This could be the root of the gearbox noise. Try painting the engine blue if adding oil doesn't work.

 

 

 

 

[darren620]

i'm reliably told. this particular engine was actually used on a sales display stand and hence its colour. 

 

hahahahahahahaha. i mentioned the paint problem i think it set off some tourettes. 

[BEngo]

Someone had a red one.

( Tom Montagu?)

 

N

[stagedamager]

The red J2 is in Harrier.

[cuthound]

16 hours ago, MtB said:

Yes those two oval plates are the fill and drain holes, and the paint looks undisturbed. 

 

One problem I've spotted is that Kelvins need to be green or blue, and no-one knows if they'll work properly painted white. This could be the root of the gearbox noise. Try painting the engine blue if adding oil doesn't work.

 

 

 

 

 

I'd be worried that once started, the engine would try to head off for London on its own...

 

[Rob-M]

16 hours ago, BEngo said:

Someone had a red one.

( Tom Montagu?)

 

N

 

5 minutes ago, stagedamager said:

The red J2 is in Harrier.

Harrier was Tom's boat.

[NB Alnwick]

2 hours ago, stagedamager said:

The red J2 is in Harrier.

Ah! the famous Montagu's Harrier

 

On some builds, the oval plate at the bottom is fitted with a dipstick tube for a flexible dipstick.