fluid flywheel diagnostics

[john fox]

Can anyone help with diagnosis of a Fox symptom which is possibly:

a) driver error (poor gear change technique):cry:; or

b) fluid flywheel ; or

c) gearbox band adjustment (not again!!):argh:

when changing up from 4th to 5th last weekend initial engagement was then followed by a subsequent noticeable late surge in power as though either the bands initially slipped before fully engaging or there was slippage from the flywheel in only one gear ?

 

please note that:

a) I have not checked the fluid level in the flywheel (will do so this weekend)

 

b) I have been experiencing pooling of a clean fluid under the drivers seat for some months now which I initially thought was just rainwater finding its own level in the hull but it does seem homogenously oily/yellowish rather than assorted hull crud floating on water.

It can't be gearbox or bevel box leakage/breathing as that would be black oil?

 

c)The rad needs topping up after each run but the fluid is not blue (my AF is) and, although very thin, the leaked fluid does feel oily.

 

d) the brake header tank needed total topping up (remember its OM13 on a Fox not brake fluid) but this was probably a weep from a flare joint which I fixed before the last drive and has not needed top up since

[sirhc]

John,

 

5th gear is not a brake band, but a clutch, so probably not band adjustment. It sounds like you may have a leak, the flywheel oil looks like water but it feels a bit different. First thing I'd do is check the level in the flywheel, if it's low then it sounds like that could be the problem.

 

Chris

[Richard Farrant]

Can anyone help with diagnosis of a Fox symptom which is possibly:

a) driver error (poor gear change technique):cry:; or

b) fluid flywheel ; or

c) gearbox band adjustment (not again!!):argh:

when changing up from 4th to 5th last weekend initial engagement was then followed by a subsequent noticeable late surge in power as though either the bands initially slipped before fully engaging or there was slippage from the flywheel in only one gear ?

 

 

 

John,

 

Have you got up to enough road speed before going into 5th? Assuming the flywheel level is OK. Could be adjustment on 5th, you would have to check out the box, under the lid.

Edited May 12, 2009 by Richard Farrant

[john fox]

John,

 

Have you got up to enough road speed before going into 5th? Assuming the flywheel level is OK. Could be adjustment on 5th, you would have to check out the box, under the lid.

 

:thanx:was doing 25 -30 mph when going up. Revs possibly at bit low at around 3K

 

will post back after the weekend when had look at fluid levels. I'm getting rather good at stripping out Fox innards now to get to that :argh: gearbox

[Topdog]

Having done the fluid flywheel seal on a Ferret - Oh God, I do not envy you!

Good Luck

 

unfortunately, the symptoms are very similar.

[Grasshopper]

It shouldn't be band (or 5th gear clutch) adjustment in the box as we set them up using the figures you had (from Richard?) using your vernier. It's more likely to be flywheel oil level as this is sometimes more noticeable in high gears (it was on old busses I used to work on).

 

Re rad coolant loss, is the amount of coolant loss just from expansion or a greater amount? If you do have a leak, it could be anywhere.... I just found that both threaded core plugs an our Spartan engine cylinder head leak. The blue anti-freeze residue was a dead giveaway, plus the fact that a couple of spark plugs had pools of coolant around them! (Did show that a couple of plugs were a wee bit loose though).

[Richard Farrant]

:thanx:was doing 25 -30 mph when going up. Revs possibly at bit low at around 3K

 

will post back after the weekend when had look at fluid levels. I'm getting rather good at stripping out Fox innards now to get to that :argh: gearbox

 

John,

 

That might be a bit of a low speed to change up to 5th. I never looked at speed or revs when driving, better doing it by feel and sound. The uparmoured Saracen was a bad one for slipping when going into top, it had to be going as fast as posssible in 4th, before an upchange. After reading Vince's post, now remember that I gave you the settings, so probably rule out adjustment then.

 

One thing to bear in mind with fluid flywheels, do not let them slip, by staying in a high gear at too low a speed, this is a sure way to overheat the oil and burn a seal out.

[Grasshopper]

To add to that only check the level when cold, and ensure that the drain plug is at the top (12 o'clock position) when you undo it as there can still be pressure in it. I was not informed of this as an apprentice, much to hilarity of the rest of the depot staff as i got covered in stinky flywheel oil from a coach.

[john fox]

cheers Guys :iloveyou:

 

I suspect driver error :cry: has come back to haunt me :sweat:as i do tend to stay in high gears too long (a petrol saving habit carried over from my car driving technique)

 

The book does suggest fywheel slippage starts from 5th and works down but I thought I'd check with the experts first

 

re coolant not too worried about this as fairly sure it's just normal expansion but I'm not sure (through gross ignorance) where it's venting to yet!

 

as for engine sound on gear change the screams it gives out above 3.5k revs are scary (I am NOT a boy racer and don't go there in my car) but it's not a car and i suspect I do need to rev harder before changing. Assuming i don't totally trash it before grasshopper's next session of TLC I might just have mastered it by next season

[Grasshopper]

I found that our CVRT needed to be taken to 3200-3400 rpm in 6th before it would pull in 7th (top gear). Our J60 engine really seems to pick up at around 3200 rpm. Having looked at a few Jaguar forums, that seems to be the way of these engines.

[Richard Farrant]

as for engine sound on gear change the screams it gives out above 3.5k revs are scary (I am NOT a boy racer and don't go there in my car) but it's not a car and i suspect I do need to rev harder before changing.

 

John,

 

It is more a question of getting up to the correct speed to suit the next selected gear, if the gear is engaged before that speed is attained then this is where you will sense the slip in the top gear clutch.

[sirhc]

John,

 

I have found that the gear changes are always better at higher revs. It may be that your water loss is through the pressure relief valve on top of the header tank. If you ever take the rear armour off there should be a small hose attached to this which is then attached to the alternator with a P clip. Any water which comes out here goes down the rear armour and collects in the bottom of the hull.

 

Chris

[john fox]

thanks again guys

 

one further thought, is there a way to manually turn the flywheel over to expose the filler plug without having to use trial and error by flicking the starter (rather not ruin my batteries and I don't have a starting handle - I assume Ferret does not fit)

 

got my Beaulieu acknowledgement today so the pressure is on to master this beast

[sirhc]

John,

 

Marcus Glenn had Fox starting handles. A Ferret one does fit if you have the rear armour off. You can carefully turn the flywheel with a screw driver if you stick it in through the opening near the starter motor.

 

Chris