'Hiss' From the Diff....
Discussion
I thought I’d check my oil level in the diff the other day as I can get the odd drip after a long run.. It did need about an eggcup full to get it back to the level so nothing much there… (5K miles since last done)
But when I removed the filler plug, I got a 'Hiss' from it… Not sure if it was air out or air going in (suspect the latter as there was no smell and Diff oil does pong a bit)
So checked the air vent… It’s a small brass thing towards the driver’s side with a spring loaded cap on it… I could not remove the cap so could not gain access to any holes etc… or is it a valve may be?..
The oil drip had not come from here so some pressurisation in use is occurring and it’s getting past the seals a tad… The cars been stood since November so it’s held the pressure / vacuum all that time.
I tried to unscrew the breather thing to get it out to have a look but it didn’t want to move… and with it being brass and me being a hand fisted sod… I didn’t want to try too hard and snap it off..
Does anyone know what it is… Is it just a hole under here… why is the cap spring loaded.. or is it some sort of valve?
My car is a 1999 so has the latter diff in there but not sure of the make…
But when I removed the filler plug, I got a 'Hiss' from it… Not sure if it was air out or air going in (suspect the latter as there was no smell and Diff oil does pong a bit)
So checked the air vent… It’s a small brass thing towards the driver’s side with a spring loaded cap on it… I could not remove the cap so could not gain access to any holes etc… or is it a valve may be?..
The oil drip had not come from here so some pressurisation in use is occurring and it’s getting past the seals a tad… The cars been stood since November so it’s held the pressure / vacuum all that time.
I tried to unscrew the breather thing to get it out to have a look but it didn’t want to move… and with it being brass and me being a hand fisted sod… I didn’t want to try too hard and snap it off..
Does anyone know what it is… Is it just a hole under here… why is the cap spring loaded.. or is it some sort of valve?
My car is a 1999 so has the latter diff in there but not sure of the make…
TVR Beaver said:
I thought I’d check my oil level in the diff the other day as I can get the odd drip after a long run.. It did need about an eggcup full to get it back to the level so nothing much there… (5K miles since last done)
But when I removed the filler plug, I got a 'Hiss' from it… Not sure if it was air out or air going in (suspect the latter as there was no smell and Diff oil does pong a bit)
So checked the air vent… It’s a small brass thing towards the driver’s side with a spring loaded cap on it… I could not remove the cap so could not gain access to any holes etc… or is it a valve may be?..
The oil drip had not come from here so some pressurisation in use is occurring and it’s getting past the seals a tad… The cars been stood since November so it’s held the pressure / vacuum all that time.
I tried to unscrew the breather thing to get it out to have a look but it didn’t want to move… and with it being brass and me being a hand fisted sod… I didn’t want to try too hard and snap it off..
Does anyone know what it is… Is it just a hole under here… why is the cap spring loaded.. or is it some sort of valve?
My car is a 1999 so has the latter diff in there but not sure of the make…
Its a vent - to stop pressure building up when the temp heats up. Didnt think it was sprung though....or brass come to think of it. I thought it was just a cap that was held down by gravity but any pressure build up was enough to lift the cap...?But when I removed the filler plug, I got a 'Hiss' from it… Not sure if it was air out or air going in (suspect the latter as there was no smell and Diff oil does pong a bit)
So checked the air vent… It’s a small brass thing towards the driver’s side with a spring loaded cap on it… I could not remove the cap so could not gain access to any holes etc… or is it a valve may be?..
The oil drip had not come from here so some pressurisation in use is occurring and it’s getting past the seals a tad… The cars been stood since November so it’s held the pressure / vacuum all that time.
I tried to unscrew the breather thing to get it out to have a look but it didn’t want to move… and with it being brass and me being a hand fisted sod… I didn’t want to try too hard and snap it off..
Does anyone know what it is… Is it just a hole under here… why is the cap spring loaded.. or is it some sort of valve?
My car is a 1999 so has the latter diff in there but not sure of the make…
Not sure what the hiss could have been other than, as you say, either air going in or out?
If that is the case it would seem to suggest that the vent is blocked though?
if it snaps then u r in trouble...diff will still work but vent will just be open? Diff out is better with two of you but still ok on your own. Depends on how easily the bolts un do. Main issue when its out is the jobs that are recommened when its out...seals, bushes, etc. Hope u get it sorted
It is a spring loaded cap.
Think tyre vavle, covered with a light tin cap cap which is sprung loaded. Inside is a small rubber washer and very light spring. Should be that difficult to get out and unlikely to snap off unless you have ham fists.
Usually take mine out when topping up or changing diff oil. It can be taken apart by gently bending the cap, but beware of the spring inside and rubber washer.
Wash it in some petrol and when you re-fit the cap make sure to re-crimp no tighter than original to allow it the movement it needs.
Think tyre vavle, covered with a light tin cap cap which is sprung loaded. Inside is a small rubber washer and very light spring. Should be that difficult to get out and unlikely to snap off unless you have ham fists.
Usually take mine out when topping up or changing diff oil. It can be taken apart by gently bending the cap, but beware of the spring inside and rubber washer.
Wash it in some petrol and when you re-fit the cap make sure to re-crimp no tighter than original to allow it the movement it needs.
Johno said:
It is a spring loaded cap.
Think tyre vavle, covered with a light tin cap cap which is sprung loaded. Inside is a small rubber washer and very light spring. Should be that difficult to get out and unlikely to snap off unless you have ham fists.
Usually take mine out when topping up or changing diff oil. It can be taken apart by gently bending the cap, but beware of the spring inside and rubber washer.
Wash it in some petrol and when you re-fit the cap make sure to re-crimp no tighter than original to allow it the movement it needs.
So it is a valve... and I guess letting air out so the Hiss could be the partial vacuum it makes as it cools down... good how it's held it all this time though!... so it may be working okay.... then no need to snap it off.... I mean remove it Think tyre vavle, covered with a light tin cap cap which is sprung loaded. Inside is a small rubber washer and very light spring. Should be that difficult to get out and unlikely to snap off unless you have ham fists.
Usually take mine out when topping up or changing diff oil. It can be taken apart by gently bending the cap, but beware of the spring inside and rubber washer.
Wash it in some petrol and when you re-fit the cap make sure to re-crimp no tighter than original to allow it the movement it needs.
'Ham Fists' Had to get a new torque wrench to do the lower ball joint bolts as thoes M8 just keep on going!! snap!
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