Rear Differential oil plug screw / sump plug screw
Discussion
Hi,
Again as a newbie to doing things on a car and with very little practical experience, I wanted to ask the following:
I'm going to change the oil in the rear differential, but this question also applies to the engine oil sump plug.
How important is it to change these plugs/screws?
I ask as it seems quite difficult to get, and the nearest car manufacturer dealership is quite far away from me to get them from them...
I get that it's better to change them, but am I looking at a world of pain if I just re-use the existing plugs?
Any help greatly appreciated!
Again as a newbie to doing things on a car and with very little practical experience, I wanted to ask the following:
I'm going to change the oil in the rear differential, but this question also applies to the engine oil sump plug.
How important is it to change these plugs/screws?
I ask as it seems quite difficult to get, and the nearest car manufacturer dealership is quite far away from me to get them from them...
I get that it's better to change them, but am I looking at a world of pain if I just re-use the existing plugs?
Any help greatly appreciated!
SlimJim16v said:
You don't change the plugs, just the copper/aluminium washer, though you can usually get away without changing that either.
When changing the diff oil, always make sure you can undo the filler plug before you drain the oil.
This - it is v impt if you don't want to end up with a non-functioning car. On the diff there are two plugs - one higher up and often harder to get to which is the fill plug and one lower which is the drain plug. If you drain it and then discover that you can't get the fill plug out...When changing the diff oil, always make sure you can undo the filler plug before you drain the oil.
Also make sure you can actually get oil into the diff - often a small pump is the best way as it can be hard/impossible to pour it in.
're the copper washers, if you can't find replacements you can re-anneal them which softens the copper and helps an old washer to seal. Clean the washer, rub a bit of soap on it and heat with a blowtorch until the soap turns black. Cool and reuse.
Good luck!
Good advice from don't look down, except.....
Rubbing soap on the metal is what you do to re-anneal aluminium after working it, as it work hardens and will fracture if worked again. Thin aluminium will soften and loose shape if heated too much, and the soap-charring heat is just right to anneal it.
Copper has a softening and melting temperature nearly twice that of aluminium. Just heat the washer over the gas (the kitchen one will do fine! Don't tell SWMBO!) until you see green in the flame, then let it cool down in air. Don't quench it in water or oil, no need.
There is a limit to the number of times you can do this, as each time the washer will be compressed and thinned.
John
Rubbing soap on the metal is what you do to re-anneal aluminium after working it, as it work hardens and will fracture if worked again. Thin aluminium will soften and loose shape if heated too much, and the soap-charring heat is just right to anneal it.
Copper has a softening and melting temperature nearly twice that of aluminium. Just heat the washer over the gas (the kitchen one will do fine! Don't tell SWMBO!) until you see green in the flame, then let it cool down in air. Don't quench it in water or oil, no need.
There is a limit to the number of times you can do this, as each time the washer will be compressed and thinned.
John
tapkaJohnD said:
Good advice from don't look down, except.....
Rubbing soap on the metal is what you do to re-anneal aluminium after working it, as it work hardens and will fracture if worked again. Thin aluminium will soften and loose shape if heated too much, and the soap-charring heat is just right to anneal it.
Copper has a softening and melting temperature nearly twice that of aluminium. Just heat the washer over the gas (the kitchen one will do fine! Don't tell SWMBO!) until you see green in the flame, then let it cool down in air. Don't quench it in water or oil, no need.
There is a limit to the number of times you can do this, as each time the washer will be compressed and thinned.
John
Many thanks for the correction. Senior moment. I knew there was something not quite right about the soap bit as I typed it, but couldn't remember what!Rubbing soap on the metal is what you do to re-anneal aluminium after working it, as it work hardens and will fracture if worked again. Thin aluminium will soften and loose shape if heated too much, and the soap-charring heat is just right to anneal it.
Copper has a softening and melting temperature nearly twice that of aluminium. Just heat the washer over the gas (the kitchen one will do fine! Don't tell SWMBO!) until you see green in the flame, then let it cool down in air. Don't quench it in water or oil, no need.
There is a limit to the number of times you can do this, as each time the washer will be compressed and thinned.
John
Before changing oils, engine gearbox axle whatever, its worth quickly inspecting the drain and filler plugs for signs of damage, if it looks like its seen abuse buy a new one because the damaged one won't improve and a few new washers at the same time for future servicing before starting the job, also if the car is a keeper and you change engine oils regularly yourself consider fitting a Fumoto or similar quick drain valve in place of the sump plug.
Worth investing in a set of 6 sided sockets, much less inclined to slip and ruin whatever you are trying to undo, impact sockets are 6 sided but tend to be much thicker so might not always fit where bolts/plugs/nuts are close to castings.
For car parts you don't need the dealer parts dept, all the years we've been running Subarus i've yet to visit the main dealer for anything, same goes for Toyota only needed the parts dept rarely, lots of genuine and good quality pattern parts available online.
Worth investing in a set of 6 sided sockets, much less inclined to slip and ruin whatever you are trying to undo, impact sockets are 6 sided but tend to be much thicker so might not always fit where bolts/plugs/nuts are close to castings.
For car parts you don't need the dealer parts dept, all the years we've been running Subarus i've yet to visit the main dealer for anything, same goes for Toyota only needed the parts dept rarely, lots of genuine and good quality pattern parts available online.
Edited by Smint on Sunday 27th February 07:23
Smint said:
Before changing oils, engine gearbox axle whatever, its worth quickly inspecting the drain and filler plugs for signs of damage, if it looks like its seen abuse buy a new one because the damaged one won't improve and a few new washers at the same time for future servicing before starting the job, also if the car is a keeper and you change engine oils regularly yourself consider fitting a Fumoto or similar quick drain valve in place of the sump plug.
Worth investing in a set of 6 sided sockets, much less inclined to slip and ruin whatever you are trying to undo, impact sockets are 6 sided but tend to be much thicker so might not always fit where bolts/plugs/nuts are close to castings.
For car parts you don't need the dealer parts dept, all the years we've been running Subarus i've yet to visit the main dealer for anything, same goes for Toyota only needed the parts dept rarely, lots of genuine and good quality pattern parts available online.
Thanks for the suggestions, but ive been on so many online parts websites, and finding what I need is very difficult. The problems i run into are, a) We seem to call things one way in normal speech, but the parts are actually called something else, so when searching you get nothing. B) manufacturer part numbers, when I have them, are meaningless on most part websites. C) little things like bolts and screws are next to impossible to get unless you use ebay, but they are more expensive than buying from a dealer!! Example, the 2 screws for the rear axle are between £7 and £9 on eBay, yet £5 from the dealer.Worth investing in a set of 6 sided sockets, much less inclined to slip and ruin whatever you are trying to undo, impact sockets are 6 sided but tend to be much thicker so might not always fit where bolts/plugs/nuts are close to castings.
For car parts you don't need the dealer parts dept, all the years we've been running Subarus i've yet to visit the main dealer for anything, same goes for Toyota only needed the parts dept rarely, lots of genuine and good quality pattern parts available online.
Edited by Smint on Sunday 27th February 07:23
So any help, to help me navigate these websites, or a particular seller that you recommend, would be invaluable. Thanks.
It's the large 'Grub Screw' types you need to be mindful of.
No Copper washers involved.
Often NPT Thread, so basically they seal by damaging the female thread form.
Don't nip them up enough- they weep.
Over tighten and it wrecks the female aluminium thread.
Always in a difficult place to use a Torque Wrench!
No Copper washers involved.
Often NPT Thread, so basically they seal by damaging the female thread form.
Don't nip them up enough- they weep.
Over tighten and it wrecks the female aluminium thread.
Always in a difficult place to use a Torque Wrench!
E-bmw said:
mickyh7 said:
Often NPT Thread, so basically they seal by damaging the female thread form.
Never come across an NPT sump plug.NPT is generally a plumbing fitting & needs PTFE tape to seal.
No PTFE required in a lot of cases.
BSP needs a collar and washer or will screw straight through.
I'm talking diffs and gearboxes not a sump plug as such.
Edited by mickyh7 on Tuesday 1st March 08:16
SlimJim16v said:
You don't change the plugs, just the copper/aluminium washer, though you can usually get away without changing that either.
When changing the diff oil, always make sure you can undo the filler plug before you drain the oil.
guess who watches M539 restorations on youtube?When changing the diff oil, always make sure you can undo the filler plug before you drain the oil.
mickyh7 said:
E-bmw said:
mickyh7 said:
Often NPT Thread, so basically they seal by damaging the female thread form.
Never come across an NPT sump plug.NPT is generally a plumbing fitting & needs PTFE tape to seal.
No PTFE required in a lot of cases.
BSP needs a collar and washer or will screw straight through.
I'm talking diffs and gearboxes not a sump plug as such.
I use it extensively at work offshore & I have never seen it used unless it has either PTFE tape or paste to create a seal as otherwise there is no seal as a male thread will not seal solely in a female thread due to engineering differences in manufacture.
It does not, as you say (in the uses I have come across) seal by deforming the female thread as that would result in cold-welding when used with Stainless steel (which pretty much all of ours is made of) due to the torque needed to deform the thread.
Hence why its stable-mate BSP with a similar thread form (apart from cut angle) uses deformable washer, shoulder o-ring, bonded seal or hose end-cone to seal.
Yes, I know the plug you are talking about, it says so in the post & title.
While I am not directly saying you are wrong, I cannot see what NPT would be used as you say because there would be no seal.
E-bmw said:
I know what NPT stands for, hence why I pointed out the link to its major use in plumbing (yes, including industrial plumbing) as in it is used primarily on threaded pipe & fittings.
I use it extensively at work offshore & I have never seen it used unless it has either PTFE tape or paste to create a seal as otherwise there is no seal as a male thread will not seal solely in a female thread due to engineering differences in manufacture.
It does not, as you say (in the uses I have come across) seal by deforming the female thread as that would result in cold-welding when used with Stainless steel (which pretty much all of ours is made of) due to the torque needed to deform the thread.
Hence why its stable-mate BSP with a similar thread form (apart from cut angle) uses deformable washer, shoulder o-ring, bonded seal or hose end-cone to seal.
Yes, I know the plug you are talking about, it says so in the post & title.
While I am not directly saying you are wrong, I cannot see what NPT would be used as you say because there would be no seal.
The amount of time you have spent typing should have been spent Googling!I use it extensively at work offshore & I have never seen it used unless it has either PTFE tape or paste to create a seal as otherwise there is no seal as a male thread will not seal solely in a female thread due to engineering differences in manufacture.
It does not, as you say (in the uses I have come across) seal by deforming the female thread as that would result in cold-welding when used with Stainless steel (which pretty much all of ours is made of) due to the torque needed to deform the thread.
Hence why its stable-mate BSP with a similar thread form (apart from cut angle) uses deformable washer, shoulder o-ring, bonded seal or hose end-cone to seal.
Yes, I know the plug you are talking about, it says so in the post & title.
While I am not directly saying you are wrong, I cannot see what NPT would be used as you say because there would be no seal.
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