Being a believer in frequent oil changes, I’m dissatisfied with Jaguar’s ‘Filled for life’ philosophy on gearbox and differential - as I’m sure many of you are.
As I’m planning to keep my ‘99 XK8 coupe for some time (It’s now covered 68,000 miles), I always change the engine oil/filter every 6 months, had the gearbox drained and replenished at 50,000 miles and now want to get the diff similarly serviced.
To that end, I’m mulling over the idea of drilling / tapping the casing’s lower face so that a drain plug can be installed.
My main questions are:–
1/ Has anyone done this – and if so, what advice can be given?
2/ What size drain plug and/or thread is recommended?
3/ What part of the unit’s base would be the best position for this.
4/ What’s the consensus on replenishment type of hypoid oil?
Naturally, the main concern is drill swarf being trapped in the housing.
In theory, most should drain out with the contents, on drill ‘break through’.
I guess the bigger the hole, the easier it will be to poke around inside with a piece of grease-covered wire, once the unit has drained - and then squirt flushing oil ‘up ‘er chuff’ to finally clear any debris after tapping.
I’ll probably wirelock the plug as it will not be touched very often.
I’m posting this on both the JEC and Jag-lovers fora – as there’s a wealth of experience from you canny Jagnuts – (all probably screaming “No. No. No!”)!
Your collective thoughts – and thanks in advance!
Michael
Diff drain plug.
Moderators:MarkX, mike020150
Would be easier to buy a 2nd hand diff and experiment surely? They normally change hands for £200-300 on Ebay.
Also what type of mileage are you doing to substantiate the 6 month oil change, also what type of oil?
Reason I ask is that most good quality synthetic oil doesn't reach it's optimal efficiency until after 3k miles. I switched to Royal Purple 5w30 fully synth 2yrs ago along with a change of oil filter from OEM to Purolator Not only did my fuel economy (albeit from tripometer) improve from 32MPG to 37MPG on the same journey/speed/temperatures, but also regular oil analysis by Blackstone laboratories showed that my oil had still retained it's anti-shear properties well in excess of 10k miles (and certainly better than the magnatec at 5k miles). So there is a school of thought that you should simply look to use a better qulity of motor oil.
I should point out the prior to the change from Dealer magnatec (semi synth) I ran a treatment dose of Auto-RX through the engine. After the change of oil and 5k miles I took it for a service to my local specialist who actually thought that I'd had a new engine dropped in since he saw it last time!
Now I've been LPG converted for 18 months the oil also retains it colour (but this isn't actually that important) since there's not the carbonisation, I now only do an oil change every 10k miles.
Car's just done 100k miles so am going for a tranny fluid change shortly (since I only paid £30 for 17l of the correct jag fluid)
Mark
Also what type of mileage are you doing to substantiate the 6 month oil change, also what type of oil?
Reason I ask is that most good quality synthetic oil doesn't reach it's optimal efficiency until after 3k miles. I switched to Royal Purple 5w30 fully synth 2yrs ago along with a change of oil filter from OEM to Purolator Not only did my fuel economy (albeit from tripometer) improve from 32MPG to 37MPG on the same journey/speed/temperatures, but also regular oil analysis by Blackstone laboratories showed that my oil had still retained it's anti-shear properties well in excess of 10k miles (and certainly better than the magnatec at 5k miles). So there is a school of thought that you should simply look to use a better qulity of motor oil.
I should point out the prior to the change from Dealer magnatec (semi synth) I ran a treatment dose of Auto-RX through the engine. After the change of oil and 5k miles I took it for a service to my local specialist who actually thought that I'd had a new engine dropped in since he saw it last time!
Now I've been LPG converted for 18 months the oil also retains it colour (but this isn't actually that important) since there's not the carbonisation, I now only do an oil change every 10k miles.
Car's just done 100k miles so am going for a tranny fluid change shortly (since I only paid £30 for 17l of the correct jag fluid)
Mark
-
mike020150
- Posts:3469
- Joined:Wed Feb 08, 2006 6:26 pm
Hi Michael, If you want to change the oil, rather than risk introducing swarf to your car's differential why don't you experiment by seeing how much oil you can suck out with some narrow bore plastic tubing? Even if you don't get all the oil out, a partial change would remove some wear particles and would result in an improvement in oil condition. According to Jaguar, XKs were filled with 1.9 litres of Shell Spirax Super TS90 oil. Mike.
Diff drainplug
Some good points/responses, gentlemen. Many thanks.
Engine oil: I’m using second-hand tractor oil, as it’s really cheap.
I jest. Normally I change the 10w-40 semi-synthetic GM stuff every 3 - 4K miles but your Royal Purple figures sound impressive, Mark. I might look into that.
Differential: I figure as the oil has been cooking in an alloy box for ten years, moisture is hygroscopically absorbed and under extreme gear pressures metal wear slowly takes place – so a good thing would be to dump it very occasionally. I used to do it on Boeing / Rolls Royce / Pratt & Chutney etc. transmissions, so I assume it’s no bad thing.
Have already considered your idea, Mike but the main drawback is the heavy viscosity – it needs to be done whilst hot, I guess - but may not pick up minute metal particles at the base.
Meantime, I’ll open a bottle of Shiraz low-viscosity gut flush and mull it over.…
Michael
Engine oil: I’m using second-hand tractor oil, as it’s really cheap.
I jest. Normally I change the 10w-40 semi-synthetic GM stuff every 3 - 4K miles but your Royal Purple figures sound impressive, Mark. I might look into that.
Differential: I figure as the oil has been cooking in an alloy box for ten years, moisture is hygroscopically absorbed and under extreme gear pressures metal wear slowly takes place – so a good thing would be to dump it very occasionally. I used to do it on Boeing / Rolls Royce / Pratt & Chutney etc. transmissions, so I assume it’s no bad thing.
Have already considered your idea, Mike but the main drawback is the heavy viscosity – it needs to be done whilst hot, I guess - but may not pick up minute metal particles at the base.
Meantime, I’ll open a bottle of Shiraz low-viscosity gut flush and mull it over.…
Michael
Hello Michael,
What a bloody good topic, how to change the diff oil!
I have a 1998 XK8 convertible and had the same thought, but after having a look the job seems impossible. As you say there is no drain plug, but for me the greater issue getting fresh oil in. I cannot touch the fill/level plug due to re-inforcement bars in the way.
This strikes me as another bean counter engineering decision,as the only way to do the job is to take the diff off, ... bonkers.
If any one with a similar car has done this I'd love to hear how you did it.
Doug Barrass,
Ashford, Kent.
What a bloody good topic, how to change the diff oil!
I have a 1998 XK8 convertible and had the same thought, but after having a look the job seems impossible. As you say there is no drain plug, but for me the greater issue getting fresh oil in. I cannot touch the fill/level plug due to re-inforcement bars in the way.
This strikes me as another bean counter engineering decision,as the only way to do the job is to take the diff off, ... bonkers.
If any one with a similar car has done this I'd love to hear how you did it.
Doug Barrass,
Ashford, Kent.
Differential drain plug.
Differential drain plug.
Well, I said I might - and now (shock, horror…), I’ve been an’ gone an’ done it.
I made and installed a drain plug/filler in my ’99 XK8’s final drive and changed the oil.
The plug has a check-valve and utilises a screw-in adaptor for filling.
Of interest, the old oil was not that dirty but the ‘floor’ of the diff had a VERY thick gooey layer on it. (72,000 miles).
Total outlay for drill, tap & oil was £21.50 and a I’ll attempt to post the write-up and pics, but don’t hold your breath – you’re talking Old Twonk here….
Next month: Nailing jelly to the ceiling.
Michael
Well, I said I might - and now (shock, horror…), I’ve been an’ gone an’ done it.
I made and installed a drain plug/filler in my ’99 XK8’s final drive and changed the oil.
The plug has a check-valve and utilises a screw-in adaptor for filling.
Of interest, the old oil was not that dirty but the ‘floor’ of the diff had a VERY thick gooey layer on it. (72,000 miles).
Total outlay for drill, tap & oil was £21.50 and a I’ll attempt to post the write-up and pics, but don’t hold your breath – you’re talking Old Twonk here….
Next month: Nailing jelly to the ceiling.
Michael
-
mike020150
- Posts:3469
- Joined:Wed Feb 08, 2006 6:26 pm
Diff drain plug - the movie..
As requested – here’s my differential drain plug mod info.
The unit has 3 parts: Plug body. (Brass ½” BSP – all I could find in my gash box - would have preferred smaller/metric). A blanking plug and a filling adaptor. (See below for photo info link).
The plug body is drilled/threaded right through 12mm and has a ½” ball bearing in the inner (wider) recess to act as a refill check-valve. (If you’ve every changed an XK8 front wheel bearing, you should have a good supply of these balls…). The ball is ‘caged’ in a countersunk recess which allows a little upward movement under refill pressure. I used two 4mm grub screws to trap the ball.
The blanking plug is made from a shortened 12mm bolt with a small magnet bonded to the threaded end. This holds and magnetises the ball which hopefully might collect any stray ferrous particles.
I made the filling adaptor from the remaining portion of the 12mm bolt, which is drilled right through 7.5mm to accept a suitable tight-fitting length of neoprene hose. The adaptor screws into the body with an outer stop-nut and seal to prevent leaks when filling. The ‘inner’ end was grooved to allow oil flow if it jams on the ball valve.
I had originally planned to put the plug in line with the existing central hole in the diff mounting plate but found the final drive has a 7mm stiffener ridge cast right where I wanted to put it! So……
FAINT-HEARTED LOOK AWAY NOW….
With the car on ramps I drilled a 30mm access hole in the triangular plate to which the differential is bolted. Next I drilled a 6mm pilot hole through the (steel - I’d assumed aluminium) - diff lower casing. The oil ran out easily although cold and was not too dirty. I drilled/reamed the hole out to 3/4”/19mm and tapped it ½” BSP. (Actual thread size is 7/8” X 14tpi). The internal threaded area was cleaned up with a riffler file and I used a magnet to remove any swarf.
After facing the diff’’s plug mating area with an end mill I screwed in the brass plug body and ‘O’ ring. Attaching the filling adaptor and plastic pipe, I gravity-fed a litre of flushing oil into the unit. With the blank plug in place I gently drove/reversed the car up and down the drive for a minute, making tight turns - to ensure the pinions and planetary gears were all treated to an oily wash - and then removed the whole plug assembly and let it drain overnight.
Filling was straightforward: Back on the ramps, I installed the plug body using an ‘O’ ring and Loctite, screwed in the adaptor nipping up its stop-nut/seal. Connecting the Shell TS-90 container and plastic tubing, I transferred 1.9 litres into the diff and then removed the adaptor.
Only one drop passed the check-valve. Once the blanking plug was fitted and locked, I lowered the car and test-drove the beast. All seems well.
Note: The corroded plate bolts seen in the photographs have since been replaced!
Photos can be found (I hope!) on:
http://img151.imageshack.us/slideshow/p ... 124pt.smil
Bit long-winded - sorry!
Michael
The unit has 3 parts: Plug body. (Brass ½” BSP – all I could find in my gash box - would have preferred smaller/metric). A blanking plug and a filling adaptor. (See below for photo info link).
The plug body is drilled/threaded right through 12mm and has a ½” ball bearing in the inner (wider) recess to act as a refill check-valve. (If you’ve every changed an XK8 front wheel bearing, you should have a good supply of these balls…). The ball is ‘caged’ in a countersunk recess which allows a little upward movement under refill pressure. I used two 4mm grub screws to trap the ball.
The blanking plug is made from a shortened 12mm bolt with a small magnet bonded to the threaded end. This holds and magnetises the ball which hopefully might collect any stray ferrous particles.
I made the filling adaptor from the remaining portion of the 12mm bolt, which is drilled right through 7.5mm to accept a suitable tight-fitting length of neoprene hose. The adaptor screws into the body with an outer stop-nut and seal to prevent leaks when filling. The ‘inner’ end was grooved to allow oil flow if it jams on the ball valve.
I had originally planned to put the plug in line with the existing central hole in the diff mounting plate but found the final drive has a 7mm stiffener ridge cast right where I wanted to put it! So……
FAINT-HEARTED LOOK AWAY NOW….
With the car on ramps I drilled a 30mm access hole in the triangular plate to which the differential is bolted. Next I drilled a 6mm pilot hole through the (steel - I’d assumed aluminium) - diff lower casing. The oil ran out easily although cold and was not too dirty. I drilled/reamed the hole out to 3/4”/19mm and tapped it ½” BSP. (Actual thread size is 7/8” X 14tpi). The internal threaded area was cleaned up with a riffler file and I used a magnet to remove any swarf.
After facing the diff’’s plug mating area with an end mill I screwed in the brass plug body and ‘O’ ring. Attaching the filling adaptor and plastic pipe, I gravity-fed a litre of flushing oil into the unit. With the blank plug in place I gently drove/reversed the car up and down the drive for a minute, making tight turns - to ensure the pinions and planetary gears were all treated to an oily wash - and then removed the whole plug assembly and let it drain overnight.
Filling was straightforward: Back on the ramps, I installed the plug body using an ‘O’ ring and Loctite, screwed in the adaptor nipping up its stop-nut/seal. Connecting the Shell TS-90 container and plastic tubing, I transferred 1.9 litres into the diff and then removed the adaptor.
Only one drop passed the check-valve. Once the blanking plug was fitted and locked, I lowered the car and test-drove the beast. All seems well.
Note: The corroded plate bolts seen in the photographs have since been replaced!
Photos can be found (I hope!) on:
http://img151.imageshack.us/slideshow/p ... 124pt.smil
Bit long-winded - sorry!
Michael
Hello Michael,
10/10 for bravery my boy!!, and an ingeneous solution.
Like the slide show, but is there any chance you might put the pictures in the gallery so that I (and others?) can study them slow time?
Also, a thought for the forum, is there an enterprising professional out there who might offer a fitting package for the job?
Doug Barrass
Ashford, Kent.
10/10 for bravery my boy!!, and an ingeneous solution.
Like the slide show, but is there any chance you might put the pictures in the gallery so that I (and others?) can study them slow time?
Also, a thought for the forum, is there an enterprising professional out there who might offer a fitting package for the job?
Doug Barrass
Ashford, Kent.
Differential drain plug.
Thanks, Doug.
I tried to put the pics in the gallery - but being a bit of an old twonk, was not successful... However, I'll have another crack at it shortly.
A possible (simpler?) method might be to put in an engine-type drainplug and refill via the breather unit on the top - but it looks a tad restricted for tools unless a trained mouse is available.
Go on - have a bash!
Michael
I tried to put the pics in the gallery - but being a bit of an old twonk, was not successful... However, I'll have another crack at it shortly.
A possible (simpler?) method might be to put in an engine-type drainplug and refill via the breather unit on the top - but it looks a tad restricted for tools unless a trained mouse is available.
Go on - have a bash!
Michael
Re: Diff drain plug.
Hello everybody.
I like to take my time, so 9 years later I have changed the fluid in my differential. And my question is, does anybody know the torque setting for the drain plug? I can't find an answer anywhere on my TIS disc.
I didn't start out with the aim of changing the fluid, I started out with a failed fuel pump... All those words on the TIS about how to do the job could just as well say "Remove complete rear suspension in order to remove the fuel tank". I'm glad I did as even with full and easy access to the fuel pipes above where the diff would have been it was still a struggle. How people get the fuel pipes out with the diff in place I do not know.
Anyway with the diff removed I rolled it over on wooden blocks so that the plug was at the bottom and took out the drain plug.
Doug Barrass,
Ashford, Kent.
I like to take my time, so 9 years later I have changed the fluid in my differential. And my question is, does anybody know the torque setting for the drain plug? I can't find an answer anywhere on my TIS disc.
I didn't start out with the aim of changing the fluid, I started out with a failed fuel pump... All those words on the TIS about how to do the job could just as well say "Remove complete rear suspension in order to remove the fuel tank". I'm glad I did as even with full and easy access to the fuel pipes above where the diff would have been it was still a struggle. How people get the fuel pipes out with the diff in place I do not know.
Anyway with the diff removed I rolled it over on wooden blocks so that the plug was at the bottom and took out the drain plug.
Doug Barrass,
Ashford, Kent.
-
mike020150
- Posts:3469
- Joined:Wed Feb 08, 2006 6:26 pm
Re: Diff drain plug.
I've never seen a torque figure quoted for the filler plug. It's only resisting splashing oil so firm tightening to ensure it doesn't come undone is all that's necessary. Mike.
2014 XK Dynamic R convertible; 1977 Daimler Double Six Coupe; 2023 XE AWD 300S
Who is online
Users browsing this forum: No registered users and 1 guest