It’s been a long time since I have had to buy oils for an old British car!
I am wanting to change both the rear axle oil and the engine oil… would have thought this would be an easy purchase, but seemingly not so.
Back in the 80s when I last played with these types of toys synthetic oil products were either not available or just not on my radar. For engine oil I would tend to use Castrol or Pennzoil 10W30… now I see they come in a number of flavors with detergents etc…
What’s the common knowledge these days for what to use in a 140 engine, and what to avoid?!
Same for the rear axle, manual says Hypoid 90… nothing on the shelf at my local store with quite that name, lots of 80W90s etc, API GL-5 or MT90 GL-4 Synthetic??
For the engine, I never operate it in the dead of winter, so I use SAE 10W-40 any of the major brands, I avoid generic store brands.
For the rear axle, SAE 80W-90 GL-5, again major brands and no winter running so no need for 70W.
a slippery slope…this topic…pun intended…lots of forum archive posts on oils…use the search magnify at top right…and you can web research and form your own opinion…I have done both…forum and web…so mine: viscosity improvers alter the actual oil…but aid in cold start up lubrication so a necessary evil. XKs tend to run hot…so 10-40 or 15-50…but…XK is a flat tappet cam and should have zddp in the engine oil… Some few are made with it…in the proper parts per million…you can add zddp but too much is also not good…so follow the mfg instructions for how much for how many qts of oil. Oil used to have zddp…most do not now as flat tappet cams are not used. Maybe more imptnt that brand or synthetic or not… of oil or weight is to have CLEAN oil…change frequently. I know…12-16 quarts. Diff does not require GL5…which did not even come about til much much later. Most gear oils now have the limited slip mix already in them…no harm done in a non LSD. Gearbox specified 30 wt engine oil. A caution on gearbox additve oils: some react badly with some gearbox metals…so my advice is do not use em: straight 30 wt. Brake fluid is normally Dot 3 or 4, may as well use 4 as its temp rating is highter, like Castrol GT LMA…(low moisture absorption)
Nick
A life-long Castrol user from the time I got my XK120 I switched when I learned that it no longer contained ZDDP. I have used Kendall GT1 20W50 because it does have the ZDDP additive for the past 20 years.
Dave…theres the usual opinions about zddp…being necessary…or whether there is some in modern oils…(there is…is some)j…so rather than take it from ol me…look it up on line…you will still find opinions…but fact is it used to be in oil…to treat the metal in pressure areas…and flat tappet cams…where the cam hits the flat tapped a bit harder than a roller cam. The 15-50 Mobil 1 oil has 1200 ppm already in it and is specified by Mobil for flat tappet cams. Other oils have some…some too much, some not enough…1200 is about right…Read this site…they did a LOT of research for flat tapped earlier corvettes." List of Flat-Tappet Oils - CorvetteForum - Chevrolet Corvette Forum Discussion
a quote is approx this…use the right amount of zddp and if you did not needed…no harm done, the oil cost of many is about the same. But if you don’t use it…and you did need it…the cost will be great to y our engine.
Many will say blah blah…snake oil…go to the website listed…or do your own web search…just type in…engine oil with zddp for classic cars or muscle cars or flat tappet cams.
Nick
Jaguar Factory Service Bulletin A6, January 1960…: says to this effect: with the many friction additives for oil that are now available, we remind that we do not recommend use of additives, especially important for axles and gearboxes where special oils for the metals are important.
Of course this was in 1960…zddp was in the oil, limited slip differentials not a factor. Toi this day I don’t know of a manufacturer that officially recommends any additives for new cars other than the limited slip modifier that is already in the oils they specify. However oil manufactures now produce hi mileage oils that have viscosity improvers for worn rings and seal conditioners that help swell the seals. Note re my prior about zddp that how much zddp is in oils varies a lot…so even in Mobil 1 for example…depending on WHICH Mobil 1 oil…the zddp level will vary. The 15-50 has the right amount for flat tappet cams, but many of the other grades have half that amount.
Nick
I’ve been doing lots of reading and digging through various manufactures sites. I had a couple of recommendations for the Shell Rotella but I just can’t get my head around putting diesel oil in my Jag!
I found the data on Mobil oils and it showed the different amounts of Zinc in their different products. I also found similar for Lucas oils which I finally went with as they are readily available to me. Interesting to note that the Lucas product I chose is their semi-synthetic 10W40 which has 1265ppm of Zinc, and is branded as their “high mileage” oil. They also have a trio of Hot Rod and Classic Car oils but they all have 2100ppm of Zinc which seems too much from what I have read.
For the rear axle I went with Red Line 75W90 GL5 synthetic as recommended on their website…
Good selections Dave. Rotella is for diesel…there are reasons not to use it, and one is simply that there are fine engine oils available for the Jaguar XK. Yes, different oils within a brand have different zddp as well as other formulas being different. 1100-1400 zddp is the range. The very hi zddp is for drag strip cars. (they blow up anyway…or are rebuilt between runs) I has posted this on the gearbox thread…re what to use: API **GL-4 lubricant designed for use with ‘yellow metals’ in synchronizers, thrust washers, bushings and other components typically found in classic manual transmissions and transaxles. BUT you do not want 75-90 wt…which nearly all GL 4 is in gear oil applications. There ARE 30 wt oils available now that meet the oil specs of the past while still being more heat resistant, anti sludge, but with the zinc and phosphorus of prior oils and are ok with the yellow metals…A Multi viscosity should not be used in the gear box as the viscosity improvers subject the oil to shear which is a problem in a gear box that has direct metal to metal contact. Jaguar specified single grade 30 wt. Castrol markets a “Classic XL” line of retro oils. Recommended for pre-1980 cars, their multi-grade 20W-50 is formulated with high-quality mineral oils plus selected additives for older technology and classic car ENGINES. Also in the “Classic XL” line is a 30W oil for pre-1950 vintage and classic cars. This mono-grade oil can also be used in most types of manually-operated GEARBOXES.
Nick
I am not as familiar with Millers products as mainly in UK…but a quick check of their website info: they offer: Millers Classic Differential Oil EP 90 GL5 for highly loaded hypoid transmissions requiring EP and GL5. OK with brass and bronze components. This would seem to be a very good selection. The axle oil specified by Jaguar was EP90. GL5 steps up the technology and is still fine to use.
GL4 is the first serious level of EP performance and is specified for many gearboxes and final drives from mid 1930’s onwards. Millers produces the following GL4 oils: Millers Classic Gear Oil EP 80w90 GL4
GL5 specification is for highly loaded hypoid differentials as fitted to most cars from 1960 onwards. Millers offer the following GL5 oils: Millers Classic Differential Oil EP 90 GL5,
Jaguar said in the Handbook, .and it is true today…Hypoid oils of different brands and even within brands, may not mix well, a drain, (or suction pump out) and flush (I would flush with the same oil you are going to use in the refill) and refill is advisable. (and every 10K miles)
Jaguar later issued a service bulletin, (#75 which reads: " It is particularly important to note that certain additives are INCLUDED in hypoid lubricants to give extreme pressure characteristics which are essential… The addition of OTHER oils or substances of any nature will cause separation of these additives and will completely DESTROY the lubricating quality of the oil. Under these conditions…where there is any evidence of oil other than the recommended lubricant…no question of guarantee will be entertained." the capital letter emphasis is mine.
Nick
in another forum thread on “difficult Moss gearbox” we have discussed gearbox oil. Millers (UK) makes a engine oil suitable for the XK Moss gearbox oil 30wt., safe for yellow metals. moderate detergent, Miller Pistoneeze 30 wt. There are likely other mfgs for classics that have similar.
Nick
digging up an old thread!
the Lucas High Mileage 10W40 oil that I put in is semi-synthetic. I’ve heard all sorts of bad things about using synthetic oils in old engines, not really sure where the “semi” class stands!
Only @ 200kms into the new oil and I have developed some odd noises! not sure, but I believe they are valve related. Show up @ 5 or 10 mins into a drive, once the engine temp has hit @ 70 deg, rattling noises of varying volume and speed, seemingly unrelated to forward motion, ie if the car is moving fast or slow, and also not really related to engine revs! just a strange rattle that pops up and goes away and sometime comes back… have been all through the engine, suspension ,brakes, exhaust etc looking for something loose - originally thought it might be tach cable but seems a little too noisy for that… strong pulls up steep hills do not exhibit any valve rattle…
Also - separately or related? - are fuel quality issues… I have been running Shell 91 as here in Canada there is not a lot of choice for fuel without ethanol, the other and preferred is Chevron 94, its just not sold in my town! So the tank currently has a blend of last years fuel, which had stabilizer added for the winter, and a 50% refill this year with fresh same fuel. I was having run-on issues shutting off the engine after 30 mins or so of driving…had previously rebuilt carbs, dizzy, done timing, dwell, etc so felt pretty confident about that side. added a bottle of Lucas Octane Boost - problem solved… but now the rattle showed up…
So is it bad oil choice, need something better to lube the valves? or is it bad fuel? thinking of draining the tank, refilling with fresh Chevron 94, see where that gets me; just also worrying about leaving the semi-synthetic oil in, should I be draining & changing the oil?
