Specialist cars require specialist fluids, so when esteemed photographer Chris Wallbank's Cayman GT4 needed some life blood for its Gearbox, we were on hand to lend assistance in the form of Motul's Gear 300 LS 75W-90

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With the summer months fast approaching and a couple of track days planned in the GT4, it was time to get thinking about getting the alignment/ geometry checked and a gearbox oil change done. As far as I could tell from the service history of the car the last four-wheel alignment was last done on the car’s 2nd service nearly three years ago, and I can only assume the car’s gearbox hadn’t been changed since 2019 at 9000 miles when the complete gearbox was replaced as part of a GT4 recall concerning cars built-in in 2016 due an issue with 3rd gear. There was no record of it being changed, and this wasn’t surprising, considering Porsche servicing guidelines only specify a gear change every 120,000 miles or ten years! I personally think this is crazy on a ‘GT’ model considering the high-performance nature of these cars and that they are most certainly going to have to be driven hard on track at certain points in their life. I couldn’t be sure whether my example has been on track or driven hard, so for peace of mind, a gearbox & diff oil change was essential. 



Having moved house in recent years to North Yorkshire, I was curious to find out what Porsche specialists fellow local Porsche owners were using for regular maintenance work in my area. I was keen to keep the GT4’s full main dealer service history intact as this seems to be a future selling point for GT models, but going forward, I wanted to find a Porsche specialist I could trust for intermediate maintenance in between servicing on the GT4, along with the Boxster S.

At recent meets at The Motorist, one name seemed to keep popping up time after time, and that was RPM Specialist Cars in Knaresborough (near Harrogate). I had always been aware of them and heard nothing but positive reviews from what seems to be a very loyal customer base, but until now, I’ve always been that little bit too far away to consider them for regular maintenance. Directors Andy and Nick have over 40 years of Porsche experience between them. Both being ex-Porsche trained technicians before setting up RPM in 2004 I knew the GT4 was going to be in safe hands. 



Once I’d had a chat with Andy Meeking and got the GT4 booked in for the gearbox oil change and geometry, I was curious to find out what gearbox oil other 981 GT4 owners were using and if there were any tried and tested potentially superior alternatives to the standard factory fill Mobil 1 Mobilube. After a lot of digging both on UK forums and US forums and cross-checking part numbers, it became clear that the specified oil used by Porsche dealers in the GT4 is the same as all other 981 manual gearboxes, which came as a bit of a surprise, as I thought Porsche may specify the higher grade of oil for the limited slip diff gearbox in the GT4 which significantly produces more torque and power than any other 981 model.


I wanted to find an oil that would give the highest level of protection and had qualities that prevented degradation over numerous high heat cycles. The most popular alternative seemed to be Motul’s Gear 300 LS oil, rated very highly amongst owners who use frequently use their GT4 on track and formulated specifically for high-performance cars with limited slip diffs. Looking into the spec further, this oil also has 0% sheer loss, making it unshearable [No loss of viscosity] in extreme track conditions with very high lubricating power to help decrease friction and wear on the gearbox. 


The only problem being was it proved tricky to actually find some of the Gear 300 oil in stock in the UK due to high demand, but luckily Octane Distribution had a full range of Motul products in stock and enough Gear 300 LS for the job. A brief chat on the phone with Richard Fearn from Octane assured me that due to the unique qualities of this gear oil, it will remain fluid at low temperatures, not changing any gearbox characteristics but also helping reduce any transmission noise & whine (Something that GT4’s are known for with the everything being so close to the driver just behind the seats).  Octane shipped the Gear 300 oil up to RPM on a next-day delivery in readiness for maintenance. 



On arrival at RPM Specialists, I had a warm welcome from Andy Meeking, who showed me around the immaculate workshop & car sales showroom, which also homed their fully equipped detailing bay and before I knew it I had a mug of Yorkshire Tea in my hand, which just happened to be my only tea of choice - It was a very good start!  


I was then introduced to another Andy (Carling), who would be working on my car for the day. Andy Carling, is a fully accredited Porsche Gold Star Technician working at Porsche Leeds for over 15 years until he joined the team at RPM in 2019. He was keen to protect the Alcantara steering wheel, gear knob and seats before even stepping foot in the car, which was nice to see, not something you see at all independent garages - It’s little details like this that make all the difference. 


First up, it was the gear oil change, which is a fairly simple process… with the car on a lift, it basically involves removing the filler plug on the side of the gearbox and then removing the drain plug on the underside of the gearbox. As the oil was draining, Andy noted that the oil that had only covered 9000 miles seemed to be in great clean condition with no sign of debris on the plug, which was nice to hear, and once fully drained, it was time to pump in the 3.2 litres of Motul. 


With the gear oil change out of the way, it was onto the alignment ramp for a full geometry check. The car had never been checked in my ownership, so it wasn’t a surprise to see that alignment was out on all four corners. Andy pointed out that the GT4 Caymans with the 911 GT3 front-end suspension have extremely precise setups from the factory, which are very sensitive to adjustment compared to a standard 981. It’s worth noting RPM do have the ability to apply custom setups for track cars, having run various cars in a number of championships, but as my car is going to be used mainly on the road, I opted for Porsche’s factory setup. After the necessary adjustments were made to the camber, caster and toe, it was nice to see all for corners firmly back in the green on the printout. 


All works completed. It was time for Andy to take the car out for a test drive to check the alignment, which all seemed fine. He also made a comment about just how slick and precise the gear change felt, which I can only assume was helped by the new Motul Gear oil.



It’s fair to say I was more than impressed with the facilities and friendly, efficient service at RPM Specialist cars, so much so that I’m booked back in a few weeks’ time for full detail on the GT4 for all the panels that are not covered in the PPF - keep your eyes out for that. 

On the drive home, I was very happy with the drive of the car, with no slight pull or wondering on the motorway and a super sharp turn-in with the fresh alignment. It also became apparent that there was noticeably less transmission noise with the new Motul 300. A successful day all around. 


Check out rpmspecialistcars.co.uk for more information. 

For more on Motul oils check out the Octaneologists web site here 

And for help in finding the right oil for your car, hit the chat box on the right of your screen.



Friday 02 June — Nathan Forster-Green

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