RRT LS90 GL5 Diff Oil

[Mike-360R]

So, I am starting to gather the bits and pieces I need to carry out a first full service on my car over the winter and spoke to RRT about purchasing a litre of their diff oil for my Titan LSD. Unfortunately, since a packaging update of their product they have had to cease shipping it out to customers due to consistent leakages in transit.

I would still like to get hold of some but Sevenoaks is a bit far to go for me so I can either wait until RRT sort out their packaging issues or see if anyone here has an unused litre they no longer need that I could buy from them including postage costs?

 

[ScottR400D]

I know some folks swear by that oil but I tried it, a couple of Redline grades and Caterham's recommended Motul and didn't see any difference at all in noise, smoothness or running temperature. When I replaced the Titan with the Tracsport I tried it again with the same result though that makes more sense in that SPC recommend 'any decent 80/90 GL5'.

I'm fairly reliably informed that the key difference is that the RRT has more friction modifiers than usual to stop the Titan locking too much and wearing out. I stand to be corrected.  

[DerekH]

I changed mine at 3 years and vacuumed out the old oil. I came out a nice dark blue colour with no bits in it. 

I was able to remove a liter of oil.  Replaced with 800ml of Castrol Transmax BMW LSD oil. Available on Amazon.

It seems to be more slippery dropping the preload by 4 pounds and made the low speed noise much less.

Diff still locks up nicely when required. I only have Sigma to push it along, so far its holding up OK.

Pre-load is still at 40 pounds.

DerekH

 

[Geoff Brown]

I do believe that the RRT SAE 90 GL5 oil does have some inhibitors.

When I had a Tracsport LSU fitted I opted for Castrol B373 SAE 90 GL5 . It used to be a GL6 but was down graded to conform with the current oil spec table. Steve Perks gave his blessing to use this oil.

It is a very thick pungent oil but so far does the job incredibly well. I changed it at the two year point after about five thousand miles with the new LSU. The colour was slightly more brown than its original amber but one expects that in the environment of a diff.

If the RRT oil is not available & one wants to stick to an SAE oil instead of a multi grade which holds inhibitors then B373 is the one to opt for.

[Dan R]

I too use Castrol B373 in my Tracsport, however i think this oil has now been discontinued so will need to look at a replacement.  

[7 wonders of the world]

Castrol Syntrax 75w/140 is also suitable for Tracsport LSD's as a replacement for B373.

 

[Geoff Brown]

#5 Dan R - B373 still in stock at OPIE & Amazon. Get it while you can !

[Colin Heseltine]

I was after the RRT diff oil but as you say due to shipping difficulties they are not prepared to send it out.  I asked them for a recommendation and they said to use Redline 75W90 GL-5 LSD oil.  I used this and noticed that the preload dropped by around 4 ft. lbs to 38.5 FT lbs.  This is on diff in 2021 420R which has done almost 16200 miles in last two and half years.

Colin