Folks – you’ll remember that recently I posted a problem with what I thought was brakes sticking. Well I went through all sorts of hoops with this one and many people’s “Do This” and “Do That”.
Eventually I had an e-mail from Lorne Goldman in Canada – he of GoMog – and following about 20 e-mails back and forth he told me he thought the problem was actually my Limited Slip Diff!! He advised to remove the parcel shelf and having warmed up the car to do the manoeuvres which caused the noise to appear. Bingo -- it was the diff after all.
He then advised me that it seemed that either the wrong diff oil had been put in the diff or it hadn’t gotten the friction modifiers which are required as recommended by the manufacturers in Australia. He checked with them and they confirmed that Friction modifiers are absolutely necessary. There is actually a metal tag on the filler nut on my diff stating that the correct oil for a LSD is required PLUS FRICTION MODIFIERS!!
It appears that without the required FM, the cones or clutches in the diff stick, and sound like sticky brakes as they release.
The advice was to add some Friction Modifiers to my diff and that would likely solve the issue.
Having acquired a bottle of “Redline” Friction Modifiers – sold in 120Ml bottles – I added 100 Mls to my diff and I am delighted to report that the sticking noises have disappeared and I am just really chuffed!!
As a further Belt & Braces move I am now going to flush the diff and add fresh oil – I have found (Again from Lorne’s GoMog) that Castrol produce the right diff oil but with the right amount of FM already mixed -- Castrol SAF-XA. This is very hard to get here in Ireland as most motor factors are reluctant to order the minimum supply from Castrol for fear of having a lot of stock which is rarely requested. My search will continue!
Anyway I owe a deep debt of gratitude to Lorne for all the trouble he took to help me and for the solution to the issue!!
If anyone with a plus4 with a limited slip diff hears what appears to be sticking brakes I would advise checking the diff – remove the parcel shelf so you can hear it properly. The issue will only begin to become evident when the diff is fully “Broken in” or at about 6000 miles. If you are hearing these noises, it will likely be solved with some friction modifiers.
