I just restored a model TT Ruckstell for my truck ,and do not know what kind of lubricant to use in it. I have installed neoprene oil seals on each side, inside the roller bearings and also new standard felt seals on both sides of the diferential assembly.Somewhere, I read that they used to put in a mixture of heavy oil, close to grease and ordinary motor oil!? Please, don´t just give the name of lubricants , but rather viscousity, as all brands you have in the US probably are not available here in Sweden. Also , as I understand, a lubricant in any Ford rear end, must not contain sulphur, as this will affect bronze parts, as the worm gear and , in the ordinary T rear end, the bronze bearings.
Hej Magnus, Här är en äldre tråd om TT bakaxelolja: (here's an older thread on TT rear end lubrication: )
For car Ruckstells, 90 W oil is often recommended compared to 140 W for standard car differentials.
I'm using Chevron Gear Compound EP ISO 680 in my '26 TT. It has a AGMA Grade of 8 EP, is ISO 680 Grade, an API gravity of 26.0, a viscosity index of 100, Timken OK load in lbs. @ 65, meets AGMA 9005 (ISO 680), rust & corrosion inhibited -- reduces corrosion on either steel or non-ferrous metals in gear sets.
Suggest using synthetic gear oil that will not attack the bronze worm gear. I buy synthetic high pressure gear oil from McMaster Carr in a 1 gal. container and use it in my Ruckstell. No more bronze in the oil using synthetic. Can't beat the price from McMaster Carr.
I started using synthetic gear oil after reading an article about not all gear oils are the same written by someone that owned a TT truck with a Ruckstell. After changing to synthetic, he claimed his TT would go further up the hill to his home before he had to shift down. Also, when going down the hill, he had to apply brakes sooner. He also claimed the oil stayed much cleaner and did not turn bronze color which happened using conventional gear oil.
The oil in the Ruckstell that is in our 13 touring which contains bronze thrust washers has not turned bronze in 15 yrs. use.
THE GIRLS I GO WITH SAY TO USE 50/50 90 W AND STP.