Yesterday I re-assembled the rear axle for my speedster.
I've used all modern axle bearings and thrust bearings from Model T Ranch but I'd like your advice on what would be the best lubricant for me to run in the rear considering it doesn't have any bronze bushes now and is completely sealed.
Should I still use the 600W grease or a more modern hypoid gear oil?
Your advice please?
Rob, I would think either the 600 weight, or a modern 85/140 would be fine. I'm currently running an 85/140 and having no issues. I even investigated axle movement and too the rear end apart. Discovered the fellow I paid to rebuild it and do the floating hub conversion neglected to install the fiber washer between the axles. I also discovered he installed the torrington axial bearings instead of bronze thrust washers.
What happens if one forgets that fiber washer between the axles? I ask because I think I did.
Rob -- I use the modern stuff and it works great!
If you have an attached garage you should use synthetic gear oil.
As Ralph Ricks would say, "So the leaks don't stink up the house.
I too would use modern gear oil, like 85-140, or 89-90.
I would not trust the 600 to lube well at higher speeds.
P. Jamison, didn't have any running problems with the fiber washer missing. Just noticed the axles would move in and out slightly when putting the hubs on. Noticing this we went in to see if there was a serious issue. There wasn't.
Thanks for your suggestions Gents.
I emailed John Stoltz (Model T Ranch) and he recommended using a modern gear oil. Nice bloke too.
I use 85/140 in the rebuilt '26 diff and '23 Ruckstell and have not had any problems.
Caution! I do not think modern rear end oil (GL-5) is compatible with brass. You need to use GL-3 or earlier l believe. Rob, Penrite has a straight 250w as well as a 140w non-additive oil made for old cars.
Constantine is correct. For those of us in the US, Royal Purple makes an 85-140 that is comparable with brass. That is what I was running before I discovered no brass in my rear end.
Rob doesn't have any bronze in his axle now. And it may take many many years until the GL-5 oil attack on the bronze will show any damage? Don't think it'll crack like lead babbitt, maybe get tarnished?
Hmm, some testing is needed..
I have been using Amsoil Synthetic R&O, AW Gear & Bearing Oil Iso-680 (RPC) in my T differentials for 6 years now. It is difficult to seal but the new Neoprene outer seals hold it. It has been seeping past rivets in the '12 housings. One rear end has bronze thrust washers and the oil is turning orange. No noticeable play has developed in 5 or 6 thousand miles yet. I can't be sure the oil is the problem but am suspicious. I will use babbit in future projects. I do like the way this oil has quieted my Warford transmission and have used it in my 1923 White touring Bus's Trans and Diff. we will know a lot more about these oils in 20 years.
I have used 90/140 since 1978 and done thousands of miles with no issues.
Regarding Constantine's post.
It is GL4 that is needed for brass or bronze thrust washers.
I doubt if you can find GL3 in the U.S.
GL5 will cause bronze to turn grey after a long time, and as far as anybody knows it WILL NOT EAT the bronze.
"... I will use babbit in future projects."
You don't mean for thrust washers do you?
Has anyone ever have an actual, (versus theoretical), problem with any rear end lube being used in a T with bronze washers????