Wondering how many of us has fitted a breather into the differential housing? With todays upgrades and better sealing with o rings, lip seals and bearings that are sealed would it be an advantage to fit a breather?? I was thinking of installing one in a similar position as modern day cars on top of the axle housing, RHS with say a 1/4" hole drilled to accept a small metal top breather. Any comments to how effective this would be?
Thinking most T's see 50+ mph not sure it be needed
Usually on my speedster I have put in weep holes
This let it breath and extra get dropped out befor reaching the outer seal
Interesting question though
Bob, yes I will be interested to hear if anyone has actually cured a troublesome on going oil leak issue by installing a breather. Australia suffer from leaks from the left hand axle ( the lower side as we drive on the left) maybe America suffers more with the RHS leaking?
It makes perfect sense. As you know breathers are installed on the differentials and gearboxes of all later cars to relieve pressure build up that causes leaks.
I have installed them on many early transmissions and differentials with excellent results after rebuilding them. Without them the pressure build up caused by the heat generated in the unit not only causes the pressure to find its way out but also the gear lube that leaks out with it.
Curious what would result if the differential is grease packed instead of oil, as it is not at all unusual to find grease packed gearboxes on industrial drives....say you installed neoprene seals for the inboard hyatt bearings and filled the differential with a product like Valvoline Crimson? Not sure where you would locate a vent, where I think it likely you would need one. You would not fill this system more than 80% full, to allow for expansion. Anybody been there done this....thoughts,comments?
My daughter & I disassembled a rear axle on her Model T a few years back and got about 3/4 cup of water out of it. This was a running car that had not been driven through water and did not have a head gasket leak. I've wondered if it needed a breather.
A T rear end was filled with 1-1/2 pounds of #2 grease at the factory. They were designed with a limited life span possibly 5-8 years. #2 Grease is almost too heavy but it met the middle of the road application, in hot climates it was fine but in colder areas it wasn't. To day grease comes in a variety of grades and weights. A 00, 1, 1.5 weights are very creamy and work well in a T rear end and won't leak out. There will be almost no heat generated to require a vent system as in modern high speed differentials. T differential housings were not designed to be "sealed", however there are many attempts to seal the housings some are successful and some are not. If a T differential housing is managed as designed it should not leak if using a non-flowing grease and "seals" should not be necessary.
Dave: Are you recommending that a non-flowing grease like the Crimson is a usable in T rear end application? I live in the midwest where we get down below zero for part of the winter....would you think that this grease is usable under these conditions? I like the Crimson grease in my universals, because it stays in there, whereas standard shop quality black bearing grease warms and becomes too flow-able, and then out of the torque ball it spills.
Every T rear axle I have seen has plenty of "ventilation" up the torque tube and out past the U joint
How many cars did they build with out a vent?? Bud in Wheeler,Mi.
Kind of what I was thinking Les. Dave
It's not about how many cars were built without a vent...rather that running neoprene seals at the axle ends in conjunction with a modern taper roller bearing spool (which has a sealed bearing up front), effectively seals the axle. Ford, of course, never made this combination, but if you choose to run it, venting the axle isn't a bad idea.
I know it voids the warranty, but for one car, I notched the ID and outer face of the bronze sleeve that John puts in the sealed bearing up front. This allows the axle to vent up the drive shaft tube and thru the u-joint housing.
A Ford service manual specifies 1-1/2 pounds of high quality gear lube "compound", a compound consists of more than one component. Originally the differentials were filled with 1-1/2 pounds of # 2 grease that would meet the average conditions. In colder temperatures a "compound" of greases would be required. Grease quantities are measured by weight and are given a reference number such as 000, 00, 0, 1, 1-1/2, 2, up to a tar like material. I use 1-1/2 pounds of #1.5 grease. In colder climates 00, 0, #1 or mixtures of these consistencies would result in a "compound" for your climate. A creamy compound like soft butter will work well. If the grease compound is brought to a point on a piece of glass it should just slump but not flow and should not stay rigid. If too stiff the crown gear will just cut a swath through the grease.
Ordinary axle or bearing grease would not be acceptable.
I have often heard that 600w was the proper stuff for the Ford rear end. Not so?
Paul -- The 600w gear oil is what Henry put in them, but there have been many improvements to lubricants over the past 80-100 years. Some diehards still use 600w lube because that's what Henry did. Most folks these days use modern gear oil, 80-140w or something similar.
I have been unsuccessful at finding any reference to Ford differentials requiring other than grease from the factory, there many alleged references but I have been unable to find a confirmed reference to same. I have disassembled three differentials that were original units and they all had grease in them, Dykes Auto Encyclopedia states that #2 grease was used, an early Ford service manual uses the term "compound". A compound would consist of more than one component such as two or more weights of grease to achieve an acceptable consistency. There have been many reports where members have separated differential housings and found "old congealed oil". Oil would not congeal, therefore the product was grease. I have a 26 touring that ran from 1926 up to about 1940(14 - 15 years) when it was retired. I acquired the '26 about 1960 and did a partial restoration and brought it back to life with the original differential and drove it occasionally. I decided to disassemble the differential to find it still had the original grease in it. It did however require some maintenance, the babbitt thrust washers had to be replaced and that was all, 90 years later it still has grease in it. I have never experienced oil leaking out the ends of the axles.
I don't believe a differential breather will add or affect anything. 600W is a steam lubricant designation, used by the petroleum industry because at the time their biggest customers owned ships and trains powered by steam. Steam lubricants were graded by weight, so 600W steam oil is not saying that the lubricant is equivalent to SAE 600 oil. SAE oils are graded by their ability to pour. The numbers on an SAE oil can have nothing to do with weight.
A while back someone posted a comparison of steam oil weights to SAE and it seems to me that the 600W lubricant was found to be roughly equivalent to SAE 150. Thus a selection of SAE 140 for your rear axle is much like the consistency of what the T came with when new, except far better quality.
Using a modern winter / summer lubricant such as SAE 75W-140 makes even more sense, because the lubricant is able to stay at the same consistency over a wider temperature range, thus protecting the fragile Model T rear axle from wear even better than straight weight 140.
Having worked on lots of OLD tractors over the years I never ran into a rusty gear in a transmission that was filled with 600 oil.
That stuff seems to stick forever.
That chart/drawing dose not show the grease cup's for the outboard bearings on the rear axel.Industry sometimes uses a lube called [Gear Lash] it look's like 600 but will cling to exposed slow moving press gears?? Bud in Wheeler,Mi.
Answer No 101 1920 owners manual calls for the housing to be 1/3 of grease (? compound as it's called in the Model T Ford Service) or "If a fluid grease is used the level should be approximately on and one half inches below the oil hole"
Answer No 117
"Extreme care must be used in lubrication the differential. An A-1 heavy fluid or semi-fluid oil, such as Mobiloil C or Whittemore's Worm Gear Protective, should be used and carried at a level with the upper oil plug.
You will note in both cases the filling hole was called an oil hole or level with the upper oil plug.
Seems to me Dad has/had a 5 gal bucket of a light creamy grease, I will have to look next time I go out to work on my 48.