37 zephyr

Many thanks to those who replied to my last post, I have just finished rebuilding the brakes today, while I was under there, I decided to check the gearbox, and rear axle oil levels,(single speed), the gearbox was ok, when I took the level plug out of the rear axle, it spit im my face, so there's a backpressure problem somewhere, Is there a vent on the axle that may be blocked, there was nothing seeping into the brake drums.

Regards Peter Smith

On ford model a and v8,and i believe also LZ,oil can run from gearbox to rear axel,when front of car is jacked.Could be the reason.Birger

On Lincoln transmission and on rear differential there is an oil seal to prevent oil from leaving the transmission or differential and puddling in the driveshaft tube. This is necessary because you don't want the oil to drain out of the trans or diff. I would think that the A and V 8 would be the same as the engineering is basicly the same.

There is a vent over one of the axle housings . Check to see if the vent is blocked. Chanages in temperature will build preasure in the rear axle assembly and cause a spitting of oil when you open the fill plug.

Bill

Hey Bill -

I've looked (I have one of my '37 rear axles out) and I don't see a vent anywhere on it. Is it an obvious valve somewhere, or is it a passive type of system?

Cecil, My post war rears have a small vent similar to the vent on the transmission mounted on the top of the left(?) axle housing.

Bill

Hello Bill, the first thing I looked for was a vent, but could not see anything obvious, and that's why I asked the question, I wonder if it was a mod on later models, are the axle tube fixing bolt holes blind, or open ended, I was thinking maybe modify one of the top bolts on the right hand side, away from the ring and pinion, to take a small breather tube. Regards, Peter Smith

Hello Birger, i had thought the same, but I have had the car up on a 4 poster to do the brakes, and it has been reasonably level at all times, the various seals, all must be in good condition, because as far as I know this car has not moved a 100 yards in two years, so it must have held on to this pressure, ( took a good 4 seconds with the plug out, to exhaust the axle, then there was maybe and egg cup full, too much oil in it)I don't think temparature difference would have created that much backpressure, Regards Peter Smith

I posted Peter's question on another forum. Evidently, there wasn't a vent on the pre-war cars. Some interesting solutions offered here:

http://www.fordbarn.com/earlyv8/forum03/messages2/5020237.html

Looks like someone thought like Peter: Use one of the upper bolts in the banjo as a vent.

Thanks for that Cecil, I did not want to drill the axle, and get swarf into it, so I think the bolt idea would be a quick fix, until such times (if ever) the axle has to be removed for other work, I was amazed at how much wind there was in there, and surprised that no oil had been blown into the hubs.

Regards.

Peter Smith.

I have never tryed to disassmbel an LZ rearaxel.The model A and v8 have no seal between torque and torquetube where it attaches to universaljointhouse.Again there is only an oilslinger at rear of gearbox wich means gearhouse and rearaxel teoretically is connected and no pressure should occure.Airpressure would at least equalize via seat at gearleveler.Is it different on LZ?Birger

Hey Birger -

I would assume the L-Z axle was the same as the Ford unit, so it would work the same way. Sometimes I talk to George Trickett who is a big L-Z expert. If I can remember, I'll ask him what the scoop is.

Post war LZ has an oil seal on the back of the BW OD unit, a seal on the driveshaft at the upper end near the speedometer drive and a seal on the differential at the pinion gear shaft. I am now in question about the vent on the rear axle housing , but will go to the garage remove a tire and double check. Will report my findings.

Bill

You guys had me going there. I thought I might be losing it. I checked my axle housing and there it was on the drivers side about 2" inboard of the bracket that mounts the flex brake hose is the vent. It is a little different than what we think of as a vent. It is a bolt that has apparantly had the shaft drilled up to the hex head and an other hole drilled thru the hex head connecting to the hollowed out shaft. A cotter pin is inserted in the hole thru the hex head to prevent too much oil from leaking out , but allowing air to vent. I believe the 36 and 37 used a Ford or Ford type rear. From 38 up to 48 a hypoid rear was used. At this time a vent might have been added. It would be interesting to know if anyone has the time to check their 38 to 42 rears and see if a vent exists.

I have been thinking about the seals in the rear of the trans and the front of the rears. If oil is allowed to leak out of the trans to fill the torque tube, the capacity specifications for the trans and rear are going to be way off. I don't think you want the torque tube to fill up with oil as it is going to leak out around the bell fitting at the trans or overfill the rear on the lower end. the rear is lower than the trans and to fill the trans and let the oil fill the torque tube and diff. the heat from the differential will force the oil out some place nasty.

Bill

Hey Bill -

Yeah, it sounds like something that was added later, because my '37 axles definitely don't have them, and frankly, neither did the '38 hypoid unit I once had in my posesssion. Very strange....

Dear Bill,Checked out my 39 this morning and it is exactly as you described.Gotta believe it was a running change during production somewhere between 38 and 39.diz