siddha

1930 Chrysler 70 rear axle pinion seal leaking.

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I wonder if anybody can help me as I have a problem with curing a leaking rear axle pinion seal. I live in the UK and am fairly new to Chryslers so this might be about unfamiliarity with the setup.

The original leather/spring seal had disintegrated. I adapted the assembly to take a modern single or double lipped seal. When removing the rear axle drive pinion flange I noticed that the very large nut held in place with a split pin was not tight; I was able to undo this with my fingers. This did not worry me as my assumption here from working on later cars was that the cone  of the taper roller bearing  should not be under a lot of pressure; my practice to date with taper roller bearings  is to tighten up the nut as far as it would go and then move back one flat or back to the next point in which the split pin can be put through.

Anyway I have fitted modern seals twice now and it still leaks! I am just wondering whether the very small amount of possible travel in the cone and therefore also in the drive pinion flange is creating a pumping/hydraulic situation.

The questions therefore are:

 1. Has anybody else met this situation and solved it?

2. Is there a torque for the drive pinion nut or should I use shims to achieve zero travel at the cone?

I will try and post a picture of the assembly.

I will appreciate any help/advice.

Many thanks

Steve Welton

Rear Axle Pic-800.jpg

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Quite often the cause of the repetitive leak is a groove worn into the sealing area of the pinion shaft, the fix is to put a sleeve over the pinion shaft so tha the new seal runs on new metal. Any good bearing supplier wil have these sleeves in stock.

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Hi,

Thanks for this but there is no visible groove on the pinion flange shaft. I shall check next time it is apart.

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Steve, it looks to me as though the nut should be tight, as the inner races are located with a distance tube. These tubes can have removable shims to take up slack in the bearings, probably at '46'. Removing shims tightens the bearing, and they could have a pre-load value. With luck, the Chrysler boys will chime in with more accurate information. The nut would need to be fairly loose to leak oil with a newly fitted modern lip-seal, assuming that the shaft  is in good order. Do you have a workshop manual for the car?

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Lateral movement of the pinion will lead to early failure of the lip seals. Make sure the adjustments are right.

 

Make sure you put plenty of grease on the seal lips. They don't run dry for long before failing.

 

Is it leaking at the seal or at the joint at "45", which is where the shims would be to adjust mesh of the drive pinion with the ring gear? BTW this design is the same on the 1930 Dodge Brothers 8. Shims are also placed at 46 to adjust the pinion shaft bearings. The correct end play of the pinion shaft should be between 0.001 and 0.002", adjusted with the shims at 46.

 

No torque figures were given before ca 1935 so our vehicles are done up "tight enough" or "goodntight" as someone said in another topic. My manual just says "The universal joint flange is then locked rigidly in place by the nut on the front end of the drive pinion shaft." I imagine yours will be worded similarly.

 

No shop manuals for these cars, just the Instruction Book. And Dyke's, perhaps.

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Just did a pinion seal change on my 1931 Dodge truck found pinion nut only snug . I was expecting more and when I laid the 3/4" drive and socket on and just my hand weight broke it free . I put it back same . Book on mine says adjustment is with shims inside cage . Talking with transmission guy who set my seal . He thought there was enough room for a second one . He said was sometimes done to work around shaft damage . Grease was added  between .  

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5 hours ago, Spinneyhill said:

Lateral movement of the pinion will lead to early failure of the lip seals. Make sure the adjustments are right.

 

Make sure you put plenty of grease on the seal lips. They don't run dry for long before failing.

 

Is it leaking at the seal or at the joint at "45", which is where the shims would be to adjust mesh of the drive pinion with the ring gear? BTW this design is the same on the 1930 Dodge Brothers 8. Shims are also placed at 46 to adjust the pinion shaft bearings. The correct end play of the pinion shaft should be between 0.001 and 0.002", adjusted with the shims at 46.

 

No torque figures were given before ca 1935 so our vehicles are done up "tight enough" or "goodntight" as someone said in another topic. My manual just says "The universal joint flange is then locked rigidly in place by the nut on the front end of the drive pinion shaft." I imagine yours will be worded similarly.

 

No shop manuals for these cars, just the Instruction Book. And Dyke's, perhaps.

 

True that there were no published torque specifications in that era. At least I've never found any.

 

But a slightly later vintage reference for a very similar Chrysler Corp. design states the "Rear Axle Drive Pinion Flange Nut" should be 180 ft-lbs minimum. I know that on my '33 Plymouth it was on very tight. Probably "really, really, goodntight" using your nomenclature. The axle was off the car at the time and it took some rigging to keep the flange stationary while I applied torque to the nut. I vaguely recall that I took some long 1/4" flat stock and cut and drilled it to be able to bolt onto the flange to hold the flange still. I also remember getting a new cotter pin into it wasn't easy either.

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The pinion flange nut on my 27 model G70 was very tight, and took some undoing. I have rebuilt the axle but have not run it.

 The flange nut on yours should be equally tight. The shims 46 are for adjusting the end float on the bearings and it probably has shims for adjusting the pinion mesh, by moving the carrier in or out slightly.

 If the leak is from the pinion seal, then I agree with the comment that the flange surface is worn or pitted ever so slightly. It may not be visible to the naked eye.

 I would first of all tighten the flange nut VERY tight and see if it still leaks.If it does then remove the flange and mike it up for wear. Another thing to check , some seals are designed for use on a shaft that only runs in one direction, if you have fitted this type of seal, it will probably leak as soon as you reverse the direction of the shaft.

Viv.

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With all that said, are you using 600wt. oil. ? 

Looks like and pours like honey. Multi viscosity travels and you need a thick oil. 

Jay 610-863-6955

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1 hour ago, pre1939chrysler said:

With all that said, are you using 600wt. oil. ? 

Looks like and pours like honey. Multi viscosity travels and you need a thick oil. 

Jay 610-863-6955

This isn't a T Model Ford. . .

 

Check the Instruction Book (owners manual) for the correct gear lubricant. Probably somewhere between SAE 110 and 160 for summer driving.

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Posted (edited)

Gentlemen,

I must thank you all very much for your excellent advice and comments on the problems I seem to be having with the rear axle pinion seal. Everything that has been said has some relevance. I shall be dismantling later this week and reassembling with greater confidence.

 I am familiar with using very thick oils in veteran (pre-1919) rear axles. In the 1929 Chrysler Handbook it recommends something called ”Fluid Gear Lubricant” I have been using Penrite Straight T140 a rear axle oil that I’ve used in many vintage cars.

I will tighten up the nut and see what happens and also check the state of the shaft in greater detail.

Many thanks guys!!

I think I’m right with the lubricant however just to check the rear axle is a spiral bevel but not hypoid…………….. I am right there I hope?

Edited by siddha
additional info (see edit history)

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Spiral bevel, yes. From a Republic ring gear catalog.

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Mention is made of 600wt oil, I think this refers to "600W cylinder oil", a product with consistency of honey, but it is not 600 weight. It is more the consistency of perhaps a 300 wt conventional oil. I bought a 5 gallon (20 quart) pail from Esso/Exxon at their regional supply depot, 5 years ago for transmission/rearend on my '31 Chevrolet, paid about $120 for the pail. It is not generally available at your NAPA or similar stores. 

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