diff oil in drum

[mercle]

HI i have a 1983 L608D mercedes van. The rear nearside drum has diff oil leaking into it, I have replaced the seal at the drum end but this has not cured the problem. Does anyone have knowledge of diff oil/drum leaks? Is there another seal up in the diff end of the half shaft? Any assistance appreciated, Thanks.

 

[wireman]

There is a vent in the top of the diff housing to allow air in and out as the oil heats and cools, any blockage here and the oil that sits around the seals at the end of each half shaft will be blown out into the drum when the axle heats up due to nornal running.
Find and check the vent plug.

 

[mercle]

re vent

Hi and thanks for your reply about vent... Have found vent, the cap seems to move up and down freely, although there is signs of old oil around the cap. I presume if this was the cause of the problem that the pressure would blow down both half shafts and not just the nearside? I'll go pop off the cap and check for a blockage, but any other ideas, any other seals in diff housing? Thanks.

 

[42864]

Just a thought, --- Are you sure that it is Diff Oil and not Dirty Brake Fluid from a leaking Wheel Cylinder ??

 

[mercle]

re oil/fluid, vent

Hi. Yes definately diff oil. But the oil is only running down the nearside shaft. I've given the vent a good clean but it wasn't blocked. I am waiting for a manual off ebay which will hopefully shed some light. Thanks.

 

[Ultymate]

The nearside hub oil seal is U/S the rear wheel bearings are lubricated by the axle oil and the oil seal has failed

 

[television]

The nearside hub oil seal is U/S the rear wheel bearings are lubricated by the axle oil and the oil seal has failed

I have to agree 100% with the above

 

[Glenn Smith]

I believe he has replaced the seal, so maybe the bearing is shot?

 

[Ultymate]

On commercial vehicles like this with what are known as fully floating hubs when refitting the hub they are quite heavy and it's easy to catch the new seal on the threaded part of the axle tube thus causing the new seal to fail. Some manufacturers supply a special steel sheath to fit over the end of the axle tube to prevent this happening, as part of their worshop special tooling. You will probably have to replace the seal again, but your friend will have to borrow the midwife's touch and possibly tape over the thread on the end of the axle while the hub is slid over.
P.S. This should have nothing to do with the bearings!!

 

[mercle]

bearings/seal

Hi. Thanks all for ideas/info. Have inspected bearings again and they seem sound, also no visible seal damage. I'm going to replace the seal as advised in last post in case previous seal was damaged when putting on the hub. Also wondering if any residual oil from previous drum infection that was possibly caught in the oil catcher and had not found its way out through blocked vent may be involved. Fingers crossed etc.

 

[television]

Just saying that it will only push oil out of the ends when the breather is blocked, or has the axle been over filled some how

 

[mercle]

Didn't think you could put too much oil in diff because filler hole at set level. Have checked level and is just below filler hole which should be OK. Still wondering about why diff oil is only travelling down the nearside shaft and the offside is dry and wether this might be another symptom, uneven pressures? Seal arrives tomorrow. Still guessing, still stumped, still fingers crossed.

 

[wireman]

Whilst you have the hub off check the suface against which the seal runs for damage and wear.

 

[Ultymate]

Not wishing to teach you how to suck eggs but did you put the seal in the right way round, the seals job is to keep the oil in the hub, so the side of the seal with the spring visible should face in towards the bearings

 

[mercle]

Just an update...thanks all

Have been away from this problem attending others but am still not sure things are solved. So just an update for those who helped before. Last test run had no oil coming down shaft... still not entirely sure if this is correct or not so don't know yet if new seal has done job. Vehicle is now SORN'd so future test runs abit of a problem. Have to replace linings from previous leak but a little nervous the whole thing will happen again. Thanks all for advice and ideas.