EP90 Leak from Splined Shaft...?

Can't seem to unearth a definitive answer to this one, so here goes and apologies for the repetition:

I have an oil leak (EP90) from the splined shaft (halfshaft), driver side rear of my early 90 (drum braked rear axle). It's definitely EP90 and is definitely leaking from the splined shaft end and into the moulded centre/dust cap. As a result, oil is escaping from the dust cap and showing on the outside wall of the rear tyre.

Common opinion seems to point to a failure of the hub oil seal (RTC 3511), but mention is made of other possible causes. Could it be anything other than failure of this seal?

I did replace this seal last year (Corteco) when checking the hub bearings and, having just removed the complete assembly from the stub axle, noticed that the inboard facing lip spring had become unseated from the seal itself.

There again, I do recall these seals being quite fiddly to fit — especially getting them properly seated on the stub axle assembly when reassembling the drum and hub components. It is almost as if the process of tightening the axle nuts compresses the seal against the stub axle, thus unseating the recessed spring.

Anyone able to help?

Thanks again in advance.

Blocked breather or cheap / ill fitting rubber cap

Are the centre/hub caps there to provide an oil tight seal? I thought they were more to prevent dust/crud ingress than anything else.

Check the breather isn't blocked had this issue myself not that long ago I changed the hub seals and cap a few times before I found it was the breather was gummed up and causing the axle case to build up pressure and the oil to be forced out of the cap. The caps shouldn't have any damage to the inside off them where they sit in hub groove and should be quite a tight fit.

RiffRaffRevival said:

Are the centre/hub caps there to provide an oil tight seal? I thought they were more to prevent dust/crud ingress than anything else.

Click to expand...

rtc3511 is the inner hub seal youd have oil on inside of wheel if it was leaking ,300 tdi on the hub cap is just a dirt cap, prior its needed to stop oil leaking past the splines ,the oil is supposed to lubricate the splines, as others have said poor cap and breather blocked

Thanks everyone for the info and suggestions.

I'll go with replacing the seal RTC3511 again, along with sourcing some genuine hub/centre caps and a set of f&r axle breathers.

Can anyone advise as to which breathers to go with... it's a suffix AA 1985 90?

Thanks again.

RiffRaffRevival said:

Thanks everyone for the info and suggestions.

I'll go with replacing the seal RTC3511 again, along with sourcing some genuine hub/centre caps and a set of f&r axle breathers.

Can anyone advise as to which breathers to go with... it's a suffix AA 1985 90?

Thanks again.

Click to expand...

changing rtc3511 wont help a hub cap leak
breather assembly is
595478 banjo
232039 washer x2
tvp100010 pipe

You might also benefit from changing the seal in the stub axle. The stub axle comes off the main axle casing and there's a little seal in the back of it - FTC5268 I think. This stops (most of) the oil getting from the main axle casing into the hub. A little oil movement of this kind is fine and reduces wear between the half shaft and drive flange, but if you get a flood of it when you go round a corner or are on a slope then it may be more than the end cap can cope with.

Brown said:

You might also benefit from changing the seal in the stub axle. The stub axle comes off the main axle casing and there's a little seal in the back of it - FTC5268 I think. This stops (most of) the oil getting from the main axle casing into the hub. A little oil movement of this kind is fine and reduces wear between the half shaft and drive flange, but if you get a flood of it when you go round a corner or are on a slope then it may be more than the end cap can cope with.

Click to expand...

not on a pre 300tdi oil is supposed run through stub axle

jamesmartin said:

not on a pre 300tdi oil is supposed run through stub axle

Click to expand...

Ah, I must be thinking about a later model then.

Once again, thanks for all of this.

James - those part references are very helpful... it's difficult at times, having such an early 90, with many parts crossing-over from the SIII.

I'll change RTC3511 again, for completeness more than anything else and focus on some decent hub/end caps, in conjunction with replacing the axle breathers front and rear.

Cheers guys... I really appreciate your time.

I have a 1985 90" and have found that cleaning the axle breathers and replacing the hub cap will sort the problem. Sometimes just refitting the existing hub cap with a layer of grease is enough to get a seal, but it usually takes a new cap - cheap enough to replace both on and axle at a time.