Sump Plug

[tel76]

I understand from a previous post that the early 230sl sump plug is an ideal blanking plug for the oil cooler pipe on the rear axle,my local MB dealer says that there is only a small one listed.Has anyone used this plug for the rear axle and what is the part number?

[Naj ✝︎]

130 997 0032 (14mm allen hex)

naj

[DavidBrough]

Hi Eric,

I used the plugs when I first installed my 3.46 axle but it leaked very badly due to pressure build up. In the end I had to have the chassis modified to allow the breather pipe to be fitted and that cured the problem.

[tel76]

Thanks Naj for the info:
David can you explain where your axle leaked from, because if you seal of the large oil cooler pipe adaptors it should not affect the internal pressure.
Any pressure that is present will be vented via the breather fitted on top of the axle.
Did you remove the felt from the breather to make sure it was clean.

[DavidBrough]

Hi Eric,

Mine leaked from the breather, it seemed as though there was a pressure build up of some kind and I couldn't stop it leaking no matter what I tried. I spoke to a lot of people about it and the general consensus was that without the large breather tube some axles leak and some don't, try yours without first but be prepared to have the chassis altered to accommodate it if it does leak. Roger Edwards did my chassis mod and it was quite straight forward and not that expensive but it cured the leak immediately.

[jameshoward]

A couple of alternative considerations, maybe (from someone yet to do the job). First, I found that I had over-filled my rear axle by doing it through the tubes a while ago. When I last serviced the car I did it on a ramp for the first time, as opposed to the car being on stands thus leaving the rear axle tubes lower than the diff and therefore giving a false reading of the oil level. When we opened the filler plug, oil flowed out onto the floor. Lots of oil. So it is possible that your axle was over filled perhaps?

A less-nuclear option to altering the axle could be to re-design (ie get a plumber to bend) the cooling tube. I know someone here spoke to a plumber about this very issue and I believe that the feedback was that it was perfectly do-able.

Not sure which approach I'll take yet, but having over-filled one axle, I'm hoping that the breather will take care of business and avoid me having to do anything other than blank off the pipe!

JH

[DavidBrough]

Hi James,

I did drain and refill the axle about three times during my efforts to cure the leak and even ran it slightly low on oil but needles to say it made no difference. I also had a flexible pipe made but as there is so little space it either fouled the body or the drive shaft during suspension movement. When you look at the underside with no load it seems like a smaller pipe set up may fit but once you hit a bump there's no space at all so I finally decided that the only way forward was to refit the original pipe which only required a small modification to one rear chassis leg and then all was well and its now done about 8,000 miles with leaks at all.