Back axle removed

[Harry]

I had about three hours in the garage today, I had popped into our local MGB center on my way from work and bought a used Gear box cross member. (£35.00) Once I got home it was a coffee then into the garage, My steering rack is behind schedule by a week ( Not back at Earpart yet ) so I decided I have time to remove the back axle, so off it came, no problem, springs too, I power washed them in the back garden, then cup brushed all the old paint and rust off them, I noticed the "U" bolts had been over tightened at some point and the fabrications ( Below the axle, damper bolts into it too ) were bent upwards, one not to bad but the other was cracked as well, so this I removed and welded up, I was going to check out the Dif but it seems fine, I'll replace the oil only, so it will be a painting job tomorrow, I also cleaned up the gear box cross member ready for the same treatment although I'll have to extend this fabrication to reach the Marlin frame / chassis. It was back to a bit off rubbing down shortly after. so I think I deserve a beer.

[stevejgreen]

Re: Back axle removed

I always wondered why a Marina rear axle never had a drain plug. The only way to remove all the oil is to take the axle off the car.
So some if not all of the oil could be 40 years old. It is of course possible to weld a drain plug into place while the axle is out.
There is some information available regarding the current Hypoy oils not being compatible with older bearing metals. Personally, if the axle has lasted 30 years, the chances are that any possible damage will not shorten the differentials life, the new oil might do more benefit than harm. I think the materials problem is much more likely in the gearbox, but again, new oil will be an advantage.

[Harry]

Re: Back axle removed

Hi Steve, yes I too wondered about that, it is odd, just a level plug and a top up plug also a breather, anyway all my oil run out when I had the axle upside down washing it, at some point someone has had the cover off the diff and must have lost a few of the nut's as there are a few nylocks fitted, the others are rounded off, so I left it along as it seems to be fine. I think I'll buy a set of brake drums as they have seen better days too.

Some hours later after removing the last blob of grease and old paint, I noticed a small screw someone had fitted as a drain plug !!

[Harry]

Re: Back axle removed

Hi Steve, just thought I'd mention that on the Marina diff, I thought there was only one plug,that doubled as a level and top up plug, however I found three on this once I'd cleaned all the old paint from it, two "home made job's " one on the top of the diff and one on the axle shoulder ?

[listerjp2]

Re: Back axle removed

Hi Harry

The one on the shoulder is a breather and normally has an upright plastic cover, which obviously stop dirt and grit getting inti the diff.

A bit like this, can be got on ebay.

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Adrian

[h_m_cumming]

Re: Back axle removed

When I built mine 24yrs ago, doesn't time fly, I put a drain plug in when i had the axle apart. Not a lot of metal to get a thread on but 1/4 BSP and plenty of ptfe tape. Works well and hasn't leaked.
Actually, might have been 1/8 BSP, must check next time it's out.

[stevejgreen]

Re: Back axle removed

I think Hugh has a good solution there.
Though it's only a small hole to drill and tap, I would be wanting to flush out and clean so far as is possible the inside of the axle.
Its rather pointless putting in nice clean oil, bearings etc, with metal particles swilling about. There is no magnet in the diff to collect them, as in a gearbox, unless you can find a magnetic plug, and cleaning is only really possible with a dismantled diff, off of the car.

The old Caterham racers who also used the Marina/Ital axle, commonly fitted internal baffles and overfilled the oil, on the basis that at race speeds and heavy cornering, the inside wheel bearing and the diff could be starved of lubricant.

[Harry]

Re: Back axle removed

Thank's, It has got the breather as well, but it's broken, I meant to get a new one from Ebay. A well timed reminder !