Overhauling a rear axle - how far to go?

[stevejgreen]

Re: Overhauling a rear axle - how far to go?

I have an original Marina Parts Catalogue for October 1975 onwards and except for the 10CWT van and Pick-up, the Oil Seals are the same for Saloons, Estate and 7CWT models.

Unless yours is a pre 1975 donor?

Adrian

Correction.
The design of the halfshaft was changed at some time in 1978 around the introduction of the Ital (?)
The woodruff key was changed from 3/16” thick to 1/4” thick at the same time as a change in the oil seal diameter.

The same part changes were made on the Triumph Dolomite range (not the Sprint) so it may not be directly an Ital related change, they use the same back axle design from the same parts bin like many of the small Triumphs.
I have seen an axle fitted on a car with both variants, it had been allegedly only Main Dealer Maintained so one would assume thoroughly (?)

I listed the part numbers on my document in Keepandshare for all to see.

[listerjp2]

Re: Overhauling a rear axle - how far to go?

I have an original Marina Parts Catalogue for October 1975 onwards and except for the 10CWT van and Pick-up, the Oil Seals are the same for Saloons, Estate and 7CWT models.

Unless yours is a pre 1975 donor?

Adrian

Thanks guys. In that case I may pull the halfshafts so I can check the diff.
Do I need a slide hammer for that?
Cheers Robin

[andyf]

Re: Overhauling a rear axle - how far to go?

@Steve, yes a bit like using spring compressors it tests your nerves They let go with a big bang!

[stevejgreen]

Re: Overhauling a rear axle - how far to go?

I bought a hydraulic three legged puller that did the job, bent the tommy bar though!

It can be done, but the hub is rectangular so a three point puller is an uneven pull and can release unexpectedly.
Don’t be tempted to use heat as it may effect the temper of the steel of the hub or halfshaft, a known weak spot.

There are two different sizes of Oil Seal.
Read my Rear Axle article on Keepandshare for full info. It’s free once you have registered.

https://www.keepandshare.com/doc/4039508/morris-marina-ital-rear-axle-differential-options-pdf-may-26-2012-10-34-pm-81k

[andyf]

Re: Overhauling a rear axle - how far to go?

I bought a hydraulic three legged puller that did the job, bent the tommy bar though!

[stevejgreen]

Re: Overhauling a rear axle - how far to go?

You will be lucky to find the service tools listed in those instructions. Don’t be fooled into thinking that a DIY three leg puller will do the job, there is a reason why there are substantial pullers nominally for Triumphs that have similar axle designs available on eBay for £100 or there abouts.
But similarly don’t be put off, many tyre fitting companies have hydraulic presses and for a large box of teabags and biscuits, they will happily do the job.
Don’t lose the woodruff key.

[listerjp2]

Re: Overhauling a rear axle - how far to go?

As per attached

rear axle and final drive 1 of 2.jpg

rear axle and final drive 2 of 2.jpg

If you do decide to replace the half shaft bearing make sure when it's pressed on the distance from the bearing to thread end of axle shaft distance is 2.84 in (69.94mm) as this is crucial.

Adrian

[listerjp2]

Re: Overhauling a rear axle - how far to go?

If you do decide to replace the half shaft bearing make sure when it's pressed on the distance from the bearing to thread end of axle shaft distance is 2.84 in (69.94mm) as this is crucial.

Adrian

[stevejgreen]

Re: Overhauling a rear axle - how far to go?

Thanks guys. In that case I may pull the halfshafts so I can check the diff.
Do I need a slide hammer for that?
Cheers Robin

everything you ever wanted to know about Marina axles can be found on Keepandshare.
access to a 25 ton press makes bearing and hub removal really easy.

[martinclan56]

Re: Overhauling a rear axle - how far to go?

Thanks guys. In that case I may pull the halfshafts so I can check the diff.
Do I need a slide hammer for that?
Cheers Robin

[meverett]

Re: Overhauling a rear axle - how far to go?

Hi Robin, if it is just the pinion oil seal you need to replace then the axle and diff shouldn’t need dismantling.
I used some strong flat bar with two holes drilled to match the prop shaft bolt holes and a cut out to access the pinion nut then with some force got the nut undone then simply remove the pinion flange and replace the oil seal.

[dogoncrazy]

Re: Overhauling a rear axle - how far to go?

Halfshafts are easy to remove, getting the outer hub bearing off the shaft isn't.

[martinclan56]

I have totally dismantled my car now and am assesing what, and what not, to replace.
The rear axle certainly needs new spring platforms as they are severely weakened by rust. That should be a relatively straightforward welding job.
And it looks like it probably needs a new pinion oil seal as it was oily in that area.
But should I attempt to strip it any further or would I just be opening a can of worms? I believe the halfshafts, for example, are extremely difficult to remove. And most of the other things that could be replaced seem to require that.
Of course I will be replacing the brake shoes and slave cylinders as a matter of course, but they are easy to get to.

As usual - all input gratefully received!

Cheers, Robin