Thread: Fitting upgraded Axles, CVs and converting to oil lubed hubs

Pull the seals in the stub axles to let pull through and when you are done put a big zip tie around the rubber outer cap. Otherwise it's very difficult to stop them losing oil.

I don't grease the bearings or cv. I let the oil do it's job. Any grease will just turn to sludge in the oil.

Originally Posted by mools

Hi all,

I recently got some upgraded Ashcroft goodies; CV's, Half shafts (axels) and drive flanges and want to fit them to my 2006 110. While I'm at it I want to go to oil lubed hubs too.

I consider myself to be reasonably practical but I've had a look around this topic for a short while but can't quite get the concise info. I need. Lots of useful stuff out there but I want to know exactly what I'm in for before I strip down a corner to find I don't have what I need to complete the job. Once-upon-a-time I may have been tempted to give this job to someone else but I think I really should be able to strip and build the hubs myself I'm just laking the confidence on a couple of items and don't want to be doing this again and again - once and properly. In return for good advise from the forum I'll write it up, with pictures, in to a step by step article for anyone else in the future.

The diagrams below are from the RAVE manual for a 300 tdi, I couldn't find any that where more specific but as far as I can tell they should be nearly correct, please point out if I'm wrong about this. So here are my questions....

Firstly for the rear....

It appears there are just two seals in there. So...

1) Aa far as I can tell outer hub / axle shaft seal (8 in the diagram above) is removed and not replaced to allow oil to migrate from the diff housing is this correct? If not then what is done here?
Correct - removed

2) What happens to the inner hub seal (7 above). Is it
a) left alone,
b) upgraded to a higher spec oil seal (if so part no.?) or
c) Just pulled out and disposed of.
Upgraded to RTC3511 (unless there's an even better one that I'm not aware of

3) Have I overlooked anything?

Now for the front:

4) Firstly can you convert later style (no swivel housing drain plus) type assemblies to be oil fed? Looking at the diagram (below) I'm a little sceptical that this can be fed adequately from the diff housing, however, if it can then there are 3 seals...
Yes

5) Axel shaft seal (8 in the above diagram) just junk and not replace? or what? Ashcroft do a larger seal (refered to as 'the oil seal fitted to the swivel ball' on their web site) for the larger shaft. But if going for oil lubed hubs is this seal just dispensed with anyway?
You have a choice here. If you remove it you have one compartment across the entire axle. If you leave it in your swivels and wheel bearings are separate from the diff housing itself. I run the latter option
6) The CV shaft seal (No. 23 above) located in the stub axel. Stay, go or upgraded?
Removed to allow oil to get to the wheel bearings
7) Part 7 above, inner and outer hub seals what happens with these? Junked or upgraded? If upgraded whats the part no.?
Upgraded to RTC3511 same as the back
an additional lubrication question....

8) What is the best way to pack the CV and bearings if going to oil fed? Do they require pre packing with grease? and if so do you need to re pack them periodically?
I pre-pack wheel bearings on initial fitment. No requirement to repack unless you have removed/cleaned them for some reason, in which case I treat them as new and repack. When I fitted my upgraded CV's from Rovertracks, Keith advised me to do an initial packing with CV grease. Not sure if Ashcrofts recommend similar
Now, I think that's all I need to know. So if you can help out with some concise and knowledgeable answers I'd be most appreciative.

Thank very much,

Ian.

Oh, and if the diagrams are too small just double click to open a larger one.

Answers in red above.

You don't want to fill the swivel completely with oil. There should be an area visible on fhe forward side of the swivel casting where the fill plug went in earlier models. I used a bamboo skewer as a dipstick to fill with oil to slightly above that level. Re-check in a week or so.

Dougal's zip-tie suggestion above isn't applicable if you're running the screw on cap style upgraded flanges.

Steve

Hey Ian,

I did this same up grade 3 years ago. I have had no problems what so ever. It is nice knowing that some very weak points and parts are now bullet proof.

Oil feed bearing seem to be the way to go, having the additional benefit of lubricating the drive flanges.

Just need the new Ashcroft hybrid P38 centre now and job done

Cheers
Grant

Originally Posted by steveG

Dougal's zip-tie suggestion above isn't applicable if you're running the screw on cap style upgraded flanges.

Steve

Um yeah. Good point.

Originally Posted by Drover

It is nice knowing that some very weak points and parts are now bullet proof.

Can you clarify what you mean by this?

Another point.

Check the seal surface on your stub axles carefully. I had one which would keep weeping oil. I finally pulled it out to polish some old seal grooves out on the lathe and found it wasn't completely concentric.

I took a small cut to clean it up and it's been oil tight ever since. Makes me wonder wehther the grooves (which were likely not where the seal was running anyway) were the issue or the eccentric stub over-working the seal.

Originally Posted by Aaron

Can you clarify what you mean by this?

Sure,

CV joints - standard item are just that, they will be fine but if you want to fit bigger tyres or if you lift a tyre under throttle and drop it down, particulary while you have the steering on full lock, then problems are likely.

Ashcroft CV are as strong as they get, alloy steel and brilliant engerneering and machining.

Oil Feed Bearings and oil lubed drive flanges.
Standard the wheel bearing are just greased and the drive Ganges are not lubed at all. Converting to oil feed solves this issue. Prolongs wheel bearing life and prevents the drive flanges chewing them selves out.

Half Shaft (axels )
standards are fine but for all the same reasons as the CV's up graded alloy steel units are so much better.

I like these upgrades just because my D'fer is set up for long range remote touring. Mostly it is just my wife and I. I don't want to have any problem while we're away and god knows how many K's from help.

It's all about bullet proofing......simple

(And as soon as the Ashcroft hybrid P38 centre is available I will fitting that as well)

Firstly, thanks SteveG - just what I was after.

With reference to the RTC3511, reading around I have heard mention of part no FRC8221 (now superseded by FTC4785) a tripple lipped seal, apparently interchangeable with the double lipped RTC3511. Anyone know more about this? True or BS?

Secondly,

Grover, three questions if I may:

When you did this were you supplied with new front axel shaft seals (swivel housing to diff casing) to match the larger half shafts? I haven't got any with the stuff I bought.

What about the rear outer shaft seal? If retained is that kept original? Or would it require a new larger seal? I presume the upgraded rear shaft is thicker than the original (although I don't know this) so a replacement one is required.

And, did you find the end float had changed much with the new CV and halfshafts? Did it require adjustment of the shims between the flange and cir clip on the front? And since the originals are one piece flange and shaft - what about the rear? I'm wondering if I should try to acquire some shims just in case, and perhaps how many, or just hope for the best. If you know the part No. that'd be helpful.

So.....

at the moment I'm toying with the idea of keeping all of the seals and just upgrading the outer seals to higher spec (RTC3511 / FTC4785 type) and tapping a fill and drain hole in each of the HD flanges. I've measured them up and it looks like theres plenty of meat on them to accommodate a couple of 5 - 7 mm holes. This way I have drainable oil lubed hubs, greased CV's / swivels (not drainable due to no drain plug), and (of course, hopefully?) oil in the diff. The main advantage to this being a reduced chance of cross contamination between these areas if / when seals fail and allow them to be checked for contamination independently. It dawned on me that without a drain plug in the swivel housing it'll always be a strip down job to replace the lube in there as you can never drain the bottom of the swivel housing through the hub or the diff. If it had a drain I'd use oil in the swivels (not tap the hubs) and change regularly but I don't plan on breaking these down too often so grease I think is a better long term option for the CV given longer service intervals.

Any comments on the above plan would be gladly received.

Thanks,

Ian.