Jump to content

Recommended Posts

Due to the forced engine extraction, I decided that with the gearbox out I would revert to a non overdrive gearbox. Got to save about 15kg and also it was pointless loosing power and also risk blowing up a good overdrive box that if some day I return the car to predominently road use I might really appreciate.

 

So over the winter I sourced a goodish SH NonOD box, mounting plates and propshaft. Gearbox should be back from rebuild next week, so today I set about stripping the propshaft to fit new UJ's so that it can go off for balancing next week.

 

OK so where does Mike Oldfield come in? Well not any tuning specialist I know, but the Guy that wrote Tubular Bells would probably liked to have had it. It rings beautifully due to what I think must be a tiny piece of weld splatter "INSIDE" the tube. However much as it makes a great sound I'm not sure if I like it or what if anything to do about it.

 

The big questions are will it do any harm, and will it make a noise when fitted.

 

If I tilt the shaft backwards and forwards it makes a loud tinging as what ever it is tumbles down the tube, and if I rotate it, it rings as the piece bounces around.

 

So obviously there won't be much tilting when fitted, it should just roll downhill to the diff end, so the big question is what's it going to do when the shaft is rotating at speed, is centrefugal (? ought to speel check that) force going to keep it in one position or is it still going to bounce around and ring?

 

Unfortunately I don't know who owned the car the prop came from to ask, but it could be that for 40 years the car drove around with a constant background pinging noise, and one of the benefits the guy found from having a Type 9 gearbox fitted was that suddenly the car was quieter.

 

So do I leave well alone and just use it, but be very annoyed if it rings, or do I try and do something about.

 

OK yes I could get someone to cut one of the end flanges off, remove, and reweld. But it seems a bit excessive.

 

Or as I'm getting it balanced anyway I wondered about drilling a 1/4" hole in the tube, rattle it out, and then just put a blob of weld in the hole before balancing.

 

Thoughts or anyone had anything similar.

 

Alan

 

 

Link to post
Share on other sites

Hi Alan,

 

I wonder if it might be a needle roller from a U/J inside?Don't know how it could as I have never studied a TR propshaft,is there any orifice at the end?

I remember an old AEC lorry where I used to work had a bolt inside the propshaft for many years ,nobody new how it got in there or how to get it out and you could only hear it at low speed never did any damage though.

Link to post
Share on other sites

I doubt you'll notice anything at all.

 

Nick

Probably the blast of reality I needed, I probably wouldn't hear if there was a stereo playing the full Tubular Bells underneath the car over the noise of everything else :-)

 

Will be interesting to see if the balancers flag it up, or are humming a Mike Oldfield tune when I pick it up!

Link to post
Share on other sites

Dropped the propshaft of at Dave Mac Propshafts in Coventry yesterday for balancing, and they confirmed that that from above 300 rpm virtually anything inside a propshaft will remain static, the little bits in propshafts are apparently fairly common and are tiny bits of metal ejected from the internal surface when the original balancing weights were spot welded on.

 

However I did get my wrists slapped (in a nice way) for fitting some of the circlips on the UJ's incorrectly. Now I never realised that UJ circlips had a right way and a wrong way (In fact often I have been gratefull to just get them into the grooves as the tollerances on modern UJ's seem to be all over the place, I now have a box of different thickness circlips to ensure that the drive shaft cups are good and tight).

 

But any way what I didn't realise (but I suspect all you old hands do) is that all circlips have a flat side and a curved side, and that it is important that the flat side is outermost i.e. against the outer lip of the groove. Apparently if the curved side is out the circlip is only gripping on a smaller part of its surface area, and they can and do work out with potentially damaging consequences.

 

Anyway the guys at Dave Mac are really nice and are going to make sure they are all fitted correctly before balancing it, they don't like them flying out at 5000 rpm on the balancing machine!

Link to post
Share on other sites

That is an interesting one.

 

The radius'd edge is caused by the stamping process during manufatcure.

 

What would cause the circlip to come out.

Centrifugal forces on the clip throwing out of the UJ with the cup also forcing it on its way.

The force would be affected by the diameter, weight of the clip and cup and the RPM.

The cups would be held in place by friction and other pressure forces as the inner bosses press on the bearing/cup - so the weight could reduce very significantly.

So the only real problem is the weight of the clip - not a lot.

 

Thus the radial force pushing the clip out is being counteracted but by the spring effect of the clip and the pinching of the clip in the groove and the cup loading that pinching effect.

 

I would suggest that the centrifugal forces would have to be very very great to overcome the spring/pinch load on the clip.

 

But more simply - has anybody experienced a properly fitted clip coming out.

 

Having said all that, it is good engineering practice to follow what the prop lads have said.

 

Roger

Link to post
Share on other sites
  • 2 weeks later...

It's not often these days that one gets the opportunity to praise suppliers, but thought I ought to put in a word for the guys at DaveMac Propshafts and their subsiduary Gripper LSD.

 

Not only did they sort out my wrongway round circlips, but also decided that they didn't like the fit of one of the new UJ's I had fitted, so fitted a new one with selected circlip depths to get the fit just right. Charged less than the current retail for a new UJ and about £15 for all the extra work. Next time "if there is one" I think I'll just ask them to quote for replacing the UJ's before balancing and save all the effort.

 

Also their Gripper folks took a NOS Gripper LSD Diff I had aquired, upgraded the LSD to the latest spec internals, set it to my specification, all for the cost of the new bits, and put it on their lifetime warranty. Also as they were unhappy about how stiff the rebuilt NOS diff was, they got a local Triumph experienced guy to strip and reset the complete diff for a no brainer amount.

 

So Service and Cost wise First Class, if the bits perform as good as the service I will be a happy bunny.

 

Alan

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...

Important Information

Please familiarise yourself with our Terms and Conditions. By using this site, you agree to the following: Terms of Use.