Plus 2 rear end

[davidcroft]

I had the rotoflex joints on my Plus 2 changed by a local garage, and on
return there was a noticeable 'hum' coming from the rear.

It turns out that the noise is coming from one of the wheel bearings.
The fitter tells me that the bearing must have been 'borderline' before,
but that the tired (and cracked) rotoflex joints weren't putting it
under tension. With a new, 'stiff' rotoflex in place, the load is
causing the bearing to complain.

Does this sound reasonable ?

The mechanic is an old racer of Elans, so he should know his stuff.

Can I check that the rotoflex joints have been installed correctly - I
know they are 'handed' but I'm not sure what to look for under the car.

I am seeing the car at the garage in 8 hours time, so any ammunition
received before then would be great.

The garage guys also tell me that changing the bearings is a long and
involved job, but that I can quite happily continue to drive the car,
for as long as the noise doesn't get any worse. True or False ?

Thanks in advance for any advice...

David
'71 Plus 2S

[paul_adamson]

The garage guys also tell me that changing the bearings is a long and
involved job, but that I can quite happily continue to drive the car,
for as long as the noise doesn't get any worse. True or False ?

Thanks in advance for any advice...

David
'71 Plus 2S
------

This depends on how bad the noise is. The problem is that if the bearing starts moving in it's mount it is likely to knacker the hub and that is REALY bad news

Brian

---------------------o0o------------------
Brian Scally - Philips Semiconductors Systems Lab. Southampton UK
tel : +44 2380 312654 fax : +44 2380 316303
mailto:[email protected] seri : bscally@ukpsshp1

[sprinterdave]

In message <[email protected]>, DAVID CROFT
<[email protected]> writes

drive shafts, this will ensure the correct length of drive drain. THe
other 3 high bosses will there fore make contact with the 3 lugs of the
outer driveshaft, those tha trun through the bearing housing, and the 3
ligs on the diff output shafts.
hope this helps
Dave

--
David Shiers

[types26/36]

Hum could be from bearings in hub carrier and/or output bearings in final
drive case. I think your mechanic should have checked all of these while
the old rotoflexes were out and contacted you if he found bad ones to ask
your OK on replacing them. As it is now, the rotoflexes will have to come
back out to replace the bearings.

Randall
Seattle

[davidcroft]

Randall

Hum is definitely coming from the hub carrier, not the diff.

Any thoughts on original question about whether this could be caused by
incorrect installation of replacement rotoflexes...or could the new
doughnuits make already-tired bearings grumble?


Regards


David

[paul_adamson]

I suppose (in italics)
that disturbing the rear suspension could push one of the bearings over the
edge.

I wouldn't say that changing a bearing is the end of the world
But as someone else said, to change the bearing will require the driveshaft
off again.
Make sure that you aren't paying for this work to be done a second time.

As far as fitting a rotoflex the wrong way round is concerned, I can only
imagine
the drive line would look very stressed indeed.

If the rotoflex couplings (or just one of them) had been installed the wrong
way round
you may be able to detect this if you jack each rear wheel up in turn and
rotate it.
They should turn smoothly, if a rotoflex had been installed backwards, I
imagine it would turn in a series
of jerks as the coupling compressed and uncompressed.


Paul Adamson

[BrianMartley]

David,

I see someone else has given the correct way of fitting the rotoflex. I just
can't imagine how anyone could fit them the wrong way round - tightening the
bolts would give you the message I think - it's going to put each one out by
around 5mm I would have thought (guessing).

New rotoflex stressing the line enough to make a bearing rumble sounds a bit
odd, they are supposed to be pretty much neutral under normal running
conditions otherwise they'd get worn out even quicker than they do. The only
reason the rubber is there is to take up slight expansion/contraction as the
wheel goes up & down, so the normal position should be zero lateral stress.
Oh, and it takes shock loads out of the diff - but I think that was a bit of
quick thinking on Lotus' part when people said they flexed a lot in the
early days .

Must admit, if it was a bearing rumbling, I'd change it, the cost of a new
hub carrier is going to spoil your Christmas. Check by jacking up the car
and looking for side-to-side play in the wheel - should be none really. It
is a long job though, I'd reckon on an evenings entertainment - so half a
day ?

Brian

Brian

[rodney]

At 09:33 AM 8/2/99 +0100, you wrote:


David

With the right equipment the job should only take a day at maximum to
complete. Even removing the strut to place the unit on a press and reinstal it
should still only take a day. We are only talking about 8 bolts to undo,
placing the unit on a press to remove the bearings. Then reassembling. I did
this job in a country garage while on holidays without the right equipment in 2
days, including driving 80ks each way to get the bearings and I had never done
it before.

Once a bearing starts to go there is no telling how long it will last. If you
drive it and get stuck miles from home on a wet winters night you will curse
your stupidity for a week. Get it fixed now and save the heartache later. As
some one else pointed out it could also damage the shaft and this would be a
long job to fix.


Rodney Stevens
Home Phone: 61 2 42942428
Email: [email protected]

Work Phone: 61 2 97106701
Work Fax: 61 2 97106789
Email: [email protected]

Elan SS s/e 45/7616
http://sites.netscape.net/rodjohnstevens/homepage

[types26/36]

I am just guessing, but it seems possible that new rotoflexes, if they are
stiffer than the old ones or have yet to take a set, could put additional
side load on bearings and make wear more apparent. Incorrect installation
could also do this, but you can verify it just by looking (another message
described what to look for.)

But as I said, I think the mechanic should have checked the bearings before
proceeding with rotoflex installation.

At 16:52 8/2/99 +0100, David Croft wrote:

[rodbean]

Brian Martley wrote:


I wouldn't be surprised if that rumble Brian heard (maybe felt) was there all
along but there was other noise (or slight resonance) masking it until the
donuts were replaced.

Rod

[davidcroft]

A quick 'thanks' for the advice about my Plus 2's rumbling rear...

It's a real help to have your input so I don't seem like such an idiot
when I talk to the spanner-man.

Regards

David