high rattle; what can it be?

[rolf]

Since a few weeks my Sprint makes a strange noise.It brings a high pitched rattle when driving<br>
When in idle there's no rattle. Just touching the clutch paddle brings up a rather high rattle in the front end of the engine. Engaging the gears and driving off the rattle is high and related to the RPM's. When taking the throttle of the rattle stops. Slow driving, no thrust and braking on the engine the sound is almost gone.<br>
The car received a new clutch kit (pressure plate et al)but had this sound before.<br>
What strikes me is:<br>
1 the rattle looks related to the clutch but varies in engaged gears and off load<br>
2 the sound is at the front of the engine<br>
3 the car performs without loss of power<br>
Can it be: chain belt or tensioner, but then it should be heard always?<br>
Is some movement in the crankshaft (we checked and think there can be some movement) to be the cause?<br>
<br>
Thanks, Rolf<br>
(1974 Sprint)<br>


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[Jon Tilson]

seems the most likely cause to me and would be the first thing to change. If it hasnt been done in a while its no great loss, relatively easy job.<br>
Crank end float should be barely detectable and IME on a Sprint is rarely a problem.<br>
Can you move the pulley in and out? If so then engine out quick...<br>
<br>
Jonners

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[alun n]

Alternator bearings?<br>
<br>
Try it briefly without the belt attached - wouldn't explain no noise at idle or the influence of the clutch peddle, but it will eliminate the alternator/pulleys/vc etc<br>
<br>
Water pump bearing?<br>
<br>
Dunno!

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[Chris Field]

.. viscous coupling? - combined with crank end float might change the angle of the belt slightly and put enough side load on the bearings to shut 'em up? <br>


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[george]

sounds like crank thrusts end float on the crank<br>
should be <br>
.003/.011 in<br>
0.08/0.28mm<br>


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[speedracer]

Worn collets? ... Hope not, but you never know ... until a valve drops into the motor of course (mind you i'm the unluckiest person i know <!--EZCODE EMOTICON START :( --><img src=http://www.ezboard.com/intl/aenglish/im ... /frown.gif ALT=":("><!--EZCODE EMOTICON END--> )<br>
<br>
speedracer

<p><!--EZCODE LINK START--><a href="http://www.triumphowners.com/2">1975 Dolly Sprint</a><!--EZCODE LINK END--></p><i></i>

[rolf]

Gentlemen,<br>
<br>
Thanks sofar for all your ideas. I've checked most of them and counted them out. There's only one alternative I can think of but it means the whole gear, clutch or engine has to come out to deal with, so I check first with all you experts. In the end I'll have to take it all out I guess...<br>
Can it be the bearing of the constant pinion shaft?<br>
I can say after some extensive gathering of information, that the rattle is "connected" to the clutch operating, only under serious load and there's no floating of crankshafts or whatsoever.<br>
<br>
Rolf

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[john 16v]

better than a low rumble.<!--EZCODE EMOTICON START :rolleyes --><img src=http://www.ezboard.com/intl/aenglish/im ... s/eyes.gif ALT=":rolleyes"><!--EZCODE EMOTICON END-->

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