signalredshaker Posted November 29, 2014 Report Share Posted November 29, 2014 Just starting to hopefully fix noise on overrun, so lifted gearbox out yesterday (well, dragged actually) and found that the clutch diaphragm markings from the release bearing are not where I expected them to be- see photo. Is this perhaps because I have the wrong release bearing- see photo? Also, the oil is really frothy man- I'm using a branded GL4 EP 80W-90 oil. Any ideas guys? (and gals). Quote Link to post Share on other sites
RogerH Posted November 29, 2014 Report Share Posted November 29, 2014 Hi SRS, the wear marks are about right. The ends of the tang never get touched (somebody will say they do but i've never seen it) What make is the release bearing. RHP from Moss etc (the expensive one) works well. Engine oil has the ability to froth but not seen EP80 doing it. However the diff gears, where EP80 oil is used, has a different action to gearbox gears. Why not change it and put in Gearbox oil (30, 40 or 50 weight). The gearbox and OD will love you forever. TRiumph changed over to EP80 oil from SAE40 gearbox oil for a reason - that reason is lost in the mists of time. Norman DeVille Laycock (the OD manufacturer) never recommended EP oils. Roger Quote Link to post Share on other sites
boxofbits Posted November 30, 2014 Report Share Posted November 30, 2014 With regard to frothing oil, you might check that if there is a breather on the box it is not blocked. Without looking into it I am not sure there is one but worth checking Quote Link to post Share on other sites
peejay4A Posted November 30, 2014 Report Share Posted November 30, 2014 (edited) Following up on Boxes point above. If you have an A-type overdrive it will/should have a breather already on it. If you have a J-type it doesn't have such a breather and a relief hole is needed in the gearbox top cover. It's towards the front of the cover and its exact position can be found by using the forum search function as I had no breather on my J-type setup and had to drill the hole. I didn't get frothing but plenty of oil loss. Edited November 30, 2014 by peejay4A Quote Link to post Share on other sites
RogerH Posted November 30, 2014 Report Share Posted November 30, 2014 Hi Folks, how would a breather stop frothing. Roger Quote Link to post Share on other sites
Lebro Posted November 30, 2014 Report Share Posted November 30, 2014 +1 The breather just helps to stop oil leaks due to pressurisation. BTW the saloon "A" type O/D does not have a breather hole as standard, I drilled the top plug on mine to create one. Rear axles also benefit from a breather for the same reason. Bob. Quote Link to post Share on other sites
john.r.davies Posted November 30, 2014 Report Share Posted November 30, 2014 Those marks on the diaphragm points look excessive to me, as if the bearing has been banging on them, rubbing or even moving about on the spring. The marks I've seen show a light polishing in a much more limited area, but I don't know what TR4 clutches should look like! Is the bearing free running? Does it fit well in the fork (or however a TR4 holds it)? Is the fork loose? Your problem was noise on the overrun - could this be a bearing that was clattering the spring, as it was poorly positioned? Glad to be shot down, for overreaching from six cylinder experience. JOhn Quote Link to post Share on other sites
signalredshaker Posted November 30, 2014 Author Report Share Posted November 30, 2014 Thanks for the replies. Wondering if the frothing could be oil contamination of some sort, but hard to see how. O/D has a breather, a short stubby one with a hole in the side at the top. could the marking on the clutch diaphragm be due to poor clutch adjustment. If so that should be easy to correct. The clutch is a 4A one and the bearing was a good'un so will replace anyway. The noise on overrun is more troublesome and I've seen little about that subject on the forum other that the death rattle syndrome, which I think I'm OK with. It seems as if it sounds like a very badly worn gearbox, but on dismantling so far it looks, to my untrained eye, to be in pretty good nick. The layshaft is unmarked and the bronze thrust washers are Ok. I think it wise to replace both mainshaft bearings and the input shaft bearing, if I can get it out. The whole of the mainshaft cluster is not yet taken apart, so I'll have a good look soon. James Quote Link to post Share on other sites
john.r.davies Posted November 30, 2014 Report Share Posted November 30, 2014 Just noticed the size of the three posts you put up, SRS. Do you realise that you have thereby used up three quarters of your picture allowance? JOhn Quote Link to post Share on other sites
graeme Posted November 30, 2014 Report Share Posted November 30, 2014 James, In the mainshaft cluster there is a top hat bush in the 2nd gear which is prone to breaking. This is likely to be the cause of your over run noise. Good information here. http://www.buckeyetriumphs.org/technical/technical.htm Cheers Graeme Quote Link to post Share on other sites
signalredshaker Posted November 30, 2014 Author Report Share Posted November 30, 2014 "Picture allowance"- come again? Thanks, I'll check the bush when I strip the mainshaft assembly tomorrow. Sounds like it might be an issue. James Quote Link to post Share on other sites
RogerH Posted November 30, 2014 Report Share Posted November 30, 2014 Hi James, I think John is refering to the size of your three pics. However you have only used 300Kb of a 1.9Mb capacity. Don't panic. Quote Link to post Share on other sites
john.r.davies Posted November 30, 2014 Report Share Posted November 30, 2014 Oops, thought it was 500 - but that's in another place. Still, it is a limitation, if you want to leave pics for future reference. John Quote Link to post Share on other sites
signalredshaker Posted December 1, 2014 Author Report Share Posted December 1, 2014 Thanks all, for your input. Graeme, you are bang on. See mainshaft bush photo- how do these get broken I wonder? Did notice a slight bronze hue to the oil, but no bits. Is the uprated bush worth it? Also, whoever said getting the mainshaft circlip off was also right- what a job! It's slightly bent. James Quote Link to post Share on other sites
john.r.davies Posted December 1, 2014 Report Share Posted December 1, 2014 Thanks for the feedback, James! Lets us all learn, except Graeme, who knew already. John Quote Link to post Share on other sites
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