mleadbeater Posted February 6 Report Share Posted February 6 Hi Just about to drop the sump and replace the thrust bearings on my ‘6, as have measured ten thou of endfloat. It seems crazy to only incorporate half bearing shims for each side of the main, so am wondering what is involved in fitting them to the bearing cap as well. I notice Racestorations sell complete sets of upper and lower shims, to double the thrust area. This seems a good way to go. Does the main cap need machining to fit these? Any experience or suggestions please. Cheers Mike Quote Link to post Share on other sites
TRTOM2498PI Posted February 6 Report Share Posted February 6 Hi Mike, Whilst I cannot answer your question specifically, if the engine has been assembled nicely, you will not have any issues with them falling out, in standard spec. Cheers. Quote Link to post Share on other sites
mleadbeater Posted February 6 Author Report Share Posted February 6 Hi Tom Thanks for your reassurance. Im more concerned about the poor service life of these half bearings, the engine was rebuilt around 30 k miles ago, and is already 2 thou over tolerance . If a simple mod can improve this, I will make it. I don’t like poor design, all too common in the UK motor industry in that era. It’s part of the fun of ownership to include upgrades wherever possible. cheers Mike Quote Link to post Share on other sites
RogerH Posted February 6 Report Share Posted February 6 (edited) Hi Mike, I don;t know if this is any help Thrust Washer There may also be another chap in the states that does bespoke offerings. Roger Edited February 7 by RogerH Quote Link to post Share on other sites
Andy Moltu Posted February 6 Report Share Posted February 6 With regular oil changes they should last ages unless you spend ages with your foot on the clutch pedal. Quote Link to post Share on other sites
mleadbeater Posted February 6 Author Report Share Posted February 6 (edited) Andy, they Should, but isn’t it common knowledge that Triumphs of this era suffer from premature thrust bearing wear? Thanks Roger, can’t seem to open that link, will keep trying. Ive seen the American guys offerings of wider shims. Mike Edited February 6 by mleadbeater Quote Link to post Share on other sites
kiwican Posted February 6 Report Share Posted February 6 This is the American guy's web site for reference https://customthrustwashers.com/ Simon Quote Link to post Share on other sites
Mike C Posted February 6 Report Share Posted February 6 Don't depress the clutch pedal while starting- unlike most modern cars. When starting with a depressed clutch the thrust bearings have a high loading but no oil pressure. Quote Link to post Share on other sites
michaeldavis39 Posted February 6 Report Share Posted February 6 So you are saying its better to put foot on clutch before you start engine to take it out of gear- then once out of gear take foot off clutch and then start engine on a Tr6? Quote Link to post Share on other sites
harrytr5 Posted February 7 Report Share Posted February 7 (edited) 10 hours ago, michaeldavis39 said: So you are saying its better to put foot on clutch before you start engine to take it out of gear- then once out of gear take foot off clutch and then start engine on a Tr6? When Starting the engine, don't touch the clutch and out of gear. Regards Harry Edited February 7 by harrytr5 Quote Link to post Share on other sites
JohnC Posted February 7 Report Share Posted February 7 My thrust bearings have lasted over 50k miles (so far) since I rebuilt the engine. Tolerances were still fine when I checked recently after a total oil loss. I'm totally unconvinced an "upgrade" is necessary except to fill the pockets of the vendor, or if you think the other components will last 200k miles + (insert ridiculous number here of your choice). Of course, you may like to ride the clutch, hold down the clutch when starting, etc, in which case YMMV. Cheers, JC Quote Link to post Share on other sites
Mike C Posted February 7 Report Share Posted February 7 3 hours ago, harrytr5 said: When Starting the engine, don't touch the clutch and out of gear. Regards Harry +1 Quote Link to post Share on other sites
Jonny TR6 Posted February 7 Report Share Posted February 7 15 hours ago, Mike C said: Don't depress the clutch pedal while starting- unlike most modern cars. When starting with a depressed clutch the thrust bearings have a high loading but no oil pressure. Thanks Mike - I’ll pop this in Tips & Tricks as I didn’t know that. Quote Link to post Share on other sites
dingle Posted February 7 Report Share Posted February 7 Mike-The TR6 engine was derived from the same family as the Spitfire, which also had half circle thrust washers. I am not sure if the TW were a problem on the Spit, but the stiffer clutch required on the 6 could be the cause of TW problem. Too bad the factory didn't full circle TW early in production, as the cost would have been minimal. Anyway, I monitor the TW wear, keep my foot off the clutch when starting the engine, and have never had over .002" wear every 5 years plus. Last year, just out of boredom, I installed one of Scott Helm's bronze TW. It should outlast me. I noticed that Scott uses a mill to machine the bearing cap to add a TW. I made a simple fixture to do in a lathe and used on an extra block, but didn't try it on my daily driver. Berry Quote Link to post Share on other sites
harrytr5 Posted February 7 Report Share Posted February 7 Berry I like the idea of a full circle Thrust washer on the thrust side ie flywheel side. Did you machine the mains cap to suit the extra thrust washer? Shame you did not try it. I am in dialogue by email to Scott Helm and will buy a set off him. Regards Harry Quote Link to post Share on other sites
dingle Posted February 8 Report Share Posted February 8 Harry-I did machine the main cap of an extra block. Later, I gave it a person in need of a block. He had Scott make a bronze TW and as far as I know it is in service. Berry Quote Link to post Share on other sites
mleadbeater Posted February 8 Author Report Share Posted February 8 Hi, Just got the blighters out, and am perplexed. My engine had 10 thou end float, ie 2 thou over the spec, not much, but as it seems an easy and low cost fix, might as well renew them. Both bearings are marked as standard, which, according to sources are .920” thick. Mine measure .9325”thick, ie. theoretically +12.5 thou oversize, so whats going on? They also look virtually unworn. Annoyingly, the parts suppiers, Rimmers, Moss, etc, only quote the oversize plus figure, +5, 10, etc. So, what oversize do I order, is it plus 5 thou, or plus 15, or what? Anyone any experience please. Cheers. Mike ps sorry, the inverted photo poltergeist is at it again. Quote Link to post Share on other sites
harrytr5 Posted February 9 Report Share Posted February 9 If you are measuring 10 thou clearance then +5 thou should do it fitted on the flywheel side. Then measure again. Make sure the grooved side is facing the flywheel and the front facing the front (bearing surfaces). Racetorations does some lovely ones but only standard. I have several sizes including +20 thou which I think I got from Racetorations years ago and look and feel the dogs do dahs. Regards Harry Quote Link to post Share on other sites
JohnC Posted February 10 Report Share Posted February 10 On 2/9/2024 at 6:24 AM, mleadbeater said: Both bearings are marked as standard, which, according to sources are .920” thick. Mine measure .9325”thick, ie. theoretically +12.5 You could always assume the sources are wrong but the stamp is correct. If they’re virtually unworn then do as Harry says. Or order a couple of spares in different sizes and mix & match until you’re happy. The postage will likely be more than the TWs themselves! Cheers, JC Quote Link to post Share on other sites
mleadbeater Posted February 10 Author Report Share Posted February 10 Thanks for your replies Have ordered some plus 5’s, from Rimmers, will see what comes. n.b. whilst waiting, i’ve been looking at making my own. It’s possible to buy a piece of aluminium bronze plate, 3 mm thick by 100 mm sq, so it shouldn’t be a problem to turn up some bearings on my lathe, and mill some oilways. Mike Quote Link to post Share on other sites
Andy Moltu Posted February 10 Report Share Posted February 10 You can mix oversizes to get the correct end float. If it is close, make sure you don’t go below the minimum as there is a risk of them grabbing when the engine is hot and doing serious damage. Quote Link to post Share on other sites
Kenrow Posted February 10 Report Share Posted February 10 On 2/8/2024 at 11:24 AM, mleadbeater said: Hi, Just got the blighters out, and am perplexed. My engine had 10 thou end float, ie 2 thou over the spec, not much, but as it seems an easy and low cost fix, might as well renew them. Both bearings are marked as standard, which, according to sources are .920” thick. Mine measure .9325”thick, ie. theoretically +12.5 Mike, you’re off by a decimal point. Standard is 0.092” with yours 0.0932”. So you are +0.00125“. Quote Link to post Share on other sites
mleadbeater Posted February 11 Author Report Share Posted February 11 (edited) Just received my new thrust washers , from Rimmers, very pleased. At plus 5 thou, they measure 0.097” which agrees with my “standards “ being 0.093”, so don’t know where the quoted standard of 0.092” comes from? Anyway , they are copper coated, not white metal, so should last well. If I fit one to the thrust side of the main, and a std original one to the non thrust side, my 10 thou lash will be reduced to 5 thou. Comparing the minimum quoted lash of 6 thou for Triumph engines, to , for example the XK engine, or XPAG, which quote a minimum of 3 thou, I reckon this will be OK. cheers Mike Edited February 11 by mleadbeater Quote Link to post Share on other sites
Andy Moltu Posted February 11 Report Share Posted February 11 They used to be available in 2.5 thou oversize but can’t find them now. Quote Link to post Share on other sites
mleadbeater Posted February 12 Author Report Share Posted February 12 Andy, the grabbing that you refer to, have you heard of instances of this happening? If 3 tho is ok for XK and XPAG engines, I think the 5 thou clearance should be fine. Mike. Quote Link to post Share on other sites
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