Derrick Posted October 24, 2018 Report Share Posted October 24, 2018 One thrust washer for crank was fitted the wrong way round. It wore in to the crank and ended up with 5 mm end float. This caused stress on the camshaft via the chain an induced wear on the camshaft slot causing end float of about 5mm . Eventually this end float was sufficient for a cam follower to drop into path of lob of camshaft and seize the camshaft. At this point the camshaft sprocket was ripped off and chain snapped. Engine has only completed 10k since rebuilt and sounded fantastic with no indication it was about to spit its dummy out. Engine out and off to the engine guys to see what can be saved :-) Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 25, 2018 Report Share Posted October 25, 2018 I have a exact cppy of that thrust , one in my 2000 was fitted back to front its not done the crank any favours Shes now running with right way round re bedded (allowed to wear in) to suit the wear on the thrust face and then re gapped for float Its still ok after 2000 miles so fingers crossed Derrick thats pretty nasty to have wrecked the cam Pete 1 Link to comment Share on other sites More sharing options...
Anglefire Posted October 25, 2018 Report Share Posted October 25, 2018 I bought an engine for my Spitfire that had been "rebuilt" - not very well its turned out - but did spot the thrust bearing being the wrong way around before I put it in the car. 1 Link to comment Share on other sites More sharing options...
Guppy916 Posted November 4, 2018 Report Share Posted November 4, 2018 I had that thrust problem on my GT6 MK3, I got the guy's in the engineering shop to modify the rear main cap so I now have a 360 thrust bearing, both sides of the mains cap, fingers crossed it will out last the clutch's life 1 Link to comment Share on other sites More sharing options...
Derrick Posted November 7, 2018 Author Report Share Posted November 7, 2018 Clever, nice job. Link to comment Share on other sites More sharing options...
GFL Posted November 7, 2018 Report Share Posted November 7, 2018 Yes a worthwhile modification to one of the weak points on the Triumph 6, although all the cars I've ever owned have never suffered excessive end float? I've seen it done on TR's too, maybe the longer stroke makes them more susceptible to this problem. Regards Link to comment Share on other sites More sharing options...
NonMember Posted November 7, 2018 Report Share Posted November 7, 2018 It's not the long stroke -- that makes them more vulnerable to big end failure but not thrusts. The reason the 2.5 is more prone to it is that the clutch needs heavier springs to take the torque, meaning the thrusts work harder. You almost never see worn thrust washers on an auto I've seen terminal thrust washer failure on an 1147cc Spitfire engine. I don't know whether they'd been fitted the wrong way round because by the time we looked they were both in the sump. Needless to say, that engine was scrap. 1 Link to comment Share on other sites More sharing options...
GFL Posted November 7, 2018 Report Share Posted November 7, 2018 A mate had a lovely 1500SE Dolomite back in the mid 1980's it was used all the time for work etc, mileage wasn't massive, 50K or so. One lunchtime he asked me to help investigate why he was struggling to get it into reverse gear, on dipping the Clutch the Fan was seen to be moving forward nearly 1/2"!!! This turned out to be the Thrust washer problem, he ended up putting a 1300 Engine in it from a local scrapyard. I think the longish stroke of the 1500 and 2500, together with the smallish Big end journals was a stretch to far by Harry Webster and his team considering the original engine was only 800 odd cc?!!! Link to comment Share on other sites More sharing options...
dougbgt6 Posted November 7, 2018 Report Share Posted November 7, 2018 Gary, My car had a massive end float when I bought it, 1/4" IIRC, only 5 years old. Replaced the thrust bearings, but the bores had worn in an elongated "S" shape with the crank whacking back and forth. Re-bore time! Doug 1 Link to comment Share on other sites More sharing options...
Pete Lewis Posted November 8, 2018 Report Share Posted November 8, 2018 We repaired a 1300fwd dropped thrusts by welding new location lugs on the bearing cap , a metal spray and regrind restored the crank and the engine ran for 10 years The thrusts do only their main take load from operating the clutch , and the clutch on 2000,25000, 2500pi vitesse 2ltr and all Gt6 use the same clutch cover the big saloon has a better withdrawl system but that does not save the thrusts Its more down to the limited half moon design and type of driving clutch duration like urban or motorway use Pete Link to comment Share on other sites More sharing options...
johny Posted November 8, 2018 Report Share Posted November 8, 2018 the thrust generated by the clutch is the reason I dont understand why some modern cars now require the clutch to be operated before starting - surely this is the quickest way to finish off the thrust bearings? Link to comment Share on other sites More sharing options...
Pete Lewis Posted November 8, 2018 Report Share Posted November 8, 2018 i think thrust tec has moved on from the old designs we suffer, and the clutch press or apply brake is now quite normal safety feature of push start self start cars equipment ,when they are 40 year old we will know how the trusts survive this operation ?? olde days some had so much cold oil gearbox drag dipping the clutch relieved the starter load and its thought to aid starting firing it up to fast idle from cold is hardly going to dregrade a thrust designed to take clutch thrusts at anything up to 6000rpm the wear takes place at premium rpm not ticking over Pete Link to comment Share on other sites More sharing options...
Nick Jones Posted November 8, 2018 Report Share Posted November 8, 2018 Cold start thrust will be largely unlubricated though.......... most moderns have full circle thrust washers though - and formed as part of a main bearing shell too so they can't fall out. Nick Link to comment Share on other sites More sharing options...
johny Posted November 8, 2018 Report Share Posted November 8, 2018 39 minutes ago, Nick Jones said: Cold start thrust will be largely unlubricated though.......... most moderns have full circle thrust washers though - and formed as part of a main bearing shell too so they can't fall out. Nick unlubricated especially as now modern oil is like water.... Link to comment Share on other sites More sharing options...
daverclasper Posted November 8, 2018 Report Share Posted November 8, 2018 It's interesting. I think Nick once mentioned, that his old Vitesse engine had kept to 16,thou of thrust play for it's past 30,000 miles of hard'ish driving (please correct me if I'm wrong Nick) and yet Doug's thrust washer had dropped out after 6 years. Dave Link to comment Share on other sites More sharing options...
Nick Jones Posted November 9, 2018 Report Share Posted November 9, 2018 Yes, that's 30,000 that I know of. I hadn't properly measured it before, just noted that it had a "small amount of clonk". So the figure could have been fairly constant for a lot longer. It did just under 70k with me but had been in 3 cars before mine so the total will be considerably more. It's an original Triumph build and still hanging on my engine stand awaiting post-mortem , though was actually still running well apart from it's oil habit. I never start with the clutch down, and don't do much town driving in that car. Nick Link to comment Share on other sites More sharing options...
dougbgt6 Posted November 9, 2018 Report Share Posted November 9, 2018 I should explain. The PO (I'm No.2) used the car to tow a boat far too heavy for it, consequently the suspension and the engine were knackered after 30k miles. He didn't believe in maintenance, trunnions not oiled since it left the factory. I oiled them, but too late, broken vertical link shortly after. His name was Keith Chitty, a serial Triumph abuser. Doug Link to comment Share on other sites More sharing options...
poppyman Posted November 9, 2018 Report Share Posted November 9, 2018 11 minutes ago, dougbgt6 said: His name was Keith Chitty, a serial Triumph abuser. Doug Have you spelt his surname right Doug? Should there not be an "S" in there at some point Tony. 1 Link to comment Share on other sites More sharing options...
daverclasper Posted November 9, 2018 Report Share Posted November 9, 2018 A lot of clutch slipping to get moving with the boat?. Link to comment Share on other sites More sharing options...
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