carld Posted June 22, 2015 Report Share Posted June 22, 2015 Gents Did a 1,000 mile trip to Spa and back and didnt miss a a beat, got in it last Friday for a local TR weekend and I have an intermittent problem when selecting 2nd gear it feels like no drive/clutch slip and then it bites. Feels a bit like overdrive trying to engage, but without me selecting over drive, all other gears and overdrive have no issues. Unfortunately I am not going to be able to investigate for sometime, but was looking for a steer in the meantime. Cheers Carl Quote Link to post Share on other sites
Motorsport Mickey Posted June 22, 2015 Report Share Posted June 22, 2015 Tain't the clutch slipping on the gearbox, clutch slip occurs in the highest gear first because that's where your applied torque is higher ie in 4th, and is there all the time gradually coming down the gears as the clutch slips more and the wear accelerates on the friction plate. Is there a problem with an overdrive inhibitor switch on the top cover ? Mick Richards Quote Link to post Share on other sites
carld Posted June 22, 2015 Author Report Share Posted June 22, 2015 Thanks Mark, that was one of my thoughts. Cheers Carl Quote Link to post Share on other sites
peejay4A Posted June 22, 2015 Report Share Posted June 22, 2015 Puzzling. I don't see how it can be down to the interlock switches as they only come into play when the overdrive is selected on the steering column, assuming it's wired correctly. Quote Link to post Share on other sites
littlejim Posted June 22, 2015 Report Share Posted June 22, 2015 When that has happened to me it has been the clutch plate worn. Quote Link to post Share on other sites
Peter Cobbold Posted June 22, 2015 Report Share Posted June 22, 2015 (edited) If it can only be made to slip in second and not at all in other gears then I think it the 2nd gear inhibitor switch trying to engage overdrive. IIRC the overdrive column switch in the 5 is between the solenoid+inhibitor switches and earth. So a leak to earth fault in the second gear inhibit switch could try to engage o/d without the column switch operated. But I could be wrong - finding the right wiring diagram for UK TRs is a nightmare. Peter Edited June 22, 2015 by Peter Cobbold Quote Link to post Share on other sites
peejay4A Posted June 22, 2015 Report Share Posted June 22, 2015 (edited) As I implied, if it's wired correctly, the inhibitor switches provide an earth for the o/d relay coil so they can only malfunction if 12v is present from the overdrive switch to the o/d relay coil. They can't engage overdrive of their own accord. Edited June 22, 2015 by peejay4A Quote Link to post Share on other sites
Lebro Posted June 23, 2015 Report Share Posted June 23, 2015 Agree with all of above, but if the clutch does not slip in top gear, then it certainly wont in 2nd. It must be something else "slipping" Overdrive is the most likely, a gearbox fault would give either no drive at all, or at least make nasty noises. It is a puzzle ! Bob. Quote Link to post Share on other sites
carld Posted June 23, 2015 Author Report Share Posted June 23, 2015 Sure is a puzzle, it does feel like the overdrive coming in without being engaged by me though. Cheers Carl Quote Link to post Share on other sites
Guest ntc Posted June 23, 2015 Report Share Posted June 23, 2015 Carl You have checked the oil level and filter? Quote Link to post Share on other sites
john.r.davies Posted June 23, 2015 Report Share Posted June 23, 2015 Gents Did a 1,000 mile trip to Spa and back and didnt miss a a beat, got in it last Friday for a local TR weekend and I have an intermittent problem when selecting 2nd gear it feels like no drive/clutch slip and then it bites. Feels a bit like overdrive trying to engage, but without me selecting over drive, all other gears and overdrive have no issues. Unfortunately I am not going to be able to investigate for sometime, but was looking for a steer in the meantime. Cheers Carl If this is only 2nd gear, then you must suspect a problem with 2nd gear! I suspect a worn synchromesh. John Quote Link to post Share on other sites
carld Posted June 23, 2015 Author Report Share Posted June 23, 2015 Neil I had thought to suggest that, but didnt want to be laughed out of town, clearly overdrive not working at all could be down to oil levels but struggled to understand why it might happen when not actually engaging overdrive. Cheers Carl Quote Link to post Share on other sites
Tr4Tony Posted June 23, 2015 Report Share Posted June 23, 2015 Carl This sounds like it could be a broken thrust washer in the gearbox, 2nd gear item being most likely but possibly 3rd also. This has the effect of letting the gear train slide about a bit and in this case perhaps just enough to appear to slip. It's possible that's its the clutch in the overdrive, but this usually slips on all overdriven gears, however it does show up earliest on 2nd. I suggest you take the car to one of the specialists who know what they are doing, eliminate all the obvious and easy fixes first as above and get it properly diagnosed. in taking the top cover this should be apparent. In either case above it's likely to be gearbox out Im afraid. If you get sudden loss of drive, it will have been the clutch in the overdrive. I've actually had this very same fault on my rally TR4, where things tend to happen quickly, so I'd say attend to it asap if you can to avoid damaging the OD unit. I spent the afternoon in the pub waiting for the RAC as you end up being stranded and TR's are heavy to push. Regards Tony Quote Link to post Share on other sites
Guest ntc Posted June 23, 2015 Report Share Posted June 23, 2015 Neil I had thought to suggest that, but didnt want to be laughed out of town, clearly overdrive not working at all could be down to oil levels but struggled to understand why it might happen when not actually engaging overdrive. Cheers Carl Carl If the filter is blocked the overdrive can have a mind of it's own.But if it is then Tony may well be right Quote Link to post Share on other sites
Peter Cobbold Posted June 23, 2015 Report Share Posted June 23, 2015 Sure is a puzzle, it does feel like the overdrive coming in without being engaged by me though. Cheers Carl If you leave the overdrive switch on and change up from first into second does it 'slip' then? If no slip then it may be that your feeling the od is trying to engage by itself is correct. And I'd check the wiring and switches first. The tunnel has to come out anyway to look deeper into the gearbox. Peter Quote Link to post Share on other sites
TorontoTim Posted June 23, 2015 Report Share Posted June 23, 2015 I wouldn't necessarily give up on it being the clutch. While it's true that slipping in 2nd and not 4th doesn't sound right (more torque applied in the higher gear) I would have thought that it's always possible that driving style means that more torque could actually be put through the clutch in 2nd. (As it happens, I have very similar symptoms on my Norton accelerating hard in 2nd.) I may be wrong in this but if the box ends up having to come out anyway (assuming it doesn't get fixed just through cleaning the OD oil filter and refilling the box/OD with new oil) I'd guess that you'd replace the clutch anyway. At least then you'll get a good look at it. Quote Link to post Share on other sites
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