David Ferguson Posted March 21, 2019 Report Share Posted March 21, 2019 I am hoping someone has experienced this issue and can provide some guidance. I have a 1974 TR6 with fuel injection. On take off in first and reverse I am getting a shudder which I have not been able to diagnose. Along with the shudder, there is a clunking noise and I know it is coming from the rear end. The clutch is ok. Differential mounts ok. Engine mounts ok. One universal joint in the left drive shaft has very slight play. All other universals are ok. The drive shafts have been greased and are not worn. When driving, there are no shudders or clunks. The overdrive works well. It has been suggested that the fault lies in the J type overdrive unit. Is there a way I can test this? Any suggestions much appreciated. Quote Link to post Share on other sites
RogerH Posted March 21, 2019 Report Share Posted March 21, 2019 Hi David, welcome to the forum. Have you had the gearbox out recently. If so, did you put the two special bolts back in the correct position on the box/engine mounting flange. These ensure that the box is aligned with the clutch. In the early days the TR6 suffered from 'ratchet' clutch. As you lift the clutch pedal the release bearing does not follow smoothly. And then it catches up with a wallop. A lesser version would cause judder. Roger Quote Link to post Share on other sites
Mike C Posted March 21, 2019 Report Share Posted March 21, 2019 Have you tried rocking each back wheel back and forth with the car in gear, handbrake off? Quote Link to post Share on other sites
Andy Moltu Posted March 21, 2019 Report Share Posted March 21, 2019 Have the diff mounts been changed? There are one or two that have slightly too long a sleeved part which stops the mounting being securely clamped. Might explain the rear end clunk Juddering on take off points to clutch. Quote Link to post Share on other sites
peejay4A Posted March 21, 2019 Report Share Posted March 21, 2019 Rear gearbox mount perished? Quote Link to post Share on other sites
SeanF Posted March 21, 2019 Report Share Posted March 21, 2019 11 hours ago, Mike C said: Have you tried rocking each back wheel back and forth with the car in gear, handbrake off? Mike, For the novices amongst us, what might this show up? Thanks Sean Quote Link to post Share on other sites
David Ferguson Posted March 21, 2019 Author Report Share Posted March 21, 2019 11 hours ago, RogerH said: Hi David, welcome to the forum. Have you had the gearbox out recently. If so, did you put the two special bolts back in the correct position on the box/engine mounting flange. These ensure that the box is aligned with the clutch. In the early days the TR6 suffered from 'ratchet' clutch. As you lift the clutch pedal the release bearing does not follow smoothly. And then it catches up with a wallop. A lesser version would cause judder. Roger I had the gearbox out about 3 years ago and replaced the throw out bearing with a new, original. It was working fine at the time and as far as I can tell, is still OK. I spent all day last Thursday with my mechanic checking everything we could. The clutch seemed OK. Thanks for your suggestion though. Maybe something has shifted. Quote Link to post Share on other sites
David Ferguson Posted March 21, 2019 Author Report Share Posted March 21, 2019 11 hours ago, Mike C said: Have you tried rocking each back wheel back and forth with the car in gear, handbrake off? Yes, I think I have tried almost everything. Rocking back and forth in gear did generate a click but really seemed to be just the tail shaft taking up the slack. There is a small amount of play in a universal joint and I understand it could give a clunk but does not explain the shudder. I am about to go and spend the morning under the car again and I will try rocking it again to see if I can narrow down the noise. Quote Link to post Share on other sites
David Ferguson Posted March 21, 2019 Author Report Share Posted March 21, 2019 3 hours ago, peejay4A said: Rear gearbox mount perished? That would have been a good outcome but sadly, it is in good condition. We tested with a lever while the car was running on the hoist and changing through the gears. There was no movement in the rear mount. Quote Link to post Share on other sites
David Ferguson Posted March 21, 2019 Author Report Share Posted March 21, 2019 11 hours ago, Andy Moltu said: Have the diff mounts been changed? There are one or two that have slightly too long a sleeved part which stops the mounting being securely clamped. Might explain the rear end clunk Juddering on take off points to clutch. No, same diff mounts. They are in good condition. The right front has been welded at some time. I have checked the welds and they are still OK. The rubber bushes look new, although they are over 5 years old. The car has probably done 10,000km in those 5 years. Tested with a lever on the hoist and no excessive movement either. Quote Link to post Share on other sites
Mike C Posted March 21, 2019 Report Share Posted March 21, 2019 36 minutes ago, SeanF said: Mike, For the novices amongst us, what might this show up? Thanks Sean Excess play in any component between the respective wheel and the gearbox output shaft. I always like to start with the simple tests when I have a problem. Quote Link to post Share on other sites
RogerH Posted March 21, 2019 Report Share Posted March 21, 2019 17 minutes ago, David Ferguson said: I had the gearbox out about 3 years ago and replaced the throw out bearing with a new, original. It was working fine at the time and as far as I can tell, is still OK. I spent all day last Thursday with my mechanic checking everything we could. The clutch seemed OK. Thanks for your suggestion though. Maybe something has shifted. Hi David, have a look here at item 117 x 2 dowel bolts https://www.moss-europe.co.uk/shop-by-model/triumph/tr5-6/clutch-transmission-drivetrain/gearboxes-components/gearbox-units-external-components-tr5-6.html Roger Quote Link to post Share on other sites
David Ferguson Posted March 21, 2019 Author Report Share Posted March 21, 2019 8 minutes ago, RogerH said: Hi David, have a look here at item 117 x 2 dowel bolts https://www.moss-europe.co.uk/shop-by-model/triumph/tr5-6/clutch-transmission-drivetrain/gearboxes-components/gearbox-units-external-components-tr5-6.html Roger I will check them out under the car shortly. Thank you. Quote Link to post Share on other sites
David Ferguson Posted March 21, 2019 Author Report Share Posted March 21, 2019 9 minutes ago, Mike C said: Excess play in any component between the respective wheel and the gearbox output shaft. I always like to start with the simple tests when I have a problem. Thanks . I will go and rock it around some more in a minute or two. Quote Link to post Share on other sites
Mike C Posted March 21, 2019 Report Share Posted March 21, 2019 18 minutes ago, David Ferguson said: Thanks . I will go and rock it around some more in a minute or two. It's better if someone rocks the wheel whilst another person examines the drive components. Quote Link to post Share on other sites
David Ferguson Posted March 21, 2019 Author Report Share Posted March 21, 2019 31 minutes ago, Mike C said: It's better if someone rocks the wheel whilst another person examines the drive components. Yes. Thanks. I will have a helper. Quote Link to post Share on other sites
David Ferguson Posted March 22, 2019 Author Report Share Posted March 22, 2019 Thanks everyone for your suggestions. I have spent a few hours today working on all of them. In the end, I think it must be the clutch. On take off with revs at idle speed, the clutch grabs about 1 inch off the floor and then the car shudders. If I rev a bit harder before take off, there is no shudder. At driving speed and through the gears, there is still no shudder. Reverse gear is the same as first. I will change the clutch and cover plate and throw out bearing. If that doesn’t sort it, then I am back to square one. Regards, David Quote Link to post Share on other sites
Mike C Posted March 22, 2019 Report Share Posted March 22, 2019 48 minutes ago, David Ferguson said: Thanks everyone for your suggestions. I have spent a few hours today working on all of them. In the end, I think it must be the clutch. On take off with revs at idle speed, the clutch grabs about 1 inch off the floor and then the car shudders. If I rev a bit harder before take off, there is no shudder. At driving speed and through the gears, there is still no shudder. Reverse gear is the same as first. I will change the clutch and cover plate and throw out bearing. If that doesn’t sort it, then I am back to square one. Regards, David I'd still have a look at the engine and gearbox mounts while I was at it. Quote Link to post Share on other sites
RogerH Posted March 22, 2019 Report Share Posted March 22, 2019 Hi David, where abouts are you? as it would appear you were working on your car at 5am GMT - enthusiastic. If you do remove the gearbox have a look at the concentricity of the gearbox splined shaft and the extension from the gearbox that the bearing carrier slides on. I had very bad judder and found these components were 0.015" displaced vertically - why it never occurred in the previous 1000's miles I don't know. Don't forget those alignment bolts on the attachment flange. Roger Quote Link to post Share on other sites
David Ferguson Posted March 22, 2019 Author Report Share Posted March 22, 2019 3 hours ago, Mike C said: I'd still have a look at the engine and gearbox mounts while I was at it. Thank you. I will give everything a check with the gearbox out. Quote Link to post Share on other sites
David Ferguson Posted March 22, 2019 Author Report Share Posted March 22, 2019 14 minutes ago, RogerH said: Hi David, where abouts are you? as it would appear you were working on your car at 5am GMT - enthusiastic. If you do remove the gearbox have a look at the concentricity of the gearbox splined shaft and the extension from the gearbox that the bearing carrier slides on. I had very bad judder and found these components were 0.015" displaced vertically - why it never occurred in the previous 1000's miles I don't know. Don't forget those alignment bolts on the attachment flange. Roger Thank you very much. I am just south of Melbourne, Australia so not working on the car at crazy times! Quote Link to post Share on other sites
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