Johnthelms Posted June 26, 2020 Report Share Posted June 26, 2020 Hi has anybody got any idea, while driving my TR6 2 days ago going round left hand corners we hear a nocking noise we think coming from the rear of the car. It sounded like nock nock nock only when cornering at a bit of speed. I look forward to your feedback. John Quote Link to post Share on other sites
rcreweread Posted June 26, 2020 Report Share Posted June 26, 2020 John - I hope your problem is not the diff bit it could very well be. As this is an expensive part, go through the rear end carefully to eliminate things like the diff mountings, propshaft UJs, and the drivesahft UJs - as it's only noticeable when cornering, does it do this on both left and right hand corners the same or is it only doing it in one type of corner? Often best to jack up one rear wheel at a time making sure other is on the ground and can't turn, and then check both front and rear diff mountings and brackets are all intact. check UJs on the driveshaft and for any play in the driveshaft splines ( you shouldn't really be able to feel any noticeable play in the splines) - if nothing untoward crops up from this, then unfortunately likely to be the diff - have you had any other issues with the diff? If you have a drain plug in the diff ( you probably haven't), drain the old and look for any broken teeth in the oil. If you conclude it is the diff, I can help you with a rebuilt one if you need one - just PM me - whereabouts are you as a matter of interest? Cheers Rich Quote Link to post Share on other sites
richard61 Posted June 26, 2020 Report Share Posted June 26, 2020 Worth eliminating hub causes, most commonly it’s the common things. Quote Link to post Share on other sites
rcreweread Posted June 26, 2020 Report Share Posted June 26, 2020 Richard - yes good point - usually manifested by play in the bearings which will show up by rocking the wheel when jacked up with handbrake off. John - might I also suggest you ask the moderators to change the title of your post to a more relevant title such " Rear end knocking noise on cornering" and you will get a lot more informed responses Cheers Rich Quote Link to post Share on other sites
Allan Jezzard Posted June 26, 2020 Report Share Posted June 26, 2020 Hi John, As it’s only apparent when bearing left, it could be a UJ striking an exhaust pipe or chassis. As the stresses of cornering bring changes to clearances, this can occur. It took one of our members months to trace such a situation. You can’t reproduce the situation in the workshop, so initially look for witness marks. If nothing can be seen it might be worth running for a while without the tunnel in place. Good luck Allan Quote Link to post Share on other sites
Motorsport Mickey Posted June 26, 2020 Report Share Posted June 26, 2020 Check out the prop shaft on the diff End catching on the tunnel area, from memory it’s offset and you can get a noise on corners where the clearance is least. Look for shiny marks. Mick Richards Quote Link to post Share on other sites
YankeeTR5 Posted June 26, 2020 Report Share Posted June 26, 2020 Sounds like a shaft rotating and whacking something on each go around. On my sons 74, when we redid the rear (rebuilt hubs, new axle shafts....) we had the same thing. Turns out the bolts we used to connect the flanges together were about 1/4" longer than the stock ones and that difference in length would make a similar noise as you describe on tight turns at low speeds (probably happening at high speeds too but can't really hear things then) and only one of the bolts making contact. No visible signs of the rubbing either. Quote Link to post Share on other sites
John Morrison Posted June 26, 2020 Report Share Posted June 26, 2020 3 hours ago, rcreweread said: Richard - yes good point - usually manifested by play in the bearings which will show up by rocking the wheel when jacked up with handbrake off. John - might I also suggest you ask the moderators to change the title of your post to a more relevant title such " Rear end knocking noise on cornering" and you will get a lot more informed responses Cheers Rich Done. John. Quote Link to post Share on other sites
Phil Read Posted June 29, 2020 Report Share Posted June 29, 2020 I had this problem it turned out to be the lever arm damper bolts attaching it to the chassis had worked loose. Quote Link to post Share on other sites
Johnthelms Posted July 7, 2020 Author Report Share Posted July 7, 2020 Hi I have now had time to investigate but I can`t find anything that might be causing the knocking on my TR. All the UJ`s are ok, wheel bearings ok, all bushes no apparent play the only thing is the diff but there is no drain plug to look to see if there are any loose metal, I think we will have to take the diff out to check it. If we take the back pate off will any problems come to light? John Quote Link to post Share on other sites
Mike C Posted July 7, 2020 Report Share Posted July 7, 2020 4 minutes ago, Johnthelms said: Hi I have now had time to investigate but I can`t find anything that might be causing the knocking on my TR. All the UJ`s are ok, wheel bearings ok, all bushes no apparent play the only thing is the diff but there is no drain plug to look to see if there are any loose metal, I think we will have to take the diff out to check it. If we take the back pate off will any problems come to light? John Can you reach the oil and get a sample from the fill plug? If you have one , a vacuum oil changer, like MB's use for engine oil changes, would get most of the diff oil out when it's warm. Quote Link to post Share on other sites
Motorsport Mickey Posted July 7, 2020 Report Share Posted July 7, 2020 (edited) 45 minutes ago, Johnthelms said: Hi I have now had time to investigate but I can`t find anything that might be causing the knocking on my TR. All the UJ`s are ok, wheel bearings ok, all bushes no apparent play the only thing is the diff but there is no drain plug to look to see if there are any loose metal, I think we will have to take the diff out to check it. If we take the back pate off will any problems come to light? John Have you checked the clearance of the diff where the prop shaft bolts to to the transmission tunnel as suggested. If it doesn’t have a good clearance the car bodywork and suspension movement will allow the bodywork to “displace” leaning across and reducing the clearance until contact with the prop shaft and U/J area, and then return to clearance When you check on it statically. Mick Richards Edited July 7, 2020 by Motorsport Mickey Quote Link to post Share on other sites
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