TwinCamJohn Posted September 16, 2019 Report Share Posted September 16, 2019 Following on from my thread on the timing chain cover leak, I am considering what else needs to be done whilst the front is off. Since I bought the car (4 years) there has been an occasional judder when reversing (more so if there is a slope). The clutch works fine normally. Is there anything external that might cause this? It is an opportunity to take the engine out but I don't want to do that to find I have missed something else obvious ! Quote Link to post Share on other sites
Motorsport Mickey Posted September 16, 2019 Report Share Posted September 16, 2019 Sometimes there is a gradual build up on the flywheel face of oil based mist which allows a greasy deposit to form unless you are driving it ...vigorously. Try deliberately slipping the clutch on 2 or 3 starts with the handbrake left engaged and releasing the clutch slowly (it won't hurt it) to clean the flywheel off and see if it helps remove the judder when driven. Mick Quote Link to post Share on other sites
Graham Harris Posted September 16, 2019 Report Share Posted September 16, 2019 Check your engine mounts? Graham Quote Link to post Share on other sites
TwinCamJohn Posted September 16, 2019 Author Report Share Posted September 16, 2019 Thanks Mick and Graham. Can't really drive it now but it does get some stick on rallyes so perhaps not the flywheel idea. I'll have a look at the engine mounts. Quote Link to post Share on other sites
james christie Posted September 16, 2019 Report Share Posted September 16, 2019 Don't just check your engine mounts as Graham suggests, change them! It's a doddle with the front end off. james Quote Link to post Share on other sites
TwinCamJohn Posted September 16, 2019 Author Report Share Posted September 16, 2019 The gearbox mounting might be suspect, too ? Has anyone tried the Moss "competition" mounting ? Quote Link to post Share on other sites
2long Posted September 16, 2019 Report Share Posted September 16, 2019 I have a similar problem with my Doretti, getting serious clutch judder when pulling out in first, especially uphill and especially after the car is fully warmed up. Other gears shift fine. I have tried slipping the clutch, to no avail. Someone suggested bleeding the clutch or altering the clutch slave attachment hole, but I can't see why this would help. Not trying to hijack the thread on John's issue but maybe address both. Cheers Dan Quote Link to post Share on other sites
Hamish Posted September 16, 2019 Report Share Posted September 16, 2019 50 minutes ago, TwinCamJohn said: The gearbox mounting might be suspect, too ? Has anyone tried the Moss "competition" mounting ? On my 3a I have fitted the comp mounts (engine and gearbox) cuts a lot of the engine rock. I had a thought after a gearbox leak on the OD plate that there was a difference in rock from the engine at the front to the gearbox at the back possibly putting a strain on the gearbox / OD joint. They are all firmer and all new now. They were all a bit soft and the gearbox mount was slimy and jelly like with oil contamination. Quote Link to post Share on other sites
TwinCamJohn Posted September 16, 2019 Author Report Share Posted September 16, 2019 2 hours ago, 2long said: I have a similar problem with my Doretti, getting serious clutch judder when pulling out in first, especially uphill and especially after the car is fully warmed up. Other gears shift fine. I have tried slipping the clutch, to no avail. Someone suggested bleeding the clutch or altering the clutch slave attachment hole, but I can't see why this would help. Not trying to hijack the thread on John's issue but maybe address both. Cheers Dan Interesting. You say the other gears are fine, so I assume that means reverse ? Quote Link to post Share on other sites
2long Posted September 16, 2019 Report Share Posted September 16, 2019 (edited) Yes, reverse seems to be fine (although backing out of the driveway when it is cold is often my only reversing time). I was concerned it was oil leaking from the rear main onto the clutch surface, but again I am not very bright on whether that is a realistic concern. Of course a clutch bleed or adjustment would be a huge relief if that were the fix for it. I may not have been vigorous enough slipping the clutch, as it is counter-intuitive for me. Dan Edited September 16, 2019 by 2long Quote Link to post Share on other sites
TwinCamJohn Posted September 17, 2019 Author Report Share Posted September 17, 2019 I should have thought the oil scenario would be there all the time. It reminds me from my racing days that a pal had oil on the clutch before the start of a race and he fired a dry powder fire extinguisher into the clutch just before going on to the grid. It dosn't take much to see that I am trying to avoid taking the engine out. I see from my files that the PO replaced the engine mounts 9 years ago. (Moss) Quote Link to post Share on other sites
John McCormack Posted September 18, 2019 Report Share Posted September 18, 2019 On 9/17/2019 at 9:53 AM, 2long said: Yes, reverse seems to be fine (although backing out of the driveway when it is cold is often my only reversing time). I was concerned it was oil leaking from the rear main onto the clutch surface, but again I am not very bright on whether that is a realistic concern. Of course a clutch bleed or adjustment would be a huge relief if that were the fix for it. I may not have been vigorous enough slipping the clutch, as it is counter-intuitive for me. Dan On 9/16/2019 at 4:55 PM, TwinCamJohn said: Following on from my thread on the timing chain cover leak, I am considering what else needs to be done whilst the front is off. Since I bought the car (4 years) there has been an occasional judder when reversing (more so if there is a slope). The clutch works fine normally. Is there anything external that might cause this? It is an opportunity to take the engine out but I don't want to do that to find I have missed something else obvious ! Do you have a J type conversion with a TR6 clutch? The stock TR6 clutch is known for it, my TR6 has it. The thrust race catches on the extension it slides over. Standard sidescreen clutches, and TR6 ones, do shudder with a buildup on the flywheel. A good slipping of the clutch cures it. Quote Link to post Share on other sites
TwinCamJohn Posted September 18, 2019 Author Report Share Posted September 18, 2019 As far as I am aware, no. Quote Link to post Share on other sites
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