mcerbm Posted February 28, 2016 Share Posted February 28, 2016 im currently at a track day and the mechanical speedo input has come lose, it's cable tied out of the way now. Will I lose gearbox fluid if I go back out on track? Not sure if it's an end of day type failure. I'm not sure where it's mounted. 1h30mins left.... Link to comment Share on other sites More sharing options...
Mankee Posted February 28, 2016 Share Posted February 28, 2016 As long as the seal is still there, you shouldn't get any leaks. When I de-speedo'd to strip some weight from the car, I removed the quill, top hat, circlip, angle drive and all the rest of it. No issues. You'll soon know if you've got a problem as you'll have a patch of smelly box oil on the floor! Link to comment Share on other sites More sharing options...
mcerbm Posted February 28, 2016 Author Share Posted February 28, 2016 No fluid lost sitting in paddock. I can't quite see the location but I can feel a boss sticking out that's threaded on the outside and free rotates but must be held in by the circlip you mentioned. Would that be enough to keep fluid in? Link to comment Share on other sites More sharing options...
MADMALC Posted February 28, 2016 Share Posted February 28, 2016 It should be OK. Drive up and down off track and then have another feel then you will know. Link to comment Share on other sites More sharing options...
Mankee Posted February 28, 2016 Share Posted February 28, 2016 Bit late returning to the party. Hope you got the rest of the afternoon on track! It sounds like the angle drive is still in the box and held in by the top hat and circlip. Maybe the speedo cable just needs to be screwed back in? Link to comment Share on other sites More sharing options...
mcerbm Posted February 28, 2016 Author Share Posted February 28, 2016 Thanks all. Got another 20mins on track before a red flag ended the day early. All seemed fine with the car. The speedo cable could probably be screwed back in yes. The outer surface has taken a bit of a battering but the inner threads seem fine. Looking at the angle it was screwed in at that's an impressive escape to freedom it's made! Link to comment Share on other sites More sharing options...
mcerbm Posted March 11, 2016 Author Share Posted March 11, 2016 Now that the car is back in the garage I have just jacked up the car to try and re-insert the speedo sensor. I cant seem to find a way to screw the sensor onto the male threaded boss that comes out of the gearbox. it just free spins making it very hard to restrain and get the female collar threaded up.I'm guessing the sensor is always attached with the gearbox out. is there a trick to getting the gearbox side thread to stop rotating so I can screw up the sleeve of teh speed sensor? Link to comment Share on other sites More sharing options...
mcerbm Posted April 11, 2016 Author Share Posted April 11, 2016 any suggestions? Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted April 11, 2016 Member Share Posted April 11, 2016 I'm confused by "sensor". Is that an electrical sensor or the mechanical cable that goes all the way to the speedometer?Jonathan Link to comment Share on other sites More sharing options...
mcerbm Posted April 12, 2016 Author Share Posted April 12, 2016 /sites/default/files/images/users/1260/IMG_6814.JPGA and D are part of the same sensor that has the square mechanical insert that inserts into the gearbox. I'm trying to thread the collar A onto the male thread B. However the male thread B also free spins and is held in place by the circlip C into the gearbox speedo housing. So im not sure how to fully get home collar A.I havent started teh car to see if the square insert is far enough into B to get a speedo reading. Even if it is then it wont be long until it vibrates itself off again Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted April 12, 2016 Member Share Posted April 12, 2016 Assembly Guide has:...Lubricate the plastic speedometer drive with gearbox oil and fit into the rear left of the tailshaft housing, Fig 1 refers, such that the speedo spindle locates in the orifice. Ensure the surface of the speedo drive housing is free from oil and apply a thin coat of silicon sealant. Tap the speedo drive housing cover gently into place. Lubricate the small oil seal with gearbox oil and slide down over the speedo drive output shaft. Gently tap into place using a suitable sized socket as a drift.The brass 'top hat' should be located over the oil seal and held in place by the circlip, Fig 2 refers. Ensure that the circlip is fully located into the groove as access is restricted when the gearbox is in the car. Do not fit the sensor. ...Screw the speed sensor onto the 'top hat' ensuring that the drive cable slots into the speedo gear output shaft. Connect the sensor to the two pin plug in the vehicle wiring loom. Fit the grommet to the RH side of the tunnel from inside the cockpit. ...Which doesn't seem to help much.Can you grip the thread on B to get it started and on as far as possible, then press and angle either inwards or outwards to seize B on C as you finish it?Or use some sealant, as Ian did?JonathanPS: I've (obviously) never done this. Mine is fully mechanical. But I'd describe yours as electronic from the gearbox.PPS: Nice diagram. Link to comment Share on other sites More sharing options...
John Vine Posted April 12, 2016 Share Posted April 12, 2016 I think you have two choices: Grip the top-hat with a pair of long-nosed pliers as close as possible to the gearbox to stop it rotating Remove the circlip and detach the top-hat completely, screw on the collar, replace and reinsert the circlip.As the gearbox is still in the car, #2 will be a right royal PITA, so try #1 first.JV Link to comment Share on other sites More sharing options...
mcerbm Posted March 27, 2017 Author Share Posted March 27, 2017 resurrecting this thread as i never managed to properly solve the problem, I managed to get the collar on as much as is shown in the picture earlier and then covered it in duct tape. It worked but was a bodge.I now have the gearbox out sitting in front of me. So i'm hoping to get a proper fix.If the manual says screw in the sensor when the gearbox is in I'm wondering if my top hat has sheared something inside? i.e. should it free spin or not. If it is meant to free spin how are you supposed to screw on a collar.... two spinning items are very hard to make up! Link to comment Share on other sites More sharing options...
John Vine Posted March 27, 2017 Share Posted March 27, 2017 The top-hat should rotate freely. It's only held in place by the circlip, and rests on a flange. Now your box is out, you'll be able to remove the circlip easily. it'll have a small hole at each end where you can insert the prongs of a pair of circlip pliers. Once you've removed it, the top-hat simply lifts out.JV Link to comment Share on other sites More sharing options...
mcerbm Posted March 27, 2017 Author Share Posted March 27, 2017 Thanks John, unfortunately it looks like the first initial threads on the collar are a bit mangled from when it bounced along the road during the track day. Top hat is fine. Looks like a new speed sensor is requird. over £100 from caterham, does anyone else do them a bit cheaper? Link to comment Share on other sites More sharing options...
John Vine Posted March 28, 2017 Share Posted March 28, 2017 Maybe a local engineering place could clean up the thread?JV Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted March 28, 2017 Member Share Posted March 28, 2017 Looks like a new speed sensor is requird. over £100 from caterham, does anyone else do them a bit cheaper?If you can't fix the thread then I think that someone identified a third-party supplier, it should be in the archives, but I might be thinking of the all-mechanical drive. I'd also ask Redline (but you have to 'phone) and JDO (who answers emails very quickly).Jonathan Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted March 28, 2017 Member Share Posted March 28, 2017 Found it.Jonathan Link to comment Share on other sites More sharing options...
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