reb78 Posted May 3, 2018 Share Posted May 3, 2018 My GKN OD has been on the car about 80,000 miles now and has behaved pretty well. I change the oil every 6,000 miles and that seems to keep it happy. Last week though it seems to have played up. After about 3 hours of motorway driving, I shifted out of the OD as I went from the M5 to the A30 and needed to change down. The OD briefly moved out of gear, then re-engaged and refused to disengage for about 20 miles. I slowed down, to let it cool a bit and eventually it came out of gear and then behaved normally afterwards. Getting out of the car at the end of the journey, i could smell oil and there was a reasonable covering of oil underneath. Checking the level yesterday, the OD was low on oil and there was a lot up around the breather pipework directly above the overdrive. I dropped the remaining oil (estimate that i got about 350 ml out) and it was pretty black (always is though as the silly thing only takes a tiny amount of ATF) and I also found the fragment in the pic below in the OD sump. Any ideas welcome. This is my only car at the moment and the input gear and carrier plate is 300 miles away! Fragment (i have blown this up a little - it is about 8mm across and 2mm thick in real life. Hard, but not magnetic, it could be hard plastic but it is hard to tell - i cannot think of any part internally that looks like this) Oil (dont know why the pic is on its side!): Quote Link to comment Share on other sites More sharing options...
western Posted May 3, 2018 Share Posted May 3, 2018 internal clutch probably failing just similar to the way my GKN failed, it's off the 110 & on my bench waiting some TLC. could be same as I had Quote Link to comment Share on other sites More sharing options...
Mo Murphy Posted May 3, 2018 Share Posted May 3, 2018 That looks like a bit of cone cluch material Reb. Mo Quote Link to comment Share on other sites More sharing options...
reb78 Posted May 3, 2018 Author Share Posted May 3, 2018 That was one of my first thoughts, but I think its too hard for the clutch and on mine the clutch material is waaay thinner than that fragment. Also, notice the curvature of the middle of that fragment - it looks like it was part of something with a hole in it of approx 5mm diameter? Quote Link to comment Share on other sites More sharing options...
reb78 Posted May 3, 2018 Author Share Posted May 3, 2018 Can anyone with a speed sensor handy tell me if it has a disc of material in the sensor end of it? I am wondering if that fragment has broken off of the speed sensor. I cant find the exact one online, but a similar one from RS one has a disc of material in the centre next to the sensor that you can see here: https://uk.rs-online.com/web/p/magnetic-pickups/0285756/?searchTerm=285-756&relevancy-data=636F3D3126696E3D4931384E525353746F636B4E756D6265724D504E266C753D656E266D6D3D6D61746368616C6C26706D3D5E5C647B337D5B5C732D2F255C2E2C5D5C647B332C347D2426706F3D313426736E3D592673743D52535F53544F434B5F4E554D4245522677633D4E4F4E45267573743D3238352D37353626 Quote Link to comment Share on other sites More sharing options...
V8 Freak Posted May 3, 2018 Share Posted May 3, 2018 I agree with you on this one Rich..... Clutch (Or more correctly... Brake) material from new is under 2mm and has no holes... I can pull the sensor out of mine tonight when home and have a look.. If your's had fallen apart, I can pop mine in the post so you stay mobile... (Or input gear and cover if that is the safer option) Quote Link to comment Share on other sites More sharing options...
western Posted May 3, 2018 Share Posted May 3, 2018 I'll go pull my speed sensor out & post a few photo's shortly Quote Link to comment Share on other sites More sharing options...
reb78 Posted May 3, 2018 Author Share Posted May 3, 2018 Great. Thanks Ralph. Found the leak/source of oil loss. Ran the overdrive on the ramp with the transfer box in neutral and oil is seeping from between the body and the forward face of the brake ring. I’ll pop to d44 tomorrow to get a gasket set. Still concerned about that fragment in the sump, but I kinda hope it’s from the speed sensor. Will wait and see Ralphs pics. Quote Link to comment Share on other sites More sharing options...
western Posted May 3, 2018 Share Posted May 3, 2018 my dead speed sensor. 22mm 12 point ring spanner or long reach socket to fit/remove it. your busted bit could be the end face of the sensor it is quite a material Quote Link to comment Share on other sites More sharing options...
reb78 Posted May 3, 2018 Author Share Posted May 3, 2018 That could be it. Ive literally had mine in pieces two or three times a long while back and looked at a couple of others and I can’t think of anywhere else that fragment could have come from. Quote Link to comment Share on other sites More sharing options...
western Posted May 3, 2018 Share Posted May 3, 2018 that black disc is 14mm across it's diameter. Quote Link to comment Share on other sites More sharing options...
reb78 Posted May 3, 2018 Author Share Posted May 3, 2018 Nervous to take mine out in case it disintegrates. I have a spare but it’s 300 miles away (as is my original input gear and carrier plate!) Quote Link to comment Share on other sites More sharing options...
Mo Murphy Posted May 4, 2018 Share Posted May 4, 2018 Devon may have a used one they could sell you. Mo Quote Link to comment Share on other sites More sharing options...
reb78 Posted May 4, 2018 Author Share Posted May 4, 2018 I have a spare one at home! I've got the gaskets now, so will take it off later and see what I can see. Peoples thoughts - Gaskets only, gaskets and a smear of grease (think I only have lithium based grease with me) or gaskets and a smidge of hylomar? Quote Link to comment Share on other sites More sharing options...
daveturnbull Posted May 4, 2018 Share Posted May 4, 2018 gaskets and a smear of grease, especially if you will be taking it apart again soon and want to try and reuse them. Quote Link to comment Share on other sites More sharing options...
reb78 Posted May 4, 2018 Author Share Posted May 4, 2018 Great. Will do. Hoping not to take it apart again too soon though!! Quote Link to comment Share on other sites More sharing options...
reb78 Posted May 4, 2018 Author Share Posted May 4, 2018 So. The source of that fragment is as I suspected. The sensor is working so how would you fix it? I’m thinking clean off with electrical contact cleaner and fill the ‘gap’ with silcoset 152. I think it’ll handle the oil and certainly the heat. The leak is also located and a new gasket set ready to be fitted tomorrow. 1 Quote Link to comment Share on other sites More sharing options...
soutie Posted May 5, 2018 Share Posted May 5, 2018 (edited) Have you remembered to clean out the high pressure filter? See below courtesy of Buckeye Triumphs write up on the J type over drive. Plus the picture from the GKN user manual. http://www.buckeyetriumphs.org/technical/jod/JOD2/JOD2.htm Edited May 5, 2018 by soutie Quote Link to comment Share on other sites More sharing options...
reb78 Posted May 5, 2018 Author Share Posted May 5, 2018 (edited) No. Not at the moment. Im going to get a new one first as i have seen them fall apart on removal so want to have a spare handy. Its changing ok (when it has all of its oil!). But i will at the next oil change. I do it every 6000 miles and i cover that distance in 2-3 months at the moment so it wont be long! So thanks for the reminder. Edited May 5, 2018 by reb78 Quote Link to comment Share on other sites More sharing options...
Snagger Posted May 5, 2018 Share Posted May 5, 2018 15 hours ago, reb78 said: The sensor is working so how would you fix it? I’m thinking clean off with electrical contact cleaner and fill the ‘gap’ with silcoset 152. I think it’ll handle the oil and certainly the heat. I'd look at high quality epoxies. Quote Link to comment Share on other sites More sharing options...
western Posted May 5, 2018 Share Posted May 5, 2018 Good you found the offending item, I would go with a epoxy resin rather than silcoset, haven't seen that filter info before, it's certainly not in the GKN istruction & owners manuals I' had with my OD, they are in the tech archive for others to read/use. Quote Link to comment Share on other sites More sharing options...
reb78 Posted May 5, 2018 Author Share Posted May 5, 2018 I’ve got some araldite epoxy. It says it’s good up to 80C. What do we reckon. Will it be ok or is there a better option? I know Ralph. There’s nothing in the OD manual. Overdrive repair services sell them. Tanuki pointed them out in an earlier thread that’s the only reason I know about them and Souties post above. 1 Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted May 5, 2018 Share Posted May 5, 2018 80c will be very borderline, if they like to run hot and burn ATF I would estimate it is getting to 130C at peak. Quote Link to comment Share on other sites More sharing options...
TSD Posted May 5, 2018 Share Posted May 5, 2018 I wouldn't use contact cleaner without checking it first. Some, like Servisol, leave a lubricant film behind. (Cheapo ones might be pure solvent? I've not checked.) Brake cleaner or Isopropyl might be better to ensure whatever filler you use sticks properly. It's only there to keep the metal-swarf bearing oil out, so whatever can stand the heat should be fine. Epoxy was my first thought too, but the RTV might be better at sealing the hot oil out? Quote Link to comment Share on other sites More sharing options...
reb78 Posted May 5, 2018 Author Share Posted May 5, 2018 Ok. Thanks. Brake cleaner it is. The datasheet for silcoset says its good to 300C and oil resistant so I think I’m going to go with that. 2 Quote Link to comment Share on other sites More sharing options...
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