Kr1s Posted May 19 Share Posted May 19 (edited) Hello again! Hope you're not getting tired of my questions 😔 It looks like my 1980 2.0 may have an oil leak and I guess it could be rear crankshaft seal or gearbox input seal, is that right? If it comes to it, I'm wondering what's the best approach to accessing those to replace them. I had the engines out of mantas several times back in the '90s and became quite adept at it but having to hire a hoist is a pain. Are there other things that would be worth doing if I had the engine out or other benefits to this approach? It's done -26000 miles. I'm assuming with the engine out I can get access to the gearbox input seal - is that correct? Getting the gearbox out sounds a bit of a faff, but I'm thinking if I did that I could do the output seal at the same time, just as a preventative measure. Can the rear crankshaft seal be accessed by removing the gearbox? If I go this route, are the input and output seals on the gearbox both easy to get out and in? The Haynes manual recommends getting the engine and gearbox out together, but I have serious concerns that I don't have the height required to do that in my garage. I'd be really interested to hear what someone with more experience would do if they were in my shoes! As always, many thanks! Chris   Edited May 19 by Kr1s adding photo 1 Quote Link to comment Share on other sites More sharing options...
Jessopia74 Posted May 19 Share Posted May 19 It’s never easy to check when the oil has spread. But it looks to me there is a few small leaks in different places. Oil sump plug needs new copper washer, easy win there. Looks like rear main seal might be letting a little too. Should be able to see oil streaks on back of flywheel if so. But might be sump gasket too. Gearbox, usual is sump gasket and the selector shaft seal.  Engine oil will be black from the carbon. Gearbox will still be light brown 1 Quote Link to comment Share on other sites More sharing options...
Sutty2006 Posted May 19 Share Posted May 19 I’d also be tempted to go with sump gasket first. The seal at the rear of the sump can perish over time. I’ve known sumps that look like that to leak aswell, with pin holes in the rust. 1 Quote Link to comment Share on other sites More sharing options...
1200bandit Posted May 20 Share Posted May 20 If that’s a 4 speed box about a hour to remove ( with a tea break) if l remember correctly 1 Quote Link to comment Share on other sites More sharing options...
Sutty2006 Posted May 20 Share Posted May 20 My freshly rebuilt 4 speed is leaking oil. I think nos gaskets and seals are not worth having anymore. The new rear seal I fitted is leaking and it’s not even been driven yet 🤣 2 Quote Link to comment Share on other sites More sharing options...
Kr1s Posted May 20 Author Share Posted May 20 I was wondering about this - I guess as far as NOS is concerned, the problem is mentioned in the name - it is still old 😆 Quote Link to comment Share on other sites More sharing options...
GTEPETE Posted May 21 Share Posted May 21 I would first apply degreaser, then jet wash box and sump, then keep an eye on the leak....maybe remove the 1/2 moon flywheel plate to check what it looks like inside... 1 Quote Link to comment Share on other sites More sharing options...
H-400 Posted May 21 Share Posted May 21 Beware if you remove the bottom plate/sump of the gearbox. There's a spring with a plunger that wants to escape! 2 Quote Link to comment Share on other sites More sharing options...
cam.in.head Posted May 21 Share Posted May 21 as mentioned by 1200 bandit above the 4 speed box is easy enough to remove in an hour. it you are going to change the gearbox input seal then its easier to remove just the gearbox itself first and then the bellhousing afterwards. ( the seal is sandwiched between the two) if you need to replace the rear crank seal then its just pressed into its housing and can be done easily. remember when refitting the flywheel to put the bolt marked P into the smallest flywheel hole .aligning is straightforward as the bolt holes are not evenly spaced so it will only fit in one place ! sump can be removed with engine in car but you will need to lift it a little off its mountings and lower the subframe too ( not too much or you willneed to loosen the steering uj. BUT as mentioned it all needs cleaning off first as the leak source is not obvious . 1 Quote Link to comment Share on other sites More sharing options...
Kr1s Posted May 21 Author Share Posted May 21 That's really helpful, thanks - a lot of that was not very clear from the Haynes manual. Yes, I'll get it cleaned up first but it's nice to know potential required work is less major than I was imagining. I will keep you all posted! Cheers! 1 Quote Link to comment Share on other sites More sharing options...
cam.in.head Posted May 24 Share Posted May 24 yes get it all spotless underneath and around the sides and back of engine then you can see where the leak starts from. one piece of advise. down the back of the engine / upper edge of gearbox / bellhousing there is a small slot ,gap which goes straight into the bellhousing.its worth jamming a big rag into this to prevent getting loads of water into the clutch and release bearing . i once pressure washed a car and then didnt drive it for a month, the next time i started it up the clutch release beari g must have gotten some water in it and was noisy. so i would say.....to be sure . drive the car around after washing to make sure all is dried out. ( especially as you may find the oil isnt from anything that requires gearbox out !) 1 Quote Link to comment Share on other sites More sharing options...
Kr1s Posted May 27 Author Share Posted May 27 Sorry, I didn't see this until just now. Luckily I didn't use a hose or pressure washer as I was concerned about water ingress as you suggest. I think I got it clean enough with Gunk, a toothbrush and some damp rags and sponges. I've not driven the car yet as I know one of the rear brakes is seized - it's going to the garage to get that sorted and a general pre-mot inspection on Friday (I hate working with brake fluid 😆) so I'll check it after that. I hope I bought the right type of cylinders. I think it's time I started a project thread! Cheers! Chris 1 Quote Link to comment Share on other sites More sharing options...
Jessopia74 Posted May 27 Share Posted May 27 1 hour ago, Kr1s said:  I think it's time I started a project thread! Cheers! Chris absolutely 🙌 Quote Link to comment Share on other sites More sharing options...
cam.in.head Posted May 30 Share Posted May 30 rear cylinders should be 19mm if i remember correctly 1 Quote Link to comment Share on other sites More sharing options...
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