JohnD Posted October 10, 2021 Share Posted October 10, 2021 I have this engine with the Borg-Warner autobox behind it. I don't want the box! Box itself off easily, torque converter with more difficulty, access to the mere four bolts is obscure and awkward. Now I face the flywheel - and it's weird! Very flexible, it won't stand a puller, I'm sure but even without the usual four big bolts, it's stuck to the back of the crankshaft. Advice please, about getting it off? And is the back of the crank different for an autobox? Thanks, John Link to comment Share on other sites More sharing options...
Nick Jones Posted October 10, 2021 Share Posted October 10, 2021 Crank is the same. Does it have a central spigot sticking out (to engage with/support the input shaft)? If so, this is pressed into the hole in the back of the crank where the spigot bearing normally sits and it’s probably got a shoulder on it that his holding the backplate. If you look up the centre of it I think you’ll see a tapped hole so you can put a long bolt in there to press it back out. Not done this on a six before but this is how it on a Sprint. Does your auto box have a removable bell housing? Link to comment Share on other sites More sharing options...
JohnD Posted October 10, 2021 Author Share Posted October 10, 2021 Yes, it does, Nick. Does that mean something? Just had a look down the hole on the flywheel, and yes! I can see threads in a small hole at the base of the much larger bore for the spigot on the TC. I'll try that, thanks! John Link to comment Share on other sites More sharing options...
JohnD Posted October 10, 2021 Author Share Posted October 10, 2021 Yes, it's 5/16 UNF and about an inch deep. Good anchorage, but how to use it to pull the flywheel off? It just seems to bottom in the hole, I'm loathe to put a lot of wellie onto it. And, it occurs to me that there isn't such a bore in the back of a crank that has a normal box. I need to get this flywheel off and see the bunny! Link to comment Share on other sites More sharing options...
Nick Jones Posted October 10, 2021 Share Posted October 10, 2021 I think the idea is that you just wind a bolt into that hole to Jack the spigot out. I think once the spigot is out the flex plate will come right off. I used the bell housing from an auto box for my MX5 gearbox conversion. Link to comment Share on other sites More sharing options...
sparky_spit Posted October 10, 2021 Share Posted October 10, 2021 It sounds like the method used to pull off the flywheel on a 45yr old Honda 125 Trials engine. Basically, you screw in the correct threaded "puller" and keep going until, at some unknown enormous torque figure, it finally goes bang and flies off across the workshop, missing your groin area by a few millimetres. Link to comment Share on other sites More sharing options...
JohnD Posted October 10, 2021 Author Share Posted October 10, 2021 Ok, I can see that if the thread is in the flywheel, and the small bolt bottoms in the back of the crank, then screwing it in will push the flywheel off. Currently looks like this, I'll try it tomorrow, because now I'm indoors, G&T in hand, waiting for the Turkish GP to start! Go, Lewis! And go, George and Lando! Link to comment Share on other sites More sharing options...
Nick Jones Posted October 10, 2021 Share Posted October 10, 2021 As said earlier, the spigot in the middle is a separate part and pressed into the hole in the back of the crank that takes the pilot bush on a manual car. It’s a shouldered spigot which is why it holds the flex plate on. Use a decent quality bolt and grease the threads and the end. Confession time….. I managed to get the one off my Sprint without using the jacking bolt as it was grubby in there and I completely failed to spot the hole. It was hard, took ages (like days) and made me swear a lot, especially when it eventually came out and I saw the tapped hole!! Link to comment Share on other sites More sharing options...
JohnD Posted October 10, 2021 Author Share Posted October 10, 2021 Thanks, Nick! Link to comment Share on other sites More sharing options...
JohnD Posted October 11, 2021 Author Share Posted October 11, 2021 Nick, you are the man! I asked elsewhere, and got lots of advice, from "hit it, hard" to "weld a slide hammer onto it"!! But a bolt screwed in, and it just slid off! Easily! BUT! The recess in the crank is so deep that a bolt with 45mm of thread (nearly 2", for the unmetricated) is needed! And the recess in the hub of the flywheel is already 35mm deep(more than an inch!). Luckily, I had some long 5/16 bolts, and could cut extra thread on one. Some copper ease and as said, it just slides off, nice and easy. Here it is as it came off, showing the extent of the bolt. John Link to comment Share on other sites More sharing options...
Nick Jones Posted October 11, 2021 Share Posted October 11, 2021 Glad my hard earned experience has finally been useful to someone. It’s taken about 32 years! Surprised the hole is quite that deep….. Link to comment Share on other sites More sharing options...
JohnD Posted October 11, 2021 Author Share Posted October 11, 2021 (edited) OK, it's out now, thanks to Nick, and on sale, so if anyone wants a BW 35 autobox, please see: http://ebay.us/NqBurl?cmpnId=5338273189 Thanks, John PS Nick, if it sells, I owe you a drink! Edited October 11, 2021 by JohnD Link to comment Share on other sites More sharing options...
Nick Jones Posted October 11, 2021 Share Posted October 11, 2021 I expect it will sell, but if not and you end up binning it, keep the bell housing fro me and I'll buy you a drink. I don't plan another MX5 conversion but...... Link to comment Share on other sites More sharing options...
JohnD Posted October 12, 2021 Author Share Posted October 12, 2021 Deal, Nick! Link to comment Share on other sites More sharing options...
michaeljf Posted October 14, 2021 Share Posted October 14, 2021 Hello, I have one from behind a Mk2 2.5 PI and it has a removable bell housing. Regards, Michael. Link to comment Share on other sites More sharing options...
JohnD Posted October 14, 2021 Author Share Posted October 14, 2021 (edited) I think they all do, Michael. The 35 was a unit fitted to many models, of many marques, and each had its own seperate bell. Unlike the monolithic, nay boulder-like, manual 'box Triumph fitted to the 2.5's! John Edited October 14, 2021 by JohnD Link to comment Share on other sites More sharing options...
michaeljf Posted October 17, 2021 Share Posted October 17, 2021 Hello John, The g/box (no. prefix MK seems to be a 2500 TC/S J type o/d) that I have in the TR6 (YES it is in) was a straight fit (apart from the o/d mounts )in place of the TR4 box that was in it when I got it. Regards, Michael. Link to comment Share on other sites More sharing options...
JohnD Posted October 17, 2021 Author Share Posted October 17, 2021 If it has an overdrive, micheal, it's not an autobox! Link to comment Share on other sites More sharing options...
michaeljf Posted October 26, 2021 Share Posted October 26, 2021 Hello John, We are talking about two different g/boxes. It's a long winded confusing story. The motor that I had in is a Mk2 2500 PI (which had an auto box which DIDN'T go in with the motor) but I fitted a (according to the serial No.) manual/ j type o.d. g/box from a 2500 TC/S sedan, which I have just re-fitted behind the original rebuilt motor. Now I am getting confused! Regards, Michael. Link to comment Share on other sites More sharing options...
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