moore101 Posted March 6, 2010 Share Posted March 6, 2010 as appears in the gearbox thread for v8s in series board its highly possible that my lightweight will be getting an lt77/230 box from a defender in the next month. i think ive got everything sorted apart from getting a diesel input shaft to fit into a v8 diesel input shaft diameter 23mm? v8 input shaft diameter 19mm? currently i have a ground down series input shaft to 19mm which gives a nice meaty bush in the end of the crank. i dont think a series input shaft isnt 23mm to start with though so the amount of the material removed just about leaves some of the outer case hardened metal there. how much can i get ground off of an lt77 input shaft before its not hardened? and how quickly would it wear in an oilite spigot bush if too much material was removed? Quote Link to comment Share on other sites More sharing options...
zoltan Posted March 6, 2010 Share Posted March 6, 2010 We have shafts and gears hardened and ask for 0.025/0.035" case depth on EN36 steel. Grinding 23mm to 19mm sounds like quite a reduction and probably through the hardening but then again what do I know? Quote Link to comment Share on other sites More sharing options...
Jon White Posted March 7, 2010 Share Posted March 7, 2010 It doesnt matter what you take off IMHO becasue the bronze bush is still the softest part. I ran mine for several years with a turned down input shaft without problems. Be warned though that LT77 shafts are very hard and a pig to machine until you've cut through the hardening. Jon Quote Link to comment Share on other sites More sharing options...
moore101 Posted March 7, 2010 Author Share Posted March 7, 2010 thats what i was thinking worst thing that happens is it wears, input shaft wobbles like mine was doing and i end up back at square one. if the clutch isnt depressed very often then it shouldnt wear at all. Quote Link to comment Share on other sites More sharing options...
mickeyw Posted March 8, 2010 Share Posted March 8, 2010 First off, I would suggest reducing the shaft diameter on a cylindrical grinder if at all possible. You won't have to worry about the hardenss of the shaft, and you'll get as smooth and accurate a finish as it originally had. As for the spigot bush, I agree with Jon White. You will have two materials of different hardness, this is a good thing. On top of this, Oilite is impregnated with lubricant. It's intended for use as a bearing material, so you should have no problem here as long as the clearance is correct. I have done all this with my Series II V8 many years ago. I always apply a thin smear of EP90 to the input shaft before assembly too. Quote Link to comment Share on other sites More sharing options...
moore101 Posted March 8, 2010 Author Share Posted March 8, 2010 planning on using the circular grinder at college (got a few ex machine shop teachers in for a few weeks ). only problem i may have is if the gearbox end of the shaft doesnt have a centre in it in which case i'll have to make up a centre to go in/on that end as there arent any chucks or faceplates for the grinder. does anyone know what sort of tolerance fit it will need to be? will 0.01mm be ok? (dont know how much wear the grinders got in it ) Quote Link to comment Share on other sites More sharing options...
simonr Posted March 8, 2010 Share Posted March 8, 2010 I take it, it's not possible to bore out the hole in the flywheel? (or is it in the crank shaft?) Then at least it's only the size of oilite bush that determines what it fits in the future? Si Quote Link to comment Share on other sites More sharing options...
zoltan Posted March 8, 2010 Share Posted March 8, 2010 I take it, it's not possible to bore out the hole in the flywheel? (or is it in the crank shaft?) Then at least it's only the size of oilite bush that determines what it fits in the future? Si The crank tail will be good and hard but a CBN tipped boring bar would probably work Quote Link to comment Share on other sites More sharing options...
Phil Hancock Posted March 8, 2010 Share Posted March 8, 2010 I thought that the modern way was the crank end with the bush in was cut short so it did not project beyond the flywheel face and using longer bolts for the flywheel a bearing housing was fitted that took a std 7/8" bore bush avoiding the gearbox strip down and machining of the input shaft. Quote Link to comment Share on other sites More sharing options...
Jon White Posted March 8, 2010 Share Posted March 8, 2010 The so called modern way of hacksawing the end of the crankshaft off is IMHO the most horrible bodge known to man! There is no reason why the end of the crank couldnt be machined, but trying to find someone with a suitablemachine and or fixture would be fun! The input shaft does have a centre in the end of it. 0.1 tolerance will be fine - it reallyisnt that accurate, but bear in mind it'll need to be 3/4" not 19mm! I'd suggest buying a new spigot bush and machining the shaft until the bush is a nice sliding fit onto the shaft otherwise you'll never get the box back onto the engine! Jon Quote Link to comment Share on other sites More sharing options...
moore101 Posted March 8, 2010 Author Share Posted March 8, 2010 i too am not a fan of cutting the end of the crank off, especially as the engine i have is meant to be our spare to go in the 101 when its engine finally dies. thought it was 3/4", got it written down on a piece of paper somewhere. i will take the bush out of the crank and machine the shaft to fit nicely. then will do what i did last time before fitting which was to take the adaptor plate off the back of the engine, and check the input shaft goes into the end of the crank without binding when the gap between bellhousing and engine is the same as the thickness of the adaptor plate. that way i know that the two will physically fit together and wont mind spending the half hour of wriggling that it took last time to get them mated. Quote Link to comment Share on other sites More sharing options...
zoltan Posted March 14, 2010 Share Posted March 14, 2010 Following the input shaft and spigot diameter discussion, anyone have a dimension for the spigot diameter for an R380 V8 input shaft? Ive bought a spigot bush p/n 614263 which has what is I assume a pilot bore of about 13mm which is to go in a 3.5 EFi auto V8 which is bushless ATM Quote Link to comment Share on other sites More sharing options...
moore101 Posted March 15, 2010 Author Share Posted March 15, 2010 i think r380 input shaft diameter is 19mm Quote Link to comment Share on other sites More sharing options...
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