Ed Poore Posted December 18, 2011 Share Posted December 18, 2011 (edited) What has been a long (two years or so) story has resulted in the following situation. I have a 300Tdi 110 with the R380 main-box exhibiting all the usual symptoms (5th -> 4th synchro-mesh and input shaft wear) and a Disco of exactly the same age that needs substantial structural repair work and a complete overhaul of all dampers and anti-roll bars to be road-legal and safe, but has an almost new gearbox in it and the power train is without fault. I've done a bit of research into this and find conflicting comments about whether it's possible to do a Disco -> Defender R380 swap. The three major questions surrounding this seem to be The bell-housing (some say it's different and some say it's identical) The selector shafts The input shaft length Essentially what it boils down to is that I need to minimise down-time (ideally something that can be completed in a weekend or long-weekend if necessary) and to make matters more interesting (although not a major hurdle) is that I'm based in Surrey with the 110 and the Disco is based in very West Wales. So is it possible to simply swap the main-boxes over (ideally don't want to have to do any modifications such as drilling new plates or machining of selectors / shafts)? The simplest would be if I could simply take out the main-box from the Disco and put it into the Defender swapping the top-housing over to keep the gear lever in the correct place. The second issue would be considering I do a lot of road mileage if I were to put the Disco transfer box onto the Defender are there any complications or is it a straightforward swap? One consideration would be what it's like towing since I do have the need to be able to pull the maximum weight possible on the odd occasion - although these are rare enough that dropping down to the low box to get started would not be a major issue I think. [edit] Looks like the selector forks would need to be changed over but to be honest after completely rebuilding the Series' gearbox I think I can manage that reasonably quickly [/edit] Edited December 18, 2011 by Ed Poore Quote Link to comment Share on other sites More sharing options...
landy V8 Posted December 18, 2011 Share Posted December 18, 2011 the box will fit but i don't think changing over the levers is as straight forward as just changing the top plate.i'm pretty sure there's more involved(do a search on here as it will have been covered). T/Box will be a straightforward swap. Quote Link to comment Share on other sites More sharing options...
ejparrott Posted December 19, 2011 Share Posted December 19, 2011 The people who tell you the bellhousings are different are sort of right..there is a stumpy R380 bellhousing option, which Ashcroft do supply. However, all the references I have seen indicate that this is only normally used when the R380 is being put in in place of an LT77, and saves having to change propshafts too. Quote Link to comment Share on other sites More sharing options...
Orgasmic Farmer Posted December 19, 2011 Share Posted December 19, 2011 I am sorry but you will never get a concise answer on this question. I am doing exactly the same conversion but have the luxury of time so have spent it in research. What I do know. The R380 from a disco will fit straight on your defender with no mods in the form of drilling welding or moving major mounting points...BUT 1 The clutch slave is on the other side so needs replumbing 2. The gear stick, as you know, will come up about 3 inched south of the seatbox/tunnel junction. I have seen a few conversions done where the seatbox has been cut and modified and the disco set up left "as is" with no adverse affects. Driving position is comfortable and with a bit of fabrication and carpet can be made to look half decent, but obviously this is not to everyone's taste. To do the job properly, ie change the gearstick top housing seems to be possible but much more involved. There are 2 ways from what I can ascertain. The difference is in the way the gearstick connects to the selector shaft and transmit the movement between them. The proper way is the change the selector shaft over completely which gives the correct clevis on the end for the forward mounted defender gearstick to operate. The other way I have read about but not found much detail on is to somehow take the clevis from the defender box and weld it to a sleeve and then weld that onto the end of the disco mainshaft. As I say, I have only found oblique references to this but it has been done so someone somewhere will know more. Anyway, the disco transfer box will be a straight swap but remember to change the transfer gear and the speedo drive too. Quote Link to comment Share on other sites More sharing options...
Orgasmic Farmer Posted December 19, 2011 Share Posted December 19, 2011 http://forums.lr4x4.com/index.php?showtopic=62745&hl=&fromsearch=1 second pic Quote Link to comment Share on other sites More sharing options...
vulcan bomber Posted December 19, 2011 Share Posted December 19, 2011 The people who tell you the bellhousings are different are sort of right..there is a stumpy R380 bellhousing option, which Ashcroft do supply. However, all the references I have seen indicate that this is only normally used when the R380 is being put in in place of an LT77, and saves having to change propshafts too. yep, the stumpy r380 was made by land rover as a retro fit for the lt77. It makes the boxes the same length. And as you say ashcroft now supply them to order, i have one and so does Ralph aka Western. Quote Link to comment Share on other sites More sharing options...
western Posted December 19, 2011 Share Posted December 19, 2011 yep, the stumpy r380 was made by land rover as a retro fit for the lt77. It makes the boxes the same length. And as you say ashcroft now supply them to order, i have one and so does Ralph aka Western. on my 2nd, which came from Ashcrofts. http://www.ashcroft-transmissions.co.uk/index.php?act=viewProd&productId=157 Quote Link to comment Share on other sites More sharing options...
Ed Poore Posted December 19, 2011 Author Share Posted December 19, 2011 1 The clutch slave is on the other side so needs replumbing To do the job properly, ie change the gearstick top housing seems to be possible but much more involved. There are 2 ways from what I can ascertain. The difference is in the way the gearstick connects to the selector shaft and transmit the movement between them. The proper way is the change the selector shaft over completely which gives the correct clevis on the end for the forward mounted defender gearstick to operate. Hmm, I had not heard about the clutch issue before. Given I did manage to re-assemble the Series' gearbox four times in one day (kept putting things back in the wrong order and forgetting various gaskets) perhaps the simplest would be to "strip" down the two side by side and then "simply" swap over the guts rather than faff-around with the housings... I think I need to have a look at both side-by-side to see what the differences are - now that we have a nice pit dug in Wales which should be able to fit both in at the same time (that took a lot of concrete to finish off). Quote Link to comment Share on other sites More sharing options...
Orgasmic Farmer Posted December 19, 2011 Share Posted December 19, 2011 Ed, I forgot that since you already have a defender r380 you "should" be able to simply swap the bell housing for the disco one and that will solve the clutch issue! Quote Link to comment Share on other sites More sharing options...
Ed Poore Posted December 19, 2011 Author Share Posted December 19, 2011 Ed, I forgot that since you already have a defender r380 you "should" be able to simply swap the bell housing for the disco one and that will solve the clutch issue! That's kind of what I was hoping, the main unknown (assuming the input shaft is the same length - which I think is "different" on the LT77 version because of the shorter bell-housing) is the selector side of things. I think I'll need to have a look at microcat when I get back home and see what the differences are... Quote Link to comment Share on other sites More sharing options...
ejparrott Posted December 19, 2011 Share Posted December 19, 2011 The input shaft should be the same length between your defender version and the disco version, the gearbox is (mostly) interchangable between defender and disco. Only the stumpy R380 LTreplacement gearbox has a different input shaft. Quote Link to comment Share on other sites More sharing options...
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