Boris113 Posted January 31, 2018 Share Posted January 31, 2018 I'm hoping to fit a 3.9 Rover V8 into the 90 soon and would ideally like to couple it to an R380 gearbox. Finding hens teeth is easier than finding a Defender V8 R380 so the options appear to be 1. take defender diesel box, fit v8 mainshaft then locate v8 bellhousing at great expense or 2; find complete disco/RR v8 R380 and using Ashcrofts conversion kit, swap the selectors to bring the g-box lever up in the correct place for a Defender. I lack the tools/skills to dismantle and swap a mainshaft so the disco option looks to be the ticket. Hunting on eBay has shown a few different versions of a V8 R380 to suit a disco 1, disco 2 and P38. I've got my head around the bearing differences from suffix J to L but was unsure if there were any further differences between D1, D2 and P38 gearboxes that may cause issues when fitting into the 90? Thanks in advance, Harry Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted January 31, 2018 Share Posted January 31, 2018 P38 has a concentric clutch release, it's totally different to the rest. Also, P38 exhaust fouls the slave cylinder on a RR/Disco box. My 109 has an Ashcroft-built R380 with Disco/RR bellhousing + Defender shifters, this was years before they started doing the kit. Quote Link to comment Share on other sites More sharing options...
ashtrans Posted January 31, 2018 Share Posted January 31, 2018 3 hours ago, Boris113 said: I'm hoping to fit a 3.9 Rover V8 into the 90 soon and would ideally like to couple it to an R380 gearbox. Finding hens teeth is easier than finding a Defender V8 R380 so the options appear to be 1. take defender diesel box, fit v8 mainshaft then locate v8 bellhousing at great expense or 2; find complete disco/RR v8 R380 and using Ashcrofts conversion kit, swap the selectors to bring the g-box lever up in the correct place for a Defender. I lack the tools/skills to dismantle and swap a mainshaft so the disco option looks to be the ticket. Hunting on eBay has shown a few different versions of a V8 R380 to suit a disco 1, disco 2 and P38. I've got my head around the bearing differences from suffix J to L but was unsure if there were any further differences between D1, D2 and P38 gearboxes that may cause issues when fitting into the 90? Thanks in advance, Harry you can use the D1 or D2 disco box to fit our adapter to along with the defender top housing, forget the P38, very different, Dave Quote Link to comment Share on other sites More sharing options...
Boris113 Posted February 1, 2018 Author Share Posted February 1, 2018 Thank you for the quick response Fridge and Dave, I'll go with the Discovery version then. I currently have the engine, exhaust and an autobox, it came from a 3.9 D1 which the previous owner subsequently fitted to his 90 so I know that all squeezes into place I'd prefer to go for a manual box rather than the auto version. With regards to the boxes, is the ZF autobox/bellhousing the same length as a v8 r380? I'm trying to keep on a relative budget and if the build is possible in stages, that's ideal. In other words can I fit the engine, existing autobox and sundries for the interim, keeping the transfer box in it's usual position then at a later date, pull out the autobox and wedge in a recon R380 without having to move engine mounts fore or aft? Thanks, Harry Quote Link to comment Share on other sites More sharing options...
SumDarkPlace Posted February 1, 2018 Share Posted February 1, 2018 Look for an R380 from a d2, as late as possible. Should be suffix K or L, and be considerably more reliable. Should fit straight in, I'm told, although I haven't done it myself (abandoned project ). I believe you'll need the correct tunnel and floor plates, or you can cut and modify your originals, depending on if they've been changed for the auto. Auto converted Defenders seem to sell well, and are quite desirable, so I would be tempted to keep it auto. Quote Link to comment Share on other sites More sharing options...
JohnnoK Posted February 2, 2018 Share Posted February 2, 2018 On 31/01/2018 at 10:42 PM, ashtrans said: you can use the D1 or D2 disco box to fit our adapter to along with the defender top housing, forget the P38, very different, Dave Opening a new thread to go off at a tangent.. Quote Link to comment Share on other sites More sharing options...
Boris113 Posted February 2, 2018 Author Share Posted February 2, 2018 Thanks SumDarkPlace, possibly managed to find an R380 locally last night, I'll likely get it rebuilt when funds allow before fitting to upgrade the carrier bearings and convert to suffix L internals at the very least. Accumulated the correct transmission tunnel, v8 front prop and seatbox so it's just a case of flywheel and clutch assembly + sundries. The conversion won't be done soon but I'd rather get all the parts ahead of time and it saves fitting the auto to pull it out/swap it at a later date. My Dad used to have a 3.9 v8 90 with an auto box and I was never a fan, whilst there are many advantages to an auto, I'd prefer the control of a manual. The 90 is a keeper so I'm not too fussed about the resale value Cheers, Harry Quote Link to comment Share on other sites More sharing options...
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