ZeroDelta Posted February 9, 2012 Share Posted February 9, 2012 Hi, I am in the process of rebuilding a 1991 200Tdi Defender 90. I used to own a TD5 and was once told that if you slapped in a Disco TD5 transfer box it made it slightly more economical and easier to drive - if you where not towing massive loads which I do not. I am at the early stage of fighting rust, but need to plan ahead and was wondering does anyone have any experience of such a transplant and is it worth? I suppose I should ask is it possible? Any other advice on how to improve the drive on my Tdi would be most welcome as I will use it to cover long distances around the UK and down to the Alps. If this is a goer I will probably give Ashcroft a bell to seek there advice, but again if anyone else has other ideas i am all ears. Thanks in advance. Quote Link to comment Share on other sites More sharing options...
scube Posted February 9, 2012 Share Posted February 9, 2012 yes all of above Straight swap Quote Link to comment Share on other sites More sharing options...
James90 Posted February 9, 2012 Share Posted February 9, 2012 Hmm Im also wondering this, I have an auto 200tdi and without a rev counter its hard to know what the engine is actually doing, annoying thing is Ive sold all my old spare transfer boxes, so now I will end up buying a new one to test! Quote Link to comment Share on other sites More sharing options...
Retroanaconda Posted February 9, 2012 Share Posted February 9, 2012 If it's a Disco 2 (Td5) box then just make sure it has the diff-lock installed. A lot of them didn't. Disco 1 boxes were 1.2 ratio as well, and all had diff-lock installed. Quote Link to comment Share on other sites More sharing options...
ZeroDelta Posted February 9, 2012 Author Share Posted February 9, 2012 Thanks Guys. If I am going to do this is it worth upgrading the gear box to an R380? Is it a straight swap with a 200Tdi too? Quote Link to comment Share on other sites More sharing options...
Retroanaconda Posted February 9, 2012 Share Posted February 9, 2012 You'd need a stubby R380 to be a direct replacement for the LT77. To be honest, if your current LT77 is in good nick then I wouldn't worry about it. If it needs replacing then it would make sense to upgrade if you can splash out the £945 + VAT that Ashcrofts want for their stubby R380 kit. The LT77 is more than up to dealing with the earth-shattering torque that the 200Tdi provides though Quote Link to comment Share on other sites More sharing options...
ZeroDelta Posted February 10, 2012 Author Share Posted February 10, 2012 Thanks Retroanacondo. Apart from a bit of a sloppy rev/1st gear selection the gear box seems to be in good nick and I have a plan to sort this problem out thanks to earlier help from tehe LR4x4 community. Sounds like I need to now source a decent Disco transfer box. Is there any specific type I need to go for or will any Disco box do? Quote Link to comment Share on other sites More sharing options...
Eightpot Posted February 10, 2012 Share Posted February 10, 2012 You don't necessarily need to change your transfer box, you can just change some of the cogs inside to change the gearing, or get a gearbox specialist to do it for you. Saying that though, you can pick up disco transfer boxes for cheap, so either way won't break the bank. Any disco diesel box will do, some have a Q suffix, which had the teeth cut slightly different to make them a little Quieter. Changing the gearing works very nicely for long road trips, especially with tall tyres as well. Did it in my last 90 and it was much more civilised on the motorway - can't say it improved mpg much - it would take more than that to make a Defender fuel efficient at 70mph, but noise levels changed from washing machine full of nails and cats on full spin to darth vaders tie fighter in a tunnel. It does make it more difficult to tow a heavy trailer though, but if thats a rarity then go for it. Quote Link to comment Share on other sites More sharing options...
ZeroDelta Posted February 10, 2012 Author Share Posted February 10, 2012 Eightpot thanks for the advice and I have found 2 Disco boxes going for £30 each which are described as LT77 LT230. I take it that these will be compatible if tehy have been split from an Lt77 gearbox? Quote Link to comment Share on other sites More sharing options...
Eightpot Posted February 10, 2012 Share Posted February 10, 2012 yep, they will fit. I'd be tempted to spend a bit more and get either a recon or known good box personally, unless you know it's a good un? (funny how all the engines and boxes for sale on ebay and photographed sitting forlornly in a puddle of oil and mud seem to have been pulled from 90,000 mile cars...) Quote Link to comment Share on other sites More sharing options...
sammyb Posted February 11, 2012 Share Posted February 11, 2012 sorry to hi jack the thread a bit but I have a 2.5 TD in my 90 ATM but plan on putting a 200 in it, how do I know what gearbox is in mine and if a disco/fender tdi transfer box is compatible? Quote Link to comment Share on other sites More sharing options...
jbs Posted February 11, 2012 Share Posted February 11, 2012 Sammyb, your 90 will have the LT77 Gearbox in it with a 1:410 ratio transfer box, If you wanted to fit a disco transfer box into it you could quite easily-It's a straight swap apart from swapping pover the hand brake bracket that'll need unbolting and your original one bolting back in situ unless of course you already have the X-eng hand brake disk brake conversion hth John Quote Link to comment Share on other sites More sharing options...
sammyb Posted February 11, 2012 Share Posted February 11, 2012 is there a good enough gain from doing this tho? to warrent the time and effort of swapping them over? Quote Link to comment Share on other sites More sharing options...
dailysleaze Posted February 11, 2012 Share Posted February 11, 2012 I did it to my 300Tdi Defender at the same time as replacing my gearbox/clutch. On the motorway, it's a hell of a lot quieter. Pleasantly so. And I went from 27mpg to 30mpg on long motorway runs. Instead of changing up to fifth at 50 it's now 55mph. The only downside is that 4th doesn't like going much beyond 50mph, and 50mph labours the engine in 5th, so when driving on fast A roads you can find yourself not having any power a lot of the time. So in reality, you can't really drive between 50-60mph when not on a motorway/dual carriageway. You also need more revs when puling away as first naturally higher, but that's just changing your habits. It's also nice to accelerate when you see a space on a roundabout and don't hit the top of the revs by the time the other car comes round to you. I'm not sure how well 300Tdi Discoveries drove? Or maybe just my engine is down on power. Quote Link to comment Share on other sites More sharing options...
RustyNissanPrairie Posted February 11, 2012 Share Posted February 11, 2012 Im debating this on my rebuild, I've got a Defender 200 to fit and a Jeremy Fearn intercooler to go with it, a straight through mid section exhaust and the usual pump tweaks all to go in my 110. Planning on doing quite a bit of towing with a large Ifor Williams box van trailer with at most a 1ton load in it. Been driving for the last 6 years with the current 2.5NA/1.6 ratio transfer box so happy at 50mph on m-ways, just debating whether to fit a 1.4 or a 1.2 transfer box but after reading 'dailysleaze's comments above its definitely edging me towards a 1.4. Quote Link to comment Share on other sites More sharing options...
Eightpot Posted February 11, 2012 Share Posted February 11, 2012 I'm not sure how well 300Tdi Discoveries drove? Or maybe just my engine is down on power. They have smaller diameter tyres, so lowering the gearing. My old ex MOD rag top 90 with a 200tdi had the disco gearing and 235/85 tyres - the gearing really suited it and it was great on the motorway, never struggled in fifth at all and would pull upto 90 odd mph (on a private motorway of course) On the couple of times I had to tow with it though it really struggled - had to tow my rangie back from the docks and all up trailer weight was over 3.5T , not something I want to do again in a 90 - had to start off in low box, and gearing was awful, struggled to keep it in fourth and nearly killed the clutch. Quote Link to comment Share on other sites More sharing options...
dailysleaze Posted February 12, 2012 Share Posted February 12, 2012 They have smaller diameter tyres, so lowering the gearing. Makes sense then! I guess there's pros and cons with both the 1.4 and 1.2. You just have to decide which type of driving you care more about - motorway noise/mpg or towing/A roads power Quote Link to comment Share on other sites More sharing options...
rusty_wingnut Posted February 13, 2012 Share Posted February 13, 2012 I did it to my 300Tdi Defender at the same time as replacing my gearbox/clutch. On the motorway, it's a hell of a lot quieter. Pleasantly so. And I went from 27mpg to 30mpg on long motorway runs. Instead of changing up to fifth at 50 it's now 55mph. The only downside is that 4th doesn't like going much beyond 50mph, and 50mph labours the engine in 5th, so when driving on fast A roads you can find yourself not having any power a lot of the time. So in reality, you can't really drive between 50-60mph when not on a motorway/dual carriageway. You also need more revs when puling away as first naturally higher, but that's just changing your habits. It's also nice to accelerate when you see a space on a roundabout and don't hit the top of the revs by the time the other car comes round to you. I'm not sure how well 300Tdi Discoveries drove? Or maybe just my engine is down on power. This has to be the most honest and correct answer ive read on this subject. This reflects how mine was when I swapped over. Quote Link to comment Share on other sites More sharing options...
Ex Member Posted February 13, 2012 Share Posted February 13, 2012 is there a good enough gain from doing this tho? to warrent the time and effort of swapping them over? I have done this with a 200TDI. It is much nicer to drive as the noise is down and you can drive faster. Fuel usage is about the same. I would suggest though that you want to have the fueling turned up a bit as the power might be a little lacking in stock tune. Quote Link to comment Share on other sites More sharing options...
sammyb Posted February 14, 2012 Share Posted February 14, 2012 I will be turning the pump up to 19 psi, decent filter and a de restricted exhaust On another note are the LT77 gearboxes the same out of the discovery and defender? as mine has shat a seal Quote Link to comment Share on other sites More sharing options...
Ex Member Posted February 14, 2012 Share Posted February 14, 2012 19 psi? That would be the turbo and has nothing to do with the pump. You need more fuel for more power. Don't waste any money on an air filter as that will make zero difference. Quote Link to comment Share on other sites More sharing options...
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