V8 Freak Posted October 2, 2007 Share Posted October 2, 2007 Is it possible? Has it been done ? I have a RPI Piper high torque cam going into the 3.9 EFi soon. I'm wondering if I can make use of the extra torque and lower the revs a little on the longer runs.... May improve the MPG a smidge and save the planet ! Your views please.... Neil Quote Link to comment Share on other sites More sharing options...
JSG Posted October 3, 2007 Share Posted October 3, 2007 I don't see why not - it would fit ok but I guess your concern is the benefit you would see in terms of revs / mph. If you feel you could do with another gear when cruising then I'd say you'd get a benefit. The Series overdrive on ALF is great on motorways even with an oldish 3.5 V8. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted October 3, 2007 Share Posted October 3, 2007 A lot cheaper is to replace your transfer box with one from a Disco or RR - they are higher geared in high box, the 3.9 should pull it fine. Or fit bigger tyres Quote Link to comment Share on other sites More sharing options...
JST Posted October 3, 2007 Share Posted October 3, 2007 1.2 box as ^^ could be the way to go but not if you live in a hilly area or tow alot in my experience (but then most of that is diesels) you can get a 1.2 box for £50-£75 Quote Link to comment Share on other sites More sharing options...
V8 Freak Posted October 4, 2007 Author Share Posted October 4, 2007 Live on a hill, but not a particularly hilly area, rarely tow..... Generally pull away in 2nd gear now and revving at approx. 3k at 70MPH... I recon the engine is good for the lower evs without having foot onthe floor all the time.. (Except I do that cuz I like the noise now..) Thanks for the guidance.. 1.22 it looks like then.... Do the RR and Disco ones literally replace current with no lever changes etc ? Neil Quote Link to comment Share on other sites More sharing options...
Mo Murphy Posted October 4, 2007 Share Posted October 4, 2007 I'd fit the overdrive to the back of the transfer box Neil, you'll find that it'll transfer the drive better than bolting it to the V8 Mo Quote Link to comment Share on other sites More sharing options...
JST Posted October 4, 2007 Share Posted October 4, 2007 Mo - bored by chance? Quote Link to comment Share on other sites More sharing options...
V8 Freak Posted October 4, 2007 Author Share Posted October 4, 2007 Now I didn't thnk of that Mo... LOL Quote Link to comment Share on other sites More sharing options...
Mark Posted October 4, 2007 Share Posted October 4, 2007 Neil, it's almost a straight swap - it's just the low operating mech that either needs swapping for your defender one, or taking off and the operating lever on the shaft moving round 90 degrees... I have just done the reverse on my disco - putting a 1.4 box (strangely off a v8 110) in place of a 1.22 one this is a defender box: and this is the disco one: as you can see, the actuating lever is in a slightly different position. I took the disco one off, and attached it to the defender t-box, as this seemed easiest, but on further investigation you can just move the lever on the shaft: If you want a disco t-box with a defender actuator attached, you would be welcome to it! it needs new bearings and seals, but it works.... cheers Mark Quote Link to comment Share on other sites More sharing options...
Pete Attryde Posted October 5, 2007 Share Posted October 5, 2007 Sorry to go slightly OT but, Mark how long did it take to change your Transfer box over? As I am going to be doing the same in the not to distant future. Pete. Quote Link to comment Share on other sites More sharing options...
Mark Posted October 5, 2007 Share Posted October 5, 2007 Pete, I did it over two days - took the old one off on one, and put the new one on the next. I was on my own, working on my back, so it is really quite a physical job, so the break in between was appreciated! It took 3 or 4 hours I guess to get the box off - bearing in mind, I have had the x-brake and propshafts off several times recently, so that was all loose and easy. The main job was moving the box back and down, which with the exhaust in place can be kinda ticklish. It is also a good idea to take the inspection panel off the back of the box to give yourself half an inh extra room before you hit the floor. Refitting took another 3 or 4 hours, a large chunk of which was spent balancing the box on the jack rasing it, and wiggliing it into place, letting it fall off, and then doing it a few more times.... Some big blocks of wood are very helpful so that it dosn't fall too far, or onto you! a transmission jack would be even better, but the sapce available means you have to lift it up, and the rotate it round before being able to fit it to the gearbox.... hth Mark Quote Link to comment Share on other sites More sharing options...
Pete Attryde Posted October 5, 2007 Share Posted October 5, 2007 Cheers Mark, At least I only just fitted an Xbrake and new props so that should all undo reasonably easily. Pete. Quote Link to comment Share on other sites More sharing options...
V8 Freak Posted October 5, 2007 Author Share Posted October 5, 2007 Thanks for the heads up Mark... Would have stumped me for days or weeks ! Neil Quote Link to comment Share on other sites More sharing options...
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