steve_d Posted July 25, 2009 Share Posted July 25, 2009 For those that don’t know I converted my 87 RRC 3.5 Auto into a Dakar kitcar fitted with 33” tyres. I now find that it is reving about 2000 at motorway speed. When I come to an incline or try to accelerate it (most annoyingly) kicks down because 2000rpm is way below its ideal torque. The most obvious item to change is the transfer box but I have no idea what model it is but it is marked 1.222:1 4WD. Any ideas what ratio I should look for and which vehicle a suitable replacement would come from? Many thanks Steve PS Anybody got one? (had to ask). Quote Link to comment Share on other sites More sharing options...
western Posted July 25, 2009 Share Posted July 25, 2009 1.22 is from a Discovery, you could try a 1.410 that defenders use. Quote Link to comment Share on other sites More sharing options...
bishbosh Posted July 25, 2009 Share Posted July 25, 2009 What about changing your ring and pinions? Would give you back some off road low gearing too..... Quote Link to comment Share on other sites More sharing options...
David_LLAMA4x4 Posted July 25, 2009 Share Posted July 25, 2009 Great knowledge on this site..... I am after the various diff ratios in 2wd Audi auto gearboxes depending on engine etc. and have asked the question everywhere with no sensible reply!!! First one out the bag here answers the question! Does anyone here happen to know about Audi final drive ratios? I need the lowest and highest and which ones are in a Tdi A4 / 80 / 90 as standard. David Quote Link to comment Share on other sites More sharing options...
steve_d Posted July 26, 2009 Author Share Posted July 26, 2009 What about changing your ring and pinions? Would give you back some off road low gearing too..... That may be the easier job. So what ratios are out there? What ratio should I use? And which model will it come from? Are the diff housings the same or have I to look just for ring and pinion? Steve Quote Link to comment Share on other sites More sharing options...
will_warne Posted July 26, 2009 Share Posted July 26, 2009 Steve, it's a toss up between changing the t.box or the diffs. As you have auto the low range is less of a problem and 33's aren't that big I'd be inclined to try a t.box swap first especially as it can be done pretty cheaply. If you decide to change diff ratios you'd be after just ring and pinions. There are really 2 options: 4.11 or 4.75. You'd probably want 4.11s as the latter will bring down gearing a lot (stock is 3.54). Also, if you're thinking about change diff ratios it would be silly doing it with standard, 2-pin, centres as there's a high chance of the centre breaking and damaging the expensive ring and pinion. Therefore you'd be into spending quite big money for either 4-pin open centres or lockers/LSDs. Quote Link to comment Share on other sites More sharing options...
nas90 Posted July 26, 2009 Share Posted July 26, 2009 For those that don’t know I converted my 87 RRC 3.5 Auto into a Dakar kitcar fitted with 33” tyres.I now find that it is reving about 2000 at motorway speed. When I come to an incline or try to accelerate it (most annoyingly) kicks down because 2000rpm is way below its ideal torque. The most obvious item to change is the transfer box but I have no idea what model it is but it is marked 1.222:1 4WD. Any ideas what ratio I should look for and which vehicle a suitable replacement would come from? Many thanks Steve PS Anybody got one? (had to ask). Steve I had Ashcrofts part-ex a 1.22 transfer box for my standard Defender 1.41 on the nas Like you with 4 speed auto and BFG 255/85 tyres @ 33 inch on motorways the main box was either revving its nuts off or bogging down with not enough torque. A real pain The 1.22 box when towing allows the nas to pull hard in top and the fuel consumption if anything is now better than with the 1.41 box. The box came fully refurbed so nice and quiet.................... Quote Link to comment Share on other sites More sharing options...
Ben_J85JTY Posted July 26, 2009 Share Posted July 26, 2009 I have a Defender 1.411 that I want to swap for a 1.22 May have to remove it from the Defender first tho! Quote Link to comment Share on other sites More sharing options...
webbsite Posted July 28, 2009 Share Posted July 28, 2009 Hi Steve, You need to change to a defender LT230 1.4 ratio transfer box. I am running my 3.5 efi auto Traka on 33/12.50x15 tyres and use 3.5 diffs with a 1.4 transfer box. So, our vehicle weight will be about the same and i find the on road and off road performance to be pretty good. I did my swap with a defender box from Ashcrofts and the only problem was I needed two holes tapped for the handbrake brackets and the speedo drive gear is way off but I havent bothered to change it from the original RR one. Regards, Roger Quote Link to comment Share on other sites More sharing options...
nas90 Posted July 28, 2009 Share Posted July 28, 2009 SteveI had Ashcrofts part-ex a 1.22 transfer box for my standard Defender 1.41 on the nas Like you with 4 speed auto and BFG 255/85 tyres @ 33 inch on motorways the main box was either revving its nuts off or bogging down with not enough torque. A real pain The 1.22 box when towing allows the nas to pull hard in top and the fuel consumption if anything is now better than with the 1.41 box. The box came fully refurbed so nice and quiet.................... Did I change a 1.41 for a 1.22 or a 1.22 for 1.41? Doh! The original auto and transfer were from a RR classic and both the auto and transfer have been back to Ashcrofts So I must have changed the 1.22 (same as Disco and RR I guess) for a 1.41 which gives me more revs for less speed so back to a standard Defender set-up. Back to the original question, the 4 speed needs more revs with the bigger than standard tyres. Quote Link to comment Share on other sites More sharing options...
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