need4speed Posted February 18, 2015 Share Posted February 18, 2015 When fitting 35" tyres it obviously raises the gearing a lot. I know the simplest way to lower the gearing to suit would be via the transferbox, but in my case my tbox has just been totally rebuilt and i dont fancy messing about with it again for a long time (fingers crossed). The only unknown on my Defender are the diffs. All i know about them are that they are TD5 vintage. I havent had them apart, so with this in mind would i be better changing the cw&p ratio to suit 35" tyres while im in there? And if so, what would be the best ratio to go for? Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted February 18, 2015 Share Posted February 18, 2015 Td5 will be as others - 3.54 Changing TBOX ratios ONLY changes the high(road) speds, its still going to be wrong on the low box...CW&Ps change both high and low. Heres my calculator http://forums.lr4x4.com/index.php?showtopic=86617&hl=gearing Quote Link to comment Share on other sites More sharing options...
landroversforever Posted February 19, 2015 Share Posted February 19, 2015 Having played with the calculator before I've ended up with the following: 4.75 ratio diffs 1.2 ratio transferbox That will give almost standard defender on 235/85R16 gearing, slightly lower in low and slightly higher in high. Quote Link to comment Share on other sites More sharing options...
need4speed Posted February 19, 2015 Author Share Posted February 19, 2015 Yep i was thinking 4.75 cw&p would suit my planned 35" tyres. What size tyres are you running Ross? Quote Link to comment Share on other sites More sharing options...
landroversforever Posted February 19, 2015 Share Posted February 19, 2015 Will be 35" of some flavour. Quote Link to comment Share on other sites More sharing options...
need4speed Posted February 19, 2015 Author Share Posted February 19, 2015 Ive been considering 315/75/16 Cooper Discoverer STT's. I just need to identify which rear TD5 axle i have, as im not sure if Ashcroft sell a 4.75 if the axle is after 2003.. Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted February 19, 2015 Share Posted February 19, 2015 TD5 90s are standard LONG NOSE 24 spline diffs FRONT AND REAR Choices are wide : 3.50 ratio, with a tooth count of 28/8 4.12 ratio, with a tooth count of 33/8 4.37 ratio, with a tooth count of 35/8 4.75 ratio, with a tooth count of 38/8 Less teeth = stronger !...I have a 3.50 in the workshop at the mo for a rebuild ....HUGE gearset, will shove a pic up laters ! Late TD5s - ie post the horrible Salisbury unit - TD5 110s 130s etc are Short Nose P38 type diffs For these there is only 4.1s : http://www.ashcroft-transmissions.co.uk/ring-pinions/4-10-r-p-for-the-p38-type-diff.html Quote Link to comment Share on other sites More sharing options...
landroversforever Posted February 19, 2015 Share Posted February 19, 2015 Phil's is a 110 Nige Quote Link to comment Share on other sites More sharing options...
Les Brock Posted February 19, 2015 Share Posted February 19, 2015 My 3.50 Ashcroft Heavy duty Diffs I just stuck with a 1.4 and these lol Quote Link to comment Share on other sites More sharing options...
Nigelw Posted February 19, 2015 Share Posted February 19, 2015 My 3.50 Ashcroft Heavy duty Diffs I just stuck with a 1.4 and these lol IMG_0733.JPG Holy smokes, think jaws might come a knocking to re-claim his dentures Les Quote Link to comment Share on other sites More sharing options...
need4speed Posted February 19, 2015 Author Share Posted February 19, 2015 TD5 90s are standard LONG NOSE 24 spline diffs FRONT AND REAR Choices are wide : 3.50 ratio, with a tooth count of 28/8[/size] 4.12 ratio, with a tooth count of 33/8[/size] 4.37 ratio, with a tooth count of 35/8[/size] 4.75 ratio, with a tooth count of 38/8[/size] Less teeth = stronger !...I have a 3.50 in the workshop at the mo for a rebuild ....HUGE gearset, will shove a pic up laters ![/size] Late TD5s - ie post the horrible Salisbury unit - TD5 110s 130s etc are Short Nose P38 type diffs For these there is only 4.1s : http://www.ashcroft-transmissions.co.uk/ring-pinions/4-10-r-p-for-the-p38-type-diff.html As sig its a 110 i have I will try to find the serial number on axle to see if i can id it. Unless someone could post a pic of the 2 possible different types so i could maybe id it by having a quick look? Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted February 19, 2015 Share Posted February 19, 2015 Salisbury Diff LONG NOSE - "Normal LR Diff Short Nose / P38 Diff Nige Quote Link to comment Share on other sites More sharing options...
need4speed Posted February 19, 2015 Author Share Posted February 19, 2015 Ok. If im reading things right, my choices are limited here. Ive had a looksee under the 110 and its definately not a salisbury rear as there is no pressed steel plate on the rear. As Nige says, if its not a salisbury then its the P38 type i have. Now this raises more questions than answers.. 1. Am i right in thinking that all i can do is go 4.10 on the rear and 4.12 on the front? 2. Wont the difference between the 2 (slightly) different ratios kill something very quickly? 3. For 35" tyres wont the 4.10 still be too high? 4. Will it just be better for me to junk the P38 axle and look for a salisbury so i can go 4.75 front & rear? 5. Any other options ive maybe not thought of? Sorry for all the questions... Quote Link to comment Share on other sites More sharing options...
need4speed Posted February 19, 2015 Author Share Posted February 19, 2015 Anyone? Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted February 19, 2015 Share Posted February 19, 2015 I can help but not till next week as at mums funeral tomm... But reckon next week will need something to take my mind off things But No don't go fitting a Salisbury ffs Ratio difference to minimal to worry....that's about 5 psi difference on pressure as an equivalent Go 4.2 and if not right change tbox gears Be in touch Nige Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted February 19, 2015 Share Posted February 19, 2015 http://www.kamdiffs.com/shop/product-category/kam-crown-wheel-and-pinions/for-short-nose-differentials/ 4.75 Quote Link to comment Share on other sites More sharing options...
need4speed Posted February 19, 2015 Author Share Posted February 19, 2015 I can help but not till next week as at mums funeral tomm... But reckon next week will need something to take my mind off things But No don't go fitting a Salisbury ffs Ratio difference to minimal to worry....that's about 5 psi difference on pressure as an equivalent Go 4.2 and if not right change tbox gears Be in touch Nige Sorry to hear about your mum Nige. You have my condolences. There is absolutely no rush. Like you need to be reminded of that on my build right Seriously though im just getting my info together as i dont even have the big wheels/tyres yet. Who does 4.2 cw&p? Quote Link to comment Share on other sites More sharing options...
need4speed Posted February 19, 2015 Author Share Posted February 19, 2015 http://www.kamdiffs.com/shop/product-category/kam-crown-wheel-and-pinions/for-short-nose-differentials/ 4.75 Great find Nige. I didnt realise that Kam stocked stuff that Ashcroft didnt. Quote Link to comment Share on other sites More sharing options...
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