tuko Posted September 13, 2014 Share Posted September 13, 2014 What would be the optimal gears for my Series 3 Hybrid? Let me add some facts of my landy, 4.70 diff's with lockers, series 3 transmission presently with a converted series 3 transfer case with 1.15 and 2.88 gearing. I picked up the LT77/LT230 combination today, which came from western Sweden close to the border of Norway. Anyways the LT77 transmission has serial number 50A0241686E, transfer case LT230 serial number 22D058591C. This transfer case has 1.410 gear ratio. I have sitting on the work bank another transfer case with serial number 81D176148G which still has the 1.211 sticker. With my present gearing I'm very leased with how the landy goes on the road but if I use the 1.410 transfer case this would raises the rev's over what I'm use to today. Therefore I'm seriously considering using the 1.21 transfer case instead. Even this would raise the rev's ever so slightly. Low range is not the issue as they are the same in both transfer cases at 3.32......Which is even better for me. ;-) Am I thinking right that the 1.21 transfer case would be the best match? Plus another item that is steering me towards the 1.21 transfer case is the fact that the input gear is the one with the cross drill holes which is in perfect condition, not the input gear that's in the 1.41 transfer case. Todd. Quote Link to comment Share on other sites More sharing options...
Snagger Posted September 13, 2014 Share Posted September 13, 2014 1.22 would be best at the moment, but better still would be the 1.4 and a set of 3.54 diffs, which will cost very little - in the UK you'll get a 3.54 Rover diff for about £20-30. You will be able yo use the existing half shafts of you use the 10 spline diffs from early 200Tdi and pre-Tdi vehicles. Quote Link to comment Share on other sites More sharing options...
ToyRoverlander Posted September 13, 2014 Share Posted September 13, 2014 3.54 diffs hurt low range gearing. Sounds like the 1.2 Tcase would be the best option. If it raises rpm at cruising speed, when you need new tires go for some bigger ones . Rubber overdrive. Quote Link to comment Share on other sites More sharing options...
Daan Posted September 13, 2014 Share Posted September 13, 2014 I run 4.75 diffs, with a 1.2 transfer case, 300 tdi and 35s. Works ok, although it could be higher still, maybe 1.0 for nice cruising if you run smaller tyres than 35s. Be carefull though, if the gearbox is off a 200 tdi (an LT77S), it is about 10% taller through the gears (exept 4th) than an earlier LT77. Mine is an LT77S Daan Quote Link to comment Share on other sites More sharing options...
Jon White Posted September 13, 2014 Share Posted September 13, 2014 What size tyres are you running? I run lt77, 1.22 lt230 with 4.75 gears on 285/75/16 which work out about 33". I find it's great for pottering about, but has short legs for motorways etc. it's flat out and screaming at 70mph. It's 200tdi. IMHO I'd be better off with a 1.003:1 for better road manners, or 4.2 gears, but I'm not about to change it as I don't use it enough. Jon Quote Link to comment Share on other sites More sharing options...
tuko Posted September 13, 2014 Author Share Posted September 13, 2014 Nick, I was snapping half shafts nearly every time I was on the trails with 10 splines, I changed both axles to 24 spline 2~3 years ago but retained the 4.70 ratio's. "Rubber Overdrive" well that was a good laugh tonight! But it does tie into the tire combination that I have and use. As a daily driver I use 265's but when I hit the trials I change over to 255/85's which are over an inch taller. The transmission/transfer case came from a 2.5TD 110 in Oslo, so she is definitely an LT77. Also my son and I saw a stamping date on the side of the transmission today that was Nov/87. Well now I'm more convinced that the 1.21 will be better suited to my driving. Todd. Quote Link to comment Share on other sites More sharing options...
Daan Posted September 13, 2014 Share Posted September 13, 2014 With that size tyres and your TD gearbox, I'd say a 1.00 is the one to have personally. Quote Link to comment Share on other sites More sharing options...
Snagger Posted September 14, 2014 Share Posted September 14, 2014 I hadn't taken into account the big tyres, Todd. I think the 1.22 will work very well for you with that tyre and diff combination. Quote Link to comment Share on other sites More sharing options...
Soren Frimodt Posted September 14, 2014 Share Posted September 14, 2014 Hi Todd. I still think it is worth considering fitting 3.54:1 Diffs, only because of the fact that they are hugely stronger because they have a much larger pinion. Unless of course you have HD R&P Already. Quote Link to comment Share on other sites More sharing options...
ejparrott Posted September 14, 2014 Share Posted September 14, 2014 Start with the 1.2, my friends hybrid runs 200TDi/LT77/1.2LT230/3.54diffs/7.50tyres, that runs beautifully. If you still find it short when you've fitted the 1.2 transfer case, either swap it for the 1.0, or swap the diffs, Nick is/was looking for some 4.1's which may be better than 3.54's for you too. Quote Link to comment Share on other sites More sharing options...
tuko Posted September 14, 2014 Author Share Posted September 14, 2014 Changing the R&P is a future plan to further strengthen the drive train. I'm not convinced with 3.54's though, my offroading buddy has a 90 with 35" tires. David is always having to rev the nutts out of his truck with the taller tires, where I can go at tick over with the 4.7's and 33" tires. But I won't rule out 4.1's till I have tested this new setup next season. Yes I'm convinced with the comments here that the 1.2 will be best of the 2 transfer cases that I have today. Todd. Quote Link to comment Share on other sites More sharing options...
ejparrott Posted September 15, 2014 Share Posted September 15, 2014 I don't think Nick has fitted 4.1's yet I think he's still looking, I'm sure he'll let us know how it goes if he does it before you though Quote Link to comment Share on other sites More sharing options...
Snagger Posted September 15, 2014 Share Posted September 15, 2014 4.1s are on more of a wish list than a shopping list - they're too expensive for me to justify with the RRC sitting in the garage awaiting much work. Quote Link to comment Share on other sites More sharing options...
seriebil.dk Posted September 17, 2014 Share Posted September 17, 2014 Hi Todd Go with the 1,22 transfer, and if you can find a LT77S from af TDI - serial starts with 56A, that will raise your 5. gear for extra road cruising comfort. i to would keep the series diffs in order to keep the low range as stock as possible. if needed add some rubber overdrive as suggested, which i think you have with 265/255 tires. try giving this a go: http://www.ashcroft-transmissions.co.uk/calc/ratio_calc.html My own setup for the 109" will be 300 TDI+LT77S+LT230 (1.22)+series diff., with the rear being Salisbary. Quote Link to comment Share on other sites More sharing options...
tuko Posted September 17, 2014 Author Share Posted September 17, 2014 Hi Todd Go with the 1,22 transfer, and if you can find a LT77S from af TDI - serial starts with 56A, that will raise your 5. gear for extra road cruising comfort. i to would keep the series diffs in order to keep the low range as stock as possible. if needed add some rubber overdrive as suggested, which i think you have with 265/255 tires. try giving this a go: http://www.ashcroft-transmissions.co.uk/calc/ratio_calc.html My own setup for the 109" will be 300 TDI+LT77S+LT230 (1.22)+series diff., with the rear being Salisbary. Interesting, I was playing around with that calculator yesterday but never even thought to change the transmission numbers. Yes now I can see that the later LT77's 5th gears are better suited for me but at this time the nickels & dimes dictate that I'll have to make due with what I just bought. Even with that said, the new transmission/transfer case will be huge jump forward over what I have today. Todd. Quote Link to comment Share on other sites More sharing options...
Daan Posted September 17, 2014 Share Posted September 17, 2014 Interesting, I was playing around with that calculator yesterday but never even thought to change the transmission numbers. Yes now I can see that the later LT77's 5th gears are better suited for me but at this time the nickels & dimes dictate that I'll have to make due with what I just bought. Even with that said, the new transmission/transfer case will be huge jump forward over what I have today. Todd. I told you... Quote Link to comment Share on other sites More sharing options...
ejparrott Posted September 17, 2014 Share Posted September 17, 2014 and you'll know that if you think it could stand a bit more there's an option. You can look out for an LT77S at your lesiure Quote Link to comment Share on other sites More sharing options...
tuko Posted September 17, 2014 Author Share Posted September 17, 2014 Your both correct. The major part is to set this all up, make the mounts, get everything lined up correctly, propshafts, hand brake, etc, etc.... Later down the road I will certainly have my nose to the ground searching for a LT77S. Also, with ref. to gearing I can eventually upgrade the series 4.7's to stronger Ashcroft 4.1 or 4.3's. Todd. Quote Link to comment Share on other sites More sharing options...
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