 | Home > Technical > R380 / LT230 Ratios |
 
|
|
|
| Andrew95 Member Since: 27 Jul 2022 Location: Midlands Posts: 75   
|
Now I have started doing a lot more overseas trips I am looking at improving the motorway handling of my 300tdi 110. Currently on 285/75's, fairly well tuned engine, with a moderate to heavy load. Not looking for increased top speed, just better manners - reduced revs, less stress on the engine, quieter etc.
I am looking at replacing the gearbox soon, so my original thought was when the T-box is out as part of this, replace the gearing to 1.3 (I don't want to go as high as 1.2) which from what I have read sounds ideal for what I am after and has really good reviews. But, I only replaced the T-box a couple of years ago, its perfectly fine. So to save on cost and effort, do I keep the T-box as 1.4 and instead get the V8 5th gear in the R380. There are pros and cons for both - I am wondering if anyone has any real world experience of either (ideally both!) and can comment? |
||
15th Oct 2025 9:36am |
|
| Andrew95 Member Since: 27 Jul 2022 Location: Midlands Posts: 75
|
That was my original though (has been for a few years), but they are so expensive and difficult to get hold of.
|
||
|
15th Oct 2025 10:24am |
|
| bankz5152 Member Since: 02 Feb 2017 Location: South London/North Kent Posts: 2238  
|
Higher 5th is an excellent choice. Low rpms in 5th and better mpg.
I had 33s, 1.3 box and higher 5th on my old 110, new 110 has 33s and stock ratios. Everything else is pretty much the same. Old 110 got almost 50miles more per tank! |
||
|
15th Oct 2025 4:42pm |
|
| TexasRover Member Since: 24 Nov 2022 Location: Paris Posts: 1359  
|
The strain on the engine would actually be higher with lower rpm. You do need to watch for labouring the engine too much with high gearing hence an overdrive makes it easier to stay in the sweet spot.
|
||
|
15th Oct 2025 7:16pm |
|
| jst Member Since: 14 Jan 2008 Location: Taunton Posts: 8474 
|
This was the point I was going to make. Lower rpm might increase thermal load and engine stress, as alot of m57 conversions are finding out. Run the ashcroft calculator to get the correct rpm for rhe speeds you want. Cheers
James 110 2010 XS Utility 130 2011 M57 bespoke Camper 90 2010 Hardtop 90 M57 1988 Hardtop |
||
|
15th Oct 2025 9:52pm |
|
| L110CDL Member Since: 31 Oct 2015 Location: Devon Posts: 11083 
|
I have one, i bought it from Trebro, but please read this . . . . https://www.defender2.net/forum/topic51558...drive+sale I fitted this unit in Millie and it was noisier than i thought it would be, so after a week i got the unit took out and it has been stored away ever since. If it doesn't sell sometime, i'm going to get it fully serviced and try it again in Millie 
I'm open to a very sensible offer Clayton.
1996 Golf Blue 300Tdi 110 Pick up. Keeper. |
||
|
16th Oct 2025 10:15pm |
|
| MarkBrown Member Since: 03 Oct 2022 Location: Mid Wales Posts: 600  
|
I had a Triumph 2500 with an overdrive, it was brilliant! Essentially you got gears 3.5 and 4.5, along with 2.5 if the inhibitor switch was modified ( which mine was ), so seven speed in total. It was operated by a switch on the gear knob.
I had a high 5th gear in an Lt77 V8 once, following advice, but it was useless in most situations as it was just too high and the engine couldn’t pull it. I’ve read that the 1.3 transfer box is about the best overall. 1983 110 automatic OM606 |
||
|
17th Oct 2025 7:41am |
|
| TexasRover Member Since: 24 Nov 2022 Location: Paris Posts: 1359
|
The R380 Roamerdrive can be noisy on overrun, supposedly improving after running in for a few 1000km. I bought one direct from Canada two years ago as no-one in the EU/UK was stocking them anymore (additional shipping was not a big deal like $50-100 more). It has been totally quiet and yes there is a slight whine on overrun but barely noticeable and my Td5 is quiet overall. It's only really useful on the motorway where it makes a big difference, but you find yourself shifting down when you get a decent hill. |
||
|
17th Oct 2025 8:18am |
|
| leolito Member Since: 07 Jul 2025 Location: Sofia Posts: 38 
|
Is it true on a Td5 using an overdrive the cruise control function is lost?
Sorry for the half-off topic question ... |
||
|
17th Oct 2025 8:22am |
|
| jonny Member Since: 10 Mar 2013 Location: North Wilts Posts: 239 |
Will the Roamerdrive work with a 1.2 transfer box, or is it for 1.4 boxes only?
As standard, no. But if you have access to a Nanocom / MEMStools then you could change the settings to get it to work. You might lose the ability to have cruise in low gears though (from what I remember, there are 5 settings for RPM vs Speed, one for each gear. You would need to define 5th + overdrive as slot 5, 5th gear as slot 4 etc |
||
|
17th Oct 2025 9:27am |
|
| TexasRover Member Since: 24 Nov 2022 Location: Paris Posts: 1359
|
The Roamerdrive replaces the primary gear (the one on the gearbox output shaft). The roamerdrive picks up the gearbox output shaft and relays the rotation to the primary gear either direct or through a planetary gear which is the overdrive.
I always understood this gear to be the same size on all R380s so it would work on any ratio box, but obviously you might end up with a useless top end gear ratio as you stack the ratios. The cruise is a ECU feature and it does look at roadspeed and engine RPM and expects to see some matching numbers there. I suppose maybe this is to avoid you being able to engage cruise at lower gears? But if the numbers are off (because you have been messing with the ratios) then it will not engage. There are several solutions discussed here on this forum, one of which is to install a digital signal correction gizmo that 'corrects' the speed signal the ECU sees to make it happy again. These are commonly available to correct speedometers for when you change tire sizes etc. I did not know you could correct the ECU with Nanocom but I never looked into is as I don't have the Cruise buttons fitted. |
||
|
17th Oct 2025 9:49am |
|
| o4dn Member Since: 08 Jan 2010 Location: South West Posts: 601 
|
+1 for the Roamerdrive, I have one on my Series 3, it's a wonderful piece of kit! https://garagetherapy.com.au/search?q=roamerdrive (In 2025, Garage Therapy acquired Roamerdrive https://garagetherapy.com.au/pages/a-tribu...verdrives) “A Land Rover immobilized is a moral defeat for the driver and bad publicity for the vehicle, […] it's up to you to do justice to your Land Rover!” - Land Rover Driving Technique. -- 2009 2.4 Puma Defender 90 SW 1979 Land Rover Series 3 88" Last edited by o4dn on 17th Oct 2025 10:08am. Edited 1 time in total |
||
|
17th Oct 2025 10:04am |
|
| jonny Member Since: 10 Mar 2013 Location: North Wilts Posts: 239 |
I think it's used as a failsafe, so that if anything goes 'out of normal parameters' the cruise won't engage or disengages - loss of traction, being knocked out of gear, clutch depressed with a broken clutch switch etc It's fairly easy to change the parameters if you have access to a laptop and a VAG KKL cable. |
||
|
17th Oct 2025 10:08am |
|
|
|
| All times are GMT + 1 Hour |
< Previous Topic | Next Topic > |
Posting Rules
|
Site Copyright © 2006-2025 Futuranet Ltd & Martin Lewis
