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Discussion Starter · #1 ·
The question is for those with experience using a Roverdrive overdrive (the mechanical Canadian units) in a D110.
Will the overdrive work well in a D110 with 33 inch tires on long trips along flat roads or will it be overgeared?
My engine is a slightly tuned 2.8TGV engine.

I currently run 1.22:1 Discovery gears in my transfer box with 32 inch tires (265/75/16) and it is sort of OK but I will need to use my truck in the mountains more in the future and the gearing is "too long" for that kind of terrain. I will therefore go back to the original Defender gears and probably install an overdrive for long journies on flat roads but the question is: can I go to 33 inch tires (285/75/16) or will it be too much for when using the overdrive?

Your opinions will be much appreciated.
Cheers
SANTIAGO
 

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well so much for my 1.2 plan! I thought your previous thread claimed 1.2 was the bomb? i guess long term testing peoved otherwise.

I'm switching to 33's next year, and increase will effect a slightly higher ratio to my 1.4, so i would switch tires first before committing to overdrive.
 

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Discussion Starter · #3 ·
well so much for my 1.2 plan! I thought your previous thread claimed 1.2 was the bomb? i guess long term testing peoved otherwise.

I'm switching to 33's next year, and increase will effect a slightly higher ratio to my 1.4, so i would switch tires first before committing to overdrive.
Well, sorry Overlander. What I wrote before was probably what I felt before but as you say, time has made me change a little bit. Maybe it is just me and me getting bored of the high gearing. I have used my D110 a few times in the mountains recently and the gearing is just too long for this kind of terrain.

From the beginning I felt that an overdrive would be better than the Disco transfer but there was no Overdrive available at that time (no Roverdrive at least; GKN I did not trust). Now there is the Roverdrive option.
I just want to know if the overdrive is OK for using with 33 inch tires or if it restricts me to 32 inch tires.
Sorry for ruining your 1.2:1 plans. With 33 inch tires it would definitely NOT work, that is for sure. At least not without changing diff ratios.
Cheers
Stgo
 

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Santiago,

Why not use 235-85-16, they are 33 and less resistance than 285-75?

I can't remember what part of Mendoza terrain would have such a high effect between 1.2 and 1.4 or not downshifting when on the Mountain and keep your current set up?
 

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Santiago - I'd run the ratio numbers for how the overdrive will compare to your current set-up, before making the investment. Putting the 1.2 in my 110 was one of the best mods I did to my truck. Lowered the highway rpms on the flats, truck cruises much better. In the mountains I can downshift when needed - feels like 5th with the 1.4, and still do 70+. I did observe a notable difference in the 285 and 255s. As Gustavo notes 235s would offer even less rolling resistance.

When you do make it in the mountains, how about posting some pics? Would very much like to see some.
 

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1.2 flatland, 1.4 hills and mountains
This is why there are 5 gears.... You can choose..... Needing to shift to 4th is not a reason to change final drive ratios.

There should be two tests.

1) Can you start on a "normal" hill in 1st without undue clutch slippage?

2) Can you use 5th on a flat road?
 
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Hey Santiago, I was definitely not complaining! I appreciate you leading the effort on these experiments. I was just wanting to understand better why your opinion changed over time. I am still not ruling out the 1.2 as of yet, as it seems to be a popular mod. I think you mentioned that you have a 300TDI with a TGV turbo, not the 2.8 correct? Since I have the 2.8, it might just make the difference.
 

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Discussion Starter · #10 ·
Gustavo;
The problem with driving in Mendoza with my current setup is:
a) if you head West you get 100% into mountain terrain, the Andes, often very steep climbs (like going up to Laguna del Diamante). Of course you can always downshift but on many roads 1 st and 2nd gears are too high geared and starting on climbs gets tough. There is always the option of changing to LOW but it is not a smooth and fast gear change, not relaxed. Conclusion 1.4:1 is MUCH better suited
b) if you head East it is 100% flat or even slightly downhill for 1,100kms until you get to Buenos Aires. Here the 1.2:1 is a beauty.

Mark:
I am doing the maths using the Gear Ratio Calculator but I wanted to have some real world opinions.
I owe you a picture of the Andes . I will post some.

Red90:
In response to your questions:
1) Can you start on a "normal" hill in 1st without undue clutch slippage? On many occasions, NO. Especially with the truck a bit loaded. The main problem on the mountains are 1st and 2nd gears.

2) 2) Can you use 5th on a flat road? Absolutely, no problem on the flats.

------ Follow up post added September 28th, 2011 10:32 AM ------

Hey Santiago, I was definitely not complaining! I appreciate you leading the effort on these experiments. I was just wanting to understand better why your opinion changed over time. I am still not ruling out the 1.2 as of yet, as it seems to be a popular mod. I think you mentioned that you have a 300TDI with a TGV turbo, not the 2.8 correct? Since I have the 2.8, it might just make the difference.
Overlander,
No problem; I understand your concerns and I know how you feel about the 1.22:1. I "have been there" before (reading a lot before deciding).
I have the original 2.8 TGV engine, and in good (excellent) conditions. I think it is not about power. I am having problems with my Td5 clutch after only 125,000 KMS and it is partly due to the 1.22:1 ratio I believe.

------ Follow up post added September 28th, 2011 10:34 AM ------

Gustavo,
Aren´t 235/85/16 32 inch tires? Same as 265´s, just a tiny little bit shorter.
I would love to have 255/85 but you cannot get them in South America. Just 235 or 265 or 285 down here.
Saludos
 

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Santiago,

I know Mendoza ( kind of well ) from Las Heras to Las Lenas (soy tan Argentino como el Obelisco en la 9 de Julio *LOL* )

and used to be in Uruguay when the guys from the Old Christian School felt passed Curico - Chile and the rescue was organized by friends of the family

265-75-16 are like 31.9
235 are like 32.7
255 are like 33.4

I still believe I will use a less resistant tire and downshift when those few times in the mountains require it and leave your current set up alone ( solo mi opinion )

Ciao

not so much difference
 

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Discussion Starter · #12 ·
Santiago,

I know Mendoza ( kind of well ) from Las Heras to Las Lenas (soy tan Argentino como el Obelisco en la 9 de Julio *LOL* )

and used to be in Uruguay when the guys from the Old Christian School felt passed Curico - Chile and the rescue was organized by friends of the family

265-75-16 are like 31.9
235 are like 32.7
255 are like 33.4

I still believe I will use a less resistant tire and downshift when those few times in the mountains require it and leave your current set up alone ( solo mi opinion )

Ciao

not so much difference
Gustavo,
I imagined you were from down here (southern South America). The other day I saw a really good documentary on the Uruguay plane crash on Brazilian TV. It is really an amazing story. I know the area of the plane pretty well since I work as a geologist in the Andes.
Back to the subject: I did not realize 235's were so much larger compared to 265's.
Thanks for your input.

Cheers,
Stgo
 

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Thanks Santiago. Since you are having problems in 1st and 2nd in mountains, than that is clear enough for me to give up pursuing the 1.2, as I'm configured for overlanding and as a fully loaded 110 in the mountains would be my profile now and forseable future.
 

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Hey Santiago, I was definitely not complaining! I appreciate you leading the effort on these experiments. I was just wanting to understand better why your opinion changed over time. I am still not ruling out the 1.2 as of yet, as it seems to be a popular mod. I think you mentioned that you have a 300TDI with a TGV turbo, not the 2.8 correct? Since I have the 2.8, it might just make the difference.
Mark, if you do go the 1.22 route I have a new-never used kit direct from Ashcroft (these are out of stock currently at Ashcroft, btw) that I can't utilize. $385 and I'll cover shipping from VA to NC.
 

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To my other country neighbour also called Santiago: I´m currently using 34x10.5-16 Simex´s with 1.22:1 Disco I TC and a "tweaked" 2.5 300Tdi. Does just fine uphill 1st and high gear. Obviously our hills are not as steep as Mendoza ones but anyways works just fine. It does 65MPH at little more than 2000 rpm! :party (and still pulls more)

PS: Just in case not every Argentinian guy is called Santiago:lol , right Gus (Goos)?

Cheers,
 

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Discussion Starter · #17 ·
To my other country neighbour also called Santiago: I´m currently using 34x10.5-16 Simex´s with 1.22:1 Disco I TC and a "tweaked" 2.5 300Tdi. Does just fine uphill 1st and high gear. Obviously our hills are not as steep as Mendoza ones but anyways works just fine. It does 65MPH at little more than 2000 rpm! :party (and still pulls more)

PS: Just in case not every Argentinian guy is called Santiago:lol , right Gus (Goos)?

Cheers,

Hello Tocayo,
You a are kinda crazy man (just kidding), 34 inch tires and 1.22:1? :eek:
I don't know, I guess it is kind of personal, depending on the way you like driving, your mood each day, whatever......I used to like the 1.22 but I got tired.
In the Andes the 1.22 is too much, in Sra de La Ventana I am sure not.

Anyways, during the last two days and after hearing the opinion from other LR users in the UK I have decided to go for another option. I WILL NOT get rid of the 1.22. I willl change my crown wheel and pinion to 3.8 in order to end up with a gearing intermediate between my curent setup and the original Defender gearing. The result is supposed to be almost identical to the gearing of a Discovery 1 or Disco 2 as the came from factory.

I will probably buy the CW & P from KAM in the UK. I will keep this post updated with the results, especially for Overlander!

Cheers,
Stgo

PD: tocayo estás usando las cubiertas de Pedro? Que onda las SIMEX? Trepás todo me imagino?
 

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PD: tocayo estás usando las cubiertas de Pedro? Que onda las SIMEX? Trepás todo me imagino?
Right! I bought Pedro´s SIMEX. He had 5 (4 used and a new one). I bought another one (new) in Uruguay, so I use both new ones in the back and the best 2 of the other 4 in the front. So, I get 2 spares. In mud it gets boring because I do what I want on it. On the rocks they go just fine also.:cool:

Te escribo en Inglés así los muchachos no se enojan...

Abrazo!
 
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