Jump to content

Disco T-Case mate to Defender LT77?


One4adventure
 Share

Recommended Posts

I want to fit a higher ratio T-case to a military 2.5NA 110, I understand the discovery T-case is higher ratio and suspect it will fit, can anyone confirm? Will the 110 have enough power to use the higher ratio? the disco doner is a 4.0 Auto 1996 vintage. 110 is 1988 I believe.

Thanks!

Chris

Link to comment
Share on other sites

Yes it will fit although i am not sure it would be wise move with a 2.5NA. I have one for sale as well!!! but think you would be better of sticking with the stock 1.4 one.

My understanding is the low range is untouched but High range is higher.....not sure of the ratios?

Link to comment
Share on other sites

correct low not changed high will be 1.2 for disco box from original 1.4 ratio (petrols had 1.6 ratio)

i think the high will be too high for your engine for normal road use, particualrly if you live in a hilly area or tow alot. it will more like having a 4spd box with 5th for motorways, but i think your new 4th through 1.2 box will be lower than old 5th therefore more revving and clutch changes on normal roads.

Link to comment
Share on other sites

As it is a military 110 with a 2,5 n/a it has a 1,67 transfer case. It will never pull a Disco 1,22, believe me! ;) I even got fed up with 255/85 tyres, way peppier when I got back to 235/85. Sort of... :D

Link to comment
Share on other sites

correct low not changed high will be 1.2 for disco box from original 1.4 ratio (petrols had 1.6 ratio)

i think the high will be too high for your engine for normal road use, particualrly if you live in a hilly area or tow alot. it will more like having a 4spd box with 5th for motorways, but i think your new 4th through 1.2 box will be lower than old 5th therefore more revving and clutch changes on normal roads.

It's not my 110, but the owner suggests that 1st gear is basically useless in day to day motoring, so it is essentially a 4 speed now, question really is can you get better highway performance out of a 2,5 diesel with taller gears, be it t-case, tires or an overdrive? The next step would be a 2.5 turbo or a 200tdi I guess?

Link to comment
Share on other sites

I have put a Turner gas flowed head on my n/a, made quite a difference I must say regarding torque and stamina. But not enough to be able to take any higher gearing. So what I'm currently doing is 200 Tdi-ing since I happened to stumble on a cheap Disco. ;)

Link to comment
Share on other sites

Guest diesel_jim
It's not my 110, but the owner suggests that 1st gear is basically useless in day to day motoring, so it is essentially a 4 speed now,

If it's a military 110, and the gearbox suffix is 51A, then it'll have lower ratio 1st and 2nd gears (compared to a civilian LT77), this is to help with a) towing, B) off road work, c) the asthmatic engine! :lol:

which is why your customer finds 1st gear redundant.

Link to comment
Share on other sites

what size tyres are you running ?

i have a disco tbox on my 200tdi and 35's

and unless i'm in the fast lane on the m25 i struggle

to pull 5th gear (not played with the pump tho)

1st gear is good when you actually get moving

but i wouldnt want to tow anything on the road

with it

Link to comment
Share on other sites

I agree with Lars, that the 110 is most likely to have the 1.67 transfer box and changing to a 1.22 transfer would be a disaster. Even changing to the 1.4 standard defender ratio may mean that the engine may struggle to pull top gear in many situations.

The fact that 1st gear is currently almost redundant on the road is a bit of a red herring. The important thing is how the vehicle performs in the rest of the gears at speed. Hill climbing ability and general fast road driving is where it is far more important to have the correct gearing, both from a performance point of view, and a frustration point of view :) .

Many landrover drivers don't use first gear much in normal driving - they start off in second.

If very lightly laden all the time, and the engine is really good, you 'might' see some benefit to change to the 1.4 transfer NOT the 1.22.

The plain fact of the matter is that the 2.5 n/a diesel in a 110 is always going to be lacking in power and speed, which is why it came from the factory with the 1.67 transfer. If you want to raise the gearing you really need a lot more power, which in reality means a TDi or V8 :D .

Regards,

Diff

Link to comment
Share on other sites

I agree with Lars,

Well this is all good info, my original plan was to source a second hand 200tdi for him, he wanted to try to swap a 3.5 rrc running gear but the amount of work was a little daunting. Mounts,driveshafts, tunnel mods, ecu.......

So to get the most bang for the buck he should go 200tdi? I am thinking discovery motor as they are easier to come by and being a RHD the exhaust can be made to clear.

Any ideas?

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy