Defender T/Box in Disco

[Tyke]

Ok guys. Who's swapped out the Disco transfer box to a defender one and what's involved?

Since putting 265/75's on the 300 TDi I feel the gearing is a little too tall for a lot of the road work I do and am constantly up and down the top couple of gears. Not tried towing since I fitted the tyres but suspect it will be hard work.

Was thinking of doing the swap very soon. Can live with lower top speed but just need a bit of advice on what to expect in terms of the gearing changes in high and low.

Cheers.

PS:- Passed the Mot the other day, new rear brake pipe and a nip of the front wheel bearings . . . job done. Guy testing commented on 'a nicely prepared discovery' . . . . . all the work has been worth the effort to get comments like that from the Mot man  

[Budgie]

I did the T-box in mine and put the TD5 1.44:1 ratio box in.
It now drives like it did with 205's on there and it overtakes without needing to drop a gear, climbs hills in 5th, does 30mph in 4th, 35'ish in 5th (just) and pulls away without having to slip the clutch or rev the engine. So yah it's good and I wouldn't go back!  :mrgreen:

I got my box from Ashcrofts as a re-con and got our local LR service place to fit it. Only in the garage for the day and much easier than do it my self.  

The only thing is, if you do the T-box then the Low ratio remains the same as it is now, slightly overgeared and is a bit fast/uncontrolled going down steep hills when off road!
The other way of changing the gearing is to go for new ring & pinions in the diffs, again Ashcrofts do a 4.11 R&P set for the rover diff and this will give the same onroad change but also do the Low box.  

If you do the diffs yourself then this works out slightly cheaper that the transfer box swap, but if you get two recon diffs fitted with the R&Ps then it's about £200 more!

[Tyke]

Great stuff Budgie mate - that's what I wanted to hear  

Should sort out my road going side of things as I live in a hilly area and travell over the pennines daily to work . . . . Highest motorway in Englad I'll have you know

Thought about doing the diffs but have decided that because of the high road milage I cover that the t/box may be a better option. Didn't  realise the low ratio would stay the same though. Can live with that for though for the use I put the machine to. I don't do hard core off-road but thjere again, I do use the machine and don't just play with it.

Local LR man offered me a recon box and fitting at a good price and with new transfer gear to help sort the 'clunk' so I think I'll go back and have a word with him.

Best get saving up again. More I do to this motor the more I find to do, I'm sure you know what I mean. It's becoming a very capable drive now though. Think I'll be keeping it untill it's well and trully dead

[Wanderer]

Your MPG and Top speed will drop. Be prepared for that.

Ed

[Bulli]

The mpg depends, if you are having to make the engine work hard ...like mine on 35's (even with 4.1:1 ring and pinion) then economy is compromised...you dont have to work the engine as hard as the gearing may be more suitable.
If its mileage what could be better than new and stronger ring and pinion?

[Budgie]

I'm not so sure about the top speed Ed.
On the way back from Belgium the year before I changed the T-box, 33x12.5R15 tyres fitted, heading up a long hill on the M6 and with the Disco only loaded with camping gear and a moderate head wind I was reduced to 40mph in 3rd & being overtaken by lorries!!  :shock:

With the T-box change I can now maintain 70mph no matter what is in the back, what the weather conditions are like or whether I'm going up hill or not. So I would say that the top speed will be improved if anything, unless you're comparing the top speed with the vehicle fitted with the original 205R16 tyres?

MPG on mine has gone from about 30 down to 26mpg but I can live with that for the drivability I've got back from the change.  

[Tyke]

Interesting stuff guys. I knew a few of you had done this swap and I'm gratefull for your comments.

I'm all for improving the drivability of the machine and having given it some thought I feel the t/box change would be the best compromise for what I'm trying to achieve. I know a lot of the guys 'put up' with the gearing change when bigger wheels/tyres are fitted but me being me I just can't help but 'fiddle'. Standard has never been my thing as those who know me will testify.

At the moment I have difficulty reversing up my drive, (quite steep and a tight turn at the top), with the bigger tyres and standard gearing. I also have to work the engine much harder when loaded and can see this eventually knocking the clutch in and the transmission train in general, hence my feelings about lowering the gearing to give the mechanics an easier life. Less clutch slipping and gear changes on hills and into head winds would be nice.

Probably start thinking aboout upgrading the intercooler to get a bit more power then . . . . . .  :twisted:  

ooops !!!! . . . . . there I go again. Best stick to one job at a time I think :lol:

So methinks it's start looking for a T/box. I take it 1.44:1 is the one best suited - certainly sounds like it will provide what I'm trying to achieve.

[Budgie]

The 1.44:1 is what I fitted, the 1.6:1 from a 110 or earlier 90 is too low geared and you'll end up screaming the engine just to get 70mph.

Have a look at Ashcrofts site for a comparison between then all.  

[Tyke]

Cheers Budgie.

That sounds like the baby I need then . . . . . best get saving up again