TD5 Defender 90 top speed

Hi, after 5 years I replaced my 1988 petrol 2.5 Def 90 with a TD5 90 built in 2000......luxury! I'm doing a lot more distance now, and have doubled my MPG. The EGR is removed and possibly the cat too. Great performance.

I'm cruising at 70+mph But I find I'm in top way before I reach 50. I would like to reduce the revs at these high speeds. I don't tow serious weights and she's sitting on 265x75 R16s.

Should I change to a Disco 28D transfer box, consider an overdrive, or does anyone have any other suggestions that aren't going to be too complex!!

Many thanks

For towing, your maximum speeds are 50 on A roads and 60 on dual carriageways and motorways. If you need to exceed speeds of 70mph (which is against the law anyway) you probably have the wrong vehicle. Meanwhile go to the introductory section of LZ and introduce yourself before the proverbial hits the fan.

Ok, will check that area out. Just to be clear, I don't tow much weight, and when I do tow anything it's below 50mph.

I went down the 1.22 ratio (Disco) transfer box... currently on 235/85's but run 265/75's in winter... cruising at 60 is now much more comfortable, and average about 33mpg

TD5 is gutless when starting off/low revs, so a re-map helped significantly with this...

Would have preferred an overdrive, more flexible... also more expensive... and potentially more to go wrong!?

Ashcrofts would be a first port of call - they know their stuff.

Thanks Gribbin, I'll follow up on that advice Cheers.

Are there any more suggestions out there?

I run a discovery transfer box behind my 300tdi 90 auto . It does make cruising at 60 a lot quieter experience . Not good for towing anything particularly heavy tho. I would suggest that using the swap to enable low revs cruising would be a good move , using it to try and cruise faster might not be , as 90's are quite "twitchy" and things can happen real fast if anything goes wrong , not allowing any reaction time to sort things out . A 110 is much safer in that respect . HTSH

tacr2man said:

I run a discovery transfer box behind my 300tdi 90 auto . It does make cruising at 60 a lot quieter experience . Not good for towing anything particularly heavy tho. I would suggest that using the swap to enable low revs cruising would be a good move , using it to try and cruise faster might not be , as 90's are quite "twitchy" and things can happen real fast if anything goes wrong , not allowing any reaction time to sort things out . A 110 is much safer in that respect . HTSH

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mines fitted with a disco box and its bloody useless. Its fine as mentioned for low speed cruising but its bloody gutless low down because of it. Im going to go back to a defender box and get an overdrive.

Yup, I tend to put my TD5 in 5th gear at around 40. If you don't need to accelerate suddenly, it'll potter around in 5th at 30, with the engine sounding like it is just ticking over. Whilst it is not impossible to cruise comfortably at motorway speeds, I'd like an overdrive when funds permit. They're supposed to be limited by the ECU to 82 mph. Whilst I would never do something so dangerous or illegal on a public road I have seen my speedo go round to 90,and that's without a remap.

Thanks guys, think I will take my time, consider the disco box and overdrive if I ever really do some consistent higher speed driving

I've just had to get my TD5 box rebuilt, I had considered the disco transfer box route at the same time but was persuaded out of it as I do tow some heavy loads. I opted for an Ashcroft box with uprated bearings but also a higher fifth gear ratio giving the best of both worlds. I still have the ability to pull away easily and slightly more relaxed cruising when in fifth. Box is being fitted this week so will report back when it's done!

had a 110 td5 at 95mph! (private road officer!) not the most pleasant experience the sides were shaking like a soft top!

Great feedback thanks all. I especially would like to hear more about the box rebuild with higher ratio fifth gear installed....
Cheers
G

Got my 110 Td5 remaped, EGR removed, cat removed, centre box removed with a full stainless exhaust, the remap is 180hp and 400 torque thingys, will easily exceed the 100 mph barrier, but still is with 1.4 transfer box so it screams. Its quite happy at 70 and a fair bit quieter than it was. Oh the 100 mph was achieved at the old RAF Bentwaters runway, and the handling was not that of a Porsche 911 so I don't think I will bother again.