Longer gears or 6 speed gearbox for 1.9TD (XUD9TE)

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Deacon
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Longer gears or 6 speed gearbox for 1.9TD (XUD9TE)

Post by Deacon »

Hi, from some time I live in a rather flat country, the Netherlands and I have longer travels than usual. So, the shorter gears on my 1.9TD started to take my attention. First, on the highway, doing 130 km/h, the engine revs its a** off at 3000 RPM and I waste needlessly fuel whereas I drive on flat ground and a longer 5th (overdrive) or 6th gear would do to bring the RPMs lower. Are there any "upgrade" options for this engine and body (so no body modifications need to be done)?

Before anyone says "upgrade", I just love my car and it fits my needs. That's why I am even considering this idea. :)
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moizeau
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Re: Longer gears or 6 speed gearbox for 1.9TD (XUD9TE)

Post by moizeau »

I'm sure there are gearbox specialists that change the ratios, and quite possibly other boxes that would bolt straight on, with or without the need for other changes. All this will be expensive unless you can do all the work yourself. It would be cheaper to drop the k's by 15 -20. My old BX will turn nearly 50 mpg at 110 kph, it gives nearer 40 at 130! Also the obvious being tyre pressure and the make of the tyre, along with general oil, air filter stuff. Unfortunately you can't get old dogs to jump through the same hoops as new ones. My 407 136 auto has averaged 46 mpg over the last 5000, the xud won't do this on mixed driving. Enjoy the Xant but it's not got all those sensors controlling the world giving you mind blowing fuel economy, but like I said, enjoy the Xant...it's not got all those sensors controlling the world!
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Zelandeth
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Re: Longer gears or 6 speed gearbox for 1.9TD (XUD9TE)

Post by Zelandeth »

I looked into this back when I had my 1.9TD Xantia a few years ago. Sadly the answer seemed to be that there weren't any "drop in" solutions.

Easy enough for a gearbox specialist to change the final drive ratio, but sadly it's an option which needs deeper pockets than I have.

Have to admit that I find myself thinking the same about the Activa. It's got more than enough torque to handle an overdrive sixth gear.

Have it in my head that it may well be the same box actually now that I think about it.
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Re: Longer gears or 6 speed gearbox for 1.9TD (XUD9TE)

Post by Deacon »

That's sad, a little bit. For a flat terrain that engine could do with a longer final gear, shame on Citroen. I get it that the mechanical injection will never match the electronic one, but I like it for the simplicity and tidiness of the engine compartment. Seems I will just have to reduce the speed. At 110 kmh the RPMs are around 2500, which if I remember is the most economical RPM for this engine. If I go to 3000 RPM, a whirlpool starts forming in the gas tank and I just waste fuel. :/

I guess if I continue driving this amount of kilometres I would have to upgrade.
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white exec
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Re: Longer gears or 6 speed gearbox for 1.9TD (XUD9TE)

Post by white exec »

Would think that a change of final drive ratio would be the easiest, if an overall more leisurely car and taller lower gears are acceptable.
Was the same box used on another car perhaps, with different ratios, so a simple box-change might be possible?

One other option would be larger diameter tyres, but probably not practical, so forget that.
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Re: Longer gears or 6 speed gearbox for 1.9TD (XUD9TE)

Post by Deacon »

If no 6 speed gearbox is available, that would be the only solution.

I've heard that some 306s (GTI) had a 6 speed that bolts straight on XUD9s. But they are rare and the question with them fitting in the tight engine bay of Xantia with stock Xantia axles remains.
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daviemck2006
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Re: Longer gears or 6 speed gearbox for 1.9TD (XUD9TE)

Post by daviemck2006 »

Zelandeth wrote:
02 Jan 2019, 00:13
I looked into this back when I had my 1.9TD Xantia a few years ago. Sadly the answer seemed to be that there weren't any "drop in" solutions.

Its a while since I have driven your old td Zel, but I did near 10,000 miles in her in the time I had her on the road and I cant say I needed a higher top gear. I never thought that in the activa I owned previously to it either. But then I live in a rural area with very little long straight flat roads and normally not much over 50 to 60 mph.
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Michel
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Re: Longer gears or 6 speed gearbox for 1.9TD (XUD9TE)

Post by Michel »

I don't think it would make a huge difference in economy to a Xantia TD anyway. You'd use more fuel to pull the higher gearing on anything other than a flat/downhill road with no headwind.

I also never quite understood the "upgrading to a better car to save money/fuel" logic. Sure, you might save 5 or 10mpg.... but what if it costs you £4000 for the replacement car? That's an awful lot of fuel...
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Re: Longer gears or 6 speed gearbox for 1.9TD (XUD9TE)

Post by Deacon »

Ah, definitely. Longer gear in a 1.9TD would work only on a flat stretch of road. In the Netherlands, that's basically the whole country. But the minute you meet a hill, like in Germany around Frankfurt, you better keep that momentum going and turbo spooled up, or you'll need to go back to 4th, an eventual 6th gear would be a waste of fuel.

I guess I will have to leave it as it is. Burn a bit more fuel, but won't need to pay for a whole new car just to get that extra gearing and fuel saving. In my case that would be a brand new car, because I simply don't trust second hand common rail diesels.
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Michel
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Re: Longer gears or 6 speed gearbox for 1.9TD (XUD9TE)

Post by Michel »

Deacon wrote:
02 Jan 2019, 16:04
I guess I will have to leave it as it is. Burn a bit more fuel, but won't need to pay for a whole new car just to get that extra gearing and fuel saving. In my case that would be a brand new car, because I simply don't trust second hand common rail diesels.


Nothing wrong with 2nd hand common-rail diesels. I've had plenty of them, nearly all with huge mileages on them. I'd just avoid the Citroen/Peugeot 1.6HDi. For example, there's a reason why the Skoda 2.0TD Octavia is popular with taxi drivers here. My 10 year old Octavia has been a family car all it's life, but done plenty of trips to Poland and back. It's got 180,000 miles on the clock, and seriously, it's like new inside and drives absolutely perfectly. In my view, the CRD motors aren't the issue with modern cars, it's the electronics that go with them. The Skoda, being a bargain-basement VAG car, doesn't have as many fancy toys as the VW/Audi/Seat equivalents, or the price tag they attract :)

My last Xantia HDi had 251,000 on it when it was scrapped, and the engine was pretty much the only thing left working on it!
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EDC5
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Re: Longer gears or 6 speed gearbox for 1.9TD (XUD9TE)

Post by EDC5 »

When I had a 306 with the XUD9 engine, people on a forum at the time would swap the gearbox from a 2.0 HDi 306 on. Apparently the gearing was longer and it was a direct fitment.

I can't see why any HDi gearbox couldn't be swapped as it should mate to the XUD block.

In fact, one member on here has swapped his fifth gear pair of cogs to make them longer, I forget who it was, but that seems perfect for relaxed cruising.
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white exec
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Re: Longer gears or 6 speed gearbox for 1.9TD (XUD9TE)

Post by white exec »

As said, high top gear can be superb for cruising, but not necessarily for overtaking quickly on a long hill; you just need to drop down one gear for that. XM 2.5 is a good example of just that.

For hugely long legs, the very late Rover SD1 V8 Vitesse 5-speed manual 'box really cut the mustard, at 29.7mph per 1000rpm! . . . that's 2350rpm at 70mph, or 90mph at just 3030 revs. :shock: :shock:

With very tall top gears, not unusual for a petrol car's top speed to be available in one gear down from top.
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Re: Longer gears or 6 speed gearbox for 1.9TD (XUD9TE)

Post by citroenxm »

There's the answer. The xantia hdi 90 used cable clutch be3 box with rod gear change. .. With a push clutch however the bracket for the pull clutch will fit on. So you need the xud9te clutch cable and a hdi 90 gearbox.

Hdi 110 box is a different kettle of fish. It uses cable gear change and hydraulic clutch.

I'm sure I've got a hdi 90 box in the shed as I broke a hdi 90. However if its lost in with the xud box's then I've no chance.. Unless they have a plate Id on them
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Re: Longer gears or 6 speed gearbox for 1.9TD (XUD9TE)

Post by Deacon »

I wonder what the RPMs, acceleration, and speed would be on a 1.9TD with a 90 hp HDI gearbox. If anyone has tried that?

I know that the HDi boxes had a bit of longer gearing but by how much when compared to stock 1.9TD BE3?
Checked the prices, this looks like a dirt cheap alternative!
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Re: Longer gears or 6 speed gearbox for 1.9TD (XUD9TE)

Post by citroenxm »

You could probably even swap 5th gear straight into the be3 box on the xud engine already as 5th gear is external under the end cover..

I can't recall the revs to speed comparison.. The 306 hdi 90 used the same box. Might be more common option..