Interesting recovery device

nice - I like it!

Matt

On or around Sun, 21 Jan 2007 09:01:53 +0100, Matthew Maddock enlightened us thusly:

it looks like it ended up an interesting shape, but yeah, clever.

isn't the tatra another spine-frame thing with half-axles, like a bigger version of the 6x6 Pinzi?

Yep, same designer, can't remember the name now but the Haflinger, pinz (4x4 and 6x6) and a selection of Tatra big trucks are all largely identical underneath. I'd love a collection, you can fit a haflinger onto the back of a 6x6 pinz and a 6x6 pinz onto the back of an 8x8 tatra ;-)

My favourite is the Tatra 813, 8x8 with not much gap between the front two axles and the rear two axles, so almost no ramp-over angles, although it does have a large-ish front overhang. The 815 8x8 had worse ramp-over angles.

The Tatras also have pressurised drivetrains, they keep about 2PSI of air pressure inside the diffs, half-axles and portals, this helps keep water out, allows the tyres to be inflated while moving via the transmission, and of course means that they've got excellent oil seals.

I saw a prototype trials buggy somewhere on the net, using two tatra front axles to give a four-wheel-steer trialler which apparently had a swivel joint between them to give articulation as well as suspension. I'll see if I can dig it up;

Ebay item 220064287829

Not sure about the articulation joint, someone said it has it from reading the german text. Some nice pics.

thats a nice idea!

are tatra and tata completeley different companies? a guy just down the road has a tata pickup.

Isnt Tata Indian, and Tatra russian or somesuch?

Si

Very different! Tatra are a Czech car/truck manufacturer from the

1820's, Tata are an Indian company who make lots of things and started making cars/trucks in the 1940's. They apparently own Daewoo's truck arm according to wikipedia. BTW in these contexts, "truck" means lorry, not 4x4.

Wikipedia entries;

There was a Top Gear review of Rover's ill-fated "City Rover", they had to film it in secret without Rover knowing because they didn't want it to be reviewed as the car was so poor. It was a rebadged Tata Indica which was first made in 1998 so that shows how desperate Rover were at the time, in 2003 importing a 1998 car half-peugot, half-Tata, and calling it a Rover!

The chap down the road might have a LoadBeta (dreadful name, as in "Load Better"), why anyone would buy such a poorly supported vehicle I don't know.

They have usually done quite well in the "Dakar" Rally so I wonder if it was developed for or because of that.

Possibly, although the military probably thought of it first! Tatra used to be the most frequent winner of the Dakar although Kamaz appear to have taken over, the suspension design helped Tatra stay on top for a long time, it being rather good at soaking up bumps at high speed.

On or around Sun, 21 Jan 2007 09:08:02 +0000, Ian Rawlings enlightened us thusly:

f*ck that's a mean machine. air sprung as well. wild.

On or around Sun, 21 Jan 2007 09:48:13 +0000, Tom Woods enlightened us thusly:

nah, tata are an indian or something lot. Tatra are Czech and have made some well-impressive cars (V8 behind the back wheels, VW beetle stylee, for example) as well as serious trucks.

On or around Sun, 21 Jan 2007 10:37:12 +0000, Ian Rawlings enlightened us thusly:

they're piss-cheap.

Yeah but so are second-hand better-supported cars. Nowt stranger than fowk I suppose!

Some of the new BMW bikes have air suspension too. Even the new cross challenge has it. Not my bag really on a bike, but it does work apparently. The best use i suppose would be for altering the height for short or tall folk.

Feck me, bet thats good in the wet!

Is it not hard work keeping all the rubber boots (which i presume must exist in various places?) good and air/oil tight? Are they all split rubbers for easy replacement?

I was just thinking how it is tricky keeping a landrover oil tight but the pinz/tatra etc must be even harder.

Thanks!.

The tata pickup just up the road seems to do ok. Its filled to the brim with different stuff every other day so it obviously works alright!

You can get split rubbers (which normally is a dreadful thing ;-) ) but personally I'd avoid them. I know that on the pinz, replacing the rubber axle boots isn't as hard as you might think, it involved removing the brake line, one steering link if at the front, compressing the spring, unbolting the shock and strap, undoing three bolts that keep the half-axle together, then heaving the half-axle (which is in two quarter-axle parts) apart leaving you with a wheel assembly including quarter of an axle, and a quarter-axle sticking out of the diff with a boot on. You then just undo two circlips to replace the boot and reverse the process.

However it's not a common thing to have to do, they're tough and tucked up well out of the way and quite short, so it would take an unfortunately placed sharp rock to do damage.

Sorry but no ;-) Jokes are often cracked about British cars always leaking oil, and land rover certainly have made some shit oil sealing surfaces. Pinzes don't leak oil often at all, when mine leaked out of

2 portals, the pinz mailing list was aghast and correctly guessed that it must have been sat in a shed for 10 years or so (it's done 27,000 miles in 33 years).

The pinz uses oil seals protected from the elements, the seals are hidden behind either thick rubber boots, or in the case of the wheel bearings, the oil seals are behind close-fitting metal rings that stop stones etc getting through, and the seals are double-lipped. Between the diff oil and the outside world you've got a large nylon shield, then a large rubber O-ring sliding across the surface of the shield, then a more substantial double-lipped seal pressing against the shield, then a large rubber stop-ring, and *then* you've got the rubber bellows that join between the diff and the axle.

Also bear in mind that the pinz/tatra drivetrain is hidden inside the sealed chassis, and inside the chassis the oil seals that stop it leaking into the chassis are protected from the elements. From the gearbox to the wheels, only one single moving part of the drivetrain is visible, and that's a shaft from gearbox to transfer box, tucked up above the chassis.

The portal boxes have a seal on the incoming driveshaft, which is sealed inside the axle, a seal to the wheel which is protected as already mentioned, and the box itself is sealed just using sealing compound. After mine started leaking in the first month from the wheel seal, it took about an hour to replace all the seals in a portal.

I do get nervous about the portals because there's only half a litre of oil in there and the oil lubricates the wheel bearings as well as the cogs so if that tiny amount leaked out the wheel bearings would be dry, but it's not something that's cropped up in the 34 years or so that these things have been running.

The Tatra 813/815 etc oil seals are supposed to make the pinz seals look really weedy, after all they don't just have to put up with oil, they also have to seal in air at high enough pressure to inflate the tyres. I think I mentioned 2PSI elsewhere, but that's a figure taken from a completely separate discussion on a different vehicle, on the tatras (and humvees) it's at tyre pressure levels.

So no, not hard to keep a pinz oil-tight. on a 6x6, open to the elements there are 6 rubber boots, one exposed shaft tucked up above the chassis with a seal at each end, 6 rubber seals on the wheel shafts behind close-fitting metal shields and the rest is sealed inside the chassis. Tatra is largely similar but tougher and larger.

On or around Sun, 21 Jan 2007 11:51:17 +0000, Ian Rawlings enlightened us thusly:

There's a bit of video of one of the big Kamazes in the sahara. Someone in a bowler special catches up with it and goes for an overtake, whereupon the captain rings down to the engine room for full speed ahead, and the kamaz (all 27 tons of it or wotever) takes off with a cloud of black diesel smoke from the funnels.

this ain't it:

nor's this, but it's good:

'ere, a tatra 603 car from the back, showing that V8...

tatra tram:

military testing of the 813:

1988 dakar:

oh, now this is really interesting: more or less the same chassis design, from 1920. I didn't realise it was that old

and a bus - check out the demo at the end of gearbox repairs

oooh, I want one of these:

Bored today matey?