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th400 to lt230 ?


Rizla 1

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Having an off-set prop and running large horsepower !!!! not sure to are well matched

The propshaft already runs offset and the offset constantly changes as the axle moves up and down. If you think about it in "3D", providing that the flange faces are parallel, the fact that the offset, to our way of thinking, is in 2 directions instead of 1 is pretty immaterial as far as the propshaft is concerned. The phasing angle ensures that the UJ's are always in the correct position relative to each other so that each of the bearings move by the same amount during a full rotation. Only problem might be if the UJs bind at a certain axle position.

An offset propshaft from an atlas xfer box would also be around 10 inches longer than my current prop (shorter overall transmission plus the extra length of the offset) which would also reduce the angles involved.

Not saying it would work BTW but if I had an atlas box in the garage already I'd try it first and use an LT230 if that didn't work... if I can get someone else to try it before I buy an atlas, all the better :)

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I got a quote from the guy in france - he's there main europe seller ? and his price was with posting just over 900.

I can't see them selling many at that price. mine was about that in OZ dollars when they were about 2.2 to the £.

I have ran an offset rear prop for a long time (LT230 with a centred rear diff) so far no probs but it is a long prop which is where I think the problem might lie if you use a shortish prop.

I am after a NP205 with the round bolt pattern off a TH400 or a 4l80E both have 32 spline but one has a shorter I/P shaft not bothered which if anyone knows where I might get one from. I also have a LT230 to TH350 adapter somewhere in the garage, wasn't sure whether to buthcher the adapter for another project or sell it.

Gaza

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Not saying it would work BTW but if I had an atlas box in the garage already I'd try it first and use an LT230 if that didn't work... if I can get someone else to try it before I buy an atlas, all the better :)

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Why spend so much on an atlas when you can get a twin stick Dana 300 for £300 to £400 and do the same job ?

Next time I'm up workshop i will take a few pics of a autobox i got - that I'm unsure what it is ?

It looks a bit like a th400 but shorter - i thought it maybe a th350 or maybe a 4x4 th400 maybe some good for one of you ??

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Why spend so much on an atlas when you can get a twin stick Dana 300 for £300 to £400 and do the same job ?

Next time I'm up workshop i will take a few pics of a autobox i got - that I'm unsure what it is ?

It looks a bit like a th400 but shorter - i thought it maybe a th350 or maybe a 4x4 th400 maybe some good for one of you ??

I like the look of the Atlas and the option of a 4-speed transfer box appeals although the jump from 1:1 to 2:1 on the top 2 ratios suggests that it's more of a hi/low/lower/crawl box unless I change diff ratios as well. I should have bought one when I bought the engine and gearbox - when the pound was a LOT stronger than it is now ! At the time the 4 speed atlas was around £1500 and the 2 speed about £1000, built with my choice of the available ratios and output flanges.

The Atlas has the front output shaft stepped back from the gearbox connection which suggests to me that it will be well clear of my gearbox sump (4L80E has a very wide, flat sump), the Dana 300, like the LT230 looks as if it'd need a long adaptor for the front output to clear the side of the gearbox. I think the atlas will also bolt directly to my gearbox although it might need a 1 inch spacer, depending on which output shaft I have on the gearbox.

To be fair, the LT230 is doing the job for the moment and (touch wood) has behaved itself, I just have the nagging feeling that I'd be better off with something a bit stronger. Maybe the Dana 300 would be a better option, if only as a cheaper way to find out if the propshaft man is right or not :)

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the front prop will run very very close to the diff pan of the 4L80e. If you have the UK versio as fitted to astons and jags then you might find the prop impacts. If you are using anything apart from well offset diff axles (ie LR kit) then you will really really really struggle to get the prop down by the gearbox and you would be better off planning on using a 2 part prop with a centre bearing.

as it is you would be advised to get hold of a solid bar prop as fitted to TF727 boxes and range rovers- even then the clearance is tight- you only need the engine to be compressing the mounts one way and the axle being pushed the other to get the prop to impact and take the bottom of the g/box sump out.

as to transfer boxes- i was happy to run an LT230 behind an LS1 on the basis that eliot at mez runs his twin turbo, twin intercooled 5.7l chevy v8 in front of an LT230- he constantly blows up uprated 4l60e (which should easily have the capacity to cope with the torque considering what he puts in them), but has never blown up a LT230- of course the other thing to note is that an LT230 is cheap, easy to source and you can carry a spare if you need to- it's only a few hours to change especially if you are using a custom setup that allows more access around the transfer box bolts.

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Maybe I should stop worrying about the LT230 then :)

The front prop does run close to the gearbox sump but hasn't touched it, think it would have done by now if it was going to as it got some real abuse at times on the OBC. Might be worth changing over to QT mounts (already have them on the engine) on the gearbox mounts though so I don't run into any problems as the standard runner ones get a bit older.

My 4L80E is a 4wd one with both speed sensors so maybe the sump design is different ?

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Mine will be solid type mounts and i always have used the solid type props - but there getting harder to find now.

Sounds all a bit tight down there ? I hope with a good mounts things should not move about to much.

Will post some pics tomorrow of that gearbox to see if any of you people know what is is .

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Mine will be solid type mounts and i always have used the solid type props - but there getting harder to find now.

Sounds all a bit tight down there ? I hope with a good mounts things should not move about to much.

Will post some pics tomorrow of that gearbox to see if any of you people know what is is .

If it stops raining long enough for me to crawl underneath and take a pic of the front propshaft I will do - I'm using a standard prop tube btw, just had the length changed to suit.

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you can beat the carp out of an LT Dave - dont stress over it, keep it locked and the pedal in the axminster :)

Staks/Atlas/Danas will give you front/rear dig-ability + lard + lack of permenant 4wd, not sure if any of those are factors in your discipline?

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OK, here's a few pics....

post-2025-1223029544_thumb.jpg

post-2025-1223029588_thumb.jpg

post-2025-1223029571_thumb.jpg

Not sure how well you can see the distances from them, although it initially looks scarily close to the edge of the sump it's actually only close at the point where there's the least movement.

Having had a few major high speed impacts with the front axle in OZ, if it was going to hit, it would have done by now. Some of the "tussocks" of grass in the desert like areas hide solid masses of rock/sand and when you hit them at high speed the front axle hits the bump stops and you then get launched into the air at a 45 degree angle... it's a lesson you only need to learn the one time !

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Thanks for them Dave it does look a tad close - I'm waiting for my mate to bring up the 230 then i can bolt it up to see.

In them first pics of your adapter have you got a spacer as well or just the one like mine ? its a job to see in pics

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  • 2 weeks later...

Well just got back from workshop and ------------------------------------------------ it don't fit

The shaft fits the TH400 end but it don't fit through into the lt230 - the shaft seem a tad to fat ????

just rang the guy and he's trying the other in stock - and he also said the the conversion is a copy of the marks adapter , made by local company's up Sheffield.

Right he's rang back

Out of the 3 he has in stock one fitted and 2 didn't - he is now posting me the one that does so will try again when it gets here !!!!!!

:rolleyes:

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  • 2 weeks later...

Things are moving on now we have a shaft that fits :lol:

Thought you all would like to see how dam close this prop is to my th400 and it nearly touches the trans brake !!

but this is with the chassis on its bumps - i can't even use the solid narrow type prop as its way to short.

post-4167-1225206304_thumb.jpg

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