Like everyone else, Ive been made aware of the consequences of a front unit joint failing and the need to have a loop to guard against this, however,
Watched a recent eposide of mythbusters(please dont can the post yet)...., they were hit with proving whether a front uni joint dropping out could see whether the car could pole vault via the tailshaft biting in and hitting the road.
Very entertaining tv. They couldnt get the shaft to bite in at all on normal bitumen, the shaft just grinding its way along the road. After a day and a half they decided to dig an enormous pot hole for the shaft to drop into and bite and see what happened. As big as the hole was it took many attempts for the shaft to drop into this at speed. When it did bite, the results did show quite a bit of damage.
How common were these type of incidents, b4 the loops were specified, and why is the reg just for race cars and not for road cars as well?
tailshaft loops
Started by
_devilsadvocate_
, Feb 03 2006 12:33 PM
22 replies to this topic
#2
_Shevster_
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Posted 03 February 2006 - 01:50 PM
I've been told first hand from a driver in the Vic HQ series of how after his tailshaft snapped (sheared from screw poking thru the trans tunnel in cabin) then dropping and pole vaulting the car...
Thats what I've been told from the driver who reckoned it happened to him, so I can't vouch for how true it all is
Thats what I've been told from the driver who reckoned it happened to him, so I can't vouch for how true it all is
#3
_Yella SLuR_
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Posted 03 February 2006 - 02:16 PM
The road would be the last thing I'd be worried about.
Dyno day at the South Coast Nationals, guys car in the club dropped the front uni. Even with the tailshaft loop came flying through the tunnel and mangled his seat up ----> close call.
Also a race track is a much flatter surface, think it would be more about preserving the track surface than any real concern about saving your puny (insert phat if more appropriate) little arse.
Dyno day at the South Coast Nationals, guys car in the club dropped the front uni. Even with the tailshaft loop came flying through the tunnel and mangled his seat up ----> close call.
Also a race track is a much flatter surface, think it would be more about preserving the track surface than any real concern about saving your puny (insert phat if more appropriate) little arse.
Edited by Yella SLuR, 03 February 2006 - 02:17 PM.
#4
Struggler
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Posted 03 February 2006 - 03:54 PM
For $40 and an hour under your car with a drill I think it is cheap insurance.
I have seen two cars get airborne at dragstrips, both 14-15 sec slugs.
Very uncool.
I have seen two cars get airborne at dragstrips, both 14-15 sec slugs.
Very uncool.
#5
_TORANR AMORE_
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Posted 03 February 2006 - 04:10 PM
Yeah, even if you don't polvolt, it's still gonna do a lot of damage to your car and you can still get injured.
My toploader has no loop/guard on it at all, not like the supra box, so what is the best way of fitting one, or would I be looking at fitting something to the body of the car to prevent this from happening. Or maybe even welding something to the cross member.
Any ideas guys?
My toploader has no loop/guard on it at all, not like the supra box, so what is the best way of fitting one, or would I be looking at fitting something to the body of the car to prevent this from happening. Or maybe even welding something to the cross member.
Any ideas guys?
#6
_Yella SLuR_
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Posted 03 February 2006 - 04:24 PM
Usually fits up behind the gear box (ANDRA and CAMS have different required mounting positions). It is bolted up through the floor pan either side of the tunnel. Mine has four bolts per side into the pan, and about 10mm thick plate round the front of the tail shaft.
Actually looking at it mine's mounted a fair way back....Don't know if I like that.
Actually looking at it mine's mounted a fair way back....Don't know if I like that.
#7
_TORANR AMORE_
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Posted 03 February 2006 - 04:30 PM
Ahhhh COOL !!! 
So it bolts up just under the front seats !?!
Did you make that yourself? Or did you get it made up?
So it bolts up just under the front seats !?!
Did you make that yourself? Or did you get it made up?
#8
_Torana482HP_
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Posted 03 February 2006 - 04:41 PM
Atracing on ebay have them for $40 which includes the shipping by courier to your door. thats where i got mine from.
Also by the look of that picture - torrys seem to have their own tail shaft guard... The handbrake cable!
Also by the look of that picture - torrys seem to have their own tail shaft guard... The handbrake cable!
#9
Dangerous
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Posted 03 February 2006 - 04:49 PM
A busted tailshaft digging in and rolling the car is one risk, but the other is that of a long, heavy thick bar spining at high revs, and suddenly let loose under the car.
On a racetrack, the higher tailshaft revs and more vicious gearchanges would probably result in a higher risk and worse consequences if a tailshaft or uni joint did break.
On a racetrack, the higher tailshaft revs and more vicious gearchanges would probably result in a higher risk and worse consequences if a tailshaft or uni joint did break.
#10
_82911_
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Posted 03 February 2006 - 08:31 PM
People...
I have experienced a front uni letting go at speed....
Buy a 360 degree tailshaft loop....
I run one at the front and 1 at the rear... But i'm paranoid....
Beleive me If a uni lets go at speed you don't only need to replace the front seat from the damage that the tailshaft can do....The smell will stay in the seat for a long time...
All bad....
Cheers Greg..
I have experienced a front uni letting go at speed....
Buy a 360 degree tailshaft loop....
I run one at the front and 1 at the rear... But i'm paranoid....
Beleive me If a uni lets go at speed you don't only need to replace the front seat from the damage that the tailshaft can do....The smell will stay in the seat for a long time...
All bad....
Cheers Greg..
#11
Tiny
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Posted 03 February 2006 - 09:08 PM
My loop is fitted to my spare seat mounting holes.. 2 bolts either side, nice and close to the gearbox, an sturdy steel... A Defintie Must.
Never had it happen.. and i'll take greg's word on it... Dont want it to!
Cheers.
Never had it happen.. and i'll take greg's word on it... Dont want it to!
Cheers.
#12
_Yella SLuR_
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Posted 03 February 2006 - 09:12 PM
It came with the car, but looking at the pic, might change it in the future.Ahhhh COOL !!!
So it bolts up just under the front seats !?!
Did you make that yourself? Or did you get it made up?
#13
dattoman
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Posted 03 February 2006 - 09:35 PM
I think CAMS spec is 6" from the front uni if there is no other retaining method
My racecar only runs a 385mm tailshaft and has chassis members that are lower than the tailshaft
The tailshaft actually runs thru the chassis not under it due to the cars design
So I don't need a loop
I do have a Price Engineering one that will be going into the hatch though
My racecar only runs a 385mm tailshaft and has chassis members that are lower than the tailshaft
The tailshaft actually runs thru the chassis not under it due to the cars design
So I don't need a loop
I do have a Price Engineering one that will be going into the hatch though
#14
_jap-xu1_
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Posted 04 February 2006 - 09:38 AM
andra is also 6" from the end of the gearbox.
#15
_Torana482HP_
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Posted 04 February 2006 - 02:00 PM
Heres a picture of my one and you can get these ones from ATRacing on ebay for $40 delivered.
#16
_jap-xu1_
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Posted 04 February 2006 - 04:10 PM
i got one like that.
to fit to my lc it took some considerable reworking.
i ended up welding it all up,1 piece as there is no room for the bolts.
to fit to my lc it took some considerable reworking.
i ended up welding it all up,1 piece as there is no room for the bolts.
#17
_Yella SLuR_
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Posted 04 February 2006 - 04:21 PM
Those bolts just don't look big enough to be that effective, nor the steel thick enough. Looks like false sense of security to me, just my opinion. When the tailshaft lets go, it's got a fair bit of energy in it.Heres a picture of my one and you can get these ones from ATRacing on ebay for $40 delivered.
Edited by Yella SLuR, 04 February 2006 - 04:22 PM.
#18
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Posted 04 February 2006 - 04:46 PM
true,the bolts in mine are 12mm hi-tensile.
i also made reciever plates that are inside the cabin so the bolts cant tear through the floor pan
i also made reciever plates that are inside the cabin so the bolts cant tear through the floor pan
#19
_MYLJ_
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Posted 04 February 2006 - 05:40 PM
Its a nasty experience dropping the front uni, even at relatively low speed. I had the front uni fail at about 40kph in the HT monaro I had as my first car. I was living in Melbourne at the time, I was passing a tram when the car axle tramped across the bluestone pavers that were used for the gutters of the road.(full throttle as usual)
huge BANG, the rear of the car came up a few feet in the air then slewed into the side of the tram ,bounced of the side of the tram into 2 parked cars. OUCH!
2 years to build , 5 seconds to destroy (then another 12 month rebuild to fix damage) as wll as a bank loan to pay for the damage to the tram and the other 2 cars!! (19yrs old no insurance, same old story 
)
So now I fit tailshaft loops to my toys!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
They are cheap insurance, but make sure:- its strong enough, has internal plates inside the floor, is in the correct position and has bloody big bolts so it doesn't get torn off if the shaft does let go.(I've seen it happen on a speedway car)
As for bolting it to the spare seat mounting bolt holes, I wouldn't recommend it, for starters its on the wrong side of the floor pan and are only spot welded on in most cases.
Always bolt the tailshaft loop through the floor , mine have internal plates approximaitely 3inches square (1/4 inch thick) and 1/2 inch bolts, I admit its overkill but its not going to brake is it! Desent size bolts and internal plates cost SWA.
(if your wondering NO I don't still own the Monaro, sold it to buy a torana and I've spent the last 15 years regretting it)
huge BANG, the rear of the car came up a few feet in the air then slewed into the side of the tram ,bounced of the side of the tram into 2 parked cars. OUCH!
2 years to build , 5 seconds to destroy (then another 12 month rebuild to fix damage) as wll as a bank loan to pay for the damage to the tram and the other 2 cars!!
(19yrs old no insurance, same old story )So now I fit tailshaft loops to my toys!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
They are cheap insurance, but make sure:- its strong enough, has internal plates inside the floor, is in the correct position and has bloody big bolts so it doesn't get torn off if the shaft does let go.(I've seen it happen on a speedway car)
As for bolting it to the spare seat mounting bolt holes, I wouldn't recommend it, for starters its on the wrong side of the floor pan and are only spot welded on in most cases.
Always bolt the tailshaft loop through the floor , mine have internal plates approximaitely 3inches square (1/4 inch thick) and 1/2 inch bolts, I admit its overkill but its not going to brake is it! Desent size bolts and internal plates cost SWA.
(if your wondering NO I don't still own the Monaro, sold it to buy a torana and I've spent the last 15 years regretting it)
#20
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Posted 04 February 2006 - 06:09 PM
Definitely a must have.. Had one let go on me in a HZ tonner (youngandstupiddays) doing 160clicks.. did a forward flip and spent the next 3 days in hospital very very lucky to still be here...not a pretty site. my brother took photos if you want to see what it can do. i run front and back loops on all my cars a must have for everycar as far as i'm concerned..
#21
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Posted 04 February 2006 - 07:16 PM
put pics up for sure man.
it will be a real eye opener for young players
it will be a real eye opener for young players
#22
_jdss57_
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Posted 04 February 2006 - 08:12 PM
will do. it was in the days before digital cams but so i'll have to dig em out and scan em.. must warn but, they are not nice to look at..(for me anyway)
#23
LS1LX
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Posted 05 February 2006 - 07:34 AM
With the torana's you have the cable underneath and most people run a H or X pipe exhaust, this will catch the shaft, WHEN it stops spinning.
But once the uni lets go Id say its going to take out whatever is in its way until you lock up your rear brakes.
All well and said to put a loop in there and feel secure, but like others have said its pointless putting in a weak unengineered piece of metal with a few bolts that will probably shear off with the force of the shaft hitting the loop.
Get a good loop and try find out if its Andra approved or has some form of approval to it, alot of these cheap parts on ebay are taiwanesse or made in china, no shit the dearest part of the item to make is the box its in.
But once the uni lets go Id say its going to take out whatever is in its way until you lock up your rear brakes.
All well and said to put a loop in there and feel secure, but like others have said its pointless putting in a weak unengineered piece of metal with a few bolts that will probably shear off with the force of the shaft hitting the loop.
Get a good loop and try find out if its Andra approved or has some form of approval to it, alot of these cheap parts on ebay are taiwanesse or made in china, no shit the dearest part of the item to make is the box its in.
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