mikemodano9c

Seems like LOTS of people are breaking these housings...

Someone make a steel housing and ill buy one...

PLEASE!

If someone did make them strong enough im sure people would buy more factory location upgraded torque arms

samz28

or just use the yank crossmember to keep the shock of the torque arm off the tailshaft? or a spohn tq arm?

BTL FED

iTrader: (9)

MY thought on making a billet tailshaft would be, that the tailshaft wouldnt break, but it might cause the case to break, because of the force put on the tailshaft it is going to look for a new weak link, I think the best thing to do would to would to get a T/A that doesnt mount to the tailshaft

samz28

or quite dyno'ing your car j/k , but seriously 90% i'm guessing is the dyno operator and how the car has to unload the dynojet inertia back into the drivetrain (which could be called operator error).

but no-one has proven it yet.

haven't broken mine since it got off the dyno.

jimmyblue

iTrader: (11)

I thought it was more a steel driveshaft vibe problem,
than a torque arm transferred force problem? Would
like to know if there are any / many folks w/ aluminum
and CF driveshafts breaking tailhousings.

mikemodano9c

if a steel tailshaft housing was made you would only need a beefier tq arm that mounts to the stock location...

the track pak can't be used with duals, the spohn and other torque arms are pretty expensive also...

i think my output shaft is *slightly* tweaked, but i think the first breakage was caused my running a stock steel shaft...

samz28

yah problem is the stock aluminum one isnt so hot. My bro has one i could use but he twisted it on his m6 with stock 10 bolt. So with the mighty force of a flash stall launch i'd have to look at chromoly or carbon fiber as an alternative.

If you're worried about the steel shaft, just have it balanced.

How many people have broke the tailshaft housing OFF the dyno??

mshiznitzh

My friend has broken one one the dyno and off. Steel driveshaft.

mikemodano9c

im not even running the stock steel shaft anymore...i have a choromoly shaft

samz28

well mike i'm guessing relocating the tailshaft tq arm would rid your problems.

m6 folks never have this problem?steel or alum? how is their tq arm mounted to the trans?

I will say i broke mine at 66K miles, so its likely previous abuse may have contributed, or a crap casting. Mine broke radially, across about 300 degrees. was quite a site. and a bill (Tow from dyno/replacement). oh well. Hasn't given me any beef street/strip so far so i'll keep rollin got other things to think about like how to keep the 71K tranny together on the strip this season.

mikemodano9c

m6's never come with steel shafts...

they mount on the tranny for them also...

i don't think relocating the tq arm is causing any of this...

samz28

I'm saying that relocating the TRQ ARM will solve this.

say you're on a dyno strapped down with immense force.

3rd gear locked/unlocked whatever (engine braking) this is normal dyno method.

you nail it, then the poor dynojet goes ballistic as you hit 7200rpm's in mph.

now when you let off, where can the inertia in the dyno go? One place, your suspension, and likely its the torque arm transferring all the engine braking inertia
right on to the tailshaft housing.

thats my guess.

I dont think a steel driveshaft due to balancing would crack it, you never know.

But if you were worried you can pay $50 and have the steel driveshaft balanced out perfectly to 250mph if you wanted.

i don't tach out my car in 3rd even on the strip. lol. i wish i could tach out 3rd in the 1320.

and i rock the 1320 in OD which has the freewheel (no engine braking) deal, so when i let off i'm not transferring the torque back into the driveline.

usually when i drag race i graduate off the gas and let it shift into 4th gear then slam the brakes and take the late turn-around.

I suppose if you were speed racer (200 shot?) and ran in 3(D) you could snap the tailhousing shaft on the strip too if you let off suddenly after the 1320.

i'll have my buddy take a look at the suspension, anyone got a pic of the tailshaft tq arm connection/rear end.

Both yank and Spohn (who sell products) agree it is the tq arm. Both do not have solutions that are realistic (ie fitment issues).

so i'll just drive the way i do and if i break one, then tow her home and figure it out.

but im not shooting for anything more than a 11.9 this season.

mikemodano9c

i've broken one at the track, a couple on the street, and one on the dyno...

the tq arm mounting on the housing isnt my problem...

mikemodano9c

i hear so many of you guys post about breaking these things and when someone wants to figure out a solution THAT WORKS you just keep running around in circles...

i for one would pay a little extra for the peace of mind in knowing i wouldnt have to worry about this happening...its a pain to replace these things and they ARE NOT cheap either...

stock housings are PATHETIC...i could drop one on the floor and crack it...

BADFNZ

iTrader: (19)

Maybe your rear-end isn't aligned. Didn't you swap rears?

jimmyblue

iTrader: (11)

Relocating the torque arm mount will help
-if- the torque arm force or shock load is
to blame. But it won't do anything about
driveshaft oscillation (ringing). If you are
"cracking the whip" with a heavy steel
'shaft that's got to hurt. Pinion angle
(match to tailshaft) is going to aggravate
any such issue, more "lumpy" U-joint action =
energy to ring it up. A lighter, less resonant
aluminum shaft is just not going to abuse
the tailhousing as badly even with the same
percentage imbalance and pinion mismatch.

I believe if you're breaking tailhousings in a
1:1 gear, it's not strictly a torque arm force
issue. The RWT of (say) 400lb-ft or less,
along that 4' moment arm, is only 100lb of
load on the housing (you apply worse in
street launches, in the lower gears, but people
don't seem to be breaking them that way).

A billet steel tailhousing would be plenty
heavy and difficult. A CNC aluminum one might
suffice (better than thinwall cast anyway, for
shock / cracking resistance). Or, just a modified
crossmember that replicates the stock TA mount
geometry but decoupled from the trans, should
be a cheap easy weldment. But by that point
probably the same price to go with a chassis
mount TA in the first place. All that still only
addresses the TA-load potential failure mode,
though, and not the driveline vibe possibility.

mikemodano9c

it was fine for months after i swapped rears...what do you think is un-aligned?