Clocking bushes when lowering VF's.

[Skylarking]

Which suspension bolts are TTI? I haven't read that in the manual.

The comment about TTY bolts was just a throw away line.

But there are plenty of TTY bolts and nuts scattered throughout our commodores though you'd wrongly think that critical suspension bolts and nuts holding critical suspension bits to our car would be uber strong and wouldn't be TTY... Yet the manual says that the sway bar bush insulator clamp nuts are single use nuts and must be discarded upon removal with new nuts fitted. Same for rear upper and rear lower control arm to knuckle retaining nuts and the trailing arm to knuckle retaining nut which are all a discard on removal items according to the manual.

And as you know, the bolts/nuts holding the drive shaft coupling are also single use item and must be tossed on removal (though these parts aren't suspension related,).

We do have the curse of TTY bolts & nuts scattered throughout our vehicle as it makes manufacture easier at the expense of increasing maintenance costs

 

[RevNev]

But there are plenty of TTY bolts and nuts scattered throughout our commodores though you'd wrongly think that critical suspension bolts and nuts holding critical suspension bits to our car would be uber strong and wouldn't be TTY...

Personally, I don't bother with TTY nut and bolt criteria much and for the most part, I think it's nonsense. A bolt either tightens up or it doesn't, and the amount of TTY bolts we've re-used multiple times successfully in race cars where the stresses are far higher than a road car, if a bolt torques up with traditional values related to diameter and thread pitch without stretching, it's fine 99.9% of the time!

Ecotec V6 cylinder head bolts are supposed to be one use TTY torqued down to a low value and rotated so many degrees. They're a 7/16" UNC bolt I've re-used continuously torqued down traditionally to 80 ft lbs and have never stretched one yet. These engines make nearly 200 rwkw, 11.28:1 compression ratio on E85 revved to 6250rpm each gear change. I've never had a head bolt failure or pulled the thread from the block in 17 years with these engines re-using the same original head bolts!

 

[Lex]

These engines make nearly 200 rwkw

Stock they are supposed to be 147 kw at the crank.

What are you doing to get near 200 rwkw

 

[RevNev]

Stock they are supposed to be 147 kw at the crank.

What are you doing to get near 200 rwkw

Camshaft, compression and E85 with a slightly enlarged valve throat permitted in the rules. Current spec engines that make at least 195rwkw, run a Motec M130 ECU with wideband lambda trim. The older spec engines using a basic EMS ECU make a bit less from the need to run them rich to avoid lean outs on the track from atmospheric mixture drift.

 

[losh1971]

The comment about TTY bolts was just a throw away line.
And as you know, the bolts/nuts holding the drive shaft coupling are also single use item and must be tossed on removal (though these parts aren't suspension related,).

Only the rear bolts are TTY on the tailshaft. The manual says to inspect front coupling bolts and discard if deemed necessary. Whatever that means? The torquing instructions on those rear bolts are ridiculous. It's something like 90nm + 90deg. There's not enough room to turn the bolt a further 90deg unless you rotate the tailshaft while simultaneously going the 90deg. Then you have to hold the bastard from spinning while trying

Old V6 rocker bolts are TTY, yet they are torqued to 22nm or something like that. I don't see how they could stretch at that torque? I remember on my TW I had to set it just past its lowest setting as my 1/2 Repco one didn't even go low enough on the dial.

 

[Skylarking]

Personally, I don't bother with TTY nut and bolt criteria much and for the most part, I think it's nonsense. A bolt either tightens up or it doesn't, and the amount of TTY bolts we've re-used multiple times successfully in race cars where the stresses are far higher than a road car, if a bolt torques up with traditional values related to diameter and thread pitch without stretching, it's fine 99.9% of the time!

Yeah, I understand that and have even read other forums where LS engine builders have tested repeat retorquing of GM’s head bolts without issue. If memory serves correct, in that LS case, the engine builder recommend no more than I think 4 reuses.

Really, how many times a TTY bolt can be reused depends on a bolt’s design and metallurgy (which conceivably can change during manufacturing processes but probably doesn’t change). If the ultimate tensile strength is far from the yield point, multiple reuse should be possible but if the UTS is close to the yield point then reuse can be rather risky…

As such, TTY bolt reuse is somewhat related to a bolt’s QC/QA and a mechanics experience with those specific bolts. If the manufacture is consistent, reuse may indeed possible but blindly reusing all TTY bolts without some testing just because it has worked in other cases isn't for the faint hearted. And testing (like that LS engine builder) takes time and $ It’s just easier to replace TTY bolts where they are specified as single use (unless you know for certain thats not the case ).

And TTY is different to TTA. A TTY bolt will be tightened passed its yield point while a TTA bolt will be tightened a specific torque and then a further specified angle which may still see the bolt tensioned within its elastic range. (But sometimes I do think the manufacturers are telling us lies just to sell more bolts).

Still, I’d always drop the car on its wheels before tightening up suspension bolts (to clock those bushes) so this thread is good reminder which reinforce that. Thanks

I’d also buy new bolts and/or nuts when required by the manual (unless I’ve tested the bolts/nuts for multiple retorquing) but that’s just me, YMMV

 

[losh1971]

When I did the suspension on the VE we used a trans jack under the hub, while ute was on the hoist. I can't remember if we had the wheel on or not. Seemed to work reasonably well. Those blocks or a four post are probably better though. I don't know many places with a four post. I have observed garages using screw props to load up the suspension before tightening, which I have done at home myself on rear suspension.

 

[Smitty]

Which suspension bolts are TTI? I haven't read that in the manual.

ALL of them.....

and yes your local friendly dealer has them available... I have been madly buying the pharkers as I replace stuff on the Tourer
and have been buying TWO of each. One for replacement now and a spare... for next time!


ps.. for the front castor arms, buy the bolt/shim/stay alignment kit (cheaper than each bit individually)

 

[losh1971]

ALL of them.....

and yes your local friendly dealer has them available... I have been madly buying the pharkers as I replace stuff on the Tourer
and have been buying TWO of each. One for replacement now and a spare... for next time!


ps.. for the front castor arms, buy the bolt/shim/stay alignment kit (cheaper than each bit individually)

Last bolts I priced up at Holden were the rear coupling bolts and nuts. Over $35 each..... I just reused my suspension bolts. Also that being the case every time you get an alignment you would need to replace a stack of bolts. That seems ridiculous to me....

That castor alignment kit, is that a Whiteline or similar?

 

[Smitty]

................

That castor alignment kit, is that a Whiteline or similar?

naah Holden put out a castor arm bolt kit that has
the bolt (and its nut)
the alignment shim
the shim retainer

all are in this pic from the thread poster ...
except the shim retainer (which some cars need, like mine .. others not)