Half Shaft question?

[FrangaFry]

Howdy all, have just discovered some rather large movement in my rear half shafts (left shaft is MUCH worse than the right) and also diff.

Recently I have been getting annoyed by some backlash noises (specifically when in stop start traffic but also just in general driving) and thought the tranny may not be helping (as there seems to be a little lag and small flaring when driving in stop start traffic). Had a service recently and was told tranny all good... Beauty. I was nOt happy with the backlash, so threw my car onto a hoist yesterday and noticed considerable slack/movement in both the diff an half shafts (diff was rebuilt earlier this year... April/may but shafts/cv's are stock).

VYII SS wagon with HTV1900 (A4 tranny was also rebuilt and upgraded around March).

In an attempt to resolve some of the backlash, I want to get some ideas on after market axles/stubs (GForce lvl 1??). In regards to diff backlash, my understanding is that it can be rebuilt again, but probably end up with similar issues so should just live with it?

I'm currently thinking GForce lvl 1 axles/cv's and bolt together stubs; whilst doing this also considering a harrop sports diff cover and royal purple oil. What are people's thoughts/experiences with this? I also understand that a truetrac would add no value at this point (comments anyone)

Thanks as usual

[feistl]

Trutrac = Awesome mechanical LSD. Works much better than standard at getting the power down, worth the money.
Sports Cover = Seems to help a little with rear wheels bouncing (cant remember the term) and helps with cooling if your doing track work.
Gforce1320 half shafts = much stronger than stock, however remember your just moving the "weak" point of the driveline on to something potentially more expensive (tailshaft, gearbox etc). Harrop do awesome ones, but very expensive.
It might also be worth looking at inner and outer stub axles, but it depends how far you want to take it. These are normally the next to go and are harder to change.

Personally, id just replace the half shafts with stock v6 units from the wreckers ($50-75ea) and carry a spare or two if you go drag racing. They can easily be changed on the side of the road if you need to.

Use the money you saved to get a trutrac while your changing the cover over. Also a good opportunity to change the gear ratio if you want. A broken half shaft will make a bit of a mess, but nothing compared to a broken tailshaft. Its just a matter of how hard you drive the thing.

Cheers

[BLACK 346]

What feistl said is spot on. I just installed Truetrac and Harrop sports cover, bloody awesome. Straight line traction every time and zero axle tramp. I also had a Tailshaft loop installed just for peace of mind.

[FrangaFry]

What feistl said is spot on. I just installed Truetrac and Harrop sports cover, bloody awesome. Straight line traction every time and zero axle tramp. I also had a Tailshaft loop installed just for peace of mind.

Hey guys, thanks for the quick replies.

Do you mind me asking what the cost was to rebuild your Diff with a Trutrac (did you replace gears as well). As the backlash in the diff is gear related (crown and pinion movement) my understanding is that whacking a Truetrac in will not address the issue as this is an LSD replacement (traction aside...), so would also need to replace the gears again? - As I spent near 2g on re building the diff back in March, I was reluctant to do it again if I end up with the same result a few months down the track - backlask).

Just on this, I was also considering a CAM and High Stall upgrade in the near future, but the feedback I am getting when discussing my current 'backlash' concerns with folks is a little conflicting...... half the responses I am getting are that, if I already hate the backlash issue I have, then a stally will only add to this and make it worse (I can hear you Chev.......... ) and will also add much extra strain on the drive line (causing more stuff to break earlier..). The other responses I am getting is that a stally will 'soften' the lash considerably...........

Cheers,

[IJ.]

Whoever fits the TT will adjust the backlash by moving the Centre towards the Pinion gear so this will be a non issue, HiStall will liven things up off boost a bit like slipping the clutch in a manual, huge + is being able to lock the TC so there's no real downside to it.

[FrangaFry]

Thinking out loud here.... If I go upgraded axles/Stubbs, I move the weak point to other more expensive areas... If I upgrade the diff and whack in some OEM shafts, then I am 'engineering' in weak point which is cheap to replace and get all the benefits that a TT brings.....

So anyone give me an idea of cost to do a TT .....,

[IJ.]

All depends if you're talking Harrop TT or Eaton TT, big difference in price but Harrop recently were selling them both at a big discount!

I went the Harrop to give me a little overhead, not such a huge factor mine being AWD means it's shared with the front Diff.

[BLACK 346]

Do you mind me asking what the cost was to rebuild your Diff with a Trutrac (did you replace gears as well)

Install cost $850 including new bearings and enough fluid to fill Harrop cover (takes extra). I already had 3.9's, was going to go 4.11 whilst it was apart but changed my mind.
Got the Truetrac and Cover direct from Harrop for $1160 including freight.

Edit: Regarding your driveline backlash, not sure if the Auto's have driveline couplings in the tailshaft? I replaced the front one in my M6, it was shagged.

[RRR888]

Install cost $850 including new bearings and enough fluid to fill Harrop cover (takes extra). I already had 3.9's, was going to go 4.11 whilst it was apart but changed my mind.
Got the Truetrac and Cover direct from Harrop for $1160 including freight.

Edit: Regarding your driveline backlash, not sure if the Auto's have driveline couplings in the tailshaft? I replaced the front one in my M6, it was shagged.

Very helpful thread guys. After my first meet at the drags, I have been thinking about driveline wear.

Can anyone give a rough idea just how much of a beating the driveshafts can take before they go bang?

Black346 can I ask where u had the work done in SA? Pm If you prefer :)

[BLACK 346]

Very helpful thread guys. After my first meet at the drags, I have been thinking about driveline wear.

Can anyone give a rough idea just how much of a beating the driveshafts can take before they go bang?

Black346 can I ask where u had the work done in SA? Pm If you prefer :)

Brad Harris at Enhanced Automotive mate.

[FrangaFry]

Install cost $850 including new bearings and enough fluid to fill Harrop cover (takes extra). I already had 3.9's, was going to go 4.11 whilst it was apart but changed my mind.
Got the Truetrac and Cover direct from Harrop for $1160 including freight.

Edit: Regarding your driveline backlash, not sure if the Auto's have driveline couplings in the tailshaft? I replaced the front one in my M6, it was shagged.

G'day again guys, thanks for all the helpful info; Black346, I take it from the price for parts (Truetrac + cover) that you went the Eaton rather than the Harrop Truetrac? I know this has been done to death (Eaton vs. Harrop) but can you share with me the reason of your choice of Truetrac?

Cheers,

[BLACK 346]

G'day again guys, thanks for all the helpful info; Black346, I take it from the price for parts (Truetrac + cover) that you went the Eaton rather than the Harrop Truetrac? I know this has been done to death (Eaton vs. Harrop) but can you share with me the reason of your choice of Truetrac?

Cheers,

Yes, went the Eaton, couldn't justify the extra cost for the Harrop. The Eaton should cope with my 400rwhp just fine :)

[2TEAZE]

I put GForce level 1 shafts in mine & the backlash from new in those bigger 930 cv’s was terrible. It was bearable to drive with a stock driveshaft but when I put a TDS 2piece chrome moly driveshaft with universals in, it lost all drivability manners. There was no damping in the driveline anymore from the donuts ….couldn’t use cruise control on the flat it was that jerky, power on / power off it would have heaps of wind up from the backlash in the cv’s. They also developed a vibration under full torque after only 3000kms.
Diff was rebuilt just beforehand from Aussie Diffs &with a Tru Trac, vehicle has new rear xmember bushes, diff mount &insert, gearbox/engine mounts etc so no slop from anywhere other than the cv half shafts.
Sent the GForce back & replaced axles with Repco shortened shafts &drives like an absolute dream – tight as, no backlash completely smooth no vibration &with the bonus of a fuse in the system now.

[RRR888]

Brad Harris at Enhanced Automotive mate.

Ah sweet thanks mate. Brad tuned my car, so ill give a buzz in the new year re trutrack.

[BLACK 346]

Ah sweet thanks mate. Brad tuned my car, so ill give a buzz in the new year re trutrack.

No problem :)