Discussion
When driving my Monaro I can hear a constant rattle/knocking sound coming from the diff. It only ever stops when i'm driving on a smooth road.(Duel carriage way ect) Every passenger I take out in the car always ask's... 'what's that noise'
I checked underneath the car and found the culprit. The half shafts (both are new) have a large amount of slop where they enter the side carriers and into the Truetrac.
I suspect from what I have read that this is normal for a Truetrac.
So the questions are,how much would my Truetrac be worth If I sell it, and what is the best diff to replace it with.
The car is for road use only and is not used on the track.
I'm looking for something that is as good as the Truetrac, but without the constant rattle when driving on our typical crap roads.
John
I checked underneath the car and found the culprit. The half shafts (both are new) have a large amount of slop where they enter the side carriers and into the Truetrac.
I suspect from what I have read that this is normal for a Truetrac.
So the questions are,how much would my Truetrac be worth If I sell it, and what is the best diff to replace it with.
The car is for road use only and is not used on the track.
I'm looking for something that is as good as the Truetrac, but without the constant rattle when driving on our typical crap roads.
John
Thanks for the quick reply.
The constant rattle sounds like a lose rear drop link or something similar,but everything looks fastened up.
I have had fitted new pedders drive shafts,together with new shocks and springs. I wondered if the new stiffer suspension maybe transmitting the road vibrations to the lose fitting half shafts?
John
The constant rattle sounds like a lose rear drop link or something similar,but everything looks fastened up.
I have had fitted new pedders drive shafts,together with new shocks and springs. I wondered if the new stiffer suspension maybe transmitting the road vibrations to the lose fitting half shafts?
John
I have just had a thought! (yes really)
I wonder if the rattling/knock is coming from the new rear springs? I had spacers fitted to them and maybe the springs are catching on the chassis somewhere? that would seem a more likely culprit than the Truetrac. I will check tomorrow.
Anybody had issues with poly spacers?
John
I wonder if the rattling/knock is coming from the new rear springs? I had spacers fitted to them and maybe the springs are catching on the chassis somewhere? that would seem a more likely culprit than the Truetrac. I will check tomorrow.
Anybody had issues with poly spacers?
John
MyM8V8 said:
I doubt the rattle is to do with the Truetrac unless you have mega miles on it or subjected it to high or abusive loads.
Mine doesn't rattle either and it's had a decent amount of abuse I'd say 
Has done ~20,000 miles without issue, lots of 1/4 mile runs, loads of burnouts, lots of donuts, general skidding about the place, no noise I've ever noticed
Well a quick update, I have spent two days lying underneath the car....and for the life of me I just cannot find anything that is knocking or rattling. It all seems absolutely perfect and as it should be!
The only thing that has any play on it is the usual slack in the prop shaft, and the slop where the half shafts enter the Diff.
As soon as I drive the car slowly over any uneven surface I can here the rattle/ knock coming from the rear. As previously stated at speed all appears quiet and the car is planted.
Am I correct in thinking that a Monaro, fitted with a truetrack and slightly uprated suspension should be rattle and knock free. I am talking about driving along a suburban road with the usual patch work tarmac repairs at say 30 MPH?
The only thing I can come up with is the slack in the Diff is causing the noise?
John
The only thing that has any play on it is the usual slack in the prop shaft, and the slop where the half shafts enter the Diff.
As soon as I drive the car slowly over any uneven surface I can here the rattle/ knock coming from the rear. As previously stated at speed all appears quiet and the car is planted.
Am I correct in thinking that a Monaro, fitted with a truetrack and slightly uprated suspension should be rattle and knock free. I am talking about driving along a suburban road with the usual patch work tarmac repairs at say 30 MPH?
The only thing I can come up with is the slack in the Diff is causing the noise?
John
mfp4073 said:
...
Am I correct in thinking that a Monaro, fitted with a truetrack and slightly uprated suspension should be rattle and knock free. I am talking about driving along a suburban road with the usual patch work tarmac repairs at say 30 MPH?
The only thing I can come up with is the slack in the Diff is causing the noise?
John
I can't recall any untoward noises from mine...I avoid potholes though!Am I correct in thinking that a Monaro, fitted with a truetrack and slightly uprated suspension should be rattle and knock free. I am talking about driving along a suburban road with the usual patch work tarmac repairs at say 30 MPH?
The only thing I can come up with is the slack in the Diff is causing the noise?
John
Another update...with the help from MF I have traced the rattle/knock to the new rear shocks. I took them off and drove the car down my drive and all was quiet.
It appears that the top rubber mounts were somehow rattling against the body work where they pass through the hole into the boot.
I have now replaced the rubber mounts with the standard factory type. Unfortunately as I have removed the shocks so many times trying to reposition the previous set of rubber mounts, I managed to strip the thread in the lower suspension knuckle. As a result I was unable to tighten up the lower shock bolt!!!
So the next job is to drill out the threads in knuckle, and get a couple of high quality nuts and bolts for both the lower shock mounts.
John
It appears that the top rubber mounts were somehow rattling against the body work where they pass through the hole into the boot.
I have now replaced the rubber mounts with the standard factory type. Unfortunately as I have removed the shocks so many times trying to reposition the previous set of rubber mounts, I managed to strip the thread in the lower suspension knuckle. As a result I was unable to tighten up the lower shock bolt!!!
So the next job is to drill out the threads in knuckle, and get a couple of high quality nuts and bolts for both the lower shock mounts.
John
578HSV said:
Just replaced my rear shocks and got same problem. Will try this fix. Cheers
I can't believe such a simple thing as a shock absorber mount can cause so much bother! If you strip the threads on the lower knuckle make sure the replacement bolts are a little longer than the original, that way the new nyloc bolt will have enough room to tighten up.
If it ever stops raining I will finish the job off......
John
FIXED!!!!!
Yes really,
having spent hours and hours and even more hours, checking everything I could think of, not to mention removing various components from entire rear end of the car, I finally traced the knocking/rattle to the rear shock mounts.
The nuts were way to tight which compressed the rubber mounts too much. This allowed all the noise from the shock absorber to be transmitted into the car body. The nuts should be torqued down to only 10ft/Ibs.
I also replaced both the lower shock bolts with beefed up items from a local supplier, they were torqued up to 85ft/Ibs. The car had its full weight on the wheels during this time.
The road test was a revelation no matter what the road surface was like the suspension performed just how I wanted it to.
Pedders low is the way to go!
I also gave a formal apology to my Truetrac as I thought that was to blame!
John
Yes really,
having spent hours and hours and even more hours, checking everything I could think of, not to mention removing various components from entire rear end of the car, I finally traced the knocking/rattle to the rear shock mounts.
The nuts were way to tight which compressed the rubber mounts too much. This allowed all the noise from the shock absorber to be transmitted into the car body. The nuts should be torqued down to only 10ft/Ibs.
I also replaced both the lower shock bolts with beefed up items from a local supplier, they were torqued up to 85ft/Ibs. The car had its full weight on the wheels during this time.
The road test was a revelation no matter what the road surface was like the suspension performed just how I wanted it to.
Pedders low is the way to go!
I also gave a formal apology to my Truetrac as I thought that was to blame!
John
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