AU Falcon driveshafts

[boxhead]

Hey there to everyone.

When I dismantled my rear driveline/suspension from a AU falcon xr8 with irs it all came apart ok, the driveshafts are held in with 4 very thin nuts at the hub end.

I bought 2 new nyloc nuts rather than the factory setup, tonight when I tightened these nyloc nuts the drive shafts bound up and cannot be turned, my question is does anyone know if there is a special tension on these nuts, do I need to use the original type so that the multi nut setup locks on.

I think the bearings are a tappered design so they will need pre load meaing that a nyloc nut will not suffice
I mainly ask as I know that Aussie Mike used nylocs on his and was wondering if anyone else useing this rear end had the same issues?

[Rebel1]

Hey Boxhead, I dont know the answer to your question...but

Were the the thin nuts you removed when you dismantled the thing of a nyloc type?.

Reason I ask is that I have always been told never to use a nyloc where ever heat was likely to be generated...like wheel hubs...the nylon tends to melt and you know what happens then.

Cheers

[boxhead]

No the originals wherent nylocs, they where a thin nut approx 2mm wide and concaved so that as you tightened them against each other they locked tight.

I think you are right regarding the nuts, I will see if I can buy 2 new sets from the local ford dealer and ask to use whatever special tool is used.

I will also check what holden uses and see if I can use there system.

[Leeroy]

When I had my driveshaft made I asked the guy wether I could use just high tensile bolts & nyloc's. He said it was best to use the standard Ford ones which I did which at the time and they seemed rather thin. But they have a locking compound adhered to the bolts which I guess prevents them from loosening!
Leeroy

[boxhead]

The AU Falcon has tapered roller bearing whereas the Holden uses ball bearings, so I will have to use the Falcon nuts and tighten to correct spec with correct preload.

[Chris D]

Guys. On Jags the correct nuts on the inboard drive shaft nuts are Metalocks . NOT Nylocs for the reason you describe. Jag' actually spell this out in their manuals. The metalocks are readily available from most bolt shops in most threads and work well. I assume they will be fine on non Jag' applications.

Cheers
Chris

[Aussie Mike]

If you have a think about the design of the AU rear you will realise that these nuts don't do much more than stop the axle from coming loose. The AU is a double wishbone set up and there are no suspension loads on the axles. The axles use CV joints at each end instead of unis ad CV's wouldn't take the longitudinal load any way. The rear hub carrier with it's bearing installed is designed to support the wheel without the axle.

The hub uses a double tapered roller bearing and it's retained in it's housing by a large circlip. The hub presses into the center of this bearing and the axle spline runs through from the other side and keeps the hub snugged into the bearing. The spline is a tight fit into the hub and you need to use the nut to pull the axle spline into the hub spline. I think what you might find is happening is that the bearing may not be seated completely into the carrier or something is binding. The load on the nut won't affect the preload on the bearing because that's fixed by the thickness of the 2 halves of the outer bearing race. The inner race is 1 piece.

If you've seen the piss weak stack of 3 thin stamped steel nuts they use you would agree that they can't be holding much.
I think the amount of heat that will get to the nylock will be negligable but checking them will be part of my regular maintenece schedule just like checking wheel bearings and brake pads. By all means use the factory set up as that's what it was designed to use. I just wasn't very impressed with it and feel safer with a big solid nylock on there.

The thread is a 24mm or 25mm metric fine from memory. The bolt place I got mine from had to order them in.

Cheers

[boxhead]

Yeah I had to order in the nylocs nuts as well, I ave them and have fitted them up allready but I have only fitted the L/H side at this stage (there are some pics in my gallery) both sides are in but I have only tightened the left side so far.

I have loosened it of and will tighten the R/H side next time in the shed (saturday) to see if something is adrift in the left.

As a side not when I pressed the driveshafts out the R/H came out without looseining the bearing load (no free play) but when the L/H pressed out the bearing must have shifted because I could grab the hub and move it.

[Rebel1]

Hey boxhead, That FORD BLUE really sets the chassis off

Bet ya wont paint that whatyacallit engine that color

[boxhead]

Your right about not painting the engine that color, maybe polished alloy engine block, heads & sump might look better.

You say the color looks like ford blue, the name on the spray cans said ocean blue, maybe that old joke about the color ford uses on there engine blocks is true.

[BMK]

Boxhead



No boat anchor jokes now. I will stick those 'FORD' stickers I have for 'Justbetter' and 'Ausssie Mike' on your rocker covers also.

Sounds like you are making good progress.



Cheers

[boxhead]

I was searching through some old threads tonight and realised I hadnt told everyone what the final outcome here was.
Well what I found was that the old bearing had failed, Once I removed it I pulled it apart and found that 1 of the tappered rollers had turned through 90 degrees and was sideways in the cage.
My guess is that when the car my diff came out of was crashed then maybe the left rear wheel hit a solid object (street gutter) it hit sideways and damaged the bearing.
I did check all the contol arms and bushes for signs of damage (paint flakeing or bent bolts) and all appeared ok, but I will have to wait until I get it on its own feet and down to the aligners to see if all comes up ok.