Brumby Inner Driver's Side CV Boot Blowing

[Matt]

I am having all sorts of drama's with the inner drivers side CV boot blowing. I have tried heaps of different brands of boots. I also tried varying the amount of grease. I have also installed a bit of a heat shield between the exhaust and the boot. My brumby is running Adjustable Radius rods and L series Control arms with L series shafts with MY CV's. The camber and Castor is even both sides at around 1 degree negative camber (i.e / \)and around 5 positive Castor (i.e front of car > strut \ ). I am chasing peoples thoughts as to what could be causing it or solutions?

[justincase41]

I had this problem occur on a previous Brumby I owned. The drivers side boot would split constantly and would occur on longer trips. I covered 90,000km in 1st year I owned it, 87,000km in the second year. The amount of boots and cv's i went thru (Always drivers side) was insane. I was always travelling from Brisbane to Cairns and Brisbane to Melbourne. I was constantly stuck on the side of the highway changing drivers side CV's. The inner race would pretty much explode. The grease was pretty much burning away until it was dry. The inner pot would get so hot it took over 1 hour before I could touch it. This occured at least 4 times. I had Subaru and a few mechanics check it out. They always checked the gearbox and engine mounts to ensure the engine and gearbox weren't moving around and causing extra stress. They always said they could not see anything wrong and did not know what was causing it to happen. I never found out the problem as I sold that Brumby. I eventually put it down to most likely heavily worn cv splines and diff bearings on the drivers side, causing the inner pot to get really hot and blow the cv boot, and the inner race.

Not sure if it was the prob, but check all your mounts. What condition is your gearbox in?

Do you have much movement in the CV splines that come out of the diff?? The gearbox I have just had reconditioned has no movement at all. It is amazing when I compare it to the spare box I am running in the Brumby at the moment.

[Matt]

I think i might investigate the splines option. Thanks.

Does anyone now whether you can replace the Gearbox splines without removing the Gearbox? And how much they are worth new?

[subybrumby]

G'day Matt.

I've just been through all this with my 88 brumby, (EA82T with L series axles and control arms). Here's what I found and you may be able to glean something from it.

Firstly, I have a standard 91 brumby that has thrown the odd boot on that drivers side position. Grab some gal plate and make a heat shield like a letter L lying down. Make sure the long part of the L will fill the area between the boot and the exhaust joint. Now grab some exhaust wrap, that clothy stuff that's heat resistant and lie some on the shield and sandwich it between the shield and another matching piece of gal with stainless rivets and washers. Now drill a hole through the small lip and sit the lip on the back edge of the lower control arm and bolt the shield in place by the bolt and nut that holds the lower control arm onto the subframe. I have had no further problems with this car. The shield is not only effective but it is insulated.

Now with the L series hardware, you need to consider a few things. That configuration will bring the axle into a forward position. Is the boot fouling on anything?. Remember that as you scoot along the highway and things start to heat up, the centrifugul force will expand the boot which is now hot and vunerable and if it rubs against anything, "splat" it'll blow.

On mine, it was fouling against the steering extension that had been inserted to accomodate the 3" lift kit. After much hair pulling, (and many boots later)my only option was to return to the brumby front setup, bring the axle back to the position where it should be and once again make a series of insulated shields to protect the boot from the heat of the turbo and down pipe.

Shields can be made in a variety of shapes by using exhaust cloth wrapping sandwiched between 2 sheets of galv plate as described. Remember, that you not only want to shield the boot from hot gases but also direct hot flowing air away from the boot. A shield installed higher up may be directing hot air flows against the gearbox and onto the boot.

I have recently completed the conversion back to brumby front running gear using these shields and drove from Toowoomba to Woodford and back with no loss of the boot. Prior to this, I drove down to the all subaru day at Rocklea in Brisbane with a new boot and it exploded on the return journey to Toowoomba.

Good luck with it mate.

Trev.

[justincase41]

To replace the cv splines, gearbox has to be stripped apart as you need to remove the retaining clips. Give the heat shield post ago. If it doesnt work, you can then dig deeper.

[BaronVonChickenPants]

Also make sure that it isn't catching on the steering column/uni joint, the genuine subaru drivers inner boots actually have a narrower section to clear the steering column.

Jordan.

[Matt]

Already tried the heat shield option, not quite as flash as the one you describe but didn't effect it. It is sounding like ti could be the splines, i a thinking about siliconeing the splices and seeing if that slows it down a little bit, if i does then i will replace the splines. I keep you all posted and see how it goes....Also i release it could be slightly hard to get the cup off if it does work.... Thanks Again everyone for your help.

[justincase41]

Do you have much play and movement in the splines? Check the play on the splines on the passenger side and compare to drivers side. Remove the cv's and give the splines a wobble and compare the play in both sides. If you do replace your splines, the box needs to be pulled apart. Whilst your at it you might as well replace the diff bearings whilst your at it.