Front driveshaft rubbing on gearbox crossmember

[PeeBee]

I did a full fluid swap out today, total joy it was. Whilst under the beast I noticed a knarly wear strip approx 50mm wide where the front brive shaft has been hitting the gearbox crossmember.

1) why is this happening?

2) how do I fix it? Is it as simple as reversing the drive shaft end for end?

3) is there some other solution employed? This is the first i have noticed it, suspect its vehicle weight related, so is this a suspension issue to resolve?

I am not going to even try and upload pics - I think the description is enough for those in the know to advise.

thanks guys in anticipation.

Phil

[PeeBee]

Did a trawl on the net, PSR sell a solution for $40 so its basically a profiled 90 deg angle with a detailed set of instructions. I have used PSR chassis and spring tower kit thoughout my build and their gear is 100% first rate. I guess now its the details around propping the gearbox and removing the mounts to drop the cross member, do the mod and re-install. Unsure for the reasons why it happens - would appreciate a reply if you know. the chop out is a solution but would like to understand what drives the modification. I am looking at new rear springs, have 2200kg over the rear axle. I have a rear diff brace designed and manufactured that will satisfy the additional load, just need the time to install it - its a design by myself and different to the commercially avail units that dont address the direction of deflection - enough said I think.

[mudski]

Flip the shaft around mate. I did this with both my front and rear shafts.

[PeeBee]

What causes this situation?

[mudnut]

Too much lift. The only down side I can see to swapping the shaft around, is that the seal needs to be in really good nick to stop water ingress into the spline. Many have done it without problems.

[mudski]

What causes this situation?

More suspension articulation than what the vehicle come out with in a nutshell. Its standard practice to swap them around. As Craig said. Make sure the slip joint seals are in good nick. Theres a seal and the outer boot.

You can buy new seals and boots for the shaft from the likes of Hardy Spicer, Melbbourne driveshafts etc.

[PeeBee]

OK, thanks guys, I really would not put my suspension in the classification of 'too much lift'. It sits nose up with a 12mm droop at the rear from level. I am heading down to Dobinsons tomorrow to pick up another set of rear coils and they are rated at 30mm above standard height. The fronts are a 75mm lift above standard, however the weight of the mitor and hardware brings it down - certainly does not look like a monster truck or even lifted in my view.

Anyway, I have to do something, so will swap the driveshaft end for end, and also do the PSR crossmember cutout. I did this for the rear driveshaft, however it was for a bare chassis during the build. Will see how it pans out, let you know.

[PeeBee]

Righto, so its 38 Deg C so perfect temperature to swap out the front drive shaft! Anyway, 20 mins turn around, including the clean up and paint of the 60mm scored section. Still waiting on the chop infill piece for the cross member.88438

[BrazilianY60]

What does that chopped crossmember looks like?

[PeeBee]

What does that chopped crossmember looks like?

https://www.superiorengineering.com.au/patrol-front-crossmember-modification

[mudnut]

Righto, so its 38 Deg C so perfect temperature to swap out the front drive shaft! Anyway, 20 mins turn around, including the clean up and paint of the 60mm scored section. Still waiting on the chop infill piece for the cross member.88438

Sorry to be a negative bugger, but the tail shaft is case hardened. That might be a weak point now.

[PeeBee]

Sorry to be a negative bugger, but the tail shaft is case hardened. That might be a weak point now.

Craig, fair point but I would doubt there was much sustained heat, more abrasion over a 3000klm period at times. I put a vernier over the tailshaft unaffected and affected and its less the 0.005" loss of diameter - not much from a torsion perspective, but I will remember your words in the future if it lets go!