warning to check your axle!

[THE ICEMAN]

On the way home from a camping trip at the weekend felt the back end of the van go strange. At the time i was going down a steepish hill which is quite twisty. Thinking i had a puncture i went for the brakes but pedel went to the floor. Went down a gear but there was zero engine braking as well. Worried now! Reefed up the handbrake and eventually ground to a halt perhaps 150 meters from when first felt the problem. Replaced destroyed trousers and had a look underneath the camper. It was obvious what had happend. The axle shaft had come out from the diff along with the brake drum leaving the brake shoes nothing to work against, hence no brakes. In fact all that prevented the whole lot from falling off the van was the side wall of the tyre hitting the outer cill/wheel arch. On further investigation it turns out there is a bearing retaining nut on the inside end of the wheel bearing which is stopped from undoing by a pissy little tab washer. Well there was no tab now so over time the nut just undid. Once past the threaded portion of the shaft there is nothing to prevent it from simply falling out of the diff complete with wheel. How to check it? You could jack up the axle and undo the six bolts that hold the backplate to the axle tube or just give the wheel a really good push/pull. If there is any end float i would suspect the nut is loose. I think this is a real poor design and am now thinking how i can re engineer it so this cannot happen again. The original lock washers simply are not up to the job for such an important part. vital part. At the very least it will be a real solid lock washer and loktite on the threads and i think i could get a second locknut on there as well. The next thing is some sort of split brake system as total failure of ALL retardation is so not good. Thankfully the handbrake works on the front wheels or it would have been time to put it in the ditch, at 50+ kph. Not good.
check your axles folks!


I just need a good rootes...

 

[Panky]

Bloody hell[:0] That's a new one. Those nuts should be torqued up really tight, all I can suggest is that someone must have had it out to change the bearings or something and not done it up properly[V]
So glad you are all OK - apart from the nappy rash:I

 

[greg]

Thankfully, no crash and you are all okay[B)]
The Bedford CF's were offered with an optional dual line braking system with a tandem master cylinder, which mine does have.
Were any Commer/Dodges offered with similar?

The simpler the betterer...

 

[jimberlake]

Nightmare, very glad you are all ok...now I know why those Rootes engineers put the handbrake at the front, clever chaps ;-)

The Blue Toaster

 

[Suinnyboy]

Greg's on the money, that's why mine is going to be dual circuit. Loss of brakes is one of the worst feelings, there one moment nothing the next. Only happened to me once when the master cylinder seal gave up. Fortunately I could pump up the peddle and slow the car.

 

[colinthefox]

Thanks for the heads up Iceman. Coincidentally, I've just reassembled my back axle today, and that little tab washer did seem to be a bit pissy for the job, but I just turned it over as best I could. Just not enough metal to turn over the flat of the nut properly. When I took the axle apart, that nut was very loose, and the shaft could easily have come out just as yours did. Looks like I shall be pulling the half shafts out again tomorrow to make them more secure!

Commer PB Jennings

 

[bazzateer]

Shouldn't tab washers be renewed rather than re-used?

I am not a person, I am a number, 395 actually......Be seeing you!
If I told you I was a pathological liar, would you believe me?

 

[THE ICEMAN]

In my case it was not the part that is turned over the flat of the nut it was the little inner tab that sits in the slot cut in the shaft to stop it rotating. It had snapped off allowing both the nut and washer to turn together. It just does not have enough meat on it.

I just need a good rootes...

 

[Suinnyboy]

If there is space, why not fit a second nut as a lock nut.

 

[THE ICEMAN]

Thats the plan. Along with thread lock

I just need a good rootes...

 

[andrew]

Pleased your all ok.

Member of the non-Facebook club.

 

[colinthefox]

Iceman: Glad you're OK. That's about as scary as it gets.

Bazateer: Whether you can re-use tab washers depends on whether there is a fresh part to bend up, in which case it can be re-used, or if the original tab has to be bent back and forth, it is most unwise to re-use it. In this case there are plenty of new bits of the washer to bend over the nut, so should be OK to re-use.

Anyway here's what it looks like.

That nut is all that is stopping your half shaft, brake drum and wheel from coming off. You can see that even though it is a new area of the tab washer that has been turned up, it's barely enough to stop the nut rotating. I did test it by undoing the nut without opening the tab, and it was the small internal tab that broke off, just like Iceman's did.

Made a couple of new tab washers.

These are a couple of mm larger than the originals, but there is a limit to how big you can make them, because they have to clear this piece inside the axle.

Here's one fitted. There is a much better turned over bit than before, and the nut has been loctited as well. There's only a couple of threads spare, so I don't think a locknut is possible. Also a locknut would foul that piece shown in the last photo.

I found it easier to tighten up by putting the nut in the vice and turning the wheel flange with a long bar.

Commer PB Jennings