Club 80-90 Forums

As a result of a near death experience(complete brake failure at 65mpg on a duel carridge way) I've discovered that the thread on the streering knuckle has worn. After taking of the grease hub I discovered the bearing and the peen nut were both free to roam where they wanted. The only thing holding the wheel on was the brake calipers. I've tried putting the bearings and nut back on but the nut won't tighten. The start of the knuckle thread is worn and has allowed the peen nut to undo itself. I'd have thought there was need for a locking pin ut there isn't one. Now I'm not sure if the nut or the thread is the problem. The nut screws on so far then just turns lose. My problem is that the knuckle thread is only worn at the start. Further down the thread seems ok. I'm going to try another nut in the morning to see if it locks. If not then it's the knuckle thread. If this is the case I'm going to need a replacement steering knuckle. Any advice welcome. Doing the job myself, as usual.

For a start you must use a new nut. For the old one to have come undone the peening must have been done incorrectly. No lock pin is required - that is the point of peening the nut into the groove. You can tell if you have enough thread left easily enough.
You wouldn't have lost your handbrake though - didn't you use it?
I have just had the same sort of thing - a front bearing collapsed which led to no brakes the same - I just used the handbrake and had a trip home behind a breakdown truck.

Oldiebut goodie wrote:For a start you must use a new nut. For the old one to have come undone the peening must have been done incorrectly. No lock pin is required - that is the point of peening the nut into the groove. You can tell if you have enough thread left easily enough.
You wouldn't have lost your handbrake though - didn't you use it?
I have just had the same sort of thing - a front bearing collapsed which led to no brakes the same - I just used the handbrake and had a trip home behind a breakdown truck.

Yep handbrake was used, hence the reason I'm still alive. And yes again a very nice man and his truck brought us home.

My guess would be that the excessive disc movement has led to increased pad to disc contact which has resulted in the brake fluid boiling 'VAPOUR LOCK' and total loss of your brakes.

The part you refer to as the knuckle thread is infact called the stub axle and it sounds to me like you need to pick up a good used replacement and new nut because the stub axle has been worn down by a spinning outter bearing.

Remember that the front of a 2WD T25 uses taper roller bearings, these must not be tightened by the nut rather just take out the free play (wind the nut down until it touches the bearing) no more!. There should still be a slight bit of play when you push and pull the wheel/tyre at 6 & 12 O'clock.

Not sure which side you are after but here is a late O/S assembly on the bay of thieves.

http://www.ebay.co.uk/itm/volkswagen-ty ... 0399557034" onclick="window.open(this.href);return false;

Martin

Not a very good design by VW as the peened nut often damages the first couple of threads when it is wound off..so when a new nut is fitted it goes on cross threaded and damages the thread even more. I liked the old split stub axle nuts that had an allen bolt to tighten them once adjusted....they never caused damaged and were easy to adjust.

Martin

California Dreamin wrote:My guess would be that the excessive disc movement has led to increased pad to disc contact which has resulted in the brake fluid boiling 'VAPOUR LOCK' and total loss of your brakes.

The part you refer to as the knuckle thread is infact called the stub axle and it sounds to me like you need to pick up a good used replacement and new nut because of the worn damaged threads on your existing part.

Remember that the front of a 2WD T25 uses taper roller bearings, these must not be tightened by the nut rather just take out the free play (wind the nut down until it touches the bearing) no more!. There should still be a slight bit of play when you push and pull the wheel/tyre at 6 & 12 O'clock.

Not sure which side you are after but here is a late O/S assembly on the bay of thieves.

http://www.ebay.co.uk/itm/volkswagen-ty ... 0399557034" onclick="window.open(this.href);return false;

Martin

It is quite clear what lead to the loss of his brakes - exactly the same happened to me. There is no need to guess at another reason!!
The stub axle is part of the steering knuckle so his description adequately described the problem area.

as you can see the start of the thread has worn. However I thought the nut would bypass this worn bit and tighten on the good thread. I tried a washer before the nut but to no avail. Do I need a whole knuckle......looks like.

You won't get anywhere if you are using the old nut - it will be b****red internally. That thread looks exactly the same as mine - there is plenty of thread there for the new nut to go on safely. Don't put any other washers on there other than the tabbed thrust one. The new nut must be peened properly when you have it adjusted correctly. I presume that you're replacing the bearings whilst it is off as they won't be much good now.

I wasn't going to as they seem fine. No visable damage on peen nut or bearings. When I tighten the nut as far as it allows the wheel is secure, no play (other than that allowed). I'd rather not replace the bearings if I don't have to. I know the safety ones among us would recommend dooing so but I say if it aint broke and all that.

You haven't forced the old nut back on have you? The thread will not be good enough to be reused safely plus you may damage the thread on the axle forcing you to now replace it!

no I haven't forced the old nut on. I tightened it a little without the bearing on so as to see if the thread had gone. It tightened enough but not quite enough if you know what i mean?

The thread will definitely be damaged inside the nut and the nuts are single use items anyway - if you think about it you would have to peen it again in exactly the same place - which isn't a very good idea. Personally I wouldn't reuse that bearing as it will have been subjected to undesigned for stresses as it ran outwards.

Just ordered full bearing set. What do you think? They are made by VW so should be ok. He sells nearly all VW stuff so I'll try him. Good price aswell I thought.

http://www.ebay.co.uk/itm/VW-CAMPER-TRA ... 0534105473" onclick="window.open(this.href);return false;

I can't see anywhere that he says that it is made by VW! Only says suitable for!
I wouldn't touch them without the name to back them up as there are too many chocolate bearings being peddled. I replaced mine with quality ones from Brickwerks - not cheap but I don't intend to replace them again in the next year or two as you will with cheapo nasties.

Oldiebut goodie wrote:

California Dreamin wrote:My guess would be that the excessive disc movement has led to increased pad to disc contact which has resulted in the brake fluid boiling 'VAPOUR LOCK' and total loss of your brakes.

The part you refer to as the knuckle thread is infact called the stub axle and it sounds to me like you need to pick up a good used replacement and new nut because of the worn damaged threads on your existing part.

Remember that the front of a 2WD T25 uses taper roller bearings, these must not be tightened by the nut rather just take out the free play (wind the nut down until it touches the bearing) no more!. There should still be a slight bit of play when you push and pull the wheel/tyre at 6 & 12 O'clock.

Not sure which side you are after but here is a late O/S assembly on the bay of thieves.

http://www.ebay.co.uk/itm/volkswagen-ty ... 0399557034" onclick="window.open(this.href);return false;

Martin

It is quite clear what lead to the loss of his brakes - exactly the same happened to me. There is no need to guess at another reason!!
The stub axle is part of the steering knuckle so his description adequately described the problem area.

Who the hell gave you sole right to comment on a problem....now shut up critisising other people opinions and start giving out some good advice because what you have suggested so far has been poor.

Is it quite clear what lead to his brake loss and yes exactly what happened to you...I wasn't guessing at 'another reason' because I think you both had VAPOUR LOCK but to be honest what the hell has that got to do with anything anyway.

And the scariest thing here is that you are suggesting that there is nothing wrong with the stub axle even though it is clearly badly worn.

If you hadn't noticed...the smaller outter bearing has been spinning and has damaged the stub axle (it has worn a groove) so definately needs changing.

And yes I did need to correct his description as he was getting his parts mixed up even if you understood him.

Now I don't know about you but my concern is for this guys safety and not to flame others who are trying to give good advice.

Docklad....those bearings are unlikely to be good quality, that guy sells cheap pattern parts, save your money and find a replacement stub axle and go from there.
Martin