Front axle freezes when brake back plate tightened???

Hello All!

I am just reassembling my NSF wheel having replaced all bearings etc. Off Side Front was fine and spins freely whilst other side is dismantled. SO I put the swivel housing on the near side and put the halfshaft in. With it in 4WD I then test it by spinning the OSF wheel round and I happily watch it spin in opposition to the other wheel and all looks rosey. NOW THE PROBLEM: I put the stub axle and brake back plate on and tighten it right up. Run the test again and the wheel now won't move freely. In fact it moves about a turn then meets resistance and wants to bounce back - the resistance is significant as I can't push past it. Then I turn the wheel back a rotation and it meets resistance again. I am puzzled so take the stub axle et al off again and test. The wheel spins freely on the other side again and the stub axle on the side I'm working turns in opposition. I put the stub axle and brake back plate back on and don't do up. The test works still. I begin tightening the bolts and the wheel starts meeting resistance again - with the resistance getting greater as I tighten the bolts until it eventually won't turn more than a revolution of the wheel.

Is this a familiar problem to anyone?

If you've rebuilt the swivel you may have changed the clearance between the half shaft UJ and the ball/bearing/bush causing it to bind. There's a procedure in the book for checking the clearances.

Okay. I was getting tired tonight so called it a day and thought I'd throw it out here in case it was an obvious problem. I'll inspect the UJ a bit closer and see if it looks as though it could bind anywhere. From memory doesn't it suggest you need some kind of gauge to measure the clearance? - I don't have anything like that.

Thanks for the quick response.

Just thinking, if it turns out there is a problem with clearance is it because I've done something wrong with the assembly or is it just what sometimes happens? ...and what should I look to do to fix it?

does half shaft poke out the same amount from stub axle on both sides,and is seated in brg and in stub

jamesmartin said:

does half shaft poke out the same amount from stub axle on both sides,and is seated in brg and in stub

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Good thought.

I don't know as the side that (I think) went well is all assembled with the wheel back on. Is it worth me taking it back to the stub axle on both sides again to compare? What will it tell if they aren't equal?

the only thing that can jam is drive shaft which is supported both ends,inner and outer been stub axle

The side of the problem I've noticed has flat leaf springs. The result appears to be that the axle is significantly higher on that side. I guess that explains why the good side seems to have such a pronounced positive camber and the bad side appeared vertical. I'm guessing when I replace the springs the axle will be level again and both sides will show a slight positive camber equal to each other. I was just wondering if this may be causing any of my problems though with regards to putting it all back together. I don't see that it should but I know nothing

The springs shouldn't make a difference. It's not too difficult to check the UJ clearance, you need a feeler gauge to do it with. Have you replaced any of the swivel components that might have altered the position of the ball? It's possible the half shaft isn't seated into the diff properly, have you tried giving it a gentle tap inward?

oxides said:

The springs shouldn't make a difference. It's not too difficult to check the UJ clearance, you need a feeler gauge to do it with. Have you replaced any of the swivel components that might have altered the position of the ball? It's possible the half shaft isn't seated into the diff properly, have you tried giving it a gentle tap inward?

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I've stripped back to the swivel housing and can see that the collar of the UJ protrudes slightly out of the swivel housing. On the back of the stub axle there is circular scoring that looks fresh so I guess my UJ is rubbing the back of the stub axle - makes sense as it gets harder to turn the more the stub axle is tightened.

So what can I do??? Firstly, in answer to your questions:

When I put the half shaft in I turn it until I feel the splines line up and then push it in. It inserts about 3/4 of an inch I'd say and won't go any further in (have since tapped it with a mallet to check that). So I'm fairly confident it's fully engaged.

I have replaced all the swivel components including the chrome ball, housing and all associated bearings/bushes etc. The chrome ball is just bolted onto the axle housing and then the swivel housing just on the ball via it's two swivel points so I can't see where there could be any opportunity for me to have messed that up and got them aligned wrong (of course it's possible I have, I just can't see how I would have).

I have feeler gauges. Do you mean to check how much the UJ protrudes beyond the mating surface of the swivel housing? Or should it not protrude at all? I will go and read manual to try and understand what to measure myself but if you can give a quick pointer it might be more effective.

So I guess this is problem diagnosed? Just need to understand what I do from here.

Thanks again everyone (especially Oxides) for your continued support. At least it's sunny outside

does shaft sit right through properly in the bearing in ball ,should go in more than 3/4 of an inch ,new parts sometimes dont fit,and that shaft fits correctly in stub axle while off the vehicle

jamesmartin said:

does shaft sit right through properly in the bearing in ball ,should go in more than 3/4 of an inch ,new parts sometimes dont fit,and that shaft fits correctly in stub axle while off the vehicle

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Thanks James. Do you mean the half shaft may be catching on a bearing in the chrome ball thus stopping it from going any further in the diff? I guess it could be as I have replaced the bearings and the collars on the half shaft. I was trying to avoid taking the chrome ball off again but guess I might have to. How can I really know if this is the problem or where should I look? When I put the half shaft (with new collars) through the ball before I assembled it they seemed to work with each other okay with no apparent binding anywhere.

yes if its seating correctly the bearing caps on yoke of half shaft will sit under swivel pin/hole as shaft has to pinot in same place as swiwel housing

jamesmartin said:

yes if its seating correctly the bearing caps on yoke of half shaft will sit under swivel pin/hole as shaft has to pinot in same place as swiwel housing

Click to expand...

Makes sense, I'll go and check.. and if they do, does the edge of the yoke protrude at all from beyond the swivel housing or should it be flush or recessed when in all the way?

I just noticed the chamfered oil seal collar thingy that slips on the half shaft was not entirely down on the race (a few mm gap) so I will firstly try to knock that down (though can't see that that would cause the problem). Then will see how it looks to the eye in terms of where the yoke sits in relation to the swivel.

Thanks for the quick replies!

DONE!

Thank you!! It has gone right in now and the collar of the yoke sits right back in the swivel housing. All I did was knock the chamfered oil seal collar right down. Perhaps that helped or perhaps not but it definitely went through a lot more now. Shame I can't be more certain on why.

Will crack on with rest of assembly now and see how I go.

LandyZone and you wonderful people rock