Help.....Smoking front wheel

[karl webster]

As the heading states.I have an issue.

On my 80 I have the NS front wheel smoking. It smells very hot.

I noticed this a while ago and thought it was oil getting into the wheel bearing and making the bearing wear out.I change inner seal and fitted a new bearing and all seemed ok.
When I went down to Poole to collect another truck all was ok. On the way back home got a lot of smoke coming from the wheel again. I checked the bearings and they were ok but I noticed the front axle was hot where the diff is.
When I did the bearing I checked the front diff oil and nothing came out so I've now got oil in there. With the front oil seals leaking onto the balls I just thought oil level was ok.
So.I have a wine on the front diff and the diff is getting hot when working hard. Obviously I need a diff to go in.


Question is.
Would the diff be making so much heat to cause smoke to come out the breathers?
What else could it be? Bearing,I doubt it. Sticking Caliper,don't think so.

Anyone with any ideas? Thanks

 

[Bat21]

.... On the way back home got a lot of smoke coming from the wheel again. I checked the bearings and they were ok....

Did the wheel spin relatively freely when you had it up checking the bearings? Did you do this while it was a smoking.

.... Sticking Caliper,don't think so.

If it's only one wheel that would be my guess.... what makes you think it isn't?

 

[karl webster]

Hey Paul.
It spun fine when I checked it yes.

I fitted new pads a while back and that Caliper didn't seem bad at all. Main reason I don't think it's the Caliper is because of the smell plus it seems more of a burning oil smoke/smell.

 

[adrianr]

Wild guess - Any chance the front diff is a different ratio to the back diff? Like an auto diff at one end of the truck?

 

[karl webster]

Cheers for the input Adrian.
No chance at all mate. It was quiet when I got it and the truck doesn't bind up at all when drivin. I'm feeling there is loads of play in the front and that's causing it to not turn at the same speed as the rear.maytake front prop off and run it like that for a while to see what happens unless someone comes up with a possible answer.

 

[898kor]

Cheers for the input Adrian.
I'm feeling there is loads of play in the front and that's causing it to not turn at the same speed as the rear

I would have thought the chances of that happening were next to none, even if it did the centre diff would lose the wind up.

Cheers for the input Adrian.
maytake front prop off and run it like that for a while to see what happens unless someone comes up with a possible answer.

May work, but to some degree unless you take off the drive (flanges or cv out) from the wheels then some part of the diff will still turn?


All the above said, I have had very similar happen in a Range Rover when towing a caravan back from an off roading weekend, like you I went for bearings until a full axle strip found the pinion and bearings trying to melt together! I would place my bets on a failing bearing or two - any up and down movement on the pinion end?

 

[Dave_S]

Had this on a couple of trucks and always a stuck brake - heat build up in the disc can also start to fry the oil/grease in the bearings and make a hell of a smell. May be free to turn when cold too. Personally I'd start there...

 

[karl webster]

I would have thought the chances of that happening were next to none, even if it did the centre diff would lose the wind up.



May work, but to some degree unless you take off the drive (flanges or cv out) from the wheels then some part of the diff will still turn?


All the above said, I have had very similar happen in a Range Rover when towing a caravan back from an off roading weekend, like you I went for bearings until a full axle strip found the pinion and bearings trying to melt together! I would place my bets on a failing bearing or two - any up and down movement on the pinion end?

I Agree with the fact everything will still turn even with the prop off. My thoughts would be if they are turning at different speeds then this may be why the front is heating up.
A rebuild is going to have to be done on the front diff anyway or a second hand unit. If I'm pulling the half shafts out I may as well just pull the diff and have it looked at.

 

[karl webster]

Had this on a couple of trucks and always a stuck brake - heat build up in the disc can also start to fry the oil/grease in the bearings and make a hell of a smell. May be free to turn when cold too. Personally I'd start there...

Im with you Dave and I to have had it loads of times. Tbh though to get as hot as its getting it usually boils the brake fluid and the brakes start playing up. May look at the Caliper but the fact the front axle is getting hot points me more in that direction.

 

[frank rabbets]

Probably a seized calliper Karl. This would mean the dif was working harder to overcome the increased resistance and getting hotter than normal. Drive it a few miles and put your fingers on the disc. It should be the same temperature as the other side. Be careful as a hot disc does not look hot.

If all is OK try the test again after pressing the brake pedal really hard when stationery then setting off on test number 2 and check the disc again.

 

[karl webster]

Cheers Frank. I will check. Would you not think I would have had issues fitting the new pads though a month ago? Cheers

 

[frank rabbets]

Yes you might have had a problem pushing the pistons back but it's worth a check to rule it out.

 

[joinerman]

Shot in the dark Karl but have you checked tyre sizes on the front & back are the same, when i first bought mine someone had fitted odd size tyres

 

[Jon Wildsmith]

running with no or insufficient oil in the diff will have damaged it. Damaged gears or bearings in the diff can make a lot of heat, enough to burn off all the oil and turn the gears to dust. You probably lost diff oil through the oil seals to a point it made the diff run hotter and hotter and then it was a downward spiral. Often as the diff oil migrates into the swivels grease goes the other way and makes a sludge that is no good for the gears or bearings. If you suspect bad seals you should keep a close eye on the oil both quantity and quality.

When you put new pads in is probably when the pistons are most likely to seize imo because the outer part of the piston is where corrosion starts which comes into use when you push them all the way back to put new pads in.

You might have both problems but having no oil in the diff makes knackered gears a high probability.

 

[yogi]

My money is on caliper, I've had the same happen to me before and the heat that can be generated is serious!