Just wondering about the implications of driving a truck with loose bolts on the prop shaft.Was working for a firm a while ago and on it’s first inspection was informed that nearly all of the bolts were indeed loose around aforementioned area.Obviously this is not a healthy situation and thank god it was found early on,but what would the potential consequences have been if the ■■■■ thing had really come off en-route?
Don’t know about a truck but I can’t imagine much would happen. I once saw the prop shaft on a transit tipper thing fall off…it just dragged on the floor as the driver used his momentum to pull over.
It would make a nice dent in the Tarmac, you would loose drive and need to call for a spanner. It is attached at both ends so it’s unlikely to come off. Depending on what your doing at the time, it could be tricky to control your vehicle until you hit the brakes.
Because both ends have a universal joint it should just turn while lying on the Tarmac, it shouldn’t damage the underside of the vehicle much.
It’s not very common that propeller shafts cone loose because it’s not something you often remove. It’s possible that it was removed to tow the vehicle when it had broken down and not torqued to the correct amount once repaired/re-fitted.
Ive known cases of a transfer box ceasing and the prop shaft sheering off and writing off 3 cars. Also a propshaft droping out the transmission and ripping a drive axle out.
If the front end comes off it wont just drag on the tarmac.It can wreck a motor if its whipping about,burst air pipes and all the other things that happen then.
I had a centre bearing collapse on a Bedford KM. It makes one hell of a row, luckily I was in Lincoln and Charles Warner had a new one in stock. It helps if a driver can identify the parts needed and the problem when it happens. I was back on the road in about an hour.
Bolts would not normally come loose on their own, they have probably not been tightened after a clutch or gearbox replacement.
A driver can only do a visual check on a walkround, he is not expected to clamber under the lorry with a toffee hammer
I worked for a firm years ago, that had one drop on the front end of a unit running bobtail, he was on the motorway doing about 60, it dug in flipped the back up and around and turned the lot over. The driver was nearly killed, he was on life support for weeks.
Adam_Mc:
Don’t know about a truck but I can’t imagine much would happen. I once saw the prop shaft on a transit tipper thing fall off…it just dragged on the floor as the driver used his momentum to pull over.
I lost my prop shaft in Sprinter. It done quite a damage to all things underneath…
I am no mechanic but aren’t the bolts on the prop shaft supposed to have locking wire through them? The nuts can come loose but not right off.
We sometimes lost the small props between the axles on the older Foden 8 wheeler’s, very rarely heard them go though. The later model’s did away with the bolted flange’s which was a lot better idea, though you had to dismantle the U/J to remove the gearbox etc.
I was on the A610 Eastwood bypass a few years ago and saw a woman in a MGB hit a small prop from a 6/8 wheeler which was laid in the outside lane, it ripped the bottom of the car right out and threw it onto the central reservation, she was unhurt but shaken up a little!
Pete.
Santa:
I am no mechanic but aren’t the bolts on the prop shaft supposed to have locking wire through them? The nuts can come loose but not right off.
I have never seen any with locking wire, though I haven’t worked on “modern” trucks. Ours used to have nyloc nuts and some of the lighter truck’s (BMC etc) used to use tab washer’s.
Pete.
manalishi:
Just wondering about the implications of driving a truck with loose bolts on the prop shaft.Was working for a firm a while ago and on it’s first inspection was informed that nearly all of the bolts were indeed loose around aforementioned area.Obviously this is not a healthy situation and thank god it was found early on,but what would the potential consequences have been if the ■■■■ thing had really come off en-route?
I had a propshaft bearing bracket let go…made a fair old mess even though the propshaft was still bolted on at both ends.
If you’re lucky, it drops on the floor and spins round making a racket.
If you’re unlucky it digs in the floor and punts the rear end of the unit into the air.
windrush:
Santa:
I am no mechanic but aren’t the bolts on the prop shaft supposed to have locking wire through them? The nuts can come loose but not right off.I have never seen any with locking wire, though I haven’t worked on “modern” trucks. Ours used to have nyloc nuts and some of the lighter truck’s (BMC etc) used to use tab washer’s.
Pete.
I have never seen them with locking wire ether, the same as you just the nylon nuts or lock tabs, but saying that I’ve not seen all makes of lorries, so some may have the wire, it sounds a good idea.
windrush:
We sometimes lost the small props between the axles on the older Foden 8 wheeler’s, very rarely heard them go though.
Pete.
our alpha went through a phase of slackening off her flange bolts after i threw a clutch in, would have replaced them but just stuck with the 12 point head bolts, staying tight now, worst one is our fl6 has to have a tweak every checktried new bolts in her the lot,
had a 75e decide to pull its pinion shaft through the front of the diff housing, that made a nice mess