I had my clutch replaced a few weeks ago, all fine. I then needed my DPF cleaned a few weeks later by a different garage. This garage took my drive shaft off to get to the DPF and told me whoever did the clutch had wrecked the bolt and nut (ruined the threads) of the drive shaft. I got in touch with the original garage who then got a new drive shaft but when they went to replace it they said the drive shaft was 100% and only put on a new both bolt. I went and paid for my DpF work and they said they wouldnt drive the car and advised they now had no liability as its been cleared by a different garage. So one garage said its unsafe and the other said its 100% safe. What should i do, believe the independent garage (they would have made money from a new shaft fitting) that says it safe, or the electrical garage (who wouldnt have made any more money) who says its unsafe? Help!! Nissan Qashqai
There is no way anyone on the web can tell you if you have a problem or not .
Just have another shop inspect the vehicle .
I would trust the mechanical shop’s evaluation that is safe more than the electrical shop. I think you are safe but to be sure, a 3rd shop’s opinion may make you worry less.
Or more, it’s a coin toss, could go either way.
thanks, i will get another opinion, I’m just don’t understand how one mechanic tells me its fine and the other that its unsafe, very strange. The drive shaft bolt and nut isnt exactly a complicated part of a car.
For the same reason that George Carlin said anyone going slower than you is a moron and anyone going faster is an idiot 
Everybody has an opinion. Some people are more knowledgeable than others and risk tolerance varies between people as well. If one shop specializes in electrical work, they probably aren’t the best source for mechanical advice and may tend to lean heavily toward the risk averse side since it’s not their wheelhouse. Does that make sense?
It does, thanks. Ive booked into another garage tomorrow for a final say. Looking for a 2-1 win!!
One shop is either incompetent or simply lying to you. What’s not to understand?
Fasteners for that sort of application have to be rated to handle the forces involved. Look at the “metric bolt” section of the chart in the link below to get an idea. There are similar ratings for nuts too. Perhaps the shop is saying a fastener with the correct rating wasn’t used. Or maybe some other reason. Suggest to ask for clarification.
https://www.boltdepot.com/fastener-information/materials-and-grades/bolt-grade-chart.aspx
Have the shop show you the damaged interface before starting disassembly, then afterwards to see if the threads are indeed damaged.
I have photos of before, i saw some thread damage on the bolt and nut. Then i watched the new garage put a new nut on, the old garage had rubbed the front of the bolt down to get a nut on temporarily but the new garage where able to hand roll the nut right to the end and tighten it. I watched them do this. Two different opinions, it just shakes my confidence. Definitely getting a third opinion.
The threads on the half shaft where the nut sits appear to be shot. Rethreading with a die might restore them but they won’t have the same strength as they originally had. I would replace the half shaft.
The end of a fwd axle shaft isn’t usually called a “bolt”. OP’s terminology may be causing some confusion here. Both the threads on the axle shaft and the fastener (nut) that threads to it appear to be damaged. Since those parts must hold up to a lot of force when driving, suggest to do what @NYBo says above, replace the entire half shaft. Since this problem occured while replace the clutch, make sure the same thing isn’t happening on the other side. May have to replace that half shaft also.
The torque specification on the nut that holds the axle shaft on is often quite high. On my prior VW Rabbit and current Corolla, I have to stand on the breaker bar to get it tight enough.
I thought OP was driving a 3/4 tone truck or something talking about changing the DPF and talking about the drive shaft… I totally missed the Nissan Qashqai for some reason… lol
The axle threads look sharp like a nut was forced on them or something, the nut looks like the threads have pulled…
I would see if a new correct nut will thread on by hand with no floppy play in the treads and see if it will take the proper torque, looks like 136 ft lbs or 185 nm torque.(refer to service manual for accurate torque specs)… If the nut didn’t have excessive movement while on the shaft (before being hand tight) and takes torque it should be ok, but if the nuts seems “loose” on the threads and or doesn’t take the torque spec then I would replace the axle and nut…