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New driveshaft - manufacturing error?
23 May 2023 07:54 #249237
by TrondK
New driveshaft - manufacturing error? was created by TrondK
Hi all,
I've bought a new GKN / Löbro driveshaft to replace the long one in the front as mine was badly grooved from the oil seal.
The new one has a very rough surface on the area for the oil seal. You can see the grooves from the lathe that turned this. I reached out to the supplier and wondered if this was a manufacturing error. I was expecting a ground / polished surface. The reply was that this was ok and I could go ahead and install it. I'm very skeptical to this, and fear that the life of that seal will be short. I also quickly measured the diameter of this area, and the old is about 26mm, this one is about 26.2mm, which makes me think this was left for a grinding / polishing that didn't happen. What do you think?
I've bought a new GKN / Löbro driveshaft to replace the long one in the front as mine was badly grooved from the oil seal.
The new one has a very rough surface on the area for the oil seal. You can see the grooves from the lathe that turned this. I reached out to the supplier and wondered if this was a manufacturing error. I was expecting a ground / polished surface. The reply was that this was ok and I could go ahead and install it. I'm very skeptical to this, and fear that the life of that seal will be short. I also quickly measured the diameter of this area, and the old is about 26mm, this one is about 26.2mm, which makes me think this was left for a grinding / polishing that didn't happen. What do you think?
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23 May 2023 09:56 - 23 May 2023 10:00 #249239
by yakuza
Norway 2005 Jimny M16A VVT, 235 BFG MT, 2" Trailmaster, ARB rear lck, 17%/87% high/low gears.
Replied by yakuza on topic New driveshaft - manufacturing error?
No Way!
That surface is also prone to make the shaft weaker as the roughness makes cracks appear easier.
No way that any seal would last long on this.
Return it. Any used shaft would be better.
Edit: And yes, It looks like the final grinding after hardening have been "forgotten" as the surface looks like the heat treatment from hardening or annealing. Normal to leave 0.2mm (or more) for final grinding so measurements also indicates that someone had a bad day.
(I am an engineer btw, working with manufacturing large machinery. Have not had any problems with buying industrial stuff from GKN before as far as I know though.)
That surface is also prone to make the shaft weaker as the roughness makes cracks appear easier.
No way that any seal would last long on this.
Return it. Any used shaft would be better.
Edit: And yes, It looks like the final grinding after hardening have been "forgotten" as the surface looks like the heat treatment from hardening or annealing. Normal to leave 0.2mm (or more) for final grinding so measurements also indicates that someone had a bad day.
(I am an engineer btw, working with manufacturing large machinery. Have not had any problems with buying industrial stuff from GKN before as far as I know though.)
Norway 2005 Jimny M16A VVT, 235 BFG MT, 2" Trailmaster, ARB rear lck, 17%/87% high/low gears.
Last edit: 23 May 2023 10:00 by yakuza.
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23 May 2023 11:02 #249241
by LesNewell
Replied by LesNewell on topic New driveshaft - manufacturing error?
I agree. That surface will chew a seal to bits.
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23 May 2023 14:05 #249245
by TrondK
Replied by TrondK on topic New driveshaft - manufacturing error?
Well, now I'm a bit surprised.
I initially only sent the first couple of pictures to Autodoc and asked for a comment, which really should be good enough with a margin. Now I went back and sent the really close-up one and requested they had another look. I had sort of expected a reply along the lines of "yeah, that is not how it should be, send it back and we'll arrange for a new", but no. Once more they were quickly back to confirm that this one is as it should be, and that I should go ahead and use it. Kind of peculiar that the CV joint has a nice ground / polished finish, as it should be, but they (Autodoc) see no connection to the other sealing area.
General recommendations for sealing surfaces like this is surface roughness of RA 0.2-0.8 micrometer. We are not exactly there, and clearly Autodoc doesn't appear to care much after a sale, so I'll go and look for another source for a new shaft. Life is to short to get the blood pressure up. Anybody know of one?
I initially only sent the first couple of pictures to Autodoc and asked for a comment, which really should be good enough with a margin. Now I went back and sent the really close-up one and requested they had another look. I had sort of expected a reply along the lines of "yeah, that is not how it should be, send it back and we'll arrange for a new", but no. Once more they were quickly back to confirm that this one is as it should be, and that I should go ahead and use it. Kind of peculiar that the CV joint has a nice ground / polished finish, as it should be, but they (Autodoc) see no connection to the other sealing area.
General recommendations for sealing surfaces like this is surface roughness of RA 0.2-0.8 micrometer. We are not exactly there, and clearly Autodoc doesn't appear to care much after a sale, so I'll go and look for another source for a new shaft. Life is to short to get the blood pressure up. Anybody know of one?
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23 May 2023 16:10 #249246
by DrRobin
2020 blue SZ5 (one of the last to be registered in the UK)
Ex 2011 Blue Jimny SZ4
Northumberland Jimny Blog
Replied by DrRobin on topic New driveshaft - manufacturing error?
I had a bad experience with one of Autodoc's web trading companies and came to the same conclusion, not only did they try to give me the wrong information, they then took 7 days to ship items out of the warehouse (it was suppossed to be with me in 2 days) and I had realised that the items they were sending were the wrong part before they actually left.
Even though they hadn't left, as the courier had been booked, they were still shipped to me and had to reject the package un-opened. It took a few more weeks to get the money back.
I agree with everyone else, the seal would only last a few miles, if it even seals correctly and I would just reject this shaft, it is clearly wrong.
Robin
Even though they hadn't left, as the courier had been booked, they were still shipped to me and had to reject the package un-opened. It took a few more weeks to get the money back.
I agree with everyone else, the seal would only last a few miles, if it even seals correctly and I would just reject this shaft, it is clearly wrong.
Robin
2020 blue SZ5 (one of the last to be registered in the UK)
Ex 2011 Blue Jimny SZ4
Northumberland Jimny Blog
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24 May 2023 18:58 #249271
by yakuza
Norway 2005 Jimny M16A VVT, 235 BFG MT, 2" Trailmaster, ARB rear lck, 17%/87% high/low gears.
Replied by yakuza on topic New driveshaft - manufacturing error?
You got a Norwegian name Trond?
I would try Eurodel.no if you are Norway based. they at least have a norwegian customer support and warehouse or sales place. they might get the parts from the same place as everyone else, but they seem to be based in Halden. and is way faster and more often correct than skruvat, autodoc and those.
If all else fails you could find a machine shop to polish or grind your shaft as well. Wouldn't take me long, put it in a lathe and do a fine cut, hold a file to it and sand with fine grain to finish. 0.8 is ok.
I would try Eurodel.no if you are Norway based. they at least have a norwegian customer support and warehouse or sales place. they might get the parts from the same place as everyone else, but they seem to be based in Halden. and is way faster and more often correct than skruvat, autodoc and those.
If all else fails you could find a machine shop to polish or grind your shaft as well. Wouldn't take me long, put it in a lathe and do a fine cut, hold a file to it and sand with fine grain to finish. 0.8 is ok.
Norway 2005 Jimny M16A VVT, 235 BFG MT, 2" Trailmaster, ARB rear lck, 17%/87% high/low gears.
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