Light knock on drive train

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e30-wheels
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Sat Jan 15, 2022 7:50 am

Hello all let hope this year will be better than the last one.
1985 325i auto, I have a light knock when I power on and off it appears to be to the rear of the car, I have checked all the usual things and can't see anything visible except i do have what i think is a lot of rotational free play in the 2 rear inner drive shafts, the play is on the diff end of the shafts and seems to be more on the splines than the C/V joint does anyone know if there should be any rotational play at all in these shafts any help will much appreciated.
DanThe
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Sat Jan 15, 2022 8:19 am

That play is inside the diff and is supposed to be there, you shouldnt be able to hear it

Check the 4 diff bolts are tight, with a spanner not just visual, check the prop to diff coupling is tight, rear top mounts, trailing arms bolts etc
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e30-wheels
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Sun Jan 16, 2022 7:58 am

Thanks Dan The
As well as visual although i didnt mention it I did check all the all the bolts from the gearbox mounts backwards took the heatshields off to check the prop bolts and center bearing also the diff rear rubber mount all were OK, The play i have is on the actual inner drive shafts its not in the diff the diff free play is a few Thou and like you said should be there, it looks like its in the splines i cant feel anything in the C/V joints the other end by the wheel is ok, what i want to know is there ment to be any movemet at all in the inner drive shafts apart from in and out to allow for suspension movement.
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