fitted new prop and vcu now bad wobble

Can anyone help me with this one please . Ive fitted a new prop and vcu to my car tonight as the old vcu had gone very tight . But now I've got a terrible wobble that you can feel right throughout the car . They don't have to be lined up or matched do they ? Don't think they do . I've fitted the bearings straight so can't think what else it could be the rear diff mounts aint the best but this wobble wasn't there before thank you

Hi, yes the prop(s)/vcu have to be a lined up correctly, front to back but I can't remember the the measurements, (they're in the haynes manual or if you can access the genuine one on line somewhere or someone will doubtless be along with the info/pictures). The vcu support bearing carriers have elongated slots in them to aid alignment. We're the props new or second hand ? These should be balanced (you may see balance weights on the prop(s) outer surface. I must admit it sounds more like prop(s) out of balance as the vibration/wobble wasn't there before (not sure if this should be done as a complete unit, props & vcu). Even if you separate the props/vcu just to replace the carrier bearings you should always mark them so they go back together exactly the way as they came apart. Sorry I can't be more helpful I hope you get it sorted.

The bearings need to be exactly 90° to the axis of the VCU shafts. The whole assembly needs to be fitted exactly along the centre line of the vehicle. The propshaft UJs will then allow the shafts articulate to the IRD or diff.

The vcu is lined up correct then so unsure what my issue is its a proper judder vibration

Stig1 said:

The vcu is lined up correct then so unsure what my issue is its a proper judder vibration

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Are the tyres identical, same make, same type, all pumped up to the same pressure, with the least worn on the rear?

Nodge68 said:

Are the tyres identical, same make, same type, all pumped up to the same pressure, with the least worn on the rear?

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Yes

Are all the bolts tight ? and just how bad are those rear mount, the centre one is usually the worse.

Arctic2 said:

Are all the bolts tight ? and just how bad are those rear mount, the centre one is usually the worse.

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All bolts are tight . The rear mount aint that bad but I will be changing them very soon

Some background on the issue would be helpful. Did the vehicle vibrate with the old VCU?

Are you sure you didn't dislodge some of the rollers in the front CV joint when removing the shaft?

Nodge68 said:

Some background on the issue would be helpful. Did the vehicle vibrate with the old VCU?

Are you sure you didn't dislodge some of the rollers in the front CV joint when removing the shaft?

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The old prop and vcu where fine as in no wobble or judder just the vcu had started to go a bit stiff so I swaped the whole thing over . I will need to check the front cv or I may even just swap the front part of the shaft over

Did you replace the whole propshaft and VCU assembly with another, or just replace the VCU onto your old shafts?

Nodge68 said:

Did you replace the whole propshaft and VCU assembly with another, or just replace the VCU onto your old shafts?

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Its a whole prop

Stig1 said:

Its a whole prop

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So it's likely that the replacement you fitted was damaged, or the VCU is worse that the one you had.

Nodge68 said:

So it's likely that the replacement you fitted was damaged, or the VCU is worse that the one you had.

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The vcu must be better as a whole the car drives much better im suspecting the front cv

Stig1 said:

The vcu must be better as a whole the car drives much better im suspecting the front cv

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There's something wrong, as you have a vibration. My guess is the replacement is worse than the one you removed. Its always better to keep your propshafts and simply fit a quality reconditioned VCU, rather than take a chance on a completely unknown second hand one.

The front cv has way to much play and also knocks

only trouble is I can't get the front half my prop off to swap it

Let us know why you can't remove the front section.

This is about the best guide...

andyfreelandy said:

Let us know why you can't remove the front section.

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Its just won't budge . I've soaked it with plusgas chisel just won't go