1800ES propshaft centre bearing advice

[VolvoRoyS]

I'm getting vibration on the move in my 1973 P1800ES and assume it will be the propshaft centre bearing. I can move it up and down a bit but how much movement is bad?
The Haynes manual (mainly 120 and 130 series with a bit of P1800 tacked on) suggests that this bearing can be removed by removing the back half of the propshaft and then pulling the bearing off. From what I've seen on youtube videos on propshaft centre bearings this sounds very optimistic and generally the whole propshaft is removed and a puller used to remove this bearing.
I'd like to hear from any one else who has done this job for some advice.

Roy

[mike gilbert]

I haven't been under an ES for years but assuming the ES has the same set up as the S, are you confusing the bearing with the big rubber bush that supports the middle section of the prop and the bearing sits inside? A worn bearing will be noisy but a worn rubber support bush will cause vibration - and that should be more noticeable at low speeds. If you can move the prop shaft up and down by hand (more than about a centimetre) I'd say the support bush is knackered. If you take the whole prop off and split it to do the job but make sure you mark it so the two pieces line up exactly as they came off the car.

[powen1]

Hi Volvoroy

I have done this on a 1800E, the centre bearing is held in place by a rubber mount, then held on with a metal bracket 13mm bolts ? I think
I have inc pic, yes remove the rear prop 4 bolts at back pull out rear prop make sure you make a note of connection between Dif connection and where the splined meet the centre to keep balance in place, paint a mark on each. You may see a large bolt on the front prop holding the bearing on, this needs to come off to remove and refit , hope this helps

[VolvoRoyS]

Thanks for your replies. Yes it does move up and down a bit but maybe not enough to be a problem, less that 1 cm I would say. So it sounds like the Haynes manual is correct in that the centre bearing can just be pulled of the front part of the prop shaft.
However, I also noticed while I was under there that one of the bolts holding the prop shaft to the gearbox was shorter than the other 3; maybe this would cause some imbalance?

Roy

[c1800]

Have you checked the u joints?

[mike gilbert]

Well one odd nut and bolt wouldn't help but it is in a fixed position at the very end of the prop. If your centre bush support is quite firm, your getting vibration rather than bearing noise and your not getting 'clunking' on taking up drive, or on the over run, then it really sounds like a balancing issue. I'd get your prop balanced and you can check the bearing while you have the prop off the car. If you do want to replace it you can't just pull the bearing off by hand in my experience but you can drift it off by dropping the prop down into a scaffolding tube or other gap (I used my bench vice) that's wider than the prop but narrower than the bearing.

[VolvoRoyS]

The u-joints are OK; there is very little play in the drive train. I think Mike could be right about the prop shaft not being balanced. Since there is one non-standard not and bolt it would suggest that it has been interfered with and did they put it back the way it came off. I have no way of knowing. I might replace all the bolts at the gearbox end where the non-standard bolt is as a simple first measure.

I've never fully understood why the prop shaft should be fitted back the same way at the flanges either end. After all it is balanced off the car. The critical issue I would have thought is that the splines in the centre must go back the same way, as that is the way they are balanced off the car. So my worry is that someone has pulled the splines apart and put them back in a different slot.

Roy

[VolvoFan]

While you're under the car, it would be wise to check the condition of the rear gearbox mount, as the rubber softens with age and oil contamination, leading to excessive movement.

[Army]

Splines:-

If I remember correctly my PV has markings on the two parts that show where the splines should be aligned. I have no idea if that is the case for your vehicle type but I have a feeling Volvo would have been jolly good chaps.

Universal joints (UJs):-

In my experience UJs in situ often "feel good" but it is hard to detect knicks or flat spots in the bearing surfaces. My adivce is to remove the whole shaft and investigate the condition off the car.

Marking flanges:-

I agree that marking the flange positions at the differential and gearbox seems a bit excessive - I mean if you were to put on a new propshaft or replace one section (eg adding in a different longer gearbox which needs a shorter propshaft part), marks wouldn't mean a thing...

...however, from a belt and braces "chasing down the cause of vibration" perspective it is comforting to have a reference point of what you've done. A record of changes is certainly a psychological support to possible "why the eff didn't that fix it" situations (!)

Replacing + refitting:-

A good trick to help with possible vibration trouble after refitting drive train parts is to fit things loosely - roll the car backwards and forwards for a few meters and then with out raising the vehicle tighten support bolts to prescribed torque levels.

[VolvoRoyS]

Originally Posted by VolvoFan

While you're under the car, it would be wise to check the condition of the rear gearbox mount, as the rubber softens with age and oil contamination, leading to excessive movement.

I think this might be it! The rubber mount on the end of the gearbox is resting on the cross member and the studs/nuts are not in line. It looks like the mount has sheared. Brookhouse has one that includes a metal bracket but the chassis numbers quoted don't look like my car's which is 6937 (on the V5C) so don't think it can be that one. Skandix have what looks like the correct part for E24.50 and shows that the two studs should be in line. Anyone any advice on buying this mount?

Roy