centre prop shaft bearing

[rallyboy]

how much up and down play should i have in the rubber on a centre prop bearing?

mine moves alot 15mm each way ish

its all in the rubber not the bearing i have a horrible vibration from the prop but it was home made by the previous owner and just wondering if its his work or the bearings

any help pls

[alexthecheese]

I replaced the center prop bearings the UJ where the prop meets the diff as I was suffering from bad vibration issues. I think the UJ was the source of my vibrations, so get it checked out and replace centre bearings at same time. I got two for about £30.

[not-a-jappa]

Centre bearing rubbers do fail as part of normal wear and tear, the stress in the driveline gives them a real hiding, but how home made is that homemade propshaft chap

If the propshaft has been altered it should have been done in a lathe and balanced afterwards.
Also the UJ's need to be timed when it goes back together so they don't fight each other.

If it wasn't it will shake the snot out of everything, destroy the centre bearing and eventually blow to bits.

I'd be taking the propshaft to a specialist to get it checked.

cheers and good luck.

[rallyboy]

front section is std ford part rear section is td ford part mid section is made / modded to made it longer as the axle was moved back when the chassis was extended to turn it into a car transporter

the guy sleeved one inside the other about 18 inches tacked it through the outer tube by drilling holes in it tacked it at the other end all whilst it was laying in a 2 1/2inch angle iron . checked for straight then fully welded and checked again. the uj's were checked and marked for alingment before and after tacking

so all in all it should be very good

when jacked up and at idle in top gear the centre seems to ossilate a lot thats why i thought maybe centre bearings i cant feel any play in uj's and the middle prop has a bearing at both ends

the only other thing i can think of is the uj's may be tight and rusty and jumpy but will need to un bolt them to check
i just wondered how much play centre bearing rubbers should have

[wexican]

Theres going to be a natural amount of play in the rubber; if the rubber insulation hasnt started to disintegrate or crack or split away from bearing holder, its probably OK.
Sliding spline hardly dried out?
Hope you sort it out

[MrMPuk]

When the prop was extended was it correctly balanced? Any amount of imbalance in the prop shaft with result in vibration.

[not-a-jappa]

In the "technical how to" section, back in July 2005 Baconsdozen put up a post on checking and balancing a propshaft at home, theres also one there on fitting an overdrive gearbox that includes shortening a propshaft using a method similar to yours.

Personally I'd be happier doing these jobs in a machine shop, but the methodologies posted are sound, and I have seen shafts balanced successfully with jubilee clips so long as you can get them to stay in place.

Notably on the last "warrant of fitness" (MOT in UK) inspection report on my work ute the inspector has flagged the centre bearing as being marginal for movement, this at 80,000km.

15mm each way sounds like replacement time, you just need to be sure that its mileage related and not a propshaft/UJ problem thats beaten it up.

[rallyboy]

i did grease both the prop sliders when i did the kingpins which seem never to have been done last weekend.

the rearmost one (centre section) took about 15 pumps of the grease gun until i got black gunge. i kept going until it was relativley clean but havnt had the chance to drive it since as i saw the state of the lhf spring hanger at the same time i dont want to take it anywhere until thats sorted. and to think i just did a 500 mile trip in it only 2 weeks ago

[wexican]

i did grease both the prop sliders when i did the kingpins which seem never to have been done last weekend.

the rearmost one (centre section) took about 15 pumps of the grease gun until i got black gunge. i kept going until it was relativley clean but havnt had the chance to drive it since as i saw the state of the lhf spring hanger at the same time i dont want to take it anywhere until thats sorted. and to think i just did a 500 mile trip in it only 2 weeks ago

Have a look for marks of "missing" weights which should probably on the shafts too when originally being balanced, sometimes they can fly off!

[rallyboy]

update

last weekend i decided to check it all out and found both centre bearings were the same in terms of play and movement

i jacked the rear and ran it in 5th at idle to see what was going on the centre (made up section) had an occilation to it but so did the un modified rear section which actualy looked worse as it was out where it was welded (by ford) to the uj

so i looked at the rear tyres and on the left side both wheels seem to be slightly buckled and the tyres egg shaped but the eggs dont line up with each other if that makes sense

so i am going to "borrow" some wheels from a m8 and see what happens

just an observation i found the lhf tyre had gone like a 50 pence piece and was like a snake when viewed end on so i fitted the spare ( when i did the kingpins) drove it at the weekend also with big temp repair plates tacked on for the front hanger whilst i wait for the new ones and it was so much better i am now after all this not sure its the prop or bearings at all

cant believe i couldnt feel anything on the steering tyre and spring hanger hopefully it will just be tyres on the back!!!