Bongo Fury

Loud graunching noise whilst turning (forward/reverse under load) yesterday afternoon then lots of vibration.

New set of rear tyres fitted on Tuesday (less than 24 hours prior to bearing failure)

Diagnosis at garage...rear propshaft bearing collapsed (again) and splines 'locked'.

New rear propshaft needed...meanwhile ok to run 2 wheel front drive only.

Any suggestions as to underlying problem.

Rear propshaft: all bearings replaced June 2006. Warned of slight play in splines.

Front propshaft: front end bearings replaced May 2007 and those that wern't replaced first time replaced Oct 2007.

Van has done 213,000km (128,000km since August 2005)

Advice/opinions welcome.

H

Hi Harry
Has the propshaft become slightly bent during a wee "offroad" excursion, or , maybe the diff has moved sufficiently to cause a mis-alignment putting a constant minor strain on the shaft bearing, and premature failure. Sometimes even minor mis- balance of the shaft can do it.
Cheers
Helen

Bet the viscous coupling enjoys that.

You beat me to it Ralph - I've been saying V.C. at fault with Harry's for yonks now...................

Remember THIS

.........and THIS

THIS is an excellent way of checking it courtesy of Demon.

Test carried out by a transmission specialist as per instructions a month or so ago.

Test was good and transmission specialist confirmed that the viscous coupling was in perfect working order.

Back to the drawing board

H

I was thinking more like with the rear prop disconnected
all the power and torque will be going through the coupling,
and the chain in the transfer box.
A light foot is needed me thinks.

Yep...a light touch is required...and not too heavily loaded around the Lake District lanes.

Got back from NW Scotland minus rear propshaft and with 5 passengers and towing a luggage trailer in May 06 without any problems.

Don't intend to keep it front wheel drive for very long...just until I can get a new/recon rear shaft...then I might consider making it rear wheel drive only.

H

Hi Harry


Wounder why it's doing them? we had a wagon many years
back it could do a prop shaft once a month, a old and wise
mechanic said move the center bearing out of line we did
and it never did another, exactly the opposite to what you would
think if it's dead in line it gives the prop more stick than running
a bit off.

Does your gear box change gear with noticeable thump it
could be transmitting shocks to the prop.

Could the flange on the back axle be running out in some
way? cant think of anything else.



Have the revs changed much running on the front only?
must be some slip from the coupling ?

Sorry Harry - didn't realise you had the VC checked.

Do all the propshaft "yokes" line up? I've only ever seen one where there was a twist in the shaft.

I wonder if it's possible that at some time the FRONT propshaft has been wrongly assembled at the point where nut number 99922 - 1800 attaches and causing a vibration/stress?

God your good Dandy.. Where else can you get such blummin good support. Well impressed with your time and effort.

Brilliant

blushing now

I still think Ralph has the clue here. I know you say you've had the viscous coupling checked Harry but if you're putting all the drive through the front wheels again and there's no "lag" or "slip" then I still suspect the VC.

It's my understanding that when the VC fails the gel inside loses its viscosity and becomes to all intent and purpose a solid drive - this then knocks hell out of the tyres and prop/driveshafts. It'll eventually wreck the diffs!

Fitting the new tyres prior to failure also takes me back down the VC route. 4WD should have all tyres changed at the same time - otherwise the VC gets a harder time. If the viscous fluid isn't doing it's job then the tyres/propshaft joints take the strain.

No matter how gentle you drive it, putting all the available torque through the VC will bugger it - especially in the lower gears. In first gear your putting nearly 4 times the torque through the driveline - and with max. torque at only 2000 rpm it'll soon produce it! If it can't get to the rear diff, it'll try to put it all through the viscous fluid and it'll damage it.

Sorry to keep on rambling about this but I have my hunches about this................

Thanks onc again for your comments...particularly dandy & Ralph.

I too am coming more and more convinced that all is not well with the viscous coupling.

The big problem is going to be finding a reliable transmission specialist to re-check the problem then sort out getting a replacement. My regular garage would not take it on.

The van is my livelyhood so I can't afford to not have the use of it of a courtesy van whilst it is being sorted.

H

Somewhere on here is a message telling how to check the
coupling it gives a torque setting at which the thing should slip
think it was from one of our Russian members.

Sorry, can't offer a solution but I take my 4wd to the local
Landrover specialist ( not main dealer ) because they know
about 4wd systems ( obviously )
From what I've learnt the Freelander uses/used a similar set-up.
That's notorious for having vc problems.
Also classic Rangerovers used to have vcs too.
I noticed my local place had these vehicles around it's workshop ( as opposed to lots of Defenders for example ) so initially took
the Bongo there. Been happy with them so far.

I haven't really read your whole story of drivetrain probs so
probably you've already checked out most options.
Hope you find a definitive cause but could come down to the milage
and strains on the system you inevitably do .

Good luck with it all

Just a thought, but there was a recall for Bongo's for the front prop shaft. Mine was replaced by a Mazda dealer when I got it.