4WD front diff , help needed pls.

[jonah]

After picking up my 96N Bongo the front diff popped on the motorway on the way back to mine.
I sourced a diff and had it fitted by my local garage, used the van for 800kms, trip to brixham included up and down the M5, on the return leg of the journey smell of transmisson fluid in the cab, checked underneath and yup, diif seals popped again, i haven't had the bongo above 80mph, generally around 70-75mph on the motorway, traffic permitting!
I'm really not at all mechanically minded and have no hope of fixing myself.
Does anyone know of a bongo friendly 4WD specialist in the west midlands ideally, but will travel for piece of mind and just get the underlying fault cured?

Any advice, input or ideas would be greatly appreciated.

Thanks

[waycar8]

if its done it twice chances are the viscous coupling is fubar, (back end of the gearbox), loads of info in the search facility.

What size wheels/tyres you running on your bongo?

[bigdaddycain]

Does anyone know of a bongo friendly 4WD specialist in the west midlands ideally, but will travel for piece of mind and just get the underlying fault cured?

Any advice, input or ideas would be greatly appreciated.

Thanks

I know that Mike at Wheelquick would have replaced the whole axle... Quite possibly for the same £££'s as you paid for the diff alone. There (i suppose) would have been less chance of a failure had the diff not been cracked off one axle, then replaced onto another...Did you see the old diff seals lying around at the garage jonah? They would have replaced the seals i would imagine?

[jonah]

Waycar8 , i'm running 215/70r15 on the front & 215/65r15 on the rear.

BDC, the whole unit was replaced (sourced from Ian Taylor) and bolted direct onto the axle, i wasn't around when the repair took place so have no idea if the seals we're replaced, but the mechanic assure's me they we're.

I've been on the phone to Mike at wheelquick and the 1st thing he asked was about the tyre size, the sizes above give a tolerance of 3%, Mike seems to think that it should be nearer 0.7%, this may be the problem.
i'm waiting on a call today from Mike to see if he can help me resolve the situation.

Would using the hold button on the gear stick whilst doing 20mph down a steep hill have an adverse affect on the Diff?
Is a motorway speed of 75-80 mph too much for the Bongo? (this is the speed i've been travelling at both time's when the diff has popped)

Thanks for taking the time out to reply, i would have posted sooner but i've been working lot's to pay for my new Bongo habit!!

[francophile1947]

A 3.18% difference in tyre sizes will certainly wreck your viscous coupling and won't do the axles a lot of good at all Who fitted those tyres? The front ones should be 195/70, but loads of us fit 215/65 all round. Whatever you do, change the tyres before you waste any more money on axles etc.

[missfixit70]

The use of the hold button & 75-80mph should not cause any problems (other than being illegal of course ), definitely get the tyres sorted.

[jonah]

A 3.18% difference in tyre sizes will certainly wreck your viscous coupling and won't do the axles a lot of good at all Who fitted those tyres? The front ones should be 195/70, but loads of us fit 215/65 all round. Whatever you do, change the tyres before you waste any more money on axles etc.

Noted. and in process of contacing vendor to get some answer's...

[jonah]

The use of the hold button & 75-80mph should not cause any problems (other than being illegal of course ), definitely get the tyres sorted.

Thanks for the clarification and LMAO

[missfixit70]

On the subject of hold button & speed, if you try & put it on at speed that's too great for the 'box to handle, it shouldn't let you, tried it on mine, in D I think it has to be at 68mph or below before it'll let it kick in (3.5 -4k rpm? can't remember exactly), similar revs with appropriate speed in S & L, sorry, slightly off topic I know.

[waycar8]

Since you have already gone through 2 diffs already, hopefully the diffs have taken the brunt and the viscous coupling should hopefully be ok , heres how to check it, thanks To DemonAV for the info

You need to raise one of the front wheels off the floor and using a torque wrench turn it 90 degrees with a force of 59 Nm or 6.0 kgf-m. with 1 turn of 90 degrees should take around 30 seconds, any longer then the viscous coupling is on its way out and the diff may pop again.

Wether changing the front tyres will stop it popping again is another story, Dandy is the main man in regards to the workings of the viscous coupling

[dandywarhol]

Check the breather isn't blocked with underseal......................

Part 26060 - it just prises out.
http://www.lushprojects.com/bongoparts/ ... WD).html#4

[jonah]

Some great advice come out of this thread, unfortunately when it come's to hands on mechanics i'm about as usefull as a bongo temperature gauge!!, it has however enabled me to gain an understanding of the issues i'm faced with and possible solutions, and for that i'm gratefull, thanks all.
I've taken the rather expensive decision to have the Bongo transported down to Bellhill for a full diagnosis and health check, yes could prove expensive but, my skills are better applied to my own job to generate funds and leave the experts to do theirs.

Hope to see some of you at meet in the not too distant future....

Clive

[dandywarhol]

Keep us posted.....................