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Duff Diff?

Posted: Sun Feb 15, 15 6:08 pm
by sinny
I'm still trying to track down the cause of a major vibration at over 60mph.

I've norrowed it down to the rear end so pulled one of the half shafts & about 5 litres of horrible, very very thick burnt smelling oil poured out.

I filled the diff up with limited slip oil last year as it was almost dry.

This normal?

Posted: Sun Feb 15, 15 6:40 pm
by Pete
Perfectly normal, they came out the factory like that!!!

It May / many not be the cause of your vibration, but I think you have something else to spend your hard-earned pocket money on......shafts out, prop off(again, probably...) Pig out and examine, then weep slightly and reach for a Guinness............

Posted: Sun Feb 15, 15 10:13 pm
by sinny
Pete wrote:weep slightly and reach for a Guinness............
Story of my life!

Posted: Mon Feb 16, 15 7:09 am
by ANTON
The rear diff should only have about 2 litres of oil not 5.

Posted: Mon Feb 16, 15 10:06 am
by Dave999
check the uni joint at the diff end is seated properly

undo it

be careful not to let the caps fall off...the rollerers will fall out

check that both caps still have their snap ring on and it is seated in the groove

turn both caps round so that the back of the snap ring is facing into the diff yoke

tap it gently back in making sure the cap snap rings seat inside the yoke saddles and do up the straps to very-short-spanner- in -my- left hand tight. inch lbs not foot Lbs

if you wanted to you could spin the wheels while the tail shaft is down and just check the center of the diff yoke nut stays in the center as the pinion turns

a diff that has had the rear end of the tail shaft grounded can suffer from a bent pinion.

diff oil and gearbox oil always stinks....

try getting it all over your head...the smell stays with you for about a week regardless of how much swafega and head n shoulders gets used.

dave

Posted: Sun Feb 22, 15 1:23 pm
by sinny
Well I've pulled the other half shaft & diff but can't see any issues. How likely is it that it's too much bad oil that's causing the over 60 mph bad vibration (more like a pulsing)?

I'm thinking of dropping the gears from 3.91 to 3.23 while I've got it out as she's not going to be used on the strip. That is if I can get the dam uni joint bolt undone!!!

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Posted: Sun Feb 22, 15 1:32 pm
by Pete
That's good news, you might be able to get someone to swap Pigs to save re-build costs for you both....

Posted: Sun Feb 22, 15 1:42 pm
by sinny
Pete wrote:That's good news, you might be able to get someone to swap Pigs to save re-build costs for you both....
Dam good idea Pete. I've put a post in the wanted section. :thumbright:

Posted: Sun Feb 22, 15 9:27 pm
by Pete.S
is the shaft to the left of the picture bent?

or is it just the wall ?

Posted: Mon Feb 23, 15 10:45 pm
by DaveB
make sure to put shafts back on the sides you took them from

Posted: Mon Feb 23, 15 10:46 pm
by DaveB
Holds about 3 pints

Posted: Wed Feb 25, 15 2:59 pm
by sinny
I think the passenger side one (left of the picture) MIGHT have a very slight bend at the hub.

Yes Dave I've marked them so I know which side the came out of but may need a new passenger side one - need to have a good look at it over the weekend.

I'll also get the 3.23 gears in to hopefully improve the driving comfort over the 3.91's.

Measured the oil out of the diff & there was over 5 litres, how is that possible if it should only hold 3 pints?? Is there a seal to pervent the oil going into the shafts?

Posted: Wed Feb 25, 15 3:38 pm
by Dave999
you want the oil to go along the shafts to oil the wheel bearings

and flow back along the tube

surprised you didn't have it comeing out the breather by the brake pipe junction.

if shaft is bent, did you get a replacment?

Dave

Posted: Wed Feb 25, 15 3:47 pm
by Guy
If your shaft is bent that will cause your vibration more so if it is bent past the wheel bearing, sounds like it may have clobbered a kerb at some point...

Posted: Wed Feb 25, 15 3:57 pm
by Carl
Agree with Guy and the extra oil pumped in to quieten it down I recon.