Duff Diff?

sinny · Post by **sinny** » Sun Feb 15, 15 6:08 pm

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?

Pete · Post by **Pete** » Sun Feb 15, 15 6:40 pm

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............

sinny · Post by **sinny** » Sun Feb 15, 15 10:13 pm

Pete wrote:weep slightly and reach for a Guinness............

Story of my life!

ANTON · Post by **ANTON** » Mon Feb 16, 15 7:09 am

The rear diff should only have about 2 litres of oil not 5.

Dave999 · Post by **Dave999** » Mon Feb 16, 15 10:06 am

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

sinny · Post by **sinny** » Sun Feb 22, 15 1:23 pm

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!!!

Pete · Post by **Pete** » Sun Feb 22, 15 1:32 pm

That's good news, you might be able to get someone to swap Pigs to save re-build costs for you both....

sinny · Post by **sinny** » Sun Feb 22, 15 1:42 pm

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.

Pete.S · Post by **Pete.S** » Sun Feb 22, 15 9:27 pm

is the shaft to the left of the picture bent?

or is it just the wall ?

DaveB · Post by **DaveB** » Mon Feb 23, 15 10:45 pm

make sure to put shafts back on the sides you took them from

DaveB · Post by **DaveB** » Mon Feb 23, 15 10:46 pm

Holds about 3 pints

sinny · Post by **sinny** » Wed Feb 25, 15 2:59 pm

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?

Dave999 · Post by **Dave999** » Wed Feb 25, 15 3:38 pm

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

Guy · Post by **Guy** » Wed Feb 25, 15 3:47 pm

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...

Carl · Post by **Carl** » Wed Feb 25, 15 3:57 pm

Agree with Guy and the extra oil pumped in to quieten it down I recon.