VY SS ll 3.46 Diff making whinning noises???

[vykm90]

Hey People,
I have a VY SS Series 2 6 Speed 5.7Litre with 3.46 Ratio.
The Diff whines once moving sounding like a plane taking off as my mates put it (electric motor kinda sounding noise). it becomes louder under deceleration and basically the faster i go the louder it gets.
My question is, What is it in the diff that is stuffed?
and also if sumone could write up or send a link of removing and re-installing a VY 3.46 diff

Thanks kieran

[ARATIC]

How do you know its the diff? It could simply be a wheel bearing

[chevy_big_block_bro]

I have the same problem with my YV SV8 tonner. Its painful but you do get used to it after a while.
Diff guy said a good tightening should fix it.

They're easy to remove without removing the whole rear crossmember

From memory, remove the tail shaft and both axles from the diff.
Remove the rear rubber bush that holds it up.
On top there are 3 or 4 bolts (cant remember how many) but they can be removed with patience (17mm spanner or cut down socket from memory or might be 15mm)
They're a pain to remove but as i said, i've done it without dropping the whole rear end when i put an LSD in my old VT (same setup as VY)

[Calaber]

Hey People,
I have a VY SS Series 2 6 Speed 5.7Litre with 3.46 Ratio.
The Diff whines once moving sounding like a plane taking off as my mates put it (electric motor kinda sounding noise). it becomes louder under deceleration and basically the faster i go the louder it gets.
My question is, What is it in the diff that is stuffed?
and also if sumone could write up or send a link of removing and re-installing a VY 3.46 diff

Thanks kieran

Keiran

To help assess whether the diff is at fault, try this simple test.

1. Drain the old oil and replace with the correct grade (LSX90 if its an LSD) to the point where the oil starts to run out the filler hole.

2. Drive the car along a smooth road at a constant speed, say about 80kph, with stereo turned off and windows closed. You need a smooth road to eliminate as much tyre noise as possible.
3. Lift your foot off the accellerator and let the car decellerate to about 60kph - does the noise disappear suddenly or remain the same?
4. Accellerate again to 80 and check the noise.

If the noise disappears when you lift your foot off, it will probably be the crown wheel and pinion, which could either be worn or needing adjustment. Adjustment is carried out by shimming the diff centre and pre-loading the pinion - a diff specialist would be best for this job.

If the noise doesn't change, it could be either wheel bearings or tyres. Are you running a cheaper brand of tyre probably made in China or elsewhere in S E Asia? They tend to get pretty noisy, especially when they are nearing the end of their tread life.

If you can do so, change your rear wheels with someone to see if the noise changes with the alternate wheels. If it does, you can be pretty certain the noise will be due to the tyres. If not, the bearings would be suspect.

I don't think it will be the pinion bearings - they tend to grumble when they are knackered, not whine.

[colgf]

Buy yourself a Haines Workshop Manual , has a great section on removing diff. The mount bolts above the Rear Cradle are hard to get to without dropping the Rear Cradle down a couple of inches. Also you need a special C spanner to undo the Bearing Caps either sides where the axles enter the diff. These caps are the ones that double as the preload adjusters for the crown wheel /pinion. LSD Holden Diffs are notorious for Whines. Try a cheap alternative drain the oil & put 2lt bottle Penrite HP 140 LSd Diff oil + Penrite LSD small bottle of additive in it . (Avail from AutoBarn Stores-may have to order the additive in) Total cost about $45 . It does quieten them down a lot . I have heard fully overhauled LSD's still whining after installing so really , very hard to totally silence . The preload can be adjusted without removing the diff but it needs a deft hand to get the load right, diff specialists have the knack of knowing how to tighten the caps just right amount. But a novice will be hard pressed to fluke it first go. ( How do you know your with a Qantas Cabin Crew when you arrive at the terminal from a flight? - Easy, the Whining sound is still heard even after the engines are shut down!!!!!)

[Sean880]

LSD Diff Oils for VY Models.

Re the above post. For the record Penrite does NOT recommend their HP140 diff oil for these LIMITED SLIP DIFFS.

I had extensive communication with both the Penrite and Castrol technical people a few weeks ago on the correct oil for these VY LSDs. This Penrite HP 140 is a mineral oil and ONLY the fully SYNTHETIC oil is recommended by Penrite for these diffs. Castrol was also quite adamant that only their fully SYNTHETIC diff oil was recommended for these VY LSDs.

Both companies also indicated that this was also consistent with the GMH specification for these diffs - ie. you must ONLY use the recommended correct grade SYNTHETIC products for these diffs.

The SOLE diff oil recommendation from each company for the VY LIMITED SLIP DIFFERENTIALS was:

Penrite: SIN Gear Oil 80 - this is a 80W -140 graded fully synthetic oil (do NOT use any additive - it contains a friction modifier)

Castrol : SAF-XA - this is also an 80W-140 graded fully synthetic diff oil. (Do NOT use any additive in this oil).

If you have a different view on the correct oil for these VY LIMITED SLIP DFFS I would suggest readers contact the technical departments of Castrol and Penrite yourself.