Diff Question

vesssh · 27-06-2012, 09:41 PM

My AUII XR8 ute has a slight whine coming from the diff. I have heard mixed thoughts from different people.
Some say to learn to deal with it as all Ford diffs whine, other have said to just change the diff oil. When going to the wreckers today to pick up my new rotors I asked him if changing the diff oil would make a difference, he said probably not. He reckons the diff could go at any time . . .

He suggested that when it comes time to get a new one that I should look at getting my diff built with EF gears as he said they are a lot stronger?? He said that the ratio will still stay at 3.45 and will obviously still be LSD.

Has anyone ever heard of this before?

Also, is a 3.45 ratio diff good for towing?

Cheers in advance

Gaz · 28-06-2012, 12:22 AM

Step 1 - Ignore wrecker
Step 2 - Put in Castrol SAF-XA

T2TICK4D · 28-06-2012, 01:00 AM

i also have a wine coming from my au xr diff some have said mate its gone then some have said just service it

mik · 28-06-2012, 01:34 AM

the statement all ford diffs whine is a load of crap mate, on occasion there has been the odd complaint in some models about backlash, whine is not normally a problem, mine has 200,000 hard k`s still going strong, no idea about the ef gears thing.

vesssh · 28-06-2012, 09:32 AM

I will leave it for now. It whines a bit going forward, the whine increases when I reverse.
I will change the oil over the weekend and see how we go.

Mr Hardware · 28-06-2012, 04:07 PM

nearly every time someone says that their diff whines they'll find that it's actually the BTR auto that has the whine sound.
occasionally the ford diffs will develop a hum from worn bearings but not usually a whine

vesssh · 28-06-2012, 04:40 PM

I am getting my transmission serviced next week, so hopefully that eleviates that problem.
The transmission changes are very smooth

TheSly1 · 28-06-2012, 04:49 PM

my AU S3 has 335km on it, the only time i notice\d diff whine is when coming off the freeway and off the throttle and no brakes and the engine is coming down, a oil change in the diff to the proper 90w/130-140w whatever the correct oil is has fixed the problem this has happend on multiple occasions (ive had the car since 180km) the wrecker is an idiot..

vesssh · 28-06-2012, 08:36 PM

The wrecker said that when the diff fails it will just lock up, I hope this isnt true as the only time I drive my ute is when I tow my race car . . .

BHDOGS · 28-06-2012, 09:22 PM

Put a banana peel in it

Sox · 29-06-2012, 09:25 AM

Quote:

Originally Posted by vesssh

My AUII XR8 ute has a slight whine coming from the diff. I have heard mixed thoughts from different people.

A very slight whine may be normal for it's ages.

Quote:

Some say to learn to deal with it as all Ford diffs whine, other have said to just change the diff oil.

Both have some truth to it.

Quote:

When going to the wreckers today to pick up my new rotors I asked him if changing the diff oil would make a difference, he said probably not. He reckons the diff could go at any time . . .

That's the most unlikely.

Quote:

He suggested that when it comes time to get a new one that I should look at getting my diff built with EF gears as he said they are a lot stronger??

Complete bollocks, the gears are identical.

Quote:

He said that the ratio will still stay at 3.45 and will obviously still be LSD.

That's true.

Quote:

Has anyone ever heard of this before?

Only from a shonk.

Quote:

Also, is a 3.45 ratio diff good for towing?

Yes, they'll be ok.
Obviously the shorter the better.
Most cars are geared quite tall for economy and noise regs. Not good for hill starts when towing.

Depending on how much towing you do, 3.7 or even 3.9 gears might be more suitable.

I wouldn't worry too much about the whine though, they need to be making quite a racket before they're close to failure.
Changing the oil can't hurt though.

Mr Hardware · 29-06-2012, 10:14 AM

Quote:

The wrecker said that when the diff fails it will just lock up

I've seen dozens of cabs cover half a million kays each, never ever ever heard of this happening.

Sox · 29-06-2012, 03:58 PM

bartsau · 29-06-2012, 05:04 PM

Having busted a non LSD 3.23 diff and a 3.45 LSD diff I can tell you with certainty they will give plenty of warning they are on their way out. There will be a whine which will get more constant and louder and then the clunking as there is slop/play in the diff and at this point it will start off very slight until you feel it through your bones on each gear change/kickdown etc.

There was 1 stupid event which took years of life out of my first diff and the LSD...well it coped an absolute thrashing over 2 years plus some 35 1/4 mile passes with hard launches some on slicks.

Looked after and not thrashed I feel the standard diff should live for a long time without any issues.

When mine were on there way out I changed the oil regularly and I feel this certainly prolonged the life of them.

Mainlube · 02-07-2012, 11:47 AM

Diff whine is a miss match between the crown wheel and pinion.

Unless extremely bad (mothers grabbing kids ears on the foot path) it shouldn't shorten the life of a diff, generally doesn't cause excessive wear, only to your ears)

Our Group 4 super oils don't have a history of reducing diff whine, they're too thin.

You need oils school straight SAE 140 E P gear oil to quieten a diff much at all, it's a suck and see thing.

Cheers

Steve