Advice needed on Diff replacement or repair

[LTH-00L]

Hi guys,
The Diff in my VY Monaro needs some work and I’m wanting a bit of advice. The car drives fine but the LSD is not working.

Friends I talk to tell me to scrap the original diff and put something else in with different ratios. I personally was going to just get it repaired and be done with it. I don’t want to play around the with the driveability of the car, then not like it and be stuck with it. What do people here recommend? Is it really work altering the diff ratios? What does it do to the driveability of the car? I’ve never driven a car with altered diff ratios. If I do decide to change it, what ratio should I go for?

Also, where would be a good place in Sydney to either replace or repair my existing diff?

Thanks in advance.
CK

[QldKev]

First of all, why is the LSD not working. Is it an oil issue or is it stuffed?

Has it ever worked? Have you had the oil changed, if so what oil is in it?


With the ratio do you know what you have now? Is it a manual or auto. I think most commodores are way tall tall of a ratio and benifit from a change.

A lot will come down to your driving habits. If you drive mainly country you don't want it too short. I live in the country and ended up with a 4.11 and love it. But most of my driving is within 80km/h zones. A 3.73:1 is a great combo for most driving.

On my website I have some info about diffs

home.exetel.com.au/qldkev


QldKev

[LTH-00L]

First of all, why is the LSD not working. Is it an oil issue or is it stuffed?

Has it ever worked? Have you had the oil changed, if so what oil is in it?


With the ratio do you know what you have now? Is it a manual or auto. I think most commodores are way tall tall of a ratio and benifit from a change.

A lot will come down to your driving habits. If you drive mainly country you don't want it too short. I live in the country and ended up with a 4.11 and love it. But most of my driving is within 80km/h zones. A 3.73:1 is a great combo for most driving.

On my website I have some info about diffs

home.exetel.com.au/qldkev


QldKev

The LSD was working but then i did a Drift day at eastern creek and it hasn't worked since. I had it serviced before i went drifting, i'm not sure what oil was put in it but i can find out. i do know that some sort of diff additive was also put in it when it was serviced. It's a manual and has the factory diff in it. Yeah something for combo driving sounds like what i need.

i'll check out your website.. Thanks for the info!

[Toddler78]

3.9 gears in a manual work well. I have 3.9s and a kaaz in my monaro and love it. much nicer car to drive then the factory LSD, more predictable.

there was someone on here selling a whole diff with 3.9s and true trac the other day- might be with looking at, then its just a straight swap over.

the 3.9s will give you more poke off the line

[poolkeeper]

true trac and 3.9s, will be good for drifting and daily street dutys :)

[LTH-00L]

3.9 gears in a manual work well. I have 3.9s and a kaaz in my monaro and love it. much nicer car to drive then the factory LSD, more predictable.

there was someone on here selling a whole diff with 3.9s and true trac the other day- might be with looking at, then its just a straight swap over.

the 3.9s will give you more poke off the line

Sounds good, got any idea how i can find who was selling it?

[QldKev]

The additive was probably Sturaco 7098. Often the mechanic will throw in the full 100ml which in some diffs can cause them for single wheel.

Now that hard part. Is it stuffed or a oil issue.

If it's just an oil issue dropping the oil and starting with a fresh refill without any additive. Then you just add a little of the additive at a time until the chattering of the lsd stops.

If the lsd is stuffed the oil change will not help. Once the oil is dropped you could always remove the back cover and check the lsd for failure. If it's ok then do the refill and hope for the best. If it's stuffed then it's time to change it. Then you can look at the ratios and possibly a better lsd setup. Other people on here may be able to help with better diagnoses of the lsd.

Of course the other option is if you want a ratio change anyway, just go ahead and do it. With a shorter ratio the car will feel heaps more responsive at any speed.

QldKev

[LTH-00L]

The additive was probably Sturaco 7098. Often the mechanic will throw in the full 100ml which in some diffs can cause them for single wheel.

Now that hard part. Is it stuffed or a oil issue.

If it's just an oil issue dropping the oil and starting with a fresh refill without any additive. Then you just add a little of the additive at a time until the chattering of the lsd stops.

If the lsd is stuffed the oil change will not help. Once the oil is dropped you could always remove the back cover and check the lsd for failure. If it's ok then do the refill and hope for the best. If it's stuffed then it's time to change it. Then you can look at the ratios and possibly a better lsd setup. Other people on here may be able to help with better diagnoses of the lsd.

Of course the other option is if you want a ratio change anyway, just go ahead and do it. With a shorter ratio the car will feel heaps more responsive at any speed.

QldKev

Ok, thanks for the info. I know he did put the full 100ml in cos i was there when he did it. I will start with dropping the oil and putting fresh oil in it and go from there...

If i can get a diff with 3.9 in it at a good price though i might just go ahead and do that anyway..

thanks again

[vassis]

Rebuild it mate.With whatever ratio rocks your boat. i put a set of 4.11s with a cam its fine. Mine is manual too 1720rpm @ 100kmh with standard size 17" wheels/tyres. I had an issue where the power of the car was forcing it to spin both and when she clunked it was so bad that the oil i drained out was bright silver and clint at hart transmissions couldnt get it apart. I had to pay more to get a 2nd hand housing and rebuild a 2nd hand lsd unit cause it cracked in half aswell as snapping every bolt connecting the lsd unit inside to the bit that the crown bolts onto. I was going to rebuild it before hand at hart it ended up costing me $550 bucks more than the original quote before i broke it. Save your money and do it now before it becomes a mess like ti did for me and it wasnt pretty when it broke either. That was a standard m6 3.46 lsd diff

Cheers chris