240z diff replacement or refurbishment?

[jonbills]

Out of interest could a different oil cause the diff to whine? I changed mine recently to manoil (cheap but had good reviews) and after it had more noticeable whine when driving.

Coincidentally, I just switched my gearbox to Mannol and it reduced the noise. hmmm......
Many people on the internet seem to swear that switching to Redline MT90 cures all gearbox and diff ills.

 

[arcdef]

Lol yeah as I said it's got very good reviews. Probably more down to me being extra vigilant after doing the work.

The mt90 oil is super expensive compared to most others especially the manoil!

 

[uk66fastback]

Makes sense to try and cure the diff whine if all the other stuff is out already. If you do what you can to find a cure and it goes back in - maybe with that final drive ration changed - and it still whines, at least you'll know you tried!

 

[Graeme - CZ]

Out of interest could a different oil cause the diff to whine? I changed mine recently to manoil (cheap but had good reviews) and after it had more noticeable whine when driving.

Really not sure. I’m using a Millers Differential oil for classic cars. Definitely worth while doing to research on oils. I use Redline in the gearbox, as I have a US car. Also, there are some differences in oil choice depending on whether you have a EU car or US car - different components apparently. Cheers, Graeme

 

[Graeme - CZ]

Makes sense to try and cure the diff whine if all the other stuff is out already. If you do what you can to find a cure and it goes back in - maybe with that final drive ration changed - and it still whines, at least you'll know you tried!

Any idea how hard my diff will be to detach from the prop shaft? It’s not jacked up super high, so wondering if I may have a challenge disconnecting it in it’s current orientation.

 

[jonbills]

Any idea how hard my diff will be to detach from the prop shaft? It’s not jacked up super high, so wondering if I may have a challenge disconnecting it in it’s current orientation.

4 nuts. Tt can be a bit fiddly and you may want to remove the ARB (if you have one) to improve access.

 

[Graeme - CZ]

Can you remove the Diff on a ramp, e.g. leaving the wheels on the car? Wonder if it’s a take the car somewhere and they remove Diff / do rebuild and then put it back. Or is this definitely a “i have to take it off myself”, which is definitely going to be pretty fiddly to get to the prop shaft given I do not have the car super high at present. Any tips on removal?

 

[MaximG]

Can you remove the Diff on a ramp, e.g. leaving the wheels on the car? Wonder if it’s a take the car somewhere and they remove Diff / do rebuild and then put it back. Or is this definitely a “i have to take it off myself”, which is definitely going to be pretty fiddly to get to the prop shaft given I do not have the car super high at present. Any tips on removal?

Hi Grahame, it kind of depends, as a minimum you need to disconnect the drive shafts at the diff, anti role bar needs to come off to get to the prop shaft bolts. The diff carrier front member bolts x 4 need to be removed which also means the Inner front transverse link inner bolts need to be loosened. Diff Carrier to moustache bar nuts need to be removed. The nose of the carrier can then be dropped slightly and shifted toward the front of the car. When it’s free it can be dropped down on the supporting trolly jack. At this point you can either drop it off the jack onto the floor and extract it or leave it on the jack and pull it out on the jack as long as you have enough height. Because the diff needs to move forward you might have to take the prop out depending on room I didn’t so I had to take most of the exhaust off.

 

[Graeme - CZ]

Hi Grahame, it kind of depends, as a minimum you need to disconnect the drive shafts at the diff, anti role bar needs to come off to get to the prop shaft bolts. The diff carrier front member bolts x 4 need to be removed which also means the Inner front transverse link inner bolts need to be loosened. Diff Carrier to moustache bar nuts need to be removed. The nose of the carrier can then be dropped slightly and shifted toward the front of the car. When it’s free it can be dropped down on the supporting trolly jack. At this point you can either drop it off the jack onto the floor and extract it or leave it on the jack and pull it out on the jack as long as you have enough height. Because the diff needs to move forward you might have to take the prop out depending on room I didn’t so I had to take most of the exhaust off.

Thanks for the tips. Had a look at it today, but think I need a ramp / pit to get it off safely. Think I’ll pack that for now, and come back to later. About to replace all the spider bearings on the shafts, along with rear wheel bearings. Hoping that might improve some of the whining.

 

[Graeme - CZ]

Quick question. Is this an R200 diff? I’ve got a 280z engine / gearbox, so would make sense if i had the full 280z drive train.

 

[Huw]

If the drive flange have a big bolt head in the middle - R180.