A little advice about LSD please.

O

oz-ting

Well-Known Forum User
My first problem is I have a bit of vibration on the drive coming from the rear of the car under excelaration and what sounds like prop clonk. I have paperwork which suggests the car has over 200 bhp at the wheels and 276bhp at the flywheel. So if it has a stock 240 diff and being a 71 car there is a good chance the diff has had it, maybe? Ujoints also.

Can anyone tell me if it is possible to tell what diff I have in the car by looking at it? The Diff that is not the car!
Is there a LSD I can put in or have put in easily which will handle this and more power?
I spoke to these people but they don't install just supply.
http://www.quaife.co.uk/product_search.cfm

I have read good things about their diffs though.

:conf2:
 
LSD & Prop clonk

Last time I experienced Prop clonk was in a MG MIdget, my first venture into open top driving.

Turned out to be the roller bearings in the prop shaft universal joint, and was easily rectified at reasonably low cost.

As for LSD - well! Comes in various forms I believe - sorry can't offer any more advise on that line!

Hope you sort it quickly and cheaply.

bbpete
 
Thanks, I feel that could be the cause myself I will look into the prop in the mean time.
Saw your 350 in your Gallary. looks cool! Keep thinking of getting one but might find it hard to have a good reason for another car...
 
I think prop clonk is a common occurence. The vibration may be due to a worn differential mount bushing. I think that the diff would whine if it was on its way out and yours doesn't do that.

The R200 is chunkier then the R180, thus can take more power but that doesn't help much if you haven't seen either to compare.

The easiest way to determine if you have an R200 is to look at your moustache bar, if it goes behind the two vertical bars coming down would mean you have an R200 installed, if it goes in front of the two bars - then it's an R180.
 
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check for worn universal joints before thinking about the diff,you could always see if the diff needs topping up with some new oil,if you drain it you will know if it is low by the amount of oil that comes out, should be about 1 ltr.either that it might be your gear box ,out of balance prop shaft or even the rear wheels not balanced.
 
I spoke to these people but they don't install just supply.
http://www.quaife.co.uk/product_search.cfm
Click to expand...

I have one of their units in the back of my car....they installed it in the diff casing:conf2:

If you dont fancy an ATB there are a number of plate LSD's around, already fitted into diffs.

With all that power you will need something a little more substantial than an open diff.

Plus its also a statute in Z club law that when you have that sort of power you have to go to the local drag strip and stake your claim in the Hall Of Fame with a pink slip, where abouts are you located, are you in the UK if so the next one is September the 2nd at Santa Pod
 
SKiddell said:
I have one of their units in the back of my car....they installed it in the diff casing:conf2:
Thats interesting they refered me to Fourways for having it fitted. I will get back to them.

If you dont fancy an ATB there are a number of plate LSD's around, already fitted into diffs. ATB?

With all that power you will need something a little more substantial than an open diff. Its early stages but I am looking at tuning the car further once I have the drivetrain and a few other bugs sorted so I am keen to get something up to the job now rather than change it again later.
Plus its also a statute in Z club law that when you have that sort of power you have to go to the local drag strip and stake your claim in the Hall Of Fame with a pink slip, where abouts are you located, are you in the UK if so the next one is September the 2nd at Santa Pod
Click to expand...
I hear you and once the car is ready I will be bringing it out to hopefully claim a place.. I am away this early Sept too.

I gather that R200 diffs are hard come by?
Do you or anyone know of a diff specialist who could maybe sort out the ratio's too?:)
I'm in South London
 
R200's are not that hard to come by, as they were standard in most manual 260Zs as well as the manual 280ZXs. They came in different ratios, try and find the one that suits your application. The 3.9 R200 normally has a premium to the taller ratios (smaller number eg 3.7,3.54, 3.36 etc), as it's the one that most people look for. Depends what you want really. The higher the number means the quicker the acceleration but the poorer the top end speed will be, so motorway cruising will be compromised. The smaller the number will have the reverse effect.

If you do plan on upgrading your diff for an R200, then start looking for a moustache bar from a 260Z, you'll need it to replace yours on the 240Z as the 260Z bar will allow the slightly bigger R200 to sit forward and thus fit. An alternative would be to buy a nice new billet moustache bar from Arizona Z car, the advantage is that most used moustache bars may be showing signs of wear.

Other alternatives include new stronger thicker moustache bars that the rally boys use - not sure where they get them from though, maybe Japan??
 
Thicker moustache bars are available from KEW (Kameari Engine Works) in Japan.

Ref the clunk
Check the diff mount for separation of the rubber.
Spanner round all nuts & bolts on prop, half shafts (both ends) moustache bar mounts, diff to moustache bar nuts, check for excessive spline play in the stub shafts. Its common to have excessive backlash on the diff, a road test report from the early 70's mentioned excessive lash so it can only get worse with time.

Ref Quaife
Its quiet possible that they dont do this service anymore, or it maybe that when they refer to an "Install" they are refering to actually fitting the diff in the car, which is easy peasy and can be done by most competant DIYers.
 
R200 diffs available for sale soon in 3.7 and 3.9 ratios with plate type LSDs already fitted. Moustach bar available to suit as well. And with the correct rear cover and output half shafts to match the 240 hubs. ;)
 
SKiddell said:
Thicker moustache bars are available from KEW (Kameari Engine Works) in Japan.

Ref the clunk
Check the diff mount for separation of the rubber.
Spanner round all nuts & bolts on prop, half shafts (both ends) moustache bar mounts, diff to moustache bar nuts, check for excessive spline play in the stub shafts. Its common to have excessive backlash on the diff, a road test report from the early 70's mentioned excessive lash so it can only get worse with time.

Ref Quaife
Its quiet possible that they dont do this service anymore, or it maybe that when they refer to an "Install" they are refering to actually fitting the diff in the car, which is easy peasy and can be done by most competant DIYers.
Click to expand...

I just heard from a guy who knows abit of the cars history and he said he thinks its a Diff from 280ZX auto and was I think the 3.54. It dosn't wine either so that is probably fine.

I will check all the bits you mentioned and I love the look of the arazona stuff and will consider it later.

I reckon your roght about the Quaiffe guys. So I will speak to thenm again.
You happy with yours then? No probs?

I need to get the Mot done in a month and the local Datsun Guy loves 240z's and has been a star when it comes to help so I will get him to throw it on the ramps so I can have a good look.

Thanks for the help.

Austin
 
So to recap!
If I want to get an improvement via LSD I need a R200 diff from a 260
Pmac, Are you selling some, one? If so how much? You can email me you should still have my email.
Thanks for the input Mike I wouldn't have known it was a R180 and would have presumed it a R200.
I think I am going to put in a T5 cosworth box and get the prop done to suit so that should iliminate any Prop problems. (Good advice from Wyn).
So am I missing owt!

:thumbs:
 
oz-ting said:
So to recap!
If I want to get an improvement via LSD I need a R200 diff from a 260
Click to expand...

No, you just need an R200 diff from a 260Z or a 280ZX. But if you get one from a 260Z you will have less hassle as the rear cover on the 260Z diff will have no clearance issues when fitting it to your 240Z, but the diff cover on the R200 as found on the 280ZX is larger and you will have clearance issues.

The diff covers are interchangeable so that if you had a ratio you liked from a 280ZX R200 diff you just need to source a 260Z R200 diff "cover" and swap it and you're done.
 
SKiddell said:
.......Plus its also a statute in Z club law that when you have that sort of power you have to go to the local drag strip and stake your claim in the Hall Of Fame with a pink slip.......
Click to expand...

Oh yeah ?:rolleyes:

Quaifes are for pussys !
 
Quaifes are for pussys !
Click to expand...

There you go aint, talkin about stuff you have'nt got a clue about.
Quaifes are for quick cars brother....and seeing as you aint quick, you dont need one.
 
I will leave you two to it. As I am sure this will now turn into something else. Thanks for all the input I have come to what I feel will be the best for me and the car

Regards

Oz.:)
 
I don't know much about LSD's but my Brother does.....he tells me not to get a Quaife as the way they keep the other wheel in traction is through gears in the dif and under some situations they don't work properly. Clutch LSD is the way to go (Apparently)
 
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