Sway bars and diff

[240znz]

My 71 240 has front and rear sway bars. Were these standard on the early models.

Also, how do you tell the difference between a R180 and a R200 by looking at the rear face plate???? Mine clunks a bit, wonder what is causing that?

[sjcurtis]

Here is, looking from the back LH R200 and RH R180

notice the R200 is larger with a more rounded look.

cheers

Steve:classic:

[240znz]

Any ideas about the sway bars???

[sjcurtis]

I believe the Serial HS30 you have would have had a front sway bar as standard. The rear bar could be an optional one but I do not think it was deliverd like that. You would have to show digital pictures to get a clear idea yes or no for what it is.

For the clunk in the back end, a number of individual things by themselves can give the clunk. Loose top canvas strap (front diff mount), worn diff (increased backlash) failed or failing half shaft universal, drive shaft universals, and the list goes on.

You can check rotating bits easily and also establish backlash conditions in the diff. Best to get it off the wheels with it out of gear and the hand brake off. then play around with the rotating bits feeling and looking for play. Spin a wheel by hand backwards and forwards you should feel the backlash as you change direction.

Hope this helps

Cheers

Steve:classic:

[HS30-H]

Sorry to disagree Steve, but I think the REAR Stabiliser Bar / Sway Bar / Anti-Roll Bar was also standard on the HS30 models.

Sometimes cars turn up without the bar having been fitted, but they have all the stock mount brackets fitted from the Factory - unlike the USA / North American market cars.

This is one of the features that were different between the USA / North American-spec. models and the rest-of-the-World HS30 ( and other ) models. The others differences being the sportier springing and damping, and the five-speed transmission and matching diff ratio that non-USA cars got.

That's good advice on checking out the clonks from the rear, however if its not too pronounced then it might well be a symptom of the R180 diff design itself. Even when new, these cars suffered from the dreaded clonk ( magazine road testers remarked on it ) and this was pretty much down to the design of the R180 and the amount of time that it would take to set up the backlash properly for each unit. The Factory attempted to improve this situation by matching sized components of the diff as much as possible, but basically blueprinting each individual diff would have been too costly time-wise. Some R180 diffs are noisier than others, but they all seem to suffer from a rather complicated design wityh multiple shims under the side covers. The R200 is much easier to set up and has an inherently better design - so they are usually much quieter.

Alan T.

[sjcurtis]

Hi Alan,

I agree with the view every HS30 has provision for the rear sway bar.

Australian delivery appears to have been sporadic with rear sway bars. Both of my Zeds came into my possession with no rear bars. I investigated both sets of mountings appears never installed. On enquiry with local agencies and repairers, RS30 appears to have donated most HS30 rear bars in Australia including mine. As for the early delivery HS30 500 and down I can not offer comment, as I have had not enough exposure.

With the R180 I agree that clonk will always be there in some form and it is amplified in the S30 rear end, due to design considerations.

I guess what is important here is the premis that the clunk will always be there with an R180 in some form. The trick is to determine what is normal for you.

I have found the semi elliptical trailing arm system and rigid front diff mounts on 240K, R30 Skyline and 510 with only minor differences to each other suffered a lot less from the clonk affect ( an exception can always be induced with power application ).

Cheers

Steve:classic:

[HS30-H]

Hi Steve,

Yes - I've heard that some Export-spec. HS30's turned up without the rear bars. Strange isn't it? There must be a story behind that. As far as I can tell, the Australian-market cars were SUPPOSED to have them ( as were the UK-market cars ) but it did not always work out that way.

The parts lists for Japan and the corresponding parts lists for the UK market always have the rear bar in them ( listed as a stock fitting ) and then there was an optional rear bar listed that was slightly thicker. This is quite apart from the Sports Option / Competition parts lists.

There seem to be a lot more unexplained anomalies in spec. and detailing on these Australian and UK-market HS30's than there are on other versions. The UK-market HS30 to RS30 crossover point is a particularly grey area, with many conundrums that can't be solved!

I agree about the clonky R180 diff situation being worse in the S30-series Z cars than in almost anything else they were installed in. It really must be a case of the semi-trailing type of rear suspension on the other models masking the shortcomings of the R180 design. Interestingly, I've noticed that the higher numerical gear you go for in the R180 the more clonky they are. I used to run a 4.875 LSD-equipped R180 for a short while and that was really noisy. My diff rebuilding specialist told me that this would be because the pinion gear was so small and it had so few gear teeth on it. He asked me not to bring any more R180's to him for rebuild, but he doesn't mind doing R200's...............:cross-eye

I guess the most important thing for 240znz to establish is that his clonking / knocking is not coming from something else in the driveline, as you say. If its just the diff, then its probably not going to be a quick failure risk like the other possible causes might be.

All the best,

Alan T.