Restoration of BringaTrailer 240z - HLS30-35883

[Captain Obvious]

10 hours ago, inline6 said:

I started with the rear struts.  Each one calls for 50 ml of non-freezing liquid.  I used a 50/50 mix of distilled water and antifreeze.  I think this helps with heat transfer from the Koni insert to the outer strut tube. 

Maybe it's just me, but there's no way I would put a water based liquid in there. Yes, with antifreeze, it won't freeze, but there's just no way. I'd use something petroleum based.

Is there a reason you didn't use oil?

[emccallum]

Same here, actually the first time I have ever heard of using antifreeze. I have always added some oil, not for heat dissipation but because I have had inserts that were rusted so much I never got them removed. 

The shock companies instructions always suck. One set of instructions for every shock they have ever made! Once you tighten the gland nut make certain the insert has no vertical play. 

[inline6]

Ok, I will switch to oil.  That is easily done at this stage.  What types are typically used?  

The instructions show a picture... with a snowflake, and "50 ml" and a pitcher.  Only thing that came to mind looking at the snow flake was anti-freeze.  I assumed that heat transfer would be better with coolant, and that rust would not be an issue because of corrosion inhibitors in coolant.

[inline6]

Today, my focus was on the steering rack.  

I was unable to find any pictures of the shims in this third picture, neither in my disassembly pictures, nor online. They aren't in the pictures in the factory shop manual either.  

    

 

It seems incorrect to me that the spring would push directly on the brass/bronze bushing, and there were no wear marks from the spring in that surface.  There were two very thin washers and one thicker one.  I stacked them - thin - thick - thin and put them between the spring and the bushing.  Is that correct?  Other than keeping the spring from eating into the bushing, I don't know why these would be needed.  If there were just the two thin ones, I'd have put one on each end of the spring.  Given that the larger retainer screw adjusts down against the spring, I see no reason for a spacer, or shim in this location.  

    

 

    

    

 

  

[emccallum]

This video may help you on the steering rack:

As for the oil in the strut I have always used just plain motor oil.

 

[Captain Obvious]

9 hours ago, inline6 said:

I was unable to find any pictures of the shims in this third picture, neither in my disassembly pictures, nor online. They aren't in the pictures in the factory shop manual either.

I've never been inside a 240 rack but I would assume those washers are not for the bronze preload shoe, but are in fact used to adjust the pinion gear end play. On the 280 rack, the spring DOES push directly against the bronze show, and since there is no relative motion between the two in-use, I think that's OK.

So without having any of the parts in my hands, I would guess that those washers would go onto the small end of the pinion gear shaft before the pinion gear goes into the housing. I'm thinking that with those washers not installed, you're likely to have a lot of end play "in-and-out" of the housing. And unfortunately you would most easily check and measure that end play with no other parts installed into the housing.

If you take the bronze preload shoe out (which is easy) and grab the splined end of the pinion gear shaft, can you feel any play when you push it into and pull it away from the housing? There should be no movement of that splined shaft. I'm not sure you would be able to really check for that end play with the rack installed, but taking the rack back out is a lot more work than just pulling the preload shoe.

[inline6]

I can confirm that the washers do not fit on the pinion gear/shaft.  The factory workshop manual provides information about selection of different snap ring thicknesses to achieve pinion gear end play of no more than .003 something.  

In the Youtube video above, it is a little difficult to determine where that guy put the washers even slowing the video to .25 speed, but I see that he puts them (it looks like he has two) directly between the spring and the large retainer screw.  

These two freeze frames show, bronze shoe missing from parts on rag and spring is in the "well" - retainer screw in hand...

 

Washer now missing from rag, retainer screw being threaded in, screwdriver in left hand.



I have a spare rack, and will pull the retainer on that one to see what I find.




 

[Patcon]

I rebuilt the rack in my Lily thread. I don't know what page it is. There may be some info in there too.

[emccallum]

According to this video spacers go in before the spring. Start at 12:15. HTH

 

 

[inline6]

Many years ago, I grabbed 240z steering rack from a salvage car in a yard.  My thinking at the time was that I could send it in as a core on rebuild exchange some day.  Tonight, I removed the retainer nut and screw, and found two washers - one thin and one thick sitting on top of the spring.  There was no shim under the spring - the spring was sitting on the bronze retainer.  Since the rack has been in my possession since the 90's and is covered in tons of gunk, I assume it has never been apart.  

Of the three youtube videos I can see, one puts the washer(s) under the spring against the bronze bushing, one puts the washer(s) on top of the spring, and one has no washers. 

There are no shims in the picture in the factory shop manual which identifies all of the parts to the rack (15, 16, 17):

 

I suppose it is possible that the shims were used to adjust the amount of spring tension pushing the retainer against the rack... with the retainer screw in the precise installed position per the factory manual instructions.  Steps 12-15 pertain to the retainer and retainer screw installation:

 

Perhaps originally, they were added by factory worker in a fashion such that, the retainer screw was set per factory instructions, and then some type of resistance check was made.  Then this was followed by adding shims (remove the retainer screw, add a shim, replace retainer screw, then check resistance again...  Anyway, that is my guess.  

Another interesting thing I am just now seeing: the retainer spring I took out of my "undisturbed" rack does not match the specs for the 71 manual, which are here:

Free length is about .890" and it is only composed of just under 4 coils.  

Odd!

 

[inline6]

There are part numbers for shims shown in the parts book, but the location in the drawing is inaccurate - they do not go below or around the bronze bushing:

 

I see that the retainer spring in the rack I reassembled yesterday has a spring just like the one I removed from the rack today - not quite four coils. 

Interestingly, I do have one of the springs that matches the retainer spring specification from the factory workshop manual.  I may have ordered that spring from Nissan around 1994 when I rebuilt the rack on my original 240z.  At that time, I was able to source new bronze rack bushings, new pinion bushing, new bronze retainer, a new pinion gear and pinion gear bearing.  I think it likely that I ordered a new retainer spring while I was replacing all of those parts.  

I had a slight shimmy in that car for years even after rebuilding the rack, and it wore the rack considerably at dead center.  Only later did I found out that the ball joints (appeared to be new, so I looked at other things first) were the cause.  Because that rack was worn, I swapped it for another, which is still in that car.

Salvage car rack - as retainer was removed - thin shim against retainer, thick shim against spring:

 

Spring on the right is from the salvage rack - looks to be the same spring spec (even white paint on it) as the retainer spring in the rack I assembled yesterday.  Spring on the left matches the specification from the workshop manual for the retainer spring.  Coil diameter measures right at .102" .  Free length was 1.015" instead of 1.035".  But it has been compressed in a rack for about 30 years, so maybe that is why the free length is a little short.

These springs have very different lengths and loads.  I wonder what the deal is - why these differ so much from the specification in the workshop manual.

Edited October 24, 2023 by inline6

[Captain Obvious]

17 hours ago, inline6 said:

I can confirm that the washers do not fit on the pinion gear/shaft.  The factory workshop manual provides information about selection of different snap ring thicknesses to achieve pinion gear end play of no more than .003 something.  
 

OK, well then those washers clearly do not go onto the pinion gear to adjust end play.     

Without having a 240 rack here for analysis, I'm not a lot of help. Hope you figure it out!