1968 DeVille Convertible - Restoration

[DeVille68]

Well, not necessarily. Shipping is always expensive.
I have a couple of friends in the states who hold and package stuff for me. Currently some pieces (driveshaft, muffler, floor pan) are underway in the trunk of a friends car.
The upside is shipping cost, the downside is time.

I made a new sending unit wire. Of course I had to reuse the original crimp / terminal because I have no stock of those yet. Really need to buy a bag of different sizes.
I was also painting the gas tank. Looks horribly with the metal ready from POR-15 applied, but then after painting turns out quite nice.

Best regards,
Nicolas

[DeVille68]

Hello,

I made a little progress this long weekend. I have sandblasted all the suspension arms and a lot of brackets. I replaced the bushing in the upper and lower arms. The replacement bushings I got had the same part number than those that were installed in the upper arm. The upper arm has never been replaced, because I had to drill a hole into the floor to remove the screw. So, those were the factory bushings. Luckily the part number matched. See the first picture. The label reads: Harris Silentblock FG 62496 (and then some letter and number, maybe indicating a date or a cavity of the rubber press).

So, either the original manufacturer still supplies those bushings or the reproductions even copied the lettering and numbers. The shop manual says that the rubber compound is different, however I was not able to check that. Either someone replaced the lower bushings, which I doubt, or it is an error in the manual.

Either way, the restored parts turned out quite nice.

I also installed the tank and "calibrated" the gauge. Seems to work fine. Looks really good underneath now.

I removed the extension housing of the transmission, replaced the seal at the end and also replaced the o-ring on the output shaft. I used some permatex on the extension flange to transmission surface.

Next up is installing those.
I am also working on special tools to measure the LSD break torque and need to make a tool to remove and install the pinion yoke.

Best regards,
Nicolas

[James Landi]

You're way too modest-- you've made so much progress.  Would be interesting, if not too much trouble, if you'd list what needs doing... that way we bench sitters can enjoy the anticipation and further track both your narrative and your progress.  Thank you for keeping us engaged.   Happy day,  James

[spolij]

Sorry my neck was hurting. lol

[DeVille68]

Hi James

Thanks a lot! Well the list is still huge! :-D
I use Microsoft To Do (previously Wunderlist) to keep track of the things to do. Currently there are still over 60 tasks to be done! :-D Well, only about 10 are really necessary. There are a lot of long term projects.

Listing all what need to be done would be quite a list. In essence: rebuild the complete rear end, that is axle shaft bearings, all seals, remove rust, paint, rebuild brakes.

Hi John,
yeah, strange. I noticed too that the pictures are upside down. But when I click on them to enlarge them, they are displaced correctly in my browser? Hm...

Best regards,
Nicoals

[DeVille68]

Hello

Another update: During the week I was working on two tools to finally tackle work to be done to the rear axle and differential. I had to create a pinion flange holding tool and a fixture to measure torque on one wheel.
The axle shaft puller tool was already created two years ago.

See below, these are very crude but do work. I am not a professional, so scrap parts must fulfill the job.

First, I removed the two floor plates behind the front seat on the floor. The seal on these was also crusty and brittle and I noticed that underneath the (maybe original?) carpet there is a padding which has soaked up all the water and the metal started to rust some. Not major but still. Going to replace this padding on the floor. I'll leave the carpet alone. Check out the first four pictures.

Then I removed the brakes, which is pretty simple. Although a bolt of the handbrake bracket broke of on both sides. I guess I am the first one since the assembly line to have put a wrench on these!
Check out the next four pictures.

Also important: I was wondering for years why my rear brakes would brake but not as strong as I wanted to. All the stopping was basically done by the front breaks. Now I found the reason: The brake pads have made a deep (about 1mm) notch into the backing plate. Applying a little brake force would push the pads into this groove and then the stopping power from the rear would just remain the same. Usually to brake force was not high enough to push the pads out of this groove because the additional force was sufficient to stop the gar with the front brakes.

So, I am going to weld these notches and grind or sand them flat again.

[DeVille68]

On to the differential: With the aforementioned tools I was able to measure runout, torque and brakeaway torque.

pinion torque: I could not "measure" this, but it must have been lower than 2Nm because thats the lowest setting on my torque wrench. Maybe too low, lets see what reading I get when I assembly the diff again.

Breakaway torque: You measure this by holding the pinion fixed and on a limited slip it is sufficient to then start turning one wheel. With the adapter I made I could position the torque wrench in the middle. Since the axle was out on the floor and the reaction forces would go through the ground I had to hold both the torque wrench and the pinion. So in essence the reaction force was also going through my body too. I was able to get it click at around 110Nm, with a setting of 125Nm I was not able to apply enough force.
So I just know that the breakaway is higher than let's say 120Nm.

After this torque difference has been overcome, the limited slip works like a diff again.
So it seems that the friction surfaces are still oke. Guidlines are a torque setting between 100 and 150 Nm.

Axial and Radial pinion flange runout:
I had to lightly sand the flange surface to remove small high spots. Then I measured a combined runout of about 0.0052'' - factory specs call for 0.004''
So, I call this good and let it be.

Axial runout of the axle was also difficult to measure due to rust high spots but I got a reading of 0.005'' on the driver side and 0.003'' on the passenger side.

Backlash on the axle was also measured. I measured at the wheel stud, that is at 2.5'' - the factory calls for measuring at the tire diameter, but one can convert to this situation too.
I measured on the driver side 0.61mm and on the passenger side 1mm, converted to the outside diameter this gives:
Driver Side: 0.14''
Passenger Side: 0.22''

Factory manual calls for 1/8, so 0.125''

This means that the driver side is oke, but the passenger side not. The passenger side is the side where I had a tire blow out on the highway and since then I have a vibration.
The splines on the axle look good, so my only guess for the increased backlash on one side is that the bearing is damaged and the axle shaft can move fore and aft and give a "false" reading.

Well, anyways, I am going to replace the bearings and seals.


Looking at the differential itself: The ring gear diameter is 9'' and there is a patent number on the casting: CA620899
This patent is available and I have it attached below. Pretty cool stuff.
Check out the gears and teeth. Look like brand new!

If you have any recommendations on how to tackle the bearing replacement on the drive axles, let me know!

Best regards,
Nicolas

[Roger Zimmermann]

I'm wondering why you removed the small floor covers? Just for cleaning?
To replace the wheel bearings: the shop manual is describing it well. You will need a press. If you have such equipment avalable, put the bearing the right way: the spring you can see at the seal is going towards the differential.

[DeVille68]

I'm wondering why you removed the small floor covers? Just for cleaning?
To replace the wheel bearings: the shop manual is describing it well. You will need a press. If you have such equipment avalable, put the bearing the right way: the spring you can see at the seal is going towards the differential.

ok! Yes I read the manual multiple times! :-D
But I was seeking for the undocumented tips and trick to make life easier. Thanks for the hint about orientation. Anyone else having some tips?

Yeah, while cleaning the undercoating and repainting the underside of the car I noticed that the rear covers (in the trunk) were still perfect, but the one behind the rear seat and the one behind the driver seat were a bit brittle and loose. So, everything is nicely black now, only those covers not. Looks bad and it is an easy fix. Just need to clean, paint and seal them.
The ones on the front floor are also in bad shape but I need to replace the complete floor anyway, so that can wait till next winter comes.

Best regards,
Nicoals

[The Tassie Devil(le)]

When you do the front floor, there is no need to replace the covers as they are only there for the construction process, to let out excess liquids that are used in the finishing of the car, as metal cleaning fluids and paint and primer so the excess can drain out.   Then the covers are installed, just before the insulation and carpet gets installed.

Bruce.

[savemy67]

Hello Nicolas,

Five years and three days ago you replied to my post about the rear axle bearing replacement on my '67.  In my post then, I was determining whether I should buy a press.  I decided shortly after the post to buy a cheap press (Harbor Freight) which I purchased for $154.  I used the press to install the bearings and retainers after I cleaned up and painted the axle tube cover which is between the bearing/retainer and the axle flange.

There is another method you can try if you do not have access to a press.  I have used this method with transmissions.  You can "shrink" the shaft by cooling it in a freezer, and you can expand the bearing and retainer by heating them in an oven.  You cannot heat the bearing too much without destroying the seal, maybe 150 degrees F.  You may need to experiment on an old bearing of similar construction.

The '67 manual calls for the use of an arbor press for the removal and installation of the bearing/retainer.  Most arbor presses generate a force of three tons or less so the differential between a "shrunken" axle shaft and an "expanded" bearing may be just enough to allow the bearing/retainer to be installed on the shaft without a press.  You have to be set up to do this, and you need to act fast, and you only get one opportunity to do this method correctly.  The parts "normalize" very quickly at room temperature.  Good luck.

Respectfully submitted,

Christopher Winter

[DeVille68]

Hi Bruce

ok, interesting. I was wondering what those are used for because lifting to body seems impossible. Have not thought about letting liquid out!

Hi Christopher,
Well at my fathers house we have a simple press, I think its 6 ton. I extended the base to be able to press out the front A arm bushings. This press was also used on the rear  arms. But the drive shafts are a lot longer. I know about a few presses in my company, but they don't have the travel needed. Friday night I discovered yet another press, I think this one is up to a few hundred tons, it seems to have the travel needed.

Sorry, I did not remember your post but I am going to read it again.

Today, I was able to measure the backlash on the ring gear and the contact pattern of the gear.
The backlash is 0.0075'' -> according to my books about differentials a reading of about 0.008'' for new gears is good. So, after 50 years this differential is still slightly better than a new one!

Visualizing the contact pattern, I had to use the poor guys gear contact compound, which is bolt anti-seize. Worked pretty good, not a very clear picture but enough to make a decision. Check out the picture below.
It seems that the initial contact is closer to the toe and a little high on the side. But I read that with load applied the contact pattern would move towards the heel. Possibly down somewhat too. 

So, I am not going to mess with the limited slip. I just follow my usual restoration practice which is: paint it black, put it back! :-D

The difference in backlash measured a the axle end must have to be influenced by the bearings. At least this is my guess. Let's see what the measurements are with the "new" bearings installed.

Best regards,
Nicolas

[savemy67]

Hello Nicolas,

A press does not need much travel to remove/replace the axle bearings/retainers - maybe a couple of inches.  A press does need to have enough height to accommodate the length of the longest axle.  I had to elevate my Harbor freight press on wood blocks to get sufficient height to press on my bearings/retainers.

In the picture showing the dial gauge set up to measure backlash, I noticed that you have the pinion flange bolted to your holding fixture.  In this set-up there is probably a thousandth or two of pinion bearing side loading that may be affecting your readings and your tooth contact pattern.

A differential holding fixture should be bolted to the carrier (the casting into which all the differential components are installed) so that there is no unnecessary loading of the pinion or side bearings (see attached picture).  I am sure you can construct such a fixture.  Good luck.

Respectfully submitted,

Christopher Winter

[DeVille68]

Hi Christopher

Regarding press: yes, that is what I wanted to say. However, I still had to enlarge the base because the press is not mounted on a surface but the force flow goes through the bottom structure. Unfortunately this structure is exactly in the middle and below the vertical force axis.
The professional presses are much better, most have a "table" with some holes in it. That basically closes the force loop and a axle can have enough room below the "table".

Regarding gear pattern: ok, well I think I am not so concerned about backlash, but I think what you mentioned did have more impact on my gear pattern measurement. The unit is laying on the ground so there is some force on the pinion and it is oriented in a 90° angle to the normal position. Hence the gravitation pulls in a different direction than in the car.

If I have time I do the measurement again, but I already decided to not mess with it. The gear really looks brand new. So there is nothing I can improve up on.

Just clean it, paint it and but it back :-D

The axle shaft bearing however really do need some help. There is noticeable axial play in the bearings. Unfortunately the bearings I got are from HBC, some chinese manufacturer. I would have preferred bearings from skf or timken.

Best regards,
Nicolas

[DeVille68]

Hello,

This post is about how I replaced the axle shaft bearings.
You need to create two tools out of scrap metal. The first one is the bearing pusher and the second tool the bearing installer. The shop manual calls for a press and to press on the axle shaft. However, there is rarely such a large press available (not the stroke of the press but the room to place the axle) and I think it dangerous to press at the of the shaft. Also the shop manual specifies an additional plate with a hole to hold the bearing outer ring, in case the bearing explodes from the pressure. The outlined method is not very safe, so I created a bearing pusher.

The first picture shows my rough drawing and dimensions for the tools. The top tool is not needed, only the middle and the last one. The next four pictures show how someone in my company made me this tool.

I drilled and tapped six holes on a circle larger than the cover plate but still toughing the rear of the axle flange. Then I used long screws M8x80 and aluminum pieces between screw end and axle flange. Then I used some scrap pieces to support also the inside ring of the bearing. Otherwise the cover place would just press on the outside ring of the bearing. And then all I had to to was tighten every screw in a circular pattern - this took about 10min and the bearings were out.
The first was I removed without splitting the retainer ring. The second one I did split the ring. But it made no difference, would have been fine also leaving the ring in place. I did however heat up the ring and bearings slightly just to reduce some clamping load.

Installing the bearing needs a place with a slightly larger hole diameter than the bearing. And you can either use the base of the press or the puller plate just used to give a support for the axle flange.
Then I used some 1000 grid sandpaper and some grease to make the surface smooth. Aligning the bearing to be straight on the axle was very difficult because of the long shaft of the axle. And there is no large chamfer to self align the bearing. Then you need to press the bearing until you measure from the rear of the bearing to the outside of the axle flange: 3 - 3/64. Check out the second last picture. The measurement is actually between 3-2/16 and 3-3/16. So I think there must be an error in the shop manual, because is no way to depress to bearing further on the shaft!

In the end I got the bearings replace, they have less play. I hope I got them straight on the axle, otherwise my vibration problem will be worse than before!

Best regards,
Nicolas

P.S: Sorry about the 90 degree rotated preview pictures, when you click on it the orientation is correct.

[Roger Zimmermann]

It's nice to have the possibility to use tools from such a nice shop!

[The Tassie Devil(le)]

That is a different way of removal.

As for the bearing collar, I find the simplest way to remove them is to hold the back of the collar over an anvil, and belt the collar with a Cold Chisel to expand it.   Takes a couple of sharp strikes of the Cold Chisel, and the collar will simply slip straight off.

Bruce.

[DeVille68]

Hi Roger, yes and free of charge too! 
Hi Bruce, ok, yes, this method is outlined in the shop manual. But I don't have a chisel and I did not understand why it should slip of. But thinking about it, the reason that it expands a bit might be due to the chisel forcing material inward, to only way it can go is outward, so it has to expand to make room. Just drilling holes and split it that way, like I did, does not expand the ring. okay understood now.

This post is about the backing plate. When you study the first picture you can see that the brake shoes have cut a quite deep groove into the sliding surface. Its about 1mm (0.04'') deep and this groove has the effect that the brake shoes are restrained to move any further outwards except the hydraulic force increases or the brake pad wears down. It can also give a sudden braking experience because it takes a bit of force to move the shoes out of the groove.
Anyways, those grooves had to go.

So, since I am not going to my parents (due to obvious reasons in this current state of the world), I have no access to a welder. But I got lucky, again in my company, someone was able to fill the grooves with a welder.
Check out the pictures below. Then the next problem arose, because I wanted to file down the welds by hand but realized that the six surfaces would never be level and straight. So I asked my boss, who has a milling machine at home, if he could mill down those surfaces. He did, and you can see the final product below. I measured from the underside to the topside of a good surface a distance of about 14mm. This is the distance now that all the surfaces have.

If you look at picture two you see some dimples within the surface. Maybe to lower the contact area and thus the friction?
Does anyone know what they are good for?
I did not replicate those dimples. I do not recall seeing them on the front brakes.

I forgot to order enough axle housing gaskets, but this is actually good, because those replacement gaskets are so thin that I had troubles getting those to seal correctly. Now I created my own gaskets out of gasket paper, the new gaskets are about three times as thick. You need four of those gaskets for a complete axle. The gasket papers are available in different thicknesses.

The last two pictures show the, still original, star wheels. As you can see, some teeth are completely missing. There are no correct star wheel replacements for this type of brake. I replaced them in the front but they are not the correct diameter or length. Now, however, I just used an angled file and cut new grooves into the star wheel. It needs those grooves such that the paddle can turn it and adjust the setting when you drive backwards and brake at the same time. As you can see in the last picture - no need to throw those away. If it would have been worse, I would have welded some material on and recut the grooves that way. There just need to be grooves, no exact amount necessary.

More posts coming soon!

Best regards,
Nicolas 

[DeVille68]

On to the axle:

I used some wire wheels, a lot of time and finally cleaned the axle to be ready for paint. I then used my favorite POR15. 
Then came the task of removing the pinion nut and seal. Someone was in here before because where was a European style "simmerring" (made by Freudenberg) installed.
I had to create a special holding tool to keep the pinion from turning while trying to loosed the nut. I used quite a lot of heat and WD40 and was finally able to remove the nut without too much trouble. The flange basically just slid off, wasn't even pressed on tight. Strange...

Anyway, back to the seal. At the time this seal probably seemed to be a good idea, because the rubber is replaceable and they use a 5mm thick aluminum ring to give support. Well this ring did not want to come out. So I had to carefully drill a hole and split it. I finally was able to remove the ring but some debris found its way into the bearing below.

The pinion bearing has some markings on it: HM89448. Google shows that this bearing is available from Timken. Very good, because those differentials  are "not rebuildable"  as noted in the shop manual.
The new seal I install is the "regular" type, this one is from SKF 18922. Fits perfectly.

Regarding copper washers (picture nr. 3): You need to use copper washers because the studs are in the oil, which means that oil can find its way up through the threads and then exit either between the washer and the housing or between the washer and the nut. The path through the nut is not possible because you torque the nut and lock the threads. So I was trying to locate some copper washer. They are made out of gold or something similar. I called 5 companies and no one had those in stock. The only way would have been to buy 100 pieces for about 70$. Way to much. So I asked around in my company, guess what, the mechanic of the experimental machine shop had special washers with an integrated seal "laying" around in the perfect size of M10. Which fits just right a 3/8''. He had just enough for me (I needed 14). In the end, I hope that those special washers will keep the oil in the housing for years to come! :-)

Best regards,
Nicolas

[The Tassie Devil(le)]

Nicholas,

Never seen dimples on any backing plate wearing spots.

With the extreme damage that was caused to the star wheel, I would be thinking that someone had placed the dimples there to try and raise the worn surfaces, and with all that wear, those brakes have done a LOT of work.

Nice job on the re-filing and shaping of the teeth, and the restoration of the tabs.

Bruce.