Squeak from rear of BJ8

[RAC68]

Hi John,

I have seen both recommended but did contact a zinc product producer and asked for direction. I have also viewed suggestions to use "Cold Galvanized Paint" containing 93% Zinc Power for use in leaf application. Yes, I agree that zinc compound liners would be best and after that I would use the Vinyl liners. However, there is too much that I still don't understand before I actually act.

One last point I found, our springs, without leaf liners, creates friction that acts as a shock absorber diminishing osculating movement. One group suggest this is a good thing and part of their purposeful elimination of the liners.

Go Figure,

Ray(64BJ8P1)​

 

[steveg]

Hi John,

I have seen both recommended but did contact a zinc product producer and asked for direction. I have also viewed suggestions to use "Cold Galvanized Paint" containing 93% Zinc Power for use in leaf application. Yes, I agree that zinc compound liners would be best and after that I would use the Vinyl liners. However, there is too much that I still don't understand before I actually act.

One last point I found, our springs, without leaf liners, creates friction that acts as a shock absorber diminishing osculating movement. One group suggest this is a good thing and part of their purposeful elimination of the liners.

Go Figure,

Ray(64BJ8P1)​

Hi Ray,

Leaf friction used to be considered a good thing in the days of Hartford friction shocks (pre-WWII). Now not so much. The hydraulics don't need any help.

IMO galvanzed iron strips would not be a substitute for sheet zinc, as the galvanizing would quickly wear off, leaving the springs with steel-to-steel contact as before.

If you cannot find sheet zinc to make strips from, you're departing from concours, therefore you might as well go with a known permanent solution, such as the plastic channel shown above. Just my 2p.

 

[dcarlg]

Ray,
Removing rear springs would be at the very bottom of my list of Healey projects. My springs don't squeek, so I haven't applied Slip Plate to them. At $10, it would be my first choice, though.
Douglas

 

[John Turney]

As much work as removing and disassembling rear springs are, I would still lube them first.

 

[RAC68]

Douglas/John,

I must say I very much appreciate the basis of your points and logic as I have followed that approach in the past with other lubricants then the one you had mentioned. However, I have experienced only very short releaf from squeaking with some lubricants and no relief at all from other.

I am now on a path to complete the job with a permanent solution and, although the Vinyl liners seem an easy solution, I am concerned about available space for the new liners, even after the remove the SS strips inserted years ago. Since much of the available shackle space had been taken up by adding a second #2 leaf to each spring set (7th leaf), the space needed for each 6-liner vinyl set (@ 1/16 per) would require each spring set to had at least 3/8" to 1/2" of free shackle space. But, if I can find Zinc metal liner replacements, I expect they would be near the thickness of my present SS strips and be very close to an even swap with respect to space between the shackles.

Will it take more time and effort to remove and replace liners? Undoubtedly it will but I expect to have a maintenance-free permanent result (hopefully).

I really value your comments,
Ray(64BJ8P1)

 

[John Turney]

Ray,

Since you know the cause of your squeaks, proceeding to insert zinc strips is the appropriate action. For the OP, lubing the springs to confirm that they are the source of the squeaking before disassembling them, only to have the steaks continue seems like a better idea.

 

[AUSMHLY]

I respectfully suggest spraying Slip Plate on the springs. Both while loaded and also unloaded. It penetrates well and leaves a graphite coating. Sheds water and resists rust, too.
Good luck.
Douglas

Slip Plate (graphite) vs Wurth HHS 2000 (grease) vs CRC Heavy duty clear penetrating grease (grease and teflon). All water resistant, so may stay put longer.

 

[Keoke]

^^^ Although these seem like good solutions, seems like a lot of work to remove the leaf spring, take it apart, install product, put everything back together. Are special tools need to take leaf springs apart and reassemble?

Yeah:

But if you wanna stop the squeak just use coppa-slip in between the leaves

 

[dancrim]

While your at it, you might want to replace the radius arm bushings if they never were. The
steel bushings can seize to the pins and damage the rubber. I had a set squeak once. Your
job could be easier to just pull the rear end out anyway. Easy on the BJ8. Just my $.02.....

 

[dezand]

I recently rebuilt the leaf springs on my BT7.
Since I am an engineer with access to test equipment and I was curious,I used a load cell and display to measure load v. displacement as I compressedthe spring to flat on the bench using a 14 inch C-clamp.
The spring was disassembled and the zinc strips were noted for locationand thickness (.031 inch).
New zinc sheet was sourced from an online metal supplier for about $30and spent $10 to have a local sheet metal shop shear them to the correct width.
The leaf spring bushings were the biggest hassle. The ones availablefrom both Moss and AHSpares in the UK are made poorly with thin metal andincorrect inside diameter. The original bushings have very close tolerance boresthat fit quite closely to the bolt that secures the leaf spring to the chassis.These bolts are precision ground to very close tolerance.
The bushings that worked out the best were purchased from XK’sUnlimited (now owned by Moss), and they fit the Jaguar XK120, the onlydifference being the length is ¼ inch too long, but they are easily modified.Keep in mind the length of these bushings are critical since the chassis andshackles have to be able to ‘pinch’ them on each end. The OD and ID of thesebushings are spot on compared to the originals.
I re-arched the leafs using my 20 ton press which turned out quite nicefor the height increase I was looking for. Re-assembled the springs with a thincoat of moly grease between the leafs and repainted them after assembly.
At the same time I had the rear shocks rebuilt by World Wide Auto inWisconsin.
Big improvement in ride and handling, plus much less scuttle shake onthe freeway.

 

[Keoke]

dezand


Good show:

Perhaps you can share the sources you used to supply your zinc liners for the forum.

 

[dezand]

for the zinc sheet I purchased it here:
https://www.onlinemetals.com/en/buy/zinc-sheet?q=:relevance:Thickness:0.03%22&checkbox=on#
The liners are 1.75 wide, so a 12" wide sheet will make the six pieces
I decided to make original zinc liners instead of using the flanged Delrin type available after reading that the Delrin is so slippery that it tends to wiggle out.

Here are the bushings:
https://xks.com/i-7080117-jaguar-le...k-vii-mk-ix-co-1219.html?ref=category:1207344
They need to be shortened by .25 inch, otherwise they measure identical to the original bushings

 

[Bob_Spidell]

...
Big improvement in ride and handling, plus much less scuttle shake onthe freeway.

The 'scuttle shake' issue has been beat to death, both here and elsewhere, and this is the first time I've seen rear suspension anomalies mentioned as a possible cause. Intriguing.

 

[dezand]

I was surprised also, since I had been considering having my brake drums balanced. But after the leaf spring and shock rebuilding, by far, most of the scuttle shake is gone. I'm sure the scuttle shake is related to the bending and torsional stiffness of the frame and body structure and the forcing frequency is the speed/road surface. The damping has been increased with the shock rebuild and the rubber in the leaf spring bushings is now soft compared to the rock hard rubber in the original 60 year old bushings, which changes that locations natural frequency.

 

[RAC68]

Hi All,

After doing some research, I have purchase a roll of "Master Flow Zinc Moss and Mildew Preventer Strips" used to eliminate this growths from rooves. This strip, purchased at Home Depot for $31.98+tax, is specked at between 90-94% pure 20-guage (.030") Zinc with a 2.67" wide, that I expect to be easily cut down to the require 1.75" size with mettle sheers. At a roll length of 50-ft, there should be enough material to create leaf liners for my two 7-leaf springs and a Club full of other British cars.


One last thought. I was intrigued by Dezand's comments about scuttle shake being affected by the rear suspension, other then imbalanced brake drums, wheels, and tires. Once I have completed the installation of leaf liners, I will be sensitive to any changes in ride.

Ray(64BJ8P1)​

 

[dezand]

As long as the Zinc sheet has copper and titanium added, per EN988 spec.
I measured the hardness of the original zinc and it was very hard. Pure zinc sheet is soft and will wear quickly and deform. The EN988 spec zinc I purchased online matched the hardness closely.
In regards to the scuttle shake, all of the bushings on the rear end come into play, so that might be a good time to change those out.

 

[HEALEYJAG]

Have had this on 3 cars..Aston martin....Jaguar XJS. Austin Healey 100..All fixed with copious lubricant...easy peasy...never came back....think simple boys!

 

[RAC68]

Hi All,

Although I've tried the copious ampunts of different penetrating lubricants, after a while the creaking could be heard again. With relatively new bushings and balanced wheels, drums, and tires, scuttle shake has disappeared.

As far as EN988, I had researched this standard and the Zinc used on my springs has additional mineral content but I don't think it is consistant with the standard. However, I appreciate the point made by Dezand and will see if the hardness of my formulated Zinc is sufficient to last. Keep in mind that my Healey is not my daily driver and will not get the hard use it did when it was new and was.

I must admit that I needed far more zinc liner material then could have been secured by (1) 12"x12" sheet to satisfy the liner requirement of (2) 7-leaf springs with liner lengths 2 to 3 times what could be satisfied by a 12" square. Continued searches yielded en988 zinc of appropriate quantity but at costs too high for practicality. The grade of Zinc I have chosen seemed sufficiently stiff, with the quantity required at a reasonable price to try.

Additionally, my BJ8 Phase-1 has a different rear suspension configuration then that of a BJ8 Phase-2 and I have added an additional 2nd leaf to stiffen and raise the ride height to allow more clearance for the resonator. These spring packs are tight with little clearance for liners and all is held in vertical place with 6 clamps and the center axel clamp. As a result, movement is reduced to provide a firm but compliantly comfortable ride I really like.

I can't say if my choice of zinc in my suspension configuration will succeed. However, as many others, I am not apposed to trying something different and soliciting comments and suggestions to improve the approach. That's how we discovered the commonality of scuttle shake and determined approaches toward its elimination.

Thanks all,
Ray(64BJ8P1)

 

[dezand]

Sorry, the link to the zinc sheet I provided defaults to the 12x12 size. The size I ordered was 12x36", the BT7 uses three zinc strips per spring, the BJ8 spring may be different.
During leaf spring rebuild process I measured some spring data, which applies at least to the spring type used on the BT7:
The average spring rate for the spring deflected 3" from free height was 160 lb/inch.
I also put a load cell under each rear spring while jacking the car up just to the point where the tire was above ground. The weight at each spring at the connection to the rear axle was 600 lb.
Probably useless data but I couldn't find much info on the springs in the manual or online.

 

[RAC68]

Hi Dezand,

I just completed the lining of my second 7-leaf spring and refitted it back into my Healey when I read your post. I was intrigued that you only inserted 3-liners per spring as I was under the impression that your BT7 was equipped with a 6-leaf spring (as mine originally was). If I remember correctly, when originally dismantling my original 6-leaf springs, there was a liner between every leaf and, not finding any documentation, I followed that liner insertion pattern (using stainless steel in error). Now, with the 7-leaf spring sets, I have inserted 6 liners of varying sizes, per the original insertion pattern.

Where did you find that only 3-liners per spring were required? Between which leaves did you inserted the liners (longest top being #1). It seems we are working on 2 different understandings and now our economic and product choice differences are in better focus for others to consider and evaluate for their installation consideration.

I look forward to testing my new installation once the rain finally stops and the ground dries as moisture will impede the transmission of creaking.

All the best to all,
Ray(64BJ8P1)​