|The MGA With An Attitude
Bad, BAD REBOUND STRAPS and rear leaf springs -- FT-023
An ongoing problem for more than eleven years, and the vendors are still screwing the customers with these bad parts.
At 08:45 PM 1/30/05 -0500, Steven Clarke wrote:
".... having to use my forklift to hold my frame down so I could jack up my new Moss Motors leaf springs so that the rebound straps could be fitted. The leaf springs seem to have too much arc to them. .... Once all was hooked up, we lowered the rear end and as soon the jack was down the springs caused the rebound straps to completely split across the top on both sides."
The new leaf springs currently available have too much arch, which can cause the rear of the MGA to sit more than an inch too high (and sometimes a lot more). This problem has been around since at least 1989. I haven't seen much change in that situation in recent years, except that some springs are more "too tall" than others. But that's a subject for another time.
The original rebound straps were made of thick woven cotton web strap, looped and heavily stitched at the ends. These were originally plenty strong to serve the purpose for many years, but they were also prone to rot with time and would ultimately break. The ultimate failure could be either a break in the center or a split out at one end. Any MGA today either had these straps replaced or needs to have them replaced.
(Click for larger images)
For decades (at least since 1977) the replacement parts have been fabricated with similar web strap but also molded with a heavy rubber jacket for environmental protection and durability. I have a set of these on my car for nearly 20 years and 200,000 miles on the road, and they are holding up just fine. But some recent issue parts are apparently much weaker. These are probably made with much thinner webbing, and the thick rubber cannot make up for the lost strength.
Moss Motors does know about the faulty rebound straps and is (presumably) pursuing a solution. I will post another note here if/when there is any news.
Addendum March 9, 2005:
At 03:01 PM 3/9/06,Kelvin Dodd from Moss Motors wrote:
>At the time a number of straps were cut apart and inspected. They were found to have inadequate reinforcing. They were shipped back to the supplier in the UK.
>Another supplier was contacted and their product tested. Their straps still stretched more than we think they should, but did have reasonable reinforcement and did not break when installed.
>Unfortunately there are no specs that we can find of how elastic the original straps were, so it is difficult to determine whether the new ones are within spec or not.
Addendum March 9, 2007:
MORE JUNK? How about this for coincidence, exactly two years to the day?
At 08:05 AM 3/9/2007 -0600, Rick Schnittker wrote:
"I think the check straps Moss is selling are just for show. I had the car jacked up on the frame right behind the doors so the check strap was under stress because the weight of the axle and leaf springs were fully extended. It lasted less than 24 hours. The original one I removed, 47 years old probably, was still hanging on when I removed it."
This one has nothing to do with new over height leaf springs, as these are the original 47 year old springs, well settled. So two years on Moss is still selling junk check straps. They don't seem to get the idea that these are supposed to be heavy web straps with a rubber coating, not rubber straps with a fake web lining. So Moss has been notified again, but I have no idea if they will ever have these parts fabricated properly, or if they will ever bother to load test a sample from a production batch.
If the Moss excuse is that there were no original spec's, then they should write their own spec's. I have tried to tell them how to write the spec's and how to test the things, but still they won't bother. Apparently their primary form of product testing is still customer complaints, so LETS ALL GET TO COMPLAINING LIKE HELL. In my book parts that fail before they get to the road are entirely unacceptable. Also any management that will sell known suspect parts without testing for years after knowing the problem is guilty of customer fraud. Mince no words.
Another year on, as of Spring of 2008 I am no longer receiving notices of failure of these parts. Prior report from Moss Motors (noted above) is that the current parts have "more" internal webbing, and that they do not stretch as much as the prior parts when tested. Amount of stretch or breaking strength is not noted. Comment was made referring to lack of original specifications for this part. If no one is currently complaining it will be assumed that all is right with the world (until someone reports otherwise).
Addendum May 15, 2012:
Here we go again. This time I have a report from South Africa of Check straps that stretch enough to allow the rear axle to sit firmly on the exhaust pipe when car is supported and rear axle is allowed to drop.
Addendum August 5, 2012:
On 8/6/2012, Giuseppe Maggi wrote:
"I've started a restoration of a 1956 MGA 1500. I have noticed this article mentioning "new" rebound straps that broke just a day after being installed. I am having the very same problem. I've bought several pair of check straps from Moss, mgbits.com and from an ebay seller named lotsofclassicbits, and they broke in the very same point after few days. I attach some photos of the right check strap, it is still mounted on the suspension. I also made some comparison with the "original" check strap I found when I bought the car. I noticed the original ones are a bit longer than the new ones (the old one *might* have been extended after years of service but the difference in length with the new one is too much, in my opinion). .... It really scares me thinking about the moment when those check straps will have to face the road instead of just the parking lot".
On 8/6/2012, Giovanni Delicio wrote:
"The ones below I bought the retaining straps from London Classics. They break as soon as I installed them on the old leaf spring. My request for replacement was ignored"!
On 8/9/2012, André M. Kunz in Switzerland wrote:
"I bought rebound straps for my MGA from MGOC Spares, 13 November 2011. Didn't survive the first outing"! -- André
On October 10, 2012, Neil McGurk in Cumbria, UK wrote:
"I bought a set of straps in April this year which have also failed, but in a more worrying manner. I suspect that most owners who purchase these will never be aware that they are not working. The straps will stretch indefinitely (until the axle is supported by the springs and or exhaust), but when load is removed they revert to their original shape. I have informed the supplier and have so far been pretty much fobbed off. Initially I was told their parts were good and they even had installed a test fixture to check (although it seems it is no longer used!). I sent the pictures to explain that all was not well with their parts and was told they would investigate. .... but so far no response. I bought mine from Moss Europe".
On June 30, 2013, Bob K in Arlington, Virginia, USA wrote:
"We had our first part failure, I guess its time for the original style webbing".
"Purchase date was April; I 'think' they were from Moss".
Addendum, December 2013:
Moss Motors has recently had these parts remanufactured to their order. Parts in the following picture (from Moss Motors Ltd, UK) were selected for photo specifically because they have some of the webbing showing at the edges.
I don't have any test result information, and no field reports, but also no known complaints as yet. Fingers crossed, as this is the only source I know that may have serviceable original style rebound straps for MGA. The same parts should be available from Moss UK and Moss USA.
On 5/5/2015, Bob Shafto in Hudson, Michigan USA wrote:
"I finally replaced my rebound straps with Moss Parts while doing a total restoration of my 1960 MGA. After a few days of up and down on the hoist, one broke. Still using the original springs. .... I got the straps from Little British Car Co, but the owner (Jeff Zorn) gets them from Moss".
From the minimal fiber inside, I suspect these may be older stock, possibly held in inventory for 18 months or more. -- Barney
Addendum, June 8/2016:
I replaced all rubber suspension buffers and the rear rebound straps on May 3, 2016. At the time I was dealing with 48 year old leaf sprigs that were sagging badly, so had no good way to test the new rebound straps. Today I installed new leaf springs, and the stretch on the rebound straps is downright shocking. Free length of the straps was 9-inches center to center of the studs. When the suspension was lowered the straps stretched 1-1/2-inches to 10-1/2-inches final length. This was with weight of the rear axle and pressure from the mostly relaxed springs. The only reason it stopped there was because the shock absorbers ran out of mechanical travel, which is exactly what the rebound straps are supposed to prevent.
Rebound straps are not supposed to stretch at all, or certainly not more than 1/4 inch under load of the axle weight and leaf spring preload. These straps when installed give the impression that they should get the job done, leaving the car owner with some confidence that all is well, when in fact damage to the rear shock absorbers is imminent. The new straps should be cut off and removed to assure the driver that the straps in fact do nothing, and it should be driven accordingly. No doubt the fault of these non-functional straps should void the warranty on shock absorbers. I am really sorry that I removed the 30 year old straps that were tatty but still functional. Now I will have to find suitable replacement parts, and VERY SOON.
Addendum, July 3 2016: Installed new latest issue rebound straps from Moss Motors. When the axle was allowed to drop the straps stretched from 8-3/4" to 9-5/8" with almost 1 inch stretch. This is not even with dynamic bounce conditions, just gentle lowering of the floor jack. While this is not as bad as the prior issue straps, it is still unacceptable (and I suspect they will stretch more with use). So this is not the end of the story, as better parts must be found.
Addendum, July 26, 2016: Just 3500 miles of all paved roads, changed the straps again. The most current issue three week old straps from Moss Motors were badly stretched and broken at one end, so off to the dust bin.
This time some friends in New Zeland who make their own have sent me a pair of synthetic web straps. The eye ends are lined with truck air brake hose for the heavy bushings. They are indeed quite substantial, and look like they will handle the job nicely. It was a quick change. See article RS-113 for more details.