Hi all, My trusty 318 (1997) was in the garage having a new cat fitted and i was advised there was a rear offside suspension coil spring broken, the mechanic told me its best to replace both coil springs, something about road holding and balance. Do you guys and gals agree with him to replace both or just the broken one. BTW the car has done 158000 miles. Thanks in advance.
Some things, such as shocks and springs, are best replaced in pairs. Especially after that kind of mileage.
It's also surprising that the garage noticed it before the driver did, but maybe that's just a woman driver thing...
Hi, I had a similar experience with my first E36 M3. I thought it over for quite some time. After giving the undercarriage a good inspection I found that it was also time for new struts and shocks. I did a lot of research and decided to replace all of the springs and struts (and shocks) with a matched set. I believe the manufacturer was Boge? I bought them from BavAuto.com. It made a wonderful difference in the handling and ride. I never regretted putting that much money into it. If you cannot afford such a replacement kit then I would suggest just changing both rear springs. it will keep the car symmetrical and balanced in the read of the chassis.
Just my opinion; however, I hope it helps.
Cheers, Wayne K.
It's pretty unusual for a spring to fail on these cars so I wouldn't replace the other one based on concern that it would fail soon. My 318i has 340,000 on it and the springs are fine. There is also no reason to replace the good one in order to make sure they are matched because there's no reason to believe that two 'new' springs of the same part number will be matched any better than an old one and a new one of the same part number. Some people contend that spring characteristics change over time and that springs get 'tired' after years of use but there is no physical explanation to support this myth so that also would not support replacing the good one. Save your money.
Well i did notice the gap differed between the tyre and arch on either side but thought i was just the weight of all the shopping in the boot ;)
It's not that the other spring will fail, it's that it won't match the new one. As soon as they are installed springs begin to lose rate and loaded hight (slowly...). The new spring will be higher than the used one. Now if this car is just transportation to you and you don't really care about handling, then it's probably not a big deal.
-jim
Jack wrote:
You could tell that easily by measuring the height of a new one against an old one - unloaded.
"Jack" wrote
It's not that they get "tired", but they eventually sag - ie, lose their original height. Replacing both will ensure that one side won't be lower than the other. If you don't believe me, I can show you pics of my '91 E34 new, and now. It's sagged at least an inch. Or my '87 motorhome, which looks like a low-rider - about a 3" sag from new.
Floyd
Yes.
-Fred W
Absolutely yes. Replace both springs in the same axle, NEVER replace just one spring on an axle. You should give serious consideration to replacing all of the springs, but at the very least you should replace both springs on the same axle.
Well, as I said, you can check the condition of a spring by measuring its free height. If it's the same as a new one, then it's ok.
I think the loaded height would be considerably more telling than the unloaded height.
Only a foolish man would replace one spring, unless the car was new.
Still not convinced by this. Spring are in permanent compression and are obviously designed for this. There could be any number of reasons why a spring could fail. You don't replace both headlamp bulbs when one blows, do you?
Lousy analogy, completely off the mark, but you've been struggling with this all along.
Do you really believe coil springs don't change their spring rates/ride height over time?
You're obviously too young to remember Back In The Day when mechanics would stuff a bunch of funky "nuts" into tired coil springs to get a few more years out of them...
Yes, I do, unless I know how long they have been in the car. I replaced the lamps once, then 6 months later replaced a single lamp, but usually the lamps last for years, and when one goes the other is not far behind.
Youi don't replace springs to avert a future failure, you replace them to keep them balanced from side to side. This is certainly true when one is replacing a factory part with an aftermarket part. Arguably, if one used a new factory part, then it should be a match for the remaining factory part, however I feel this is a weak argument and that springs are an item that should be replaced in axle sets.
No. Far more difficult to measure.
I'd agree. But through science rather than folklore. ;-)
Not a good analogy. Halogen light bulbs loose their output with age. And springs sag. ;-)
? It's the first I've commented on this!
I accept that over a very long period of time there will be some sag, but seeing as replacing springs is a relatively uncommon repair, the life span of a spring in the manufacturers eyes is probably very close to the intended life span of the car as a whole. If one breaks after say 6 years because of impact damage or inherent defect I can't see why the other has to be replaced.
True, I probably am a bit young to remember the old engineering tricks, but then again we used to have to change the oil every 3000 miles. Modern technology, manufacturing and materials has changed pretty much everything on a car, can't see the springs being left in 50's technology.
I guess, like the oil change argument, this one is entirely down to individual preference. Each to their own!
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