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MG Midget and Sprite Technical - Rear Suspension
I'm changing the rear leaf springs on my 1500 this weekend. Mine are rusteeee. Infact they were an advisory the last MOT.
I've got the workshop manual, but surprisingly, there is no guidance on changing the rear springs. I can't imagine theres much to it, but wondered if anyone has done this recently and can remember if there is anything that went wrong or that I should look out for.
|C L Carter|
|I don't envy you that job.|
First problem you are likely to encounter is rusted nuts on u-bolts and rusted bolts on front hanger plate.
Another good one is the rear shackles going over-centre due to the arch of the new springs - assuming that you are fitting NEW springs!
|Oh yeah - and don't forget that your spring hangers are probably rusted through, and you'll need at least an angle grinder to get the bolts out - and you should have waited awhile and put your name down on Kim's list for new ones - coz any other ones are likely to break anyway :)|
There ya go - a pile of grief and misery :)!!!!
|One question I always wondered was, while we're on the subject, is it possible to install the leaf springs on backwards? |
While replacing my springs recently (1500), I was confused as to which way they mount. I t occured to me that it would bolt on either way. I looked at another midget for guidence, but that was a 1275. I assume i put them in in right, but I'm not sure.
On the leaf retainers, the side from the axle mounting pad which had those retainers spaced further apart, I placed facing the rear shackles, while the retainers spaced closely, I faced towards the front spring bracket. I always wonder though! Suppliers books don't show a good enough picture, neither did the factory workshop manual.
|I'm expecting to have to grind off the nuts... and I have new ones from the MGOC - they will be fine.|
The springs are second hand... but in really good condition - picked them up off eBay for about £37 postage included.
What do you mean by "the rear shackles going over-centre due to the arch of the new springs"
Also, where do you jack from, when lifting the car for putting on axle stands... I'm reluctant to jack under the diff cos it would put alot of strain on the drain plug (which is leaking already)
|C L Carter|
|I just jack under the drain plug and trust to luck but I would have thought the easiest thing if you are concerned would be to drill a hole in a piece of four by two to recess the drain plug and jack up on that. You're going to put axle stands just north of the front spring hangers anyway aren't you?|
Thereafter you can just keep the weight of the axle on the trolley jack as you fanny around trying to get the rear springs into place!
When fitting up to the rear shackles you just need to ensure that the lower pivot bolts are behind the top ones so that you don't have too much arch on the springs. Getting the offside one in is a bit of a pig due to the offset of the petrol tank. I foundwhen fitting poly bushes earlier this year that a selection of g clamps and a big hammer was very helpful in getting the whole lot together!
|x2 what Matt said: axle stands on the body, forward of the front hangers (use a 2x6 to spread the load out), I always jack the rear up from under the diff and never had a problem, but a drilled hole in a block of wood would be clever.|
you can use a long crow bar as a lever arm to bend the rear of the spring enough to rotate the rear shackles into place (that's how I did it)
In answer to Ron's question: it would be difficult to install them backwards because of the center "stud" that engages into the hole on the axle bracket. The rear of the spring is several inches longer than the front half, so if you tried to install them backwards the drive shaft wouldn't reach!
The front of the spring is stiff, for controlling the axle, and the rear of the spring is long/soft for bending / absorbing the road.
yes was planning on supporting under the sills...
Re getting poly bushes in... I'm using standard rubber ones... I wanted poly - but couldn't find anything reasonably priced... best i found was £60 for a complete set - which is 3x the price of rubber or metalastic stuff... didn't think it was worth it...
If you can link me up to some cheap ones by the end of the week though I'd appreciate it.
|C L Carter|
|I know it probably wont work but it’s worth a try and costs very little apart from a bit of time and it cuts down on potential for damage to you or car|
spray with a penetrating/releasing fluid and leave as long as possibly overnight or a day if possible, use something like Plus Gas not WD-40
then try slightly tightening nuts to break rust/crud seal then undo, if it doesn't work try soaking again and leaving as long as possible again before retrying
I’ve had a lot of success with this method just takes a bit of time and patience
I’ve done the hole in bit wood to avoid jacking on the drain plug, not 4”x2” as I’ve nowhere near the ground clearance, I used ¾” thick wood and found hard and soft woods both crack and split under the strain
|Why not fit poly bushes on rear only? The shackle end has the most stress / unwanted movement.|
Contact Kim at Magic Midget for bushes:
x2 on what Nigel said with the penetrating oil for the Front spring hangers.
Doesn't matter about the rears or the shakles so much, you can grind them or break them, but if you sheer a head of the 2 bolts that enter the captive nuts in the chassis, you have more of a problem. So use the oil before you attempt to losen them first before you attempt to undo them. ESP if the springs are rusty and have never been removed before.
|Regarding the bushes. |
The front one is fine in metalistic it lasts for ever.
The rear ones are rubish in rubber go for poly.
Remember you get what you pay for!!
|Will defo try and get the bolts out without destructive force is poss. I have some plus gas so okay there.|
Re the Poly bushes - full set costs £70 - have inquired with Kim as to how much she'll charge for a rear set...
Everyone keeps telling me you get what you pay for... this isn't true... when it comes to selling your car... you'll never get back what you paid for all its upgrades. Unless you plan to keep the car forever... you'll never reep the benefits. Even then its debatable.
|C L Carter|
|FYI Kim is male! However, as for the you get what you pay for - if you intend a quick sale then yes, do what you have to as cheap as you can as chances are you'll sell it on - but if you intend to keep it awhile, then the difference is well worth a few quid and handling far better, so you are paying for your own convenience!|
|EEK - thanks for the warning lol!|
No quick sale... just - this is a battered up 1500 - I just want to keep it in good running order until I can afford a tax free chrome bumpamajumpa.
Is it really worth £70 v £15 ?
|C L Carter|
|you could keep the car a little longer and enjoy the benefits yourself of the better replacements for a bit|
people tend to get a bit mercenary and do the bare minimum if they think they’re going to be selling something on – great for the next owner and nice attitude, reminds me of official and unofficial car traders and car businesses
|Yup - it is!|
And, having driven both 1500 and 1275 - that's not always worth the price difference!!!!
For poly bushes try here
I got a remarkably good deal on a whole car set buying from them at Stoneleigh a couple of years ago. I only got round to fitting the rear bushes and spring pads earlier this year and they really do make a difference! It may have had something to do with my old rubber spring pads being completely shot however!
If I feel brave enough I may get round to doing the fronts this winter. If the difference they made at the back is replicated, it might be worth the hassle!
Part of the reason I've been putting it off is the thought that if I start with the front bushes I'll end up replacing the whole of the front suspension. I've a mild leak on my nearside damper and that is tempting me down the Frontline route but the cost these days is eye watering and as I said to Gary at the Ace a couple of months ago, my wife believes nothing for the Midget costs more than £50 a pop!
|One further comment on using penetrating oil on the front spring mount bolts that go up from underneath the car into threaded blocks welded on top of the floorpan - use the openings in the floorpan to get the oil onto where the bolt comes out of the top of the block. If you're just spraying it on the bolt head, you're nowhere near any engaged threads because the thickness of the bracket and the spacer bar leave the bolt head a good 3/4 inch farther down. There's a large opening on the inboard side and a small, round opening to the outside. I didn't do this on the first side I did last fall and broke off both bolts which lead to a lot of drilling and filing work to get the broken off bolts out. Got it right on the other side.
|To address Ron Koenig's question - from your description, it sounds like you put yours in right. I installed mine the same way the originals were oriented in the car. In this photo, the front of the spring is to the left. The new springs came with the front bushing already installed and that matched the way the old springs were oriented as well.
|Thanks for the links. Very useful. Got some much better quotes now - I'm definitely going poly now. Although shame you can't get the front of the rear susp bush in anything except metalstic from these people.|
Perhaps I should also do the front end while I'm at it... I dread potholes at the moment cos of the big clunk that arrives when I go over it!
|C L Carter|
|rear set @ £34 delivered from Doug at Autobush. Happy with that. Roll on the weekend!|
|C L Carter|
|I just rebuilt one of my springs a few weeks ago, and can echo most of the above comments. I was lucky and got everything undone without breaking or rounding off any nuts/bolts. Just note that in the past I twisted off one of the shackle pins while replacing bushes, so it's best to order new shackles... and all other hardware, for that matter... before you start the project.|
As for getting things apart, I supported the car on the affected side with a jackstand and a board, just inboard of the forward spring hanger. I undid the nuts on the U-bolts first, and was then able to jack the axle up off of the spring and support it with another jackstand. This unloaded the spring, and it was then pretty easy to undo the rear bracket and front hanger and drop the spring out.
I had a broken leaf on this particular spring, and decided to replace just that leaf (with one from a donor spring) and not the entire spring. I cleaned the surface rust off all the spring parts and bracketry with a wire wheel in my electric drill, and then painted everything separately with a black POR-15 type stuff in rattle cans.
If you do a spring rebuild, you'll want new rebound clips. (I.e., the straps that go around the leaves.) I got mine from Eaton Springs in Detroit... they arrived as flat straps, so I had to come up with a method of bending them around the springs. I made patterns from strips of cardboard, noted where the bend lines needed to be, and then marked the parts, drilled the retainer clip and locator holes, chucked them in my vice, did the initial bends with a hammer, then clamped them to the springs with C-clamps and finished fitting them with a hammer - with the entire spring held in the vice. This worked a treat, and once I'd fitted them I sprayed them with the same black paint. Note that I also fitted rubber isolators between the rebound clips and the spring, as original.
I also fitted poly/vinyl spring liners between the leaves. I ordered them from Speedway Parts (http://www.speedwaymotors.com/Spring-Liners-with-Lip,2079.html), but you'd probably want to source such bits on your side of the pond.
Rebuilding the spring was a bit of work, but it was considerably cheaper than buying new (at least here in the US), and even though new Springs from Moss are apparently better than they used to be, I decided I'd rather rebuild than replace.
By the way, the front bush is a very tight fit. I tried drifting it out with a socket and a small sledge, but then found it was easier to twist the inner bit out with vice grips and then split the outer sleeve by running a hacksaw blade in, making a cut through one side, and then whacking it out with a hammer and screwdriver.
Hope this helps,
|Thanks for you ideas. I hope I don't break the shackle bolts! Cos I haven't got any in as back up... An extravagant extra insurance plan if you don't break them. |
I have got new U bolts and mounting bolts and new front hanger brackets though.
What I have noticed is that what starts as a simple and cheapish job - quickly esculates to spending lots of money on lots of bits.
|C L Carter|
You're just unlucky because you are the first person to have done this job on your car (by the sound of it). But next time, because you will keep everything rust free, it will be easier and cheaper.:)
P.S. I spray my springs, bolts etc, in WD40 once a year or so. Sadly this will give Nigel ammunation to accuse me of being a service nutter. LOL
|One little part to remember also is the little "top hat" or "saddle" that sits on top of the axle and upon which the u bolts sit. They usually always rust away.|
|>>I spray my springs, bolts etc, in WD40 once a year or so<<|
tut, obsessive behaviour
|>>> I hope I don't break the shackle bolts! Cos I haven't got any in as back up... <<<|
Well, even if you don't twist one off you may want to check the condition of the pins in the old shackles. If they're even slightly corroded, with any roughening of the surface, they'll be very hard on any bushes you install. That's the "other" reason to replace them.
Oh, I didn't mention above that the bolt that runs through the bush at the forward end of the spring was rather difficult to get loose. Meaning, I had to chuck the front spring hanger in a vice and go at the bolt with a socket and breaker bar. It did NOT want to let go.
Remember too that when you're done, and buttoning things up again, don't tighten the shackle nuts until you've lowered the car and put full weight on the wheel to get the spring to normal ride height. Otherwise you'll preload the bushes with a twist that will always be there, and perhaps cause them to fail early.
|Christian, not sure where exactly you are but if unlucky enough to bust anything over the weekend I have a large boxfull of good s/hand parts - shackle brackets etc - to get you out of trouble, I'm in Wokingham so hopefully not too far.|
|Thanks David, very kind - if you drop me an email, carter.christian @ gmail.com with your contact number then you may well expect a call from me. Hopefully I won't need to though!.|
I was plannning on covering everything in copper ease so it comes apart again!
|C L Carter|
|Never mind... I'm just being an IDIOT!|
|C L Carter|
|Re-reading your original post, I see that you're replacing your springs just because they're rusty. If they're still holding an acceptable ride height, there shouldn't be any need to replace them. Just clean them up and paint, and you probably won't even have to disassemble them.|
As for the mounting bits and hardware, yes - replacing all that would be a good idea, and a smaller expense than new springs.
The spring that I rebuilt had the usual coat of surface rust, but a wire wheel made short work of that. Once painted, the spring looked like new, as did the mountings. I want to do the same for the other spring during the off-season.
I don't recall if it was mentioned above, but if you install a spring backwards it will be painfully obvious. The measurement from the spring's center pin to the front eye is noticeably less than from the pin to the rear eye. If you get one in backwards, the axle will be located well to the rear of your wheel opening.
|So I was all set to start changin my leaf springs over when I first detected my Saddles looked like this... job postponed until new saddles arrive.|
I dropped the fuel tank instead and repainted it! Looks lovely now.
|C L Carter|
|Yep, I agree, that is rusty.|
Where was it sitting?
Often it's all covered in oil and crud, but yours are bone dry.
|Its previous owner is a friend of mine... has all sorts of classics in various conditions... all garaged up. He has had it for 4 years so its been dry for that long. I'm now keeping it on the road so I need to address these rusty bits! |
There are some more photos here: you'll have to copy and paste the address into your browser.
|C L Carter|
|Hi Can't access the pics.|
Anyway, when I said dry, I meant as in no oil or grease. If it was stored dry, then that rust is old rust. Probably looks worse than it is. But def new u bolts and ancilliaries.
This thread was discussed between 08/11/2011 and 14/11/2011
This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.