Rear springs

[Brown Job]

Hello All,

Just seeking a bit of advice on spring lengths.  I have the saloon, where the rear springs were a progressive type and (in my opinion) not man enough for the job, being very inclined to weaken off and/or break, snapping near the top coil.  For 25 years or more, I've run on the uprated, standard rear springs for the Hatchback.  Which I just used to go an buy from motor factors, job done.  Not so easy any more.  I ordered some online, but they do seem very short - I think they are the lowered springs.  Looking at my stock of springs (for some reason I have 3 odd springs, despite always fitting in pairs), I have 3 of different lengths.  Deeply unhelpful.

So, could someone with some genuine standard length springs for the Hatch please tell me what length they are?  I'd rather ask than fit what I bought and find they are indeed too short - if the back end was any lower than it is already, the tailpipe would be ground off on the floor.

Subject to the answer, you may find a set of lowered rear springs offered on the "Parts for Sale".

BJ

[cam.in.head]

the only rear springs i have are the standard issue type. with the last turn of so of a thinner guage.and are the same saloon coupe or hatch.(pre 82 anyway)

i have never seen these available ever as aftermarket and have always used my stock of these type.dont know what i will do if i run out !    i can dig one out and do some measurements if you have a standard spring to compare it to otherwise someone who has had success with aftermarket types can advise .

[Brown Job]

Interesting.  I was always told that Hatch springs were stronger than Saloon (hence my use of the word "uprated") and to me that made sense, since the hatch load deck was more likely to be used for heavy stuff than the boot of a saloon or coupe where you'd need to lift stuff high up over the lip compared with the much smaller lip of the hatch.  One of the few good ideas of more modern cars was to do away with the blasted lip that led to bad backs when loading!

I will put my tape on the aftermarket springs tomorrow and tell you the uncompressed measurement.  They are heavy gauge springs, same thickness all the way.  Hard to tell with springs, you don't know how far they'll compress until the weight of the vehicle goes on them - by which time, you've done the work and will have to pull them out again if the body sits too low/high.

BJ

[Jessopia74]

You would expect the hatch to have a slightly heavier back end than the coupe based on the kerb weighs ( it can only be based on what the difference would be). 

[Brown Job]

I'm thinking it's not just the overall weight, but the distribution of it.  On the Saloon/Coupe, the rear screen is mainly more or less over the rear wheels, hence straight above the springs.  The boot  and rear wings are comparatively lightweight behind the springs, being of thin steel.   On the Hatch, the big glass of the tailgate is at least partly behind the rear wheels, so the very heavy glass is tending to be tail weight behind the springs.  Plus the weight of the metal tailgate itself, all weight acting on the Hatch springs with more leverage due to its distribution?

Anyway, to the business in hand.  The springs I have are Kilen ones, marked as Coil Spring Rear Vauxhall: Cavalier H/D 71-81.  (presumably a misprint as the Cavalier didn't exist until 1975) and the Item number is 71040-1

Overall length is 12.75", or 323mm for those who voted to remain in the EU.

Anyone know about these, or used them?

BJ.

[cam.in.head]

so

checking in the gm parts book. saloons and hatches can use the same spring 90093636 but strangely the coupe has a different one 90093632.

however there is a heavy duty one listed for all if required 90093633 .

i only own saloon and hatch and can confirm as book says that springs are same.

 

[Brown Job]

10 hours ago, cam.in.head said:

so

checking in the gm parts book. saloons and hatches can use the same spring 90093636 but strangely the coupe has a different one 90093632.

however there is a heavy duty one listed for all if required 90093633 .

i only own saloon and hatch and can confirm as book says that springs are same.

 

Thanks for the help with this.

So how weird is that?  Memory must be at fault, I thought it was the Hatch that had different springs.  However, good news that there was indeed a heavy duty spring listed.  I say "was", but does anyone know where they can be obtained from now?  And does anyone have any genuine new springs they can measure for me to compare with the dimensions of my aftermarket ones?

BJ

[Brown Job]

Anyone help on the spring heights/lengths? Please?  Looked back on Ride Height topics in 2012, and the comment was that overall spring length wasn't a very good guide to final ride height, as it depended on the stiffness of the spring.  However, people back then were quoting spring length on the rears of 335 or 342mm.  That makes me a bit uneasy about sticking the Kilen springs of only 323mm on the car.  The coils, however, are equal thickness (not measured it yet, but about 1/2 inch) along the whole spring, where the standard springs taper for a progressive action.

BJ

[cam.in.head]

this is the problem.so to speak. because the tapered ones rarely if ever pop up for sale .

if you have already got the springs then seeing as we are talking rear springs which are 10 mins a side to fit then its worth just putting them in to see.

ive never used any non gm for rears as i still have a few original spares so cannot offer any real advice im afraid and can only say that non gm ones for the front have always been ok ( think the last pair were SUPLEX) and were 9.5 turns of 12.9mm steel.

and like you say ,open spring length would only be a way of checking original spring or ones with a known length/ make and known to fit and work correctly.

 

[Jonathan Pounsett]

I’ve seen rear springs with and without rubber shoes. These dense rubber shoes must equate to another 10-20mm top and bottom. 

[Brown Job]

5 hours ago, cam.in.head said:

this is the problem.so to speak. because the tapered ones rarely if ever pop up for sale .

if you have already got the springs then seeing as we are talking rear springs which are 10 mins a side to fit then its worth just putting them in to see.

ive never used any non gm for rears as i still have a few original spares so cannot offer any real advice im afraid and can only say that non gm ones for the front have always been ok ( think the last pair were SUPLEX) and were 9.5 turns of 12.9mm steel.

and like you say ,open spring length would only be a way of checking original spring or ones with a known length/ make and known to fit and work correctly.

 

Yes, I may go with the idea of just banging the damn' things in and see what happens.  I have non-OEM springs on the front; unlike the OEM ones, they have NOT softened and settled with age, so the front end is permanently too high - that's why I don't want to fit over-short springs at rear.  It would exaggerate this imbalance even more, so I'd be driving round permanently seeming to climb a 1-in-7 hill...and rubbing the tailpipe on the ground.

Thanks

BJ

1 hour ago, Jonathan Pounsett said:

I’ve seen rear springs with and without rubber shoes. These dense rubber shoes must equate to another 10-20mm top and bottom. 

Not sure if there are rubbers on mine or not;  I think so, but it's not with me at present, so will ask the bloke who's got it to check when it's next on the lift.  If there are none, does anyone know the supplier?  Thanks for the reminder on this one.

BJ

[scottboyd]

Hi,

Not sure if this helps or not, I have a full set of Kilen springs (front and back) on my Exclusive coupe. They are fitted with the rubbers top and bottom. The springs are non-tapered and look just like the originals (or at least the ones that were on my car), including same un-sprung height.

Car ride height and handling is spot-on for my tastes, only slight issue is if you lift the car by the sills the rear springs become slightly unseated at the full travel of the shock. You'd still have to lean on one side of the axle to remove it so not totally falling out, just have to make sure it's seating correctly when coming down from a lift by the sills.

Previous MOT gave me an advisory for it, subsequent MOTs didn't mention it. I still mean to check (a) if the standard springs which I still have are the same or (b) if it is the travel of the shocks (KYB) that is causing it. 

Agree with cam.in.head, rear springs are a pretty easy job so I'd be inclined to fit and see how it looks and feels.

Photo to illustrate my car's ride height 🙂

Hope this helps 🙂 

Scott

[Jonathan Pounsett]

1 hour ago, scottboyd said:

Hi,

Not sure if this helps or not, I have a full set of Kilen springs (front and back) on my Exclusive coupe. They are fitted with the rubbers top and bottom. The springs are non-tapered and look just like the originals (or at least the ones that were on my car), including same un-sprung height.

Car ride height and handling is spot-on for my tastes, only slight issue is if you lift the car by the sills the rear springs become slightly unseated at the full travel of the shock. You'd still have to lean on one side of the axle to remove it so not totally falling out, just have to make sure it's seating correctly when coming down from a lift by the sills.

Previous MOT gave me an advisory for it, subsequent MOTs didn't mention it. I still mean to check (a) if the standard springs which I still have are the same or (b) if it is the travel of the shocks (KYB) that is causing it. 

Agree with cam.in.head, rear springs are a pretty easy job so I'd be inclined to fit and see how it looks and feels.

Photo to illustrate my car's ride height 🙂

Hope this helps 🙂 

Scott

I have the original springs on the rear and they do become unseated but as I also have KYB shocks I think you have pinpointed the problem.

 

I wondered why this was considered an mot failure but I suppose under certain circumstances they could pop out on the road. 100mph over a hump-back bridge for example.

[scottboyd]

1 hour ago, Jonathan Pounsett said:

I wondered why this was considered an mot failure

Teehee, the guy really hated my car and failed it on plenty. He was a little better on the retest, he said don't you like the old Fords... And the humpback bridge scenario was exactly what he quoted 🙂

[Brown Job]

Thanks for all the help guys.

TBH, not sure the photos of the Exclusive help (apart from being a really nice thing to look at of an evening) as the wheels and tyres are different (I am on 185/70/13s)  It does look suspiciously lower than mine, though, as I have a massive clearance between top of tyre and front wheel arch.  But then, I'm not sure what else was different on the Exclusive from the standard Saloon to give the ride height.  As I never lift the car on the sills, but only ever jack under the back axle - no, not on the diff, before everybody shouts at me - the idea of springs popping out doesn't worry me, as I'd not be on KYB shocks anyway.

By the way, what's a "Ford"?

BJ

[cam.in.head]

the rear spring popping out is always an issue if the free length is shorter or the shock is longer(you definately dont want this.) 

original springs could only be removed if you unbolted the shock so there was no way they could pop out. would have thought that would have been a fail rather than an advisory but wouldnt want it either way.

yes just try the rears in and see how they look. should have a thick UN reinforced rubber on the top and a thin one on the bottom ( fronts only have a thick metal  reinforced rubber on top with a retainer around them) no doubt due to the extra weight up front.