MGA Forum

Replacement Front Springs

Moss Motors
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Pawtucket, RI, USA   USA

I think you are confused, no one is saying to use the MGA Twin Cam spring AHH5789 instead of the proper AHH5546 MGA pushrod car spring which is currently made correctly in the UK. Reread Kelvin's response, and you'll see what he has said which I have copied in below.

"I knew that the MGA springs were shorter and stiffer than either the MGB or GT ones. Luckily, I had a set of original low mileage springs to test and I compared the compression curves to the range of performance MGB springs we had. It turned out that the Suplex 1" lowering springs for the MGB had almost identical free height and compression curves. The free height is 8.75" with a spring rate of 480 lbs/inch.
After some positive test fittings, I asked the catalog staff to list the 264-386 Suplex springs for all MGA applications."

Interpret as you wish.


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barneymg Avatar
barneymg Barney Gaylord
(Somewhere in USA), Pick one (or more), USA   USA
1958 MG MGA "MGA With An Attitude"
Cecelia, -- It wasn't Kelvin's note, it was your note #27 above that finally made the connection between using different springs to compensate for lower profile radial tires. You had mentioned in an earlier note, "the original specs on Barney Gaylord's MGA GURU site although are the original, those were designed to be used with old type bias-ply tires, end not with modern radial type tires, that has to be taken into account, and the UK springs we sell have been designed and manufactured to use with modern tires fitted to MGA models". Probably not intentional, but I recon that comment was confusing.

Barney Gaylord - 1958 MGA with an attitude - -

MGAdavid Avatar
MGAdavid David Werblow
Portland, CT, USA   USA
1954 MG TF
1959 MG MGA
Cecelia and Barney,

The only other person in the world who knows as much about MGAs as the two of you is Bob West.. Sure wish somebody would find out what he thinks.

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DevonMG John Russell
Okehampton, Devon, UK   GBR
The springs arrived today from the MG Owners Club. So here are the three springs for a side by side comparison.

In the middle is the original standard spring off my MKII Deluxe. This is the same spring as fitted to all the later pushrod cars.
On the left is the first spring I ordered, which Moss claim is a suitable replacement for standard MGAs: AHH6451. It's actually the MGB spec.
And on the right is the AHH5546 obtained from the MGOC which seems identical to original standard spring.

The height difference is clear to see. The wire diameter of the AHH5546 and the orignal spring is identical: 14mm. The MGB spring is 13mm.

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3 springs comparison.jpg

Be Coming Avatar
Be Coming Kelvin Dodd
So. Calif., USA   USA
Hi John.

Thanks for the images, if possible free height measurements would be very handy.
The MGB spring has a lower spring rate, so will compress more than the other two springs when fitted. I have made Moss Europe aware of the research I've done over here, but they have chosen to continue their historic listings.

A major complaint from many owners of classic British cars is that new springs make the car look too tall. This is perception is exacerbated by changing from the relatively tall, skinny bias ply tires to modern radials. The shorter tires expose much more of the inner fender and the car appears unbalanced to our modern eyes. It's important to look at period photographs of the cars to understand how the car looked when new.

With modern 165/78 - 15 radials, the MGA (and most other British classics) does need a lower ride height to look balanced. I believe that is the point being made by the UK spring manufacturer. The new free spring length in the above image being the same as the original spring tends to indicate that either the original spring is not fatigued, or the new springs are designed for a lower ride height. It's difficult to tell without doing a compression test on the spring.

Getting back to my bit of automotive archeology, which is by the way a passion of mine. The suplex lowered MGB springs (264-386/AHT21PR) that Moss US are currently recommending do drop the nose of the car by about 3/4" from what appears to be the original ride height with good condition springs. That is from Jim Alcorn, who has been using these springs in his restorations for many years. The result can be seen below in one of the cars that he built a while ago that recently sold on "Bring A Trailer". The fender gap with radial tires appears pleasing, which in the end is what I think the majority of owners are looking for.


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Pawtucket, RI, USA   USA
Dear Kelvin,

'The Plot Thickens!'

A question for clarification, the car shown in your photos appears to be a Twin Cam which takes a different factory spring AHH5789 which is different than those fitted to the pushrod MGA models. Are you saying MOSS is supplying the same coil spring for ALL MGA models? I'll check what the factory specs are for the TWIN CAM spring which should be listed in the factory service parts list and compare those to the ones in the 1500 & 1600 service parts list previously posted in my earlier posting.


DevonMG John Russell
Okehampton, Devon, UK   GBR
Hi Kelvin,

Read up the thread what Barney has said. Modern 165/80/15 radial tyres have the same rolling circumference as the original factory cross-ply. If you put them on a car with the original spec. 5546 springs, the ride height will be exactly as the car came out of the factory.

I agree the MGB spec 6451 spring which is 10 and 1eigth" long when unloaded and 350lbs/inch, will probably sit down to an acceptable level—but it will also tend to be too soft and the car will wallow when driven over an uneven road surface or cornered enthusiastically. Maybe that's why MG dropped the 350lbs/inch springs (see Barney's table) on the early 1500 cars and uprated the to the 480lbs/inch 5546 spec for the rest of MGA pushrod production.

I'm building my Deluxe to be standard, so detail matters to me :-)

Hi Cecelia

Moss sells the correct spring for the Twin Cam—AHH5789. It's only the standard models they recommend the MGB springs for.

Cheers, both.

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colynf Avatar
colynf Colyn Firth
South Yorkshire, UK   GBR
This is a picture of my car showing the ride height of my car now that I have fitted the new MGOC AHH5546 springs.

Previously I had the Moss lowered front springs and lowering blocks on the rear springs which made the car look amazing, but the ground clearances all round were just too low and I had constant problems scraping over the slightest bumps.

I was really surprised that the higher ride height has not affected the handling in any way, if anything, it is better than before.

I was also very pleased with the new ride height which I think looks perfect for the MGA.



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Pawtucket, RI, USA   USA
OK, as promised here are the specs from the AKD926 MGA Twin Cam Factory Workshop Manual for the Twin Cam front coil spring.

The factory workshop manual lists the fwg specs for the Twin Cam models as follows..

Part no. AHH5789
Coil diameter (mean) 3.28 in. (82.25 mm.)
Wire dia: .54 in. (13.72 mm.)
Free height: 9.09 in (+ or - 1/16 in (23.09 cm. + or - 1.6mm).
Static laden length 6.6" (16.76 mm.)
Static laden length at load of 1,193 lb. (541 kg.)
No of free coils: 7.2

Can anyone correlate this to the other 2 factory coil springs used for the pushrod models? AND..which spring should be used for the 1962 MGA 1600Mk2 Deluxe model, the AHH5546 or the AHH5789?

All comments are welcomed.


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DevonMG John Russell
Okehampton, Devon, UK   GBR
In reply to # 3681684 by Cecelia Bruce
AND..which spring should be used for the 1962 MGA 1600Mk2 Deluxe model, the AHH5546 or the AHH5789?

Barney mentions this on his spring page. As the Deluxe has the same sprung weight as other pushrod models, the correct spring is the one that's fitted to the standard cars: AHH5546. The T/C is a heavier engine, so the AHH5789—while it has the correct spring rate—is slightly taller and will raise the ride height slightly above the correct 6.6 inches.

And that's why I wanted the standard AH5546 for my Deluxe.

David8831 Avatar
David8831 David Halliday
Thame, Oxfordshire, UK   GBR

Back in Australia people often go to a spring works and get springs made up for them to whatever specification they want. There are such places here in the UK such as Springcoil Ltd.

I would have thought that they or a similar company would be able to make a set up for you to original specifications at a very reasonable price.

DevonMG John Russell
Okehampton, Devon, UK   GBR
Hi David

Yes, you're right. With the desired spec. (diameter, length and spring rate), as a last resort I've had springs made in the past—but typically you're looking at about £100/pr in the UK for one offs.

The correct standard springs I've now received from the MGOC cost £46.35 including VAT for the pair. So not only are they correct spec but they're almost half the price of the incorrect spec. ones from Moss.

David8831 Avatar
David8831 David Halliday
Thame, Oxfordshire, UK   GBR
That’s all got to be good news John - finally. You got there in the end. Very helpful for the rest of us too..

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