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MG MGB Technical - Compressing MGB front coil springssprings

I need advice on how to install the coil springs in the front suspension. You can see from the photo that the chassis frame is TD. But the suspension is MGB. When I try to compress the springs using a trolley jack under the spring pan, the springs only compresses partially before the car began to lift. After adding the 1800 engine, the chassis was still not heavy enough to compress the spring sufficiently. I tried passing two 3/8th all-thread shafts through the spring pan bolt holes and the matching cross member bolt holes and cranking it up but that did not work either. I had no idea how powerful these springs are ! Can anyone provide me with a working solution?

R. S. Hines

Here's what I do.
Trying to compress the spring doesn't work. You need to take the tension off the spring.
Have the car on stands and take the wheel off.
The shock is held on with four bolts. Take off the left rear and right front bolt. Replace them with a bolt about 1/2 inch longer and leave about 1/2 between the shock base and the head of the bolt.
Then take out the left front and right rear bolt, loosen them a little at a time. As you loosen them the spring will push the shock up until the first pair of bolts stop it. Replace the left front and right rear bolt with ones that are about an inch longer that the original. Leave a gap and take out the ones that were 1/2 inch longer. The shock will rise up again releasing more tension.

You can see where this is going. You might have to do it one or two more times. Each time you do, reach in and see if you can turn the spring by hand.
If you can't, use the next longer bolts. If you can turn the spring, all the tension is off. Take out all the bolts holding the shock on. Use a big screwdriver or pry bar to lever the shock up about 1/4 inch or so and pull the shock toward you. The suspension will unfold and drop a little and you can take the spring out. Put the shock back on the pedestal and put two bolts in to hold it in place.

Installation is just the reverse. Make sure the sping is seated in the spring pan and in the upper retainer. Start with the longer bolts and alternate using shorter ones pulling the shock back down.

This may seem like a time consuming way to do it, but it is much much easier that trying to jack up the spring pan and get the bolts in from the side.
Lann Mauck

You could always tie the trolley jack to the car. A loop of strong rope from the front wheels around the cross-member. Just make sure it is inline/vertical and won't slip.

However, you have other problems. If the jack is lifting the car through the spring, before the spring pan bolts line up, then when you do get the springs in they are not going to compress with the weight of the car. The suspension will be at maximum, hard up against the shock absorber bottom arm bump stops, and will stay that way.
You will need to find out the sprung weight of the front of your car. That's the front of the car less the unsprung bits like wheels,hubs and brakes i.e. 800lbs to pick a number at random. Work out how far you want the springs to compress for your ideal ride height ie 4 inches (number at random). Go buy some springs with a rating of 400/4= 100lbs per inch. Places like Hypercoil http://www.hypercoils.com/
Peter Sherman

Try a coil spring compressor. You can buy them online for $25-50. I did not need it when I redid my front suspension, but it had the engine in.

Brian Leary
r. LEARY

What I would try is remove the spring from the suspension. Bolt up the inner A-arm bolts to the crossmember (not very tight). Undo the upper trunnion bolt (joining the kingpin to the lever arm) and let the whole front hub pivot down. Insert the spring where it belongs. Prop up the hub so that the kingpin is roughly vertical. Put your hydraulic jack under the lower trunnion bolt and jack the assembly up until you can line up the upper bolt hole with the lever arm, and insert the bolt and snug it up. Let the hydraulic jack down.

This should allow you to take advantage of greater leverage at the outer extremity of the A-arm compared to jacking under the inner A-arm. If the car lifts before the upper hole lines up with the lever arm holes, then the spring has too high a spring rate for the weight of the car, or not enough of your car is assembled to weigh it down!

Once both sides are done, and the weight of the whole car is on the spring, then tighten up the inner A-arm bolts, and the upper and lower trunnion bolts. Again, you would want the car fully assembled before tightening these bolts, as this sets them so that the neutral position of the bushings is when the full weight of the car is loaded on the spring.
HTH,

Erick
Erick Vesterback

I have just done with my V8 GT conversion (with engine installed and chrome bumper spec front springs)precisely what Erick has suggested. Admittedly my springs are a little shorter than their rubber bumper predecessors but there appeared to be plenty of leeway available as I jacked things up and aligned the top king pin/lever shock assembly.
Peter M
Peter M (member)

"the chassis was still not heavy enough to compress the spring sufficiently"

Sufficiently for what? On an MGB all you need to do is compress them sufficiently to lift the damper arms off the rebound rubber (can't see these), then you can remove the top or bottom fulcrum pin, then lower the spring pan and remove the jack. After that it depends on what springs you have - the longer springs may need the two rear bolts removing from the spring pan and the front ones loosened to get the pan down far enough to pull out the springs by hand. The shorter ones should come out without that. If the body is off your TD chassis then there may not be enough weight left to achieve this, in which case you will either have to load up the chassis or use spring compressors, but I don't think there is enough room to use the external type. One I have seen uses a single bar up the middle of the spring but is contructed from a Land Rover drive shaft.
Paul Hunt 2

I had a similar problem when installing the front suspension on my MGA project without an engine. I made up a spring compressor from a couple of pieces of 1/4" plate and a length of threaded rod. I placed the plates as close to each end of the spring as I could and still clear the spring pockets in the crossmember and a arms then ran the rod between them and cranked on the nut until I could compress the spring enough to connect the upper trunion bolt. I had the lower spring pan pivot fully fastened to the crossmember. I needed some way to keep the plates from rotating, will have to add a handle or stop next time to prevent that, but otherwise it worked pretty good. I've since bought a commercial spring compressor, but I haven't tried it yet.
Bill Young

sounds like the springs you have are either the wrong height or the wrong poundage for your chassis. If you have to seriously compress the springs in order to assemble, it's going to rattle your fillings in use!!Find the length and strength suitable for your chassis.
Allan

I had the same situation but without the same possible solutions when doing the front suspension on my CGT project. That enormous lump of cast iron 6 cylinder wasn't in yet, and what's worse, torsion bars instead of coil springs! I ended up filling the engine compartment with bricks, concrete pavers, an old piece of railroad rail, and the unrebuilt head itself before I had enough weight on it to allow the floor jack to force the lower suspension arm up to the proper position! I have a picture of the pile in the engine compartment somewhere, and it was full! I sympathize with your plight.

Paul
Paul Briggs

IMHO you've gone about it in the wrong order. The fulcrum bolt in the kingpin should be the last thing to be fitted. The wishbone support should be bolted to the Xmember & fully torqued. Then jack up the fulcrum end of the wishbone & fit the bolt. Make sure the antiroll bar attachment bar is in the right posn.also , otherwise you might have to undo it all again. Barrie E
Barrie Egerton

All this discussion about various ways to remove springs. Anyone think to use a spring compressor? That's what they're for.

Undoubtedly many of the methods discussed above will do the job, but I don't see the logic in risking injury and damage to save $35 on the proper tool.
Steve Simmons

Roni,

Pretty easy if you don't have a spring compressor (I didn't have one when I did the TD) Here is a photo.

I put a chain around the axle of my jack, and up over the top of the shock. You can pad the axle. Proper spring length for a TD with a stock engine is 9.59 uncompressed. Loaded to 1095 lbs the springs should be 6.44 inches. I believe the B-Series engine is lighter than the XPAG, which weighs 326 lbs, dressed.

warm regards,
dave

Dave Braun

And here was my solution.

LaVerne

LED DOWNEY

Another shot.

LED DOWNEY

This thread was discussed between 06/03/2008 and 10/03/2008

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