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MG MGB Technical - Rear Lift w/shakles

I am planning a Blue Ridge Parkway 800mi trip and want to get a little lift in the rear of my 66-B due to the added weight I will be carrying. Many years ago, we used rear leaf-spring shackles that extended the rear of the vehicle a couple of inches. My plan is to design a set that is 2" longer than the original one on the car. By the time I add the extra weight, the car should ride at a level position, which I want. The car usually has the tipical sagging rear end look. Other then the handling, does anyone see any other problems? It has had the tube type shocks added, so the extended height should not be an extension problem.
Thanks
Steve C.
And another PS-I know that the real answer is to have the leaf-springs re-done, but I don't want to get into that now.
Steve C.

Steve. I had my shackles extended by my local engineer by about 2 inches. I think it handles better now as it has dropped the front end by about 1 inch as well as raising the rear.

Tony
Tony Oliver

Thanks Tony, Did he make a new set, or extend the existing ones by cutting in half and inserting an extention? It would be an easy job to make new ones, but the pressed indentation for the bushings worry me if they are not made the same. I guess an alternative would be to make them flat and shave the bushings flat to match.
Thanks for any thoughts
Steve C.
Steve C

Steve. Mine were cut in half and welded but I am going to get some suitable steel and make new ones. I was thinking of using bolts that will be just long enough on the non threaded part to suit the distance between the two plates, if you see what I mean, so that the nut will stop at the end of the thread at the correct distance. May need a washer or two on the bolt head side to adjust that distance.

I'll be trying it within a couple of weeks and will let you know.

Tony
Tony Oliver

Tony, I had a set of shackles made 2" longer at our local machine shop. I was surprised as to how much they look like original equipment, including dimples for the rubber spacers. I will photograph them this weekend and let you see them. I am now thinking I may have went to long, we shall see.
Steve C.
Steve C.

Thanks Steve. My memory has improved and I now recall that the distance from centre to centre of the bolts was 4 inches on the finished product. I can't recall the original distance. When I get around to doing the job from scratch I am going to have longer shackles on the drivers side to correct the lean as well as raising the ride height.

Tony
Tony Oliver

I extended mine by 1.25" from 2.5" to 3.75" and that got me enough clearance to stop bottoming and grounding when touring fully loaded. If you go too far, unloaded the car will be on its check-straps all the time, unless you fit the longer rubber bumper ones, then you will have to fit the longer damper drop-arms and higher bump-rubbers to stop the dampers topping or bottoming.

Rather than insert a piece and have two welds each side I bought two new pairs (I wanted to keep my originals in case I needed to go back for any reason) and cut and shut one half of each pair to get the additional length with a single weld. See http://www.mgb-stuff.org.uk/wn_suspensionframe.htm and click on 'ride height' and 'extended shackles'.
Paul Hunt2

Yep, thats where I got all my info from. Thanks Paul.

Tony
Tony Oliver

Holly Cow, what a difference. I put my new shackles on last night and went for a ride. The difference was simply amazing. The car had the normal sag and I had 4" shackles made, probably about 1/2" to long but it was such a differance. The ride included no weight and no spare tire, with the exception of my wife as a passenger, and she even noticed the improvement in the ride. It actually felt like it had a working suspension under it. My big test was crossing a railroad track that I normally have to craul over. At 30mph, it felt like I was in a BMW***Almost. I highly recommend this to anyone that has the same problem and if needed, I will photograph them for you, but they look exactely like the original except 2" longer. What a difference 2" makes and my wife agreed, but wait, Im talking about shackles!!!!
Steve C.
Steve C.

Interesting. I went the other way & shortened my shackles by 3/4".
Carl Floyd

Interesting point Carl, I did give up cornering somewhat by having some increased roll in curves. I have a 67 parts car that has the sway-bar and I may end up rebuilding that front end and putting it under mine. Maybe someone can tell me if this will help. It is Not bad enough to cause problems in normal driving but my plan is to eat the Parkway up at times. I will just have to be aware that it's not as sticky on the road as it was when it was lower.
Steve C.
Steve C.

"What a difference 2" makes and my wife agreed" ...
Paul Hunt2

What with all of the complaints about replacing leaf springs and winding up either way too high or way too low, I don't know why more people don't do this.

I do it as a matter of course as we need to have a method of adjusting height when corner-weighting a race car. The old leaf springs probably aren't going to sag much more any time soon on a street car so adjusting height this way should serve for a decent length of time.

I just make extended shackles up using heavy band iron stock, drilled with a series of holes (starting with the stock location as you rarely need to lower the car more than the height you start with).

Use the heavier size bolts that fit through the bushings isntead of having stepped bolts machined up and drill the holes in the shackles to suit. Make sure that you use a good lockwasher or double nut the bolts so that once tightened (you don't want to over tighten) they don't move.

That way you can get more height for that heavily laden weekend and then adjust back down to normal load specification afterward.
Bill Spohn

Good point about the bolts Bill. Using two nuts would alleviate the problem of getting the bolts exactly the correct length to stop the bushes being loose or crushed. Thanks for the tip.

I did consider drilling a series of holes but thought that it may weaken the structure of the shackle. I assume this is not the case.

Tony
Tony Oliver

I finally found my before and after measurements. The distance between bolt centers on the modified shackles is 3.9 inches with the following results

Rear drivers plus 7/16 is now 14 1/4
Rear passenger plus 5/16 is now 14 1/4

Front driver minus 1/8 is now 15
Front passenger no change is now 15/1/4

(from center of wheel to bottom of
chrome strip in all cases)

The front passenger is still higher than the driver but I suspect that if I had swapped springs during the re-build this would have been cured.

Tony
Tony Oliver

Thanks Bill for the info on alternate holes, this will help when I return from my trip to put it back to slightly above level, thats my preference. Tony, it would help to know how much fuel you had in the car when measured.
Steve C.
Steve C.

Thats a good question Steve, I wish I had a good answer!

I think it is on Paul's V and B site that there is a ride height chart which shows a fair variation in the height of a number of cars. I suspect that there was no standard as far as fuel load, or any other load such as spare wheels, was concerned.

Cheers
Tony
Tony Oliver

This thread was discussed between 06/05/2008 and 13/05/2008

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