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MG TD TF 1500 - Leaf Spring Bushes Too Long?

I replaced the bushes in the spring eyes shackles on the left side of my TF today with Moss urethane bushes #280-625. I'll replace the ones on the right side tomorrow.

The combined length of two bushes is longer that the width of the spring eye or the upper shackle support. The combined length below the collar of two bushes is 1.604". The width of the spring eye is 1.499". So there is a 0.0525" (about 1/16") space between the spring eye and the underside of the collar on each bush.

I don't believe that the small shoulder on the shackle pin will keep the shackle plate from crushing the bushes when the nuts are finally tightened.

Is something wrong? Will the bushes be damaged when the nuts are fully tightened against the shackle plate after restoration is complete? Should I trim about 1/16"+ off of each bush so that they don't meet inside the spring eye?

FYI - the bushes that I removed were new Moss #282-848 rubber bushes. They split and tore apart before the car was ever driven. I don't know if the nuts were tightened when the bushes were installed. They appear to be the same length as the urethane bushes.

Thanks for your help,

Lonnie
TF7211
LM Cook

I think you might be overthinking it, just do one up and see what happens the plate will stop when it hits the shoulder--
William Revit



Lonnie.there is an article in the current totally

T-Type 2 mag about polyurethane bushes.

The bushes should be 3/4" long not including the

flange. cheers.Ralph.
R E J Stewart

Thanks Ralph, you answered my question. Of course I just now completed installing bushes in the other side of my TF before I read your post. I'll remove and trim the inside ends.

For anyone installing Moss urethane bushes, here is a picture of the problem.

The nut and lock washer are firmly against the shackle plate on the right side. The shoulders of the shackle pins are against the inside of the shackle plate. The shoulder limit the amount that the bushes can be compressed.

The shoulders of the shackle pins on the left side can't touch the plate because the bushes are pushed outward as a result of touching in the center of the spring eyes.

The red arrow shows how much too long the bushes are. And also show how much I must cut off of the bushes. I don't believe that the bushes could be crushed that much inside the eyes plus the normal amount at the plates without damage.

Lonnie
TF7211


LM Cook

Overthinking it , do the nuts up and see if it all fits up
William Revit

"Too long" shackle bushes - fixed.

I searched the archives and found a couple of posts by Tom Lange in which he said that urethane shackle bushes that he used were too long by the same amount as mine. He trimmed his to the correct length. So I trimmed 1/16"+ off of mine.

I cut them with my scroll saw. Drilled a hole in two blocks of wood for a half-inch wood dowel. Pushed the dowel through one block, through a bush, and through the other block. The holes were high enough that the shoulder of the bush did not touch the scroll saw table.

A piece of 3/4" tape around the bush acted as a cut-line. I didn't cut all the way through the dowel; only about 1/8".

Result:
Straight, square cuts on the bushes. Final size slightly less than 3/4" from tip to underside of the shoulder. The spring eyes and supports are 1-1/2" wide, so there is a gap of 1/32" to 1/16" between the two bushes inside the eyes, which was my objective.

The bushes set solidly against the shackle plates and the spring eyes/supports with no gap. The shoulders of the shackle pins are solidly against the shackle plates. Nuts fully tightened in photo. I'll loosen them until restoration is complete, per instructions in WSM.

Lonnie
TF7211





LM Cook

Lonnie, your timing is impeccable. TF 2071 sends its thanks for this thread and will have its new, modified, urethane bushes installed in a couple of days.
Chris
C I Twidle

Good article in Moss Motoring about rubber and poly bushes. Note that poly bushes should rest against smooth surface.
http://www.mossmotoring.com/rubber-polyurethane-bushings/

Lonnie
TF7211
LM Cook

So guys. What's the verdict? Are they too long? If so why? It's just as easy to make something to spec as it is to stuff it up. Is this yet another Moss cock up? If so I'll add it to the list. Cheers
Peter TD 5801
P Hehir

Aside from several typos, the terminology in the Moss article is askew. A rubber bush is unlikely to bond to a metal surface unless a bonding agent has been used as in Metalastic products, i.e. its the wrong word. More appropriately, its deformation and friction that give the required grip. As with tyres / tires, a smooth surface causes less abrasion than a rough surface. A rubber bush or pad footprint, if not constricted, expands with the applied load until friction limits movement, a Metalastic product does not.
Dave Hill

This thread was discussed between 13/04/2020 and 16/04/2020

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