Torque Mount / Dog Bone

[lookforjoe]

I've gone through two dog bones from Vicks in a year or so - not many miles, and the bushings have torn the same way both times.

I had modified a stock mount previously with a Volvo torque mount bush (with the open slots like stock) but the bushes were already worn when I put them in.

So, I took a pair of Volvo 240 control arm bushings (1205825) and made them fit.

File out dog bone about 1mm to 37mm ID (bush is 38mm OD

Press bushing until flush on the backside

Then cut down topside shoulder to slight protrusion off face of dog bone.

EDIT: Added sleeves inside to bring ID down to the M8 bolts, I used a pair of old Fiat valve guides.

Back in the car - this is more rigid

 

[kmead]

I had been considering a dog gone from them. My 85's doggone is like new. My 87's allows the engine to rock to and fro which is not good.

How much of the bushing from the 240 ends up sticking out, enough to get it on a metal cutting bandsaw?

A little confused by the "File out dog bone to 37mm ID (bush is 38mm OD)", its not clear what part is going to be the right size. The rubber? Is there an outside steel sleeve on the rubber of the Volvo part?

Nice sneaking yet another Volvo part in there.

 

[lookforjoe]

How much of the bushing from the 240 ends up sticking out, enough to get it on a metal cutting bandsaw?

A little confused by the "File out dog bone to 37mm ID (bush is 38mm OD)", its not clear what part is going to be the right size. The rubber? Is there an outside steel sleeve on the rubber of the Volvo part?

Nice sneaking yet another Volvo part in there.

240 bushing is on the counter - steel sleeved. Remnants of first bushing is sitting below dogbone in pic. I'll pull it out the scrap pile tomorrow & take a pic/measurement. The ID of the dogbone is increased by 1mm so that OD of bushing is an interference fit. Hopefully that makes it clearer

 

[kmead]

Thats what I thought I saw, clearer.

So it is steel on steel interference fit of inner Fiat dog bone to outer Volvo part with a rubber bush inside the inner steel of the Volvo part. Any concerns about the thin edge of the dogbone profile allowing the shallow overlap of the Volvo steel outer sleeve to drop out and into the deeper recessed part of the dogbone?

 

[lookforjoe]

Thats what I thought I saw, clearer.

So it is steel on steel interference fit of inner Fiat dog bone to outer Volvo part with a rubber bush inside the inner steel of the Volvo part. Any concerns about the thin edge of the dogbone profile allowing the shallow overlap of the Volvo steel outer sleeve to drop out and into the deeper recessed part of the dogbone?

No. I pushed the bush in enough so that the steel sleeve sits proud of the dogbone lip by approx 1mm, and the dogbone lip (original) is pretty meaty - I didn't measure it though.

Don't forget sleeves are needed to reduce the ID for the Fiat mount bolts. I can measure one of the valve guides I used to give you reference values.

Also the inner sleeve needs to be filed to remove the serrations visible in first pic - to make sure full bushing width does not exceed stock gap in brackets.

EDIT: I also removed the original Fiat bush with a holesaw - that leaves a section of the bush sitting within the lip area of the dogbone. I did not remove that before pressing the new bushing in. Just use plenty of grease/lube when pressing the bush through.

 

[Dr.Jeff]

Nicely done Huss. Thanks for sharing it.

Any concerns about the thin edge of the dogbone profile allowing the shallow overlap of the Volvo steel outer sleeve to drop out and into the deeper recessed part of the dogbone?

That was my first thought. But it sounds like a tight enough press-fit.

There are also some old threads with other approaches to rebuilding the dogbone: NAPA shock bushing # 650-1110, old American car (50's GM?) engine mount insert # 31-2123, Fiat 124 rear trailing arm bushings. All are along the same concept; remove part or all of the original rubber, modify things as needed, press in new item, modify more as needed. Each seem to have its pros and cons but all appear to be good candidates. Yet another task on my list, although the existing mount isn't too bad so it might have to wait.

 

[kmead]

Thanks for bearing with me Hussein. I appreciate you clarifying it for a compleat idiot.

Karl

 

[lookforjoe]

Thanks for bearing with me Hussein. I appreciate you clarifying it.
Karl

Hi Karl

With the Volvo bushing, about 7-8mm is cut off the shoulder side. I used a angle grinder with cutting disc, hence the messy cutoff

Outer serrations that need to be ground off

Cross section of bushing, and Valve guide I used - 18mm OD 8.5mm ID

Insert/bushing must be cut down to 40-41mm to match bracket spacing / stock mount