Brake Booster Clearance Issue

[Mbufford]

Hello all,

I’ve been working on getting my Whitby booster kit installed with the 1990 GT booster. I’ve looked at every thread I can find on installing this kit and haven’t seen this particular issue addressed.

I’ve got everything mocked up, and I have sufficient clearance of the U-joint by the firewall. But, the set screw makes contact with the booster, limiting steering travel each way:

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After perusing back through threads on this forum and the other one, it looks like FFR has changed the u-joints they supply, and the newer ones have a larger radius at the ends—it doesn’t taper like the ones I’ve seen on others’ builds.

So the question is, how can I address this?

My thoughts on options are:

1) slightly dent the booster body where the set screw makes contact (don’t know if this would ruin the booster)

2) get a different u-joint that has a smaller radius at the ends, like FFR used to supply. If that’s the route to go, I have no idea what part to order and would appreciate guidance on that.

Thank you in advance!

[Mbufford]

Another option that looks like it could work is to shorten the set screw enough to clear the booster, and reinstall without the locknut and with thread locker. Would this be safe?

[mrglaeser]

Can you confirm that your Booster is from a GT and not a Cobra? The Cobra booster is bigger and causes an issue. This happened to me, I had a Cobra booster and the knuckle would rub. Once I changed it out the problem went away.

Looking on web site the difference is 7.5 inch diameter to 8.75 inch diameter. So 1.25 in diameter difference cut in half is about 5/8 inch difference in clearance. That would be enough for the set screw.

[michael everson]

I have run into this and you have 2 options. Remove the lock nut, shorten the set screw and red loctite in place. The second option is to move the joint further out until you have clearance then shorten the double D shaft where needed. It shouldn't stick into any of the joints. There is enough overlap in the upper steering column so moving it wont be an issue.
Mike

[PG_Cobra]

Have you looked at the Unisteer joint with the pinch bolt design? It may give the clearance you require.

[Mbufford]

Can you confirm that your Booster is from a GT and not a Cobra? The Cobra booster is bigger and causes an issue. This happened to me, I had a Cobra booster and the knuckle would rub. Once I changed it out the problem went away.

Looking on web site the difference is 7.5 inch diameter to 8.75 inch diameter. So 1.25 in diameter difference cut in half is about 5/8 inch difference in clearance. That would be enough for the set screw.

It is the 1990 GT version. That was the first thing I checked after seeing that as an issue on a former thread.

[Mbufford]

I have run into this and you have 2 options. Remove the lock nut, shorten the set screw and red loctite in place. The second option is to move the joint further out until you have clearance then shorten the double D shaft where needed. It shouldn't stick into any of the joints. There is enough overlap in the upper steering column so moving it wont be an issue.
Mike

Thank you. I think I’ll go with the locktite route, since that keeps me from having to disassemble the linkage again!

[Mbufford]

By way of update on this, I shortened the set screw just above flush, and locktited it in. It has about 1.5mm of clearance from the booster, but that’s enough to make the close-fitting parts work together.

[Benchwarmer]

Another option that looks like it could work is to shorten the set screw enough to clear the booster, and reinstall without the locknut and with thread locker. Would this be safe?

I would be confident in this if you used a ny-lock nut.

[Jonathan D]

I have run into this and you have 2 options. Remove the lock nut, shorten the set screw and red loctite in place. The second option is to move the joint further out until you have clearance then shorten the double D shaft where needed. It shouldn't stick into any of the joints. There is enough overlap in the upper steering column so moving it wont be an issue.
Mike

Ran into this exact same issue and decided to shorten the double D shaft....you dont have to take much off it to make it all work together and clear the booster