Sprint Silencer Fixing

[William2]

Am I correct in saying that the single pipe Sprint silencer box is only attached to the underside by the rear hanging strap? Mine is stainless steel and feels quite heavy to rely on one fixing point if that is the case.

[oldelanman]

There should be a bracket at the front of the muffler mounted on 2 rubber bobbins. Mine is homemade and slightly modified as they tend to crack over time but you get the idea.

There should also be a bracket supporting the pipe on the back of the gearbox.

[gjz30075]

On my Federal Sprint, there's a bobbin moulded in the body for an attachement for the rear of the muffler. This said, the Parts Manual shows the Sprint muffler having a provision for something to attach to it but shows nothing else. Every Sprint I've seen has a rear attachment. My bobbin was perhaps added later. It just clears the spare tire and works we

I know there are other Sprint owners on this forum, hopefully they'll chime in.

Greg Z

[rcraven]

My muffler hangs from a coat hook in my hallway. My Sprint's silencer hangs from a rear bracket much like Roger's.
PS, Roger, the underneath of your car looks far too clean.

[john.p.clegg]

John

[pharriso]

I have the muffler bracket at the front of the box (as Roger's) & a rear mounting:

I do not have the bracket hanging off the gearbox.

I was originally missing the bracket at the front of the muffler & had a bodge on the rear of the muffler, I acquired all parts through Ray (RDent.)

[oldelanman]

My muffler hangs from a coat hook in my hallway. My Sprint's silencer hangs from a rear bracket much like Roger's.

Well..........does your silencer actually silence the exhaust of your Sprint or merely muffle it ? I rest my case.

[William2]

Gentlemen, thankyou for your help and the photos. It looks like there are two different mounting methods depending on whether the silencer has the front bracket attachment.

[oldelanman]

Gentlemen, thankyou for your help and the photos. It looks like there are two different mounting methods depending on whether the silencer has the front bracket attachment.

I think the muffler (silencer) should always have both front and back brackets, not one or the other. The parts list shows both, and the gearbox bracket too.

[pharriso]

I think the muffler (silencer) should always have both front and back brackets, not one or the other. The parts list shows both, and the gearbox bracket too.

Agreed

[rcraven]

I think the muffler (silencer) should always have both front and back brackets, not one or the other. The parts list shows both, and the gearbox bracket too.

Yes, mine has front and rear supports.

[Grizzly]

Bring this back from the dead a little but can any one tell me what size Rubber bobbins are needed for the front back box mount? I have just been to my local Exhaust shop and they have about 15 different sizes and as i forgot to order some with the Brackets (which haven't arrived yet) i'm not sure how tall etc they need to be?

Also, Is there a bracket or a backing Plate on the Inside on the boot floor behind the Bobbins or just penny washers?

Thanks.
Chris

[Concrete-crusher]

Good pictures , particularly the gearbox bracket , can I ask what the ground clearance is at the lowest point ?

You may have seen my thread showing 70mm

Steve

[elanner]

Ah, the S4 twin box silencer/muffler doesn't have a support at the front. There's just the strap at the rear, as Phil's photo shows (in his case with a single box Sprint silencer).

This seems to be a weakness of the S4 twin box implementation because the silencer weight inevitably pulls down on the intermediate pipe, slowly separating the two, reducing ground clearance at the joint and leaking. From other replies I've now learned that the Sprint single box silencers fix this problem by having both front and rear brackets. So I guess I should put some effort into figuring out how to implement this on a twin box S4 silencer. Currently mine only grounds with two people on board going over a nasty dip, so it may linger on the to-do list.

As for the gearbox bracket, there are several good notes in the forum that describe why it's important to have it. Essentially, without it, the entire exhaust system hangs off the head manifold studs. As the engine torques left and right the studs have to twist the entire exhaust, overcoming the leverage of the downpipe. This can't do the studs, or the manifold and Y piece joints much good.

When the gearbox bracket is installed the exhaust is firmly held in two places, and can readily twist the intermediate pipe and silencer. The gearbox bracket is, of course, a solid connection while the silencer brackets are flexible.

The only wrinkle is that the gearbox bracket bolt sizes seem inadequate, so I opened mine up a bit to take the next larger size bolt.

Nick

[pharriso]

The only wrinkle is that the gearbox bracket bolt sizes seem inadequate, so I opened mine up a bit to take the next larger size bolt.

Nick

Be warned that if you remove the 2 bolts that hold the gearbox bracket to the gearbox that oil will poor out (ask me how I know ). Ended up having to remove the whole transmission mount to get to those 2 bolts... One of those 30 minute jobs that ends up taking 2 hours!