Driveshaft Loop

[Fixit]

Not trying to be a smart-azz here... but what is the actual need for a safety loop on a shaft 20" long?
(Maybe a strap across the tunnel under the front U-joint, but a full SFI loop? As someone who has snapped one on a "full size" car, and sheared a pinion shaft as well, I know the need with a 5 foot long driveshaft...)

I'm thinking more a scattershield in the U-joint "fling" zones... .040 aluminum between me and 5000+ rpm shrapnel isn't healthy.

[phileas_fogg]

I believe the idea is to prevent the free end of a broken drive shaft from "helicoptering" and taking out the transmission tunnel frame, seat, and legs.

Most of us building street machines install some version like the Metco safety loop, pictured below.


John

https://farm5.staticflickr.com/4300/36123030332_90be987c60_k.jpg (https://flic.kr/p/X34YpN)IMG_3369 (https://flic.kr/p/X34YpN) by jhsitton (https://www.flickr.com/photos/91016165@N07/), on Flickr

[FLPBFoot]

Not trying to be a smart-azz here... but what is the actual need for a safety loop on a shaft 20" long?
(Maybe a strap across the tunnel under the front U-joint, but a full SFI loop? As someone who has snapped one on a "full size" car, and sheared a pinion shaft as well, I know the need with a 5 foot long driveshaft...)

I'm thinking more a scattershield in the U-joint "fling" zones... .040 aluminum between me and 5000+ rpm shrapnel isn't healthy.

I think its pretty cheap insurance. If you look where you will be sitting, basically your hip and kidneys are about a foot from the shaft, anything coming through 0.040 AL sheet will be going into you. Anything to help control the chaos happening down there is a good thing. At build school they tell a story of one cutting right through the 3/4 tube like it was nothing. Guy walked with a limp after that. For $130 Metco loop with easy installation to me it's a no brainer.

[Papa]

+1 Cheap insurance.

Super simple to install, too.

https://thefactoryfiveforum.com/attachment.php?attachmentid=94617&d=1538592041

[Fixit]

Gotcha guys...
My head is still somewhat into lets say "longer wheelbase" cars.
As I think about it, these things are pretty much like vintage front engine dragsters - you're sitting on top of mechanical mayhem, and your nuggets are really at risk.

[Railroad]

Well, this thread cost me $150 or saved me from physical harm, just put in an order. I am still building, nearing the 1st go cart stage and this is a good time to install the loop.

[Jacob McCrea]

I've seen on this forum photos of a roadster's driveshaft failure and yes, "mechanical mayhem" is an apt description. Having seen the impressive damage, I installed Forte's loops on both u-joints, and may put some titanium sheet inside the tunnel at some point.

[initiator]

I've seen on this forum photos of a roadster's driveshaft failure and yes, "mechanical mayhem" is an apt description. Having seen the impressive damage, I installed Forte's loops on both u-joints, and may put some titanium sheet inside the tunnel at some point.

I like Titanium, too (especially on rub strips - great big white sparks!), but if you're looking to stop an energetic penetration, spend the same amount of money and use 4x the thickness of steel. Titanium's main benefit is at high temperatures, which doesn't help here. At the same thickness, Titanium isn't going to stop a penetration any better than plain steel.

I almost wonder if ballistic nylon would be a better choice. You know, body armor.

[JohnK]

I almost wonder if ballistic nylon would be a better choice. You know, body armor.

Your question piqued my curiosity so I did a quick search to see what's available. Nothing for driveshafts specifically, but plenty for transmissions. I don't see why you couldn't fab a cylindrical enclosure out of alumimum around the driveshaft, and then wrap it in a ballistic transmission blanket like this one:

https://www.jegs.com/i/JEGS/555/60970/10002/-1

That way you'd have 100% containment of any driveshaft failure.

[aspbite]

I have been considering a loop also. Then I saw the list of safety features of the Mark 4 roadster from FFR.
Listed is "Driveshaft safety bars". Not sure what that means

[CraigS]

Since I am not an engineer I don't know for sure but I would be leary about trans blanket material in this use. To me that works for shrapnel. If you blow a drive shaft there may be some shrapnel but the real damage is done by that shaft swinging around. I would rather contain that w/ steel plate.

[mike223]

I would be leary about trans blanket material in this use. To me that works for shrapnel. If you blow a drive shaft there may be some shrapnel but the real damage is done by that shaft swinging around. I would rather contain that w/ steel plate.



+1.


A similar concern of mine is flywheel / pressure plate safety - Steel (not cast) flywheel for me along with a Quick Time steel bellhousing - too close to the knees for comfort...


Here's a pic of a roadster u-joint / yoke failure from a few years ago:


97456

[Papa]

+1.


A similar concern of mine is flywheel / pressure plate safety - Steel (not cast) flywheel for me along with a Quick Time steel bellhousing - too close to the knees for comfort...


Here's a pic of a roadster u-joint / yoke failure from a few years ago:


97456

Great example! Looks like it took out everything in the tunnel (e-brake cables, battery cable, electrical harness). This should answer the questions about running brake and fuel lines through the tunnel.

Dave

[Jeff Kleiner]

Mike just posted the photo I was going to show---Joe Lloyd back in 2003. Thanks for saving me from having to dig it up Mike!

It's kind of like using a seat belt or wearing a helmet on a motorcycle...unneeded unless something goes wrong.

Jeff

[mike223]

Thanks for saving me from having to dig it up Mike!



lol - I looked at this thread yesterday and knew I had that picture saved somewhere...

[Jacob McCrea]

That is the photo I recall, which looks like a "once is enough" life experience.

That being said, are there any common denominators for these things failing on roadsters and the like? An imbalanced driveshaft? Improperly installed u-joints? I'm not surprised by that kind of failure on a truck with an ill-designed lift kit, or on a drag car that lifts the wheels. Assuming non-defective parts, what would you have to do (or not do) to have that sort of failure on a 2,300 pound car with 300-500 horsepower?

[Papa]

That is the photo I recall, which looks like a "once is enough" life experience.

That being said, are there any common denominators for these things failing on roadsters and the like? An imbalanced driveshaft? Improperly installed u-joints? I'm not surprised by that kind of failure on a truck with an ill-designed lift kit, or on a drag car that lifts the wheels. Assuming non-defective parts, what would you have to do (or not do) to have that sort of failure on a 2,300 pound car with 300-500 horsepower?

Jacob,
Just search pinion angle to see how many times this question enters the forum and assume that a fair number of builds are on the roads and tracks with drive line angle/phasing issues that could eventually lead to a part failure.

Dave

[Texas Driver]

What about Carbon Fiber sheets that lined the tranny tunnel? Obviously as well as using the steel the driveshaft loop. A guy I race with designs and makes customer carbon fiber wings and splitters for race cars. He might have some insight as to how well it would stop mayhem from entering the cockpit and keep it under the car. I am sure not the cheapest idea but if it would work essentially the same as plates steel and save a lot in the weight department. Thoughts?

[initiator]

What about Carbon Fiber sheets that lined the tranny tunnel? Obviously as well as using the steel the driveshaft loop. A guy I race with designs and makes customer carbon fiber wings and splitters for race cars. He might have some insight as to how well it would stop mayhem from entering the cockpit and keep it under the car. I am sure not the cheapest idea but if it would work essentially the same as plates steel and save a lot in the weight department. Thoughts?

Commercial airliners use carbon fiber burst containment around the engines. A LOT of engineering goes into their design. Which I appreciate, when I sit above the wing, in the plane of rotation for the hot section.

[UnhipPopano]

There is a difference in smallish parts that go ballistic and a driveshaft that is still attached at only one end to something driving it around and around. For example, a bullet proof vest will stop a bullet, but is not much protection from someone repeatedly hitting you with a tire iron.

[CraigS]

I think CF could be OK but it would need some careful design and fabbing. One concern would be how it is attached to the frame. For me, if I were really concerned running drag tires, I would buy some 3/16 steel plate and weld it into the frame on the inside of the 3/4x3/4 tubes on top and both sides and full driveshaft length plus an inch or two.

[frankb]

Titanium is a good choice from the standpoints of strength and low weight. However, it is really (read: REALLY!) expensive at more than 20 times the cost of similar thickness steel! Save your money and get the driveshaft loop! :)

Frank B

[Texas Driver]

I think the question has turned more into what about the miscellaneous shrapnel vs the driveshaft. I DO think the driveshaft loop for me is a must have, but that doesn't stop the U-Joint caps or pieces of the yoke that may break off from making their way into the cockpit of the car. Cars with IRS, is there a way to install a fixed pipe that would go from the trans output seal to the pinion yoke to encapsulate the entire thing and all its moving pieces?
9752097521
Metal seems a little thin for me but this gives you a visual of my thought.

[Jeff Kleiner]

... Save your money and get the driveshaft loop! :)



Awwww, come on Frank. It's that kind of thinking that keeps the wheel from being reinvented. Well that plus the fact that the wheel is working perfectly well as is. :rolleyes:

Cheers,
jeff

[Jim1855]

Now you guys have me scared to buy a new car. No driveshaft loops, no scattershield, no trans blanket, not even a fuel cell.

I'm just not going to get out of bed.

Thanks a lot, jeeezzz, yup, thanks a lot.

Jim

[Crawleyscobra]

I installed Forte's loop to contain the drive shaft and I installed 16 gauge steel plates all along the inside of the tranny tunnel to help slow down the small projectiles that might occur during a failure. I also plated the foot boxes, Just not comfortable with that thin aluminum between me and the road, which is one of the reasons mine is a hog, weighting in at 2600 lbs. But I feel safer :-).

[Avalanche325]

I think anything more than a driveshaft loop is simply not needed. A U-joint cap would have to be shot out of a cannon to come through the floor.

[rich grsc]

Awwww, come on Frank. It's that kind of thinking that keeps the wheel from being reinvented. Well that plus the fact that the wheel is working perfectly well as is. :rolleyes:

Cheers,
jeff
Ya, what Jeff said, lets reinvent the wheel at least 6 different ways, using the most outlandish ideas and materials we can think up. You know, like 1" thick stainless steel tubing, mounting the shaft inside of it, then wrap bullet proof vest material around that.

[Fixit]

About the only plausible reply has been to "Keep the shaft from helicoptering"... and beating the snot out of the tunnel (which the reply pic indicates).

A simple mid-shaft loop, and call it done. These cars have 247 other ways to kill/maim you - many of which don't involve mechanical failure.

[CraigS]

Jeez Rich, need stronger meds? I think this is an interesting discussion.

[TBull]

Jeez Rich, need stronger meds? I think this is an interesting discussion.

There aren't any stronger. We've tried. ;)

[NAZ]

I'm with Craig, this is an interesting discussion. Anytime you have a free-flow of ideas about a subject you will get a broad spectrum of thoughts. Even if you don't find them particularly good ideas some may stimulate further thought about how to tackle a problem. You may pick and choose bits and pieces of how others do things to develop your own method of dealing with an issue.

I'm glad this subject is getting attention. Having experienced two driveshaft explosions I know first hand how much damage can occur and how quickly it can happen. I used the word "explosion" as that best describes how quickly it happens and the damage reminds me of when I was in the Army using explosives to demo metal structures. So when I built my car I installed a driveshaft restraint system that exceeds what NHRA requires as I know what the risks are.

So if you're reading this thread and not quite sure if you need a safety loop I suggest you do an internet search and look for pictures of driveshaft failures and think about you and your passengers setting next to that spinning driveshaft. Then decide.

[miller7448]

Has anyone priced out a carbon fiber drive shaft?

https://www.hotrod.com/articles/the-lowdown-on-carbon-fiber-driveshafts-from-qa1/

[mike223]

A simple mid-shaft loop, and call it done. These cars have 247 other ways to kill/maim you - many of which don't involve mechanical failure.



+1.







I suggest you do an internet search and look for pictures of driveshaft failures and think about you and your passengers setting next to that spinning driveshaft. Then decide.



+1.

Another thought - driveshafts are most likely to fail at launch or on the shift to 2nd.



Flywheels, pressure plates and clutches generally fail near the rev limiter.

Just food for thought...

975469754797548

[Papa]

This one got my attention!

https://thefactoryfiveforum.com/attachment.php?attachmentid=97549&d=1542385450

[CraigS]

Wow!

[DadofThree]

This one got my attention!

https://thefactoryfiveforum.com/attachment.php?attachmentid=97549&d=1542385450

It even shattered his shirt!!



All that money and they didn't use a safety loop? Or do you think this was the result while even having a safety loop?

[Railroad]

My Metco loop arrived today. Great people and show quality product. They follow up on your order immediately. I was surprised the loop included the hardware.

[BEAR-AvHistory]

I'm with Craig, this is an interesting discussion. Anytime you have a free-flow of ideas about a subject you will get a broad spectrum of thoughts. Even if you don't find them particularly good ideas some may stimulate further thought about how to tackle a problem. You may pick and choose bits and pieces of how others do things to develop your own method of dealing with an issue.

I'm glad this subject is getting attention. Having experienced two driveshaft explosions I know first hand how much damage can occur and how quickly it can happen. I used the word "explosion" as that best describes how quickly it happens and the damage reminds me of when I was in the Army using explosives to demo metal structures. So when I built my car I installed a driveshaft restraint system that exceeds what NHRA requires as I know what the risks are.

So if you're reading this thread and not quite sure if you need a safety loop I suggest you do an internet search and look for pictures of driveshaft failures and think about you and your passengers setting next to that spinning driveshaft. Then decide.

Agree 100%. A hundred dollars or so against a $30,000 & up hand built car with a drive shaft at your hip is a no brainer.

[Papa]

It even shattered his shirt!!



All that money and they didn't use a safety loop? Or do you think this was the result while even having a safety loop?

I don't think a safety hoop would have helped much in this case, but I couldn't resist sharing the picture.

[rich grsc]

Jeez Rich, need stronger meds? I think this is an interesting discussion.
Jeez CraigS, EVER HEARD of sarcastic humor?

[SSNK4US]

Has anyone priced out a carbon fiber drive shaft?

https://www.hotrod.com/articles/the-lowdown-on-carbon-fiber-driveshafts-from-qa1/

In my early drag racing days I broke a lot of u-joints on the 1-2 shift close to 9 grand. Never twisted a driveshaft. Don’t think I ever saw one twist, it’s always been joints, u-bolts or yokes. IMHO I think twisting one our length shafts would be REALLY hard to do.
$600-$1000 carbon fiber driveshaft.... bragging rights?
$130 driveshaft loop (saved my butt many times 40 years ago)..... definite no brainer.

Kurt

Then of course line your transmission tunnel with old tiles from the space shuttle ;)

[CraigS]

Rich, sorry if I misunderstood your intentions. Sometimes things that would be obvious in a person to person discussion are not knowable over the web. :D

[Packer fan]

How about this for a driveshaft.


97594

[Papa]

How about this for a driveshaft.


97594

That looks like GoDadGo's drive shaft!

[Packer fan]

That looks like GoDadGo's drive shaft!

That is the result of a t56 magnum transmission ( a little longer than tko600) and a IRS.

[SSNK4US]

Wow!!!

[Railroad]

How about this for a driveshaft.


97594

good that it fits an IRS, not much room for axle travel.

[Packer fan]

Thank god for removable slip joints or I would have to pull the motor to change a clutch.

https://www.markwilliams.com/holland_media/shafts-rr_yokes.gif97643

[Fixit]

One of my Chevelle Club buddies posted this an eon ago... but it is useful info - the angles in the demonstration are exaggerated, but reinforces the need for accuracy...

Driveshaft angles & phasing (https://youtu.be/Idk3BVDVHq4)

[boat737]

And don't forget about the turbo encabulator.

https://www.youtube.com/watch?v=Ac7G7xOG2Ag

[Papa]

And don't forget about the turbo encabulator.

https://www.youtube.com/watch?v=Ac7G7xOG2Ag

Sounds like a typical day at work for me. Only a room full of engineers could spend an eight hour day developing and documenting a procedure for the extraction and installation of a device used to produce electromagnetic radiation in the visible spectrum produced by energizing a tungsten element encased within a vacuum.

[frankb]

I think we have drifted away from the original subject...:p

[DavidW]

You have now entered the twilight zone.

[chrisarella]

Anyone know for certain if the Metco Safety loop fits an IRS with a T56?
https://www.metcomotorsports.com/proddetail.asp?prod=MDL2500

[rich grsc]

Sounds like a typical day at work for me. Only a room full of engineers could spend an eight hour day developing and documenting a procedure for the extraction and installation of a device used to produce electromagnetic radiation in the visible spectrum produced by energizing a tungsten element encased within a vacuum.

How many engineers DID it take to screw in the light bulb?

[Papa]

How many engineers DID it take to screw in the light bulb?

None. They decided to put out a request for proposal for a maintenance contract and are now paying about $120 for the contractor to do it for them.

[Papa]

Anyone know for certain if the Metco Safety loop fits an IRS with a T56?
https://www.metcomotorsports.com/proddetail.asp?prod=MDL2500

Chris,

I suspect this would work exactly the same for the IRS cars, but give them a call. They were very responsive when I contacted them.

Dave

[phileas_fogg]

The picture I included with Post #2 is with the T-bird IRS and T5; that should give you a pretty good idea of whether the T56 would fit. Note that I shimmed the differential up 1/4" to get the pinion angle where I wanted it; that in turn forced me to use 3/4" spacers under the loop.


John

[BB767]

Looked on Fortes web site and could not find the "loop". Anyone have a direct link to it?

[chrisarella]

It isn't on the site. Just call him.

[magicmarto]

Guys,
Here is the link make for our cars:
https://www.metcomotorsports.com/search.asp?pg=1&stext=Factory+Five&sprice=&stype=&scat=

$129
Well worth the insurance-just like the quick time explosion proof bell housing.

Do it
Martin

[chrisarella]

Guys,
Here is the link make for our cars:
https://www.metcomotorsports.com/search.asp?pg=1&stext=Factory+Five&sprice=&stype=&scat=

$129
Well worth the insurance-just like the quick time explosion proof bell housing.

Do it
Martin
Thanks Martin. Are these in stock? And will it work with the extra short driveshaft in a T56-Magnum/IRS setup?

BTW, just an observation... you should add a link for Factory Five to your Vehicle navigation. ;)

[CFranks]

Guys,
Here is the link make for our cars:
https://www.metcomotorsports.com/search.asp?pg=1&stext=Factory+Five&sprice=&stype=&scat=

$129
Well worth the insurance-just like the quick time explosion proof bell housing.

Do it
Martin

Just ordered mine. I'm pretty sure this is going to be the strongest sales month in the history of Metco Motorsports thanks to this thread!

[RickP]

Guys,
Here is the link make for our cars:
https://www.metcomotorsports.com/search.asp?pg=1&stext=Factory+Five&sprice=&stype=&scat=

$129
Well worth the insurance-just like the quick time explosion proof bell housing.

Do it
Martin


yup, got mine too this week.

RickP

[JohnK]

I got mine a few weeks ago. When I reached out to them, they had just fabbed them but they had not yet been powder coated. That was perfect for me since I ordered my chassis bare, so I got a bare driveshaft safety loop and I'm going to have it PC'ed along with the chassis so they match.

[Rook]

Anyone know for certain if the Metco Safety loop fits an IRS with a T56?
https://www.metcomotorsports.com/proddetail.asp?prod=MDL2500

I'm late to this thread, but wanted to post an answer here for anyone else who needs the info:

I talked to Metco today and they said their test car actually used a T56 Magnum and IRS, so the answer is a definite yes!

[chrisarella]

I'm late to this thread, but wanted to post an answer here for anyone else who needs the info:

I talked to Metco today and they said their test car actually used a T56 Magnum and IRS, so the answer is a definite yes!
Ugh, already got one from Mike Forte but good that the info is here for others in the future.

[timmil]

Hey everyone,

Totally on board and agree with the need but I am curious how hard and how much time would it take to install on a completed car? If anyone has any tips or insights please share. :D

Tim

[Sdonnel]

If you're talking the Metco on a Mk4, my son and I did it in 40 minutes from the time we jacked the car up to setting it back on the ground. If you're talking the Forte unit, it takes quite a while longer, as you have to remove the driveshaft slide it inside the hoop and then reinstall the driveshaft. Those threaded nutserts are quite tricky to get aligned on round tubing.

Scott

[timmil]

Thanks Scott. I am going to be installing a Metco on an MK 3.1. Don't know if that changes anything.

Tim

[phileas_fogg]

That 40-minute number is best case. If you're like me, you'll need some spacers under the loop, which meant longer bolts. Between fabricating the spacers & a trip to the hardware store in Northern VA traffic, the job turned into half a day.

I also had to re-route my brake cables so that they didn't rub the loop. I didn't find that out 'til later in the build.

Still worth doing though.


John

https://live.staticflickr.com/4300/36123030332_9768b18771_4k.jpg (https://flic.kr/p/X34YpN)IMG_3369 (https://flic.kr/p/X34YpN) by jhsitton (https://www.flickr.com/photos/91016165@N07/), on Flickr

https://live.staticflickr.com/4316/35455972514_61f621b178_4k.jpg (https://flic.kr/p/W288mW)IMG_3530 (https://flic.kr/p/W288mW) by jhsitton (https://www.flickr.com/photos/91016165@N07/), on Flickr

[GTBradley]

...or spend only 20 bucks on a speedmaster (https://speedmaster79.com/Heavy-Duty-Universal-Bolt-On-Driveshaft-Tail-Shaft-Loop-Safety-Loop-Kit) universal loop and spend three days fabricating your own mounting:confused:

https://thefactoryfiveforum.com/attachment.php?attachmentid=119269&d=1576899972

https://thefactoryfiveforum.com/attachment.php?attachmentid=119270&d=1576899986

[alexmak]

Anyone experiencing an issue of the loop vibrating on big bumps and hitting a driveshaft?

[phileas_fogg]

That would have to be some bump! As you can see from the pictures I posted, there's at least a full inch of clearance between the hoop & the drive shaft.


John

[alexmak]

That would have to be some bump! As you can see from the pictures I posted, there's at least a full inch of clearance between the hoop & the drive shaft.


John

In your case, with spacers - yes. I don’t have spacers and I feel like the loop vibrates on bumps and sometimes touches the driveshaft. I’m gonna lift the car later this week and will take a closer look

[NAZ]

Anyone experiencing an issue of the loop vibrating on big bumps and hitting a driveshaft?

If your safety loop is vibrating that much I'd be concerned that it would have little chance of containing a driveshaft failure. The energy released when a u-joint lets go is impressive.

[alexmak]

OK, so here’s what my issue with driveshaft loop was:

1. It’s attached to the transmission mount in the front, but the back of the loop part is essentially hanging in the air (on the photo - right side)
https://thefactoryfiveforum.com/attachment.php?attachmentid=135498&d=1601043285
Which means that the rear part of the loop mount plate was vibrating

2. Since I haven’t used any spacers for the loop itself, it was pretty close to the driveshaft from the top
https://thefactoryfiveforum.com/attachment.php?attachmentid=135499&d=1601043306

So on some large bumps it would vibrate in way that it the loop was hitting the driveshaft.

3. Once I installed the “spacers”, the problem seems to go away
https://thefactoryfiveforum.com/attachment.php?attachmentid=135500&d=1601043328

(Unless I missed some important part of the driveshaft loop mount instructions, of course)

[boat737]

That amount of shim seems just a bit excessive. I would think you could do with half that much. Also, if your parking brake cables are anywhere close, check to make sure they are not rubbing on the edge of the loop.

I can't remember if I used a 3/8 or 1/2 shim, but it was a fine line between clearing the drive shaft (3 link) and not having the parking brake cables rubbing on it. I ended up "rounding" the edge of the safety loop so that the cables, although just barely touching, will not chafe.

[alexmak]

That amount of shim seems just a bit excessive. I would think you could do with half that much. Also, if your parking brake cables are anywhere close, check to make sure they are not rubbing on the edge of the loop.

I can't remember if I used a 3/8 or 1/2 shim, but it was a fine line between clearing the drive shaft (3 link) and not having the parking brake cables rubbing on it. I ended up "rounding" the edge of the safety loop so that the cables, although just barely touching, will not chafe.

Thanks! I started with half, but i was still able to pull the plate for loop to the driveshaft, so added more. the loop is shifted to the side to reduce the amount of touching the loop as much possible.

I’m actually reconsidering the need for this loop, since it looks like I’m going to be doing mostly street driving with a sane amount of horsepower.

[GWL]

That amount of shim seems just a bit excessive. I would think you could do with half that much. Also, if your parking brake cables are anywhere close, check to make sure they are not rubbing on the edge of the loop.

I can't remember if I used a 3/8 or 1/2 shim, but it was a fine line between clearing the drive shaft (3 link) and not having the parking brake cables rubbing on it. I ended up "rounding" the edge of the safety loop so that the cables, although just barely touching, will not chafe.

I went to mount mine and found the brake cables right in the way. I stopped and will later look at your solution.

George

[cgundermann]

If needed, Metco has some nice spacers they will shipped to you free. My setup needed a tad bit of shimming for clearance.

Chris