disc brake? long or short axle

[ddewey78]

so im totally new to vw stuff and im going to put disc brakes in the rear of my rail, but im unsure of if i have long or short axles. i know i saw a pic showing the difference, but i cant recall where. sooo.... how do i tell which ones i have?

[navynuke]

irs or swing axle? almost all the irs stubs are long.
if you pull your drum off, measure the length of the splines. long ar 65mm. short are about 50mm.

Ken

[joescoolcustoms]

Measuring from the spring plate mounting surface to the backing plate mounting surface is the differance in a long and short swing axle.

The short axle is about 3 3/8 inches whereas the long axle is about 4 5/8 inches.
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[dustymojave]

[joescoolcustoms]

[towd]

The only difference in those kits. Is the thickness of the rotor/hub. if you buy the kit for the short splines and use a bearing spacer they fit the long splines,

The advantage is, should you ever change axles short or long you hub/ rotors will still fit.

the extra length of the splines is all on the outer end,, the distance between the inner side of the hub and the caliper mount are all the same. That's IRS and swing axles

The downside of most the kits is the one piece rotor, on many the center Will break out, result the wheel tears the shit out of everything near.. The better rotors will have a star shape webbing on the inside at the splined hub, These seem to take the beating.. The most common sold have no webbing

another thing to look for is the kit that uses a floating caliper and not the stationary type

[ddewey78]

first off thanks for all the info

ok i should have told you its irs, but like i said im new to vw stuff. so all irs are long? i also know it has 944 axles, so wouldnt it have 944 stub axles? i have been told they r the same as vw stuff.

as for the centers breaking out, is that a common problem with on or off road stuff? its for my rail, and i dont use it too often, maybe 30 hours a year.

[towd]

The breaking of the center is anot very day thing, The first set of one piece rotrs I bought were on a F/G buggy, one broke on maybe the 3rd time out,, since I've talked to 4 others that had this happen every one didn't have that webbing

it doesn't make a difference how many hrs or times you use it,, it take takes the one time when they break. In my case I use paddle tires ... which have a very thin side wall.. Thesecenters breat the wheel lays over,, brending the caliper maybe even breaking that,, bend the mount, and putting that Hi $$ tire on the frame

now your out in the dunes maybe 2 miles from help or a parking lot, with a $300 tire at a 20 degree angle and pushed onto the frame... I was lucky the tire was ok,, nd I did find a new rotor,, only because I know the guy that owner the nearest buggy shop, 6hrs later in the middle of dune fest.. I'm back up and running..

one of the other this happened to rip up a paddle tire.. I have 5 buggys all the other use a 4 hole brake drum turned down to a hub, like a t3 hub and a mid 80's mercedes rotors, I and anyone else that I know of using the setp. have never had a problem

the one piece set i have now have the webbed rotors and those work great... when I say webbed, they might be called ribbed or a gusseted rotor, they are reinforced at the center

Both style of one piece rotors that Ihave seen are made in brazil I have no clue what the chinesne ones look like

[dustymojave]

Towd makes a good point here.

A friend of mine has had the same problem on a Baja used on the street and fairly gently in the desert. Broke out a center of a rotor in the desert 10 miles from pavement. He had company and they got it out of there. But it wasn't a fun day for them. His had the flat face on the hub area.

Another friend has a high powered long travel big 4-seat buggy beaten very harshly for years in the hard rock desert. He uses Porsche 914 rear hubs and rotors with 914 front calipers on it. 4-lug to 5-lug adapters convert to Big 5 pattern with 33 x 12.50 tires. NEVER had a problem with the brakes. They work very nicely too.
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[NatedoggAZ]

Difference between long and short axles:

http://www.dunebuggyarchives.com/ShortVSLong

ND
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[fujioko]

I hope hijacking this post is ok, This subject is almost perfect for my issue.

today I received a used rear disk brake kit (ebay). Anyway it appears the kit is for a long axle (stub). My buggy has short axle stubs...

The good news is the rotor assembly fits on my lathe, so it looks like I can cut down the hub.

Anyway I wanted to get a second opinion before I cut the hubs on the lathe.

thanks!

[navynuke]

its a sign, go IRS.
j/k

I did just the opposite, bought some gear one disc brakes at a swap meet, but they are for short stubs. I had to order the spacers.

[towd]

yes just turn those down........on the outside only

just match there thichness to your old drums

[navynuke]

ok, so I finally got those spacers, and they do not seem to fit quite right.

so what order should all these spacers ect. be in?

tapered stock spacer ---- hub ---- aftermarker spacer

or

aftermarket spacer --- hub ----- stock spacer?


with just the adapapter spacer, it is not long enough, and does not cover the splines completely.

thanks guys

Ken

[Dale M.]

All spacers to make short spline drums/rotors fit on long spline axles need to have the "ADDITIONAL" (aftermarket) spacer on outside, between drum/rotor and axle nut... Its the total length of short drum/rotor and spacer that makes it same length as a long spline rotor/drum... All "other" axle parts (original spacers, washers, seals etc:) remain in "stock" position unless kit specifically tells you to assemble some "standard" parts differently.

Dale
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[Dale M.]

[wibaja]

Where do you get the spacer from. I have not seen them. Jamar or what ever brake kit you have? I was going to make one out of tube but I would like an alluminum one to mate to the allum rotors.

[navynuke]

its an empi part. 3/4 of an inch is about right, I'll measure it in the morning when I get home.

and it shouldn't be aluminum, but hardened steel. I'm using Gear One discs, but got them at a swap meet, with no instructions for instal.

thanks for the help guys.

[Dale M.]

[wibaja]

thanks for the link