TheSamba.com :: View topic - IRS Axles 101

Mon Jan 14, 2008 1:22 pm

I assembled the rear of my car - rolled it out into the driveway and figured out that the the rear track is too wide. i have 5.5" silver mangels with 185-60-15.

i have an extra set of IRS trailing arms (used) coming in a week or so. i will be cutting them to narrow the rear, but i need to find out about axles first.

from whati can tell (searching here and google) is that they come in a few standard sizes.

15 5/8"
16 1/4"
16 3/4"
17 1/4"
18 3/4"
19 1/4"
20 1/4"

http://www.swayaway.com/Axles.php

i have a 1974 IRS beetle chassis. I did pull the axles, but have not taken the CV's off to measure them.

Does anyone know what came stock on the 74 chassis? i think it's the 16 1/4" one??

There is also a Type 3 axles (passenger side only) that is shorter (is it 1.5" shorter? )

Ideally, i'd liketo gain about 1.5" on either side.

i do know about hte trailing arms that you can buy that are already narrowed. i plan on making mine fit the axles i buy.

any help by folks who have experience here is greatly appreciated.

thanks.

Tue Jan 15, 2008 12:54 am

Stock Beetle axles are 415.5mm long.
The LEFT axle from a Type 3 with an automatic axle are 26mm shorter, or 389.5mm.

Tue Jan 15, 2008 9:33 am

so what are the 15 5/8" (396.875mm) length axles from?

16 1/4" (412.75mm - or 415.5mm?) stock IRS beetles?

Does anyone know a sorce for the type 3 LEFT axles?

Tue Jan 15, 2008 11:44 am

did some digging and found this:

http://listarchive.type3.org/archives/2003/december/msg00466.html
Quote: > MT shafts are 415.5mm/16.357"
>
> AT LH shafts are 389.5mm/15.333"
>
> AT RH shafts are 439.5mm/17.302"
>

It's comforting that LH auto + RH auto is about 2 x manual.

http://listarchive.type3.org/archives/1998/december/msg00655.html
Quote: You're right! This info is not in the Bentley; I'm really surprised.
Here is what you need, taken from various other sources.

Type 3 Double Joint Axle driveshaft lengths (b: OAL)
MT: 415.5mm, 113 501 211, code # 1 on end of shaft
AT-L: 389.5mm, 311 501 211B, code # 2 on end of shaft
AT-R: 439.5mm, 311 501 212B, code # 3 on end of shaft

So you can see that the type 3 MT uses the beetle shaft, but the type
3 AT uses two different shafts, one shorter and one longer than the
MT. Type 2 half shafts are all completely different.

http://www.shoptalkforums.com/viewtopic.php?p=8249...cebbd15800
Quote: OVERALL BETWEEN CIRCLIPS
Type I/III (4-spd) 415.5mm 405.3mm
Type IV (4-spd) 435mm 433mm
Type IV (Auto) 435mm 427mm
Type III Auto LH 389.5mm 379.3mm
Type III Auto RH 439.5mm 427.3mm
Type II (4-spd) 476mm
Type II Auto LH 457mm
Type II Auto RH 505mm

http://www.blindchickenracing.com/How_to/CVJoints_Axles/axles_101.htm

Tue Jan 15, 2008 3:35 pm

source for complete short IRS T3 axles
http://www.chircoestore.com/catalog/product_info.p...0ske5urgj6

EMPI makes em

Wed Jan 16, 2008 12:05 pm

wow - this forum has been pretty much no help at all...

anyway - for anyone looking in the future (via search):

John at aircooled.net says the 1.5" narrowed trailing arms:

work with:
http://www.aircooled.net/new-bin/viewproductdetail.php?keyword2=cfa0004

this means that 15 5/8" 33 spline (stiock T1 style) axles work.

Wed Jan 16, 2008 2:46 pm

I'm guessing i'm gonna be going this route in the future with 9" wides in the rear.

I'm trying to tuck them just under the edge of the fenders (+1.5") but had no idea what I was in for. I had the option of different offsets on my rims, but only the one was available and the rest were on indefinite back order due to popularity.

Sucks you had to go through all this on your own (a PITA, i know) but thanks for posting the info here. It's been bookmarked.

Kenney

Sun Jan 20, 2008 10:58 pm

westcoast-paul wrote: wow - this forum has been pretty much no help at all...

anyway - for anyone looking in the future (via search):

John at aircooled.net says the 1.5" narrowed trailing arms:

work with:
http://www.aircooled.net/new-bin/viewproductdetail.php?keyword2=cfa0004

this means that 15 5/8" 33 spline (stiock T1 style) axles work.

I had inquired about these last year. Several messages sent to technicalquestions@aircooled.net, with NO response. I did get a response from another member here that said the fitment was terrible...then, somewhere John said the jig was messed up, and fixed. Since I never got replies from them, I move my business elsewhere.

Wed Feb 13, 2008 10:19 am

bump for a thread reference: http://www.thesamba.com/vw/forum/viewtopic.php?p=2826764#2826764

Wed Feb 20, 2008 9:58 am

welder i used:

cut bearing housing at 90 degrees completely through the arm:

weld plate (thicker than arm housing) inside and out:

carefully measure and weld bearing housing on (note that this was cut at 90 degrees (laser marked), so it sits flush:

Cut and weld new cap on:

Add re-enforcement:

clean , grind, marine epoxy and compare to stock IRS:

Stub axles being removed:

Note - this was narrowed 30mm (~1.2")
the difference in axle length is 26mm (1"), but there is available play int he CV's that i used. also note the 1.5" trailing arm above uses the same 389.5mm axles / CV.

Wed Feb 20, 2008 11:10 am

That's brilliant!

Thanks Paul. It's certainly going to help my mate should we go this route.

I still *sigh* haven't gotten around to the chassis builder - dependant on someone else - so I can't get photos and measurements.

I presume measuring and cutting the arms to match up with the T3 auto axles will solve the 'play' problem, or is this a general problem when modifying the TAs?

Thanks, N.

Wed Feb 20, 2008 3:28 pm

Great work/documentation Paul. Great stuff!

Wed Feb 20, 2008 11:17 pm

What happened to the snubber mount? What brakes will you be using?

Thu Feb 21, 2008 9:34 am

i cut off the snubber mount.

i have converted to wide 5 brakes (this in itself was a tech article).

Fri Feb 22, 2008 12:41 am

Not gonna put the snubber mount back on?

Mon Feb 25, 2008 9:40 am

^ nope.

i installed them last night. They fit perfect. and can go uber low without the snubber on.

Sun May 04, 2008 10:21 pm

i've been studying how you narrowed your trailing arms and really like it.
could you go any narrower do you think? or is that it?

what i am looking to do is put irs in my 61 beetle and have it the same width as the short swing axle that is stock for my car. or atleast very close.

i'm not sure how much wider a stock irs set up is compared to a short axle set up..

Thu May 15, 2008 5:44 am

when weldng the bearing carrier back on, could you change the angle to get rid of some negitive camber that happens even with IRS?

Wed May 21, 2008 8:41 am

volksmike wrote: when weldng the bearing carrier back on, could you change the angle to get rid of some negitive camber that happens even with IRS?
absolutely.

I redid these with a jig though. I was out by a few mm (not very much) and the tire was off, so i had to correct it.

I suppse you could adjust the jig to compensate the negative camber.

also - you are limited by the axle choices. These are the narrowest ones available that are OEM. any more narrow and you need custom axles (read: $$$$$)

Thu Nov 19, 2009 5:13 pm

to put all the info in one spot:

http://www.chircoestore.com/catalog/product_info.php?cPath=257_258_308&products_id=4446