Porsche 944 trailing arms conversion

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TZepeSH
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Joined: Wed Nov 03, 2004 1:55 am

Porsche 944 trailing arms conversion

Post by TZepeSH » Fri Aug 04, 2017 1:25 am

Hello,
On my 1303S I have converted to 944 brakes long time ago, using the stock IRS steel arms rear. All good, but I wanted to have the wheels spaced out a bit more to look better under the flared fenders. So for a while I used 50mm spacers from a 911, which got the wheels exactly where I wanted them. But now the guy who borrowed the flanges do not want to sell them to me, he wants them back, and I am getting back to 21mm spacers.
Soooo, long story short I got mad and thought: If I am to buy spacers (~200-300Euro) and a rear stabilizer bar (~180Euro), why not buy a 944 complete rear axle? I get to widen the rear of my car, I get the stabilizer bar, plus I get rid of using flanges which wear out the bearings much faster. So I found a complete rear axle plus front brakes out of a 944 turbo S2, I put my money where my mouth is, and now I have also a replacement set of disks (mine were worn out anyway), and a set of 4 pot calipers (mine are the older style, sliding with one pot).

Now my question: what length and out of which car do I need the axles from? I think I need longer axles, maybe Bus or 944? What flanges do I need on the gearbox? I have read the Bus and 944 flanges are the same, and I have a Bus gearbox (002, I think, 5 rib? for sure not 091). Can I get the flanges from the bus gearbox and swap directly the bug flanges (AT gearbox), or do I need to modify anything there?

H2OSB
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Re: Porsche 944 trailing arms conversion

Post by H2OSB » Fri Aug 04, 2017 7:54 am

You need the flanges from a type 181. Or you can use the type 1 stub axles in the 944 arms (Well, SOME of the 944 trailing arms). I've no idea what axles you need

H2OSB

TZepeSH
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Joined: Wed Nov 03, 2004 1:55 am

Re: Porsche 944 trailing arms conversion

Post by TZepeSH » Fri Aug 04, 2017 8:51 am

I can not use the stub axles in the 944 arm. That works for pre '85 brakes. I have the new model, with wide aluminum arms and different stub axle. Those are already on the arms, I just need the axles from arm to gearbox. The VW Bug axles will not work, I need longer ones, but I do not know how long. I've heard people used bus axles, but maybe late 944 axles work too?

H2OSB
Posts: 472
Joined: Mon Aug 21, 2000 2:01 am

Re: Porsche 944 trailing arms conversion

Post by H2OSB » Fri Aug 04, 2017 10:00 am

Well, you've shot right past my limited knowledge base. I do know the type 181 flanges are what you need on the gearbox end...well, I think so anyway.

H2OSB

H2OSB
Posts: 472
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Re: Porsche 944 trailing arms conversion

Post by H2OSB » Fri Aug 04, 2017 10:00 am

double post
Last edited by H2OSB on Fri Aug 04, 2017 3:52 pm, edited 1 time in total.

Ol'fogasaurus
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Re: Porsche 944 trailing arms conversion

Post by Ol'fogasaurus » Fri Aug 04, 2017 11:11 am

I did the flange conversion in my stock VW transaxle that allowed me to use the bus CVs. As I remember it is not a hard conversion with the two big things being getting the snap ring out and levering the old stock drive flange out (http://www.shoptalkforums.com/viewtopic ... &start=465 The dialogue of the conversion starts about half way down the page).

The third picture shows the new seal, the second one shows the new flange in place and the first pix shows the dust shield back in place.
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Piledriver
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Re: Porsche 944 trailing arms conversion

Post by Piledriver » Fri Aug 04, 2017 1:01 pm

You need 944T or Vanagon (manual trans) axles (same length) if you have the aluminum arms.
You also need the trans side drive flanges. either Thing or aftermarket.

BTDT ~recently on my squareback.
viewtopic.php?f=51&t=148560

Note the rear shocks need some attention, I ended up making something custom based on a C1500 front shock.
The RideTech Fox 2.0 truck shocks were new/surplus and cost $40 ea in the end. I cut down the stud and welded a std uniball cup on, and converted the shocks to take aparts and revalved.
(technically they are already take aparts but they used the funky needle setup which is a PITA and can be one time use)

I mounted them IFP down but I'm running coil overs and had to for spring clearance.

I used Ford FI 1/4" flare fittings for the schraders, which allows using my AC setup for charging. (and evac/charging on my fronts, which are Bilstein S6Ms with KYBs reused as reservoirs, bilstein body shortened an inch, welded on heim cups)
I, for one, regularly embrace our new robot overlords, as I am the guy fixing the robots...

TZepeSH
Posts: 169
Joined: Wed Nov 03, 2004 1:55 am

Re: Porsche 944 trailing arms conversion

Post by TZepeSH » Tue Aug 08, 2017 1:35 am

Thank you for the information! I will look for 944 or Vanagon axles. About the shock absorber, I am not too worried, I think it is much easier to find something for the Bug. But the planning is to install all the new Porsche parts next year when I will rebuild my car again, completely. For now, just shopping and work on the type4 engine.

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Piledriver
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Re: Porsche 944 trailing arms conversion

Post by Piledriver » Tue Aug 08, 2017 1:52 am

You are welcome, but note the T3 takes the same rear shock as a Bug stock, it just has fabricated steel double shear upper mounts, rather than the cast steel T1 shock mounts.

The standard T1/T3 rear shocks are absolutely wrong with the Turbo arms. The "lowered" versions are very little better.

The 944 arms shock mounts at a different height and angle vs. an IRS arm... You will probably want a much shorter shock, and it wants to be 14mm on the lower eye.(I went 5/8" as you can get std OD uniballs in 5/8" same OD as the 1/2")
Just consider it fair warning, it requires some thought to do it right.
I, for one, regularly embrace our new robot overlords, as I am the guy fixing the robots...

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