Turbo brake conversion PROBLEM!

[Pokrajac]

I am replacing my trailing arms on my 944S.
The bottom lip the E brake rests on broke on mine,
so I have to replace one of the arms regardless.
I thought I bought 1986 Turbo trailing arms.Part#951 331 513 0
I am pretty sure I bought 1986 Turbo calipers. Part#20 4673 00
The hub in the trailing arm Part# 951 331 607 00
I bought disks Part #951 352 041 01 and they don't fit.
Was I supposed to buy Part#951 352 041 02 disks?
Are all these part numbers for a Turbo?

[doabarrelroll]

Sorry to break the bad news, but, unfortunately the 86' turbo has a different setup than the 87' on. I have an 87' S as well and you need the 87' turbo hubs/spindles/calipers/rotors.

[matthewb]

What is the difference? It seems like if he has all parts from the 86 turbo then it should all work together?

Is the issue with the depth of the rotor hat? I thin k the 86 cars require a spacer for the caliper mounting bolts. Is that possibly your issue?

[Pokrajac]

A spacer sounds like the remedy.
What does this spacer look like?
Where do I get two?
When I assembled everything
last week, everything fit, until
I torqued down my hubs!
The depth of the hat is too deep.

[Techno Duck]

The spacers are used on both late and early offset cars and the calipers are all interchangeable regardless of year. The spacer is simply a 1/2 washer you can get at any hardware store, it goes between the caliper and mounting tabs on the trailing arm.

I'm not on my computer (phone) so can't check PET, but the part combos you are using may be your problem because you are using early offset components on a normally late offset car. So unless you swap the entire suspension you will have late in the front and early in the rear.

[pontifex4]

Just to add to what TechnoDuck said: when he told me about these washers, I picked a handful up at a hardware store to do the job, but I did find that they were just a little thin on my late offset car. I suspect that the actual Porsche parts would center the caliper a little better over the rotor.

[matthewb]

I think the actual thickeness is supposed to be about 4mm. If you are going to do the hardware store washers at least try to get ones of uniform thickness. Done match a thick washer with a thin washer when you put them on the car. I dont think it would be good for your caliper to be mounted crooked.

[smokin_944]

Originally Posted by matthewb

What is the difference? It seems like if he has all parts from the 86 turbo then it should all work together?

Is the issue with the depth of the rotor hat? I thin k the 86 cars require a spacer for the caliper mounting bolts. Is that possibly your issue?

For 86 turbos, the rear spacers are 999 025 131 01 I believe. They are different for later years because of the different offset.

[smokin_944]

Pokrajac, did you check both sides of the casting on your 86 turbo calipers? I have a pair in the office, casting numbers 20 4557 00 and 20 4558 00 (both halves). I believe they are 86 calipers. The casting date is stamped, 85 in my case.

[Techno Duck]

The spacer is the same regardless of offset, 999.025.131.01 being the part number as stated. I have never had problems using a 1/2 inch washer in place, granted i am sure the dimensions of washers vary from manufacture.

[smokin_944]

Thanks Techno Duck! Of course I ordered the spacers from ******** Porsche $8.28 each, lol... Porsche OEM hurts.

[Cocacolakidd]

The calipers are the same for both early and late offset - The different parts are: for the rear are the rotors only with their early or late offset hat depth. For the front the hubs, spindles and rotors are different between na's and turbos - also the turbos are different for early and late offset in the spindles and rotors. Use of 16" wheels required for the turbo brakes.

Also check on the use of the washers in the rear set-up as the trailing arms are at an angle and the washers are used in the rear at one spot only to even up the caliper angle mounting over the rotor. Part No. 999 025 131 02 is a spacer at 4mm thk. - one spacer to each caliper.

[Techno Duck]

Originally Posted by Cocacolakidd

Also check on the use of the washers in the rear set-up as the trailing arms are at an angle and the washers are used in the rear at one spot only to even up the caliper angle mounting over the rotor. Part No. 999 025 131 02 is a spacer at 4mm thk. - one spacer to each caliper.

That is incorrect, two spacers are on each caliper.

Also the hubs are the same between the 951 (non-S / M030) and n/a.

[smokin_944]

I'm guessing the second part number is 900 028 014 02. From the diagram, it looks like a lock washer. That is what the manual says. Lets recap. On 86 turbos, 2 spacers per caliper, 2 lock washers per caliper and all should be good.

[Techno Duck]

Yes, it is one of those very thin spring washers. You can reuse the originals or buy new ones, they are pretty cheap. The same hardware is on all the cars that use the 4-piston Brembo's in the back.

[smokin_944]

Originally Posted by matthewb

I think the actual thickeness is supposed to be about 4mm. If you are going to do the hardware store washers at least try to get ones of uniform thickness. Done match a thick washer with a thin washer when you put them on the car. I dont think it would be good for your caliper to be mounted crooked.

Yup, spacers are 4mm.