944 NA ('83-'86) rear disk brakes bolt straight on to an IRS bug and type 3... same for type 4?
944 exploded view from Pelican Parts.com
944 NA Rear Brakes
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ubercrap
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Really? I had the impression that people were using the entire Porsche suspension arm, as the mounting points and other certain dimensions are identical to the Beetle, to get the 944 rear brakes. I'm not even sure we've established whether even the backing plate bolt pattern is the same between Type 3, Beetle, and Type 4. I don't have the cars or experience to know that piece of information. Most recently it sounded like Wally was saying no?
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raygreenwood
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With reference to parts from a type 3 that fit on a 411/412. The rear drums are the same part number and teh rear outer bearing cover are teh same. Thats means...that the outer hub pattern to fit a disc or drum will be the same. But...all similarity ends there.
The problem...and its not a huge one but will take some thought, is that underneath the outer bearing cover, the backing plaste though its the same....has a slightly different thickness on teh type 4. This is because the axle stub assembly, and bearing thickness under that cover are different. The outer bearing cover may or may not fit tight against the type 3 plate. This is because the outer stub of the type 4 is a solid part with two taperd roller bearings and a spacer sleeve. It passes all teh way through cover, sleeve, both bearings and is then spined into an inner hub and bolted through with a long bolt.,
But a type 3 set-up should be able to be put on with mods.
If people are using the entire rear trailing arm set up from teh 944...that is not feasible on the type 4. The type 4 uses a two point rear trailing wishbone....not a trailing arm. The trailing arm is inferior to teh wishbone. Ray
The problem...and its not a huge one but will take some thought, is that underneath the outer bearing cover, the backing plaste though its the same....has a slightly different thickness on teh type 4. This is because the axle stub assembly, and bearing thickness under that cover are different. The outer bearing cover may or may not fit tight against the type 3 plate. This is because the outer stub of the type 4 is a solid part with two taperd roller bearings and a spacer sleeve. It passes all teh way through cover, sleeve, both bearings and is then spined into an inner hub and bolted through with a long bolt.,
But a type 3 set-up should be able to be put on with mods.
If people are using the entire rear trailing arm set up from teh 944...that is not feasible on the type 4. The type 4 uses a two point rear trailing wishbone....not a trailing arm. The trailing arm is inferior to teh wishbone. Ray
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Wally
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I would love to believe that it would, but I don't see it being able to fit that anyhow..raygreenwood wrote:
But a type 3 set-up should be able to be put on with mods.
The bl**dy rear set-up of the type 4 is so unique that no VW or porsche part swapping seems possible.
Modification of one or more parts seems the only way...
Just redrilling the type 4 flange for 5x130 seems rather easy tho, as its a solid thick plate where the 4x130 is drilled into
Custom caliper brackets would be an option. Don't forget to make an extra 2 'eyes' for the separate emergency (small) brake caliper, as the vw/944/911 drum style rear emergency system seems almost undoable for a rear disk 412 set-up.
T4T: 2,4ltr Type 4 Turbo engine, 10.58 1/4 mi
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"Mine isn't turbo'd to make a slow engine fast, but to make a fast engine insane" - Chip Birks
www.apfelbeck.nl
"Mine isn't turbo'd to make a slow engine fast, but to make a fast engine insane" - Chip Birks
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raygreenwood
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You guys are making this way to complicated. Why in Gods name would you want to replace the rear bearing system of the type 4 with something type 1 based? Those are junk compared to the type 4 rear bearing system.
The outer stub for the type 3 and the type 4...though they look different...are the same fit dimensions. They use the same shoes, drums and hardware. The bolt pattern for the bearing cover on the type 4....is the same as the type 3.
Therefore...whatever caliper spacing goes onto a bolt up type 3 rear disc system (those using the stock rear hubs)...will fit the type 4. The beaing and stub axle system has no bearing whatsoever on ths conversation.
The whole object here....is to use something like the sintered iron, aftermarket caliper bracket kits....that bolt up to the type 3.....by clamping under the outer bearing cover in place of the stock backing plate and welded onspacer. If the type 4's gap...between outer bearing cover and trailing arm housings ...when backing plate is removed.....is to large...then a simple shim will suffice. If it is too narrow...then measure the difference and have that amount milled from the face of the outer bearing cover. Since the barings, stub axle,seals and spacer will remain the same.....the only critical measurements to be observed are the amount of clamping exerted on teh outer bearing race by the outer bearing cover.
The only mods needed to do to the stub axle of the type 4...is to have the outside edge slightly turned...possibly..to fit any of several rotors.
By the way...the forged type 4 rear stub axle is bullet proof and better than the type 3. Ray
The outer stub for the type 3 and the type 4...though they look different...are the same fit dimensions. They use the same shoes, drums and hardware. The bolt pattern for the bearing cover on the type 4....is the same as the type 3.
Therefore...whatever caliper spacing goes onto a bolt up type 3 rear disc system (those using the stock rear hubs)...will fit the type 4. The beaing and stub axle system has no bearing whatsoever on ths conversation.
The whole object here....is to use something like the sintered iron, aftermarket caliper bracket kits....that bolt up to the type 3.....by clamping under the outer bearing cover in place of the stock backing plate and welded onspacer. If the type 4's gap...between outer bearing cover and trailing arm housings ...when backing plate is removed.....is to large...then a simple shim will suffice. If it is too narrow...then measure the difference and have that amount milled from the face of the outer bearing cover. Since the barings, stub axle,seals and spacer will remain the same.....the only critical measurements to be observed are the amount of clamping exerted on teh outer bearing race by the outer bearing cover.
The only mods needed to do to the stub axle of the type 4...is to have the outside edge slightly turned...possibly..to fit any of several rotors.
By the way...the forged type 4 rear stub axle is bullet proof and better than the type 3. Ray
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Wally
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Because we think nothing is available anymore for the 411/412...raygreenwood wrote:You guys are making this way to complicated. Why in Gods name would you want to replace the rear bearing system of the type 4 with something type 1 based? Those are junk compared to the type 4 rear bearing system.
You lost me there Ray; I agree that the drum and shoes are the same, but that are the parts you throw away. Then you look at a totally different animal: the whole damn axle is fixed with one very long bolt that goes directly into the CV flange!!The outer stub for the type 3 and the type 4...though they look different...are the same fit dimensions. They use the same shoes, drums and hardware. The bolt pattern for the bearing cover on the type 4....is the same as the type 3.
The stock type 1/type 3 bearing cover with its 4-bolt pattern is nowhere to be found on my 412. The similarity of the 944 and bug IRS trailing arms is what makes swapping 944 parts onto an typ 1 or type 3 so easy and a bolt-on way of installing disks with 5x130 bolt pattern.
None of these 944 parts can be used as far as I could identify.
I you say that it can be done somehow, please, please show me the light
T4T: 2,4ltr Type 4 Turbo engine, 10.58 1/4 mi
www.apfelbeck.nl
"Mine isn't turbo'd to make a slow engine fast, but to make a fast engine insane" - Chip Birks
www.apfelbeck.nl
"Mine isn't turbo'd to make a slow engine fast, but to make a fast engine insane" - Chip Birks
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Bill K.
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Thanks Ray I get it now. I didn't realize the T4 hub was so unique. I like bomb-proof.
So, the bearing retainer hole pattern is the same between T1, T3, 944, and T4. Then, the 944 NA backing plate/caliper bracket (p/n 477 609 426) bolts on to the T4 trailing arm. It normally adds 22 mm of offset, but can be machined as shown here so the outer stub axle can fully seat:
Use the 944 NA ebrake system. Modify the T4 drum/outer stub axle to accept 944 NA rotor (turn drum OD and add tapped rotor mounting holes in flange of drum). Drill and stud this modified T4 "hub" for 5-lug. Add 944 NA calipers. Done?
So, the bearing retainer hole pattern is the same between T1, T3, 944, and T4. Then, the 944 NA backing plate/caliper bracket (p/n 477 609 426) bolts on to the T4 trailing arm. It normally adds 22 mm of offset, but can be machined as shown here so the outer stub axle can fully seat:
Use the 944 NA ebrake system. Modify the T4 drum/outer stub axle to accept 944 NA rotor (turn drum OD and add tapped rotor mounting holes in flange of drum). Drill and stud this modified T4 "hub" for 5-lug. Add 944 NA calipers. Done?
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raygreenwood
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Wally.....is it possible that your 412 had a different bearing cover? Did yours have self adjusting rear drums? That may have had a different cover.
On all 411/412's on this contient....that I have seen.....the outer bearing cover is identical to that of the type ..save for teh seal diameter...and that is not an issue if you are keeping the stock stub shaft.
Yes...you are getting rid of the backing plate and drum and hardware and shoes....but ...since they are all the same part number from type 3...to type 4...they are installed in the exact same relationships to each other...and to the bearing cover. That means...that if you find an aftermarket bracket for a type 3 made to clamp under the type 3 bearing cover (which has the same relationship to the trailing arm as the type 4 bearing cover)....it will bolt right upto the type 4.
The only real question that would remain...is wether the stub axles made for teh aftermarket type 3 systems are in a different relationship to the trailing arm. Since they advertize that it does not increase or decrease wheel stance....I am only assuming that they are very close to placement diemnsions of the stock type 3 stub axle, wheel flange seating face. The type 3 and type 4 wheel flange seating face...are the same. They have to be to use the same drum and backing plate. That also means that the outer bearing cover is also in teh same place. As noted ...the only differences I have found in teh type 3 and 4 backing plate is a slight thickness difference in the facing that is welded onto teh backing plate. this part makes up the clamping thickness him and also makes up teh rolled bracket that holds the star wheel adjuster. Ray
On all 411/412's on this contient....that I have seen.....the outer bearing cover is identical to that of the type ..save for teh seal diameter...and that is not an issue if you are keeping the stock stub shaft.
Yes...you are getting rid of the backing plate and drum and hardware and shoes....but ...since they are all the same part number from type 3...to type 4...they are installed in the exact same relationships to each other...and to the bearing cover. That means...that if you find an aftermarket bracket for a type 3 made to clamp under the type 3 bearing cover (which has the same relationship to the trailing arm as the type 4 bearing cover)....it will bolt right upto the type 4.
The only real question that would remain...is wether the stub axles made for teh aftermarket type 3 systems are in a different relationship to the trailing arm. Since they advertize that it does not increase or decrease wheel stance....I am only assuming that they are very close to placement diemnsions of the stock type 3 stub axle, wheel flange seating face. The type 3 and type 4 wheel flange seating face...are the same. They have to be to use the same drum and backing plate. That also means that the outer bearing cover is also in teh same place. As noted ...the only differences I have found in teh type 3 and 4 backing plate is a slight thickness difference in the facing that is welded onto teh backing plate. this part makes up the clamping thickness him and also makes up teh rolled bracket that holds the star wheel adjuster. Ray
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Wally
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Double post...
Last edited by Wally on Tue Jan 03, 2006 12:28 pm, edited 1 time in total.
T4T: 2,4ltr Type 4 Turbo engine, 10.58 1/4 mi
www.apfelbeck.nl
"Mine isn't turbo'd to make a slow engine fast, but to make a fast engine insane" - Chip Birks
www.apfelbeck.nl
"Mine isn't turbo'd to make a slow engine fast, but to make a fast engine insane" - Chip Birks
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Wally
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Yes, if my car is different, that would explain a lot of your writing about this to me 
Could very well be, as its of the last production year and USA specs differed more than once on many aspects...
I know I was very disappointed when I discovered I couldn't use a 944 rear disk set-up on that rear trailing arm/bearing-house(cover)...
However, I don't have self-adjusting drums. I did just recently replace the wheel cylinders as one leaked badly. Since the original 22mm w/c are difficult to obtain, I replaced them with stock 23mm 1303 front w/c's, which fitted exactly and I mean exactly
(tech-tip?). These were very cheap, but brand new hehe and I passed inspection cum laude 
Just the other day I noticed an original '73 model 412 over here, that had the symmetrical struts If I read your posts well, that would be odd.
It seems we only got the assymmetrical struts on the last production run ('74 model), so there may indeed be differences (?)
Regards,
Walter
Could very well be, as its of the last production year and USA specs differed more than once on many aspects...
I know I was very disappointed when I discovered I couldn't use a 944 rear disk set-up on that rear trailing arm/bearing-house(cover)...
However, I don't have self-adjusting drums. I did just recently replace the wheel cylinders as one leaked badly. Since the original 22mm w/c are difficult to obtain, I replaced them with stock 23mm 1303 front w/c's, which fitted exactly and I mean exactly
(tech-tip?). These were very cheap, but brand new hehe and I passed inspection cum laude Just the other day I noticed an original '73 model 412 over here, that had the symmetrical struts
If I read your posts well, that would be odd.It seems we only got the assymmetrical struts on the last production run ('74 model), so there may indeed be differences (?)
Regards,
Walter
T4T: 2,4ltr Type 4 Turbo engine, 10.58 1/4 mi
www.apfelbeck.nl
"Mine isn't turbo'd to make a slow engine fast, but to make a fast engine insane" - Chip Birks
www.apfelbeck.nl
"Mine isn't turbo'd to make a slow engine fast, but to make a fast engine insane" - Chip Birks
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raygreenwood
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It matters where in the 1973 year....the car was made. I have a november 1972 412 (which is early in the 1973 model year (changes in August). It came with symmetrcial (late 411 style) bushings. I think...but am not positive.....that those continued all teh way to August of 73.....wherin the model year of 74 took over and then the bushing were assymetrical.
There were a lot of oddities to the 74 model. I don't think I have ever really dug into the rear brakes of the 74. If there were going to be a difference in braking..........wait!...just remembered (how could I forget)..
About four years ago, I aquired the hardware parts for my 73 412 to add the self adjusting drums brakes. I thought...NO problem!
The big problem was....the cross bar and star lever adjuster...would not fit...with either the bearing hub...or the backing plates. So...if yours had self-adjusting drums.....type parts may be a problem. Since I did not see the car these parts came from....I never really knew visually wether this was just adifference in those with self adjusting drums...or if it was a 74 across the board difference.
Could anyone with a 74 drop in a picture of your rear bearing cover? Ray
There were a lot of oddities to the 74 model. I don't think I have ever really dug into the rear brakes of the 74. If there were going to be a difference in braking..........wait!...just remembered (how could I forget)..
About four years ago, I aquired the hardware parts for my 73 412 to add the self adjusting drums brakes. I thought...NO problem!
The big problem was....the cross bar and star lever adjuster...would not fit...with either the bearing hub...or the backing plates. So...if yours had self-adjusting drums.....type parts may be a problem. Since I did not see the car these parts came from....I never really knew visually wether this was just adifference in those with self adjusting drums...or if it was a 74 across the board difference.
Could anyone with a 74 drop in a picture of your rear bearing cover? Ray
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Wally
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Just got this pic made when my hands were still clean, than forgot to make the pics when the drum brake crap was off...
http://www.kodakgallery.eu.com/PhotoVie ... 4376213933
In retrospect, behind the bearing covers, there may be the neccesary 4-bolt mounting.
I guess I was just pissed that the drum rotor flange wasn't the type 3 part I hoped for...
Definately need to look again at it some day..
http://www.kodakgallery.eu.com/PhotoVie ... 4376213933
In retrospect, behind the bearing covers, there may be the neccesary 4-bolt mounting.
I guess I was just pissed that the drum rotor flange wasn't the type 3 part I hoped for...
Definately need to look again at it some day..
T4T: 2,4ltr Type 4 Turbo engine, 10.58 1/4 mi
www.apfelbeck.nl
"Mine isn't turbo'd to make a slow engine fast, but to make a fast engine insane" - Chip Birks
www.apfelbeck.nl
"Mine isn't turbo'd to make a slow engine fast, but to make a fast engine insane" - Chip Birks
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ubercrap
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- Joined: Sun Apr 18, 2004 8:00 pm
Hmmm...I might be able to help in this department, but I've got a lot on my plate. I have both '73 and '74's to compare and access to a junkyard with Type 3's. I'll be out of town the 4th through the 8th at the CES show in Vegas. Incidentally, my '73 has the earlier symmetrical bolt pattern style strut mount.