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  View original topic: Rack and pinion conversion 1303 74->75
jhu Thu Jun 21, 2012 12:23 pm

Hi, when I discovered serious rust in the frame head I knew the body had to come of the pan. Just welding rust is boring stuff, so I figured I would convert it to rack and pinion at the same time. My car is severely lowered and was suffering from the occasional jamming of the pitman arm in the trailing arm, not a good feeling, but a rack and pinion will cure this.
I did as much research as I could but I could not find a step by step description so I figured I could document how I did it.

I did a lot of rust welding in addition to the conversion but I will spare you those pictures.


Here is the frame head, at this point I had removed the bottom and repaired the vertical sides of the top half. I did not want to remove the locating tabs for the the trailing arms, so I cut them at an angel to gain access.


I got the frame head of a 75 from a local dealer, but when I saw it I knew I could only use pieces of it.


I cut a cardboard template of the notch in the 74 frame head to figure out how big the difference was.


Here you see the template on top of the 75 frame head... quite a big difference.


Cleaning up the 75 head for surgery. :D


Here is a picture of the reinforcement vw have placed inside the frame head.


Here is a measurement to make sure the body would fit back on after the conversion. :?

jhu Thu Jun 21, 2012 5:10 pm


Same measurement on the 75 frame head


Cleaning up the 74 head, and grinding away the fat bead of weld above the mounting point.


Laying down the cut lines at the edge of where the shapes match, also taking into consideration where Iwould have access to weld from the back side.


The first cuts made, one issue, the reinforcement don't follow the outer shape to good where I choose to cut it on the 74. (75 was much tighter at this spot) I fixed this later with a couple of notches and some panel beating on the edge.


Here is the 75 piece in its new location, fits quite nicely.


To be able to fully weld the inner reinforcement I cut back the outer edges five millimeters.


Another view of the cuts and the welds needed, here it becomes apparent why the bead above the brackets had to go.


The first welds done, one have to take into consideration the shrinkage the welds introduce and try to "balance" where to weld to avoid warping the frame head.


The front part is only single skin.



First round completed.




Second round completed.


Welds ground down and new fat beads laid above brackets. If I didn't have access to the backside I would not have ground down the welds. Strength is a good thing. :)


Inside before welding, quite good penetration of the welds, IMHO.


The shape of the reinforcement behind the brackets also differ.


Nothing a little weld can't fix. :D


Part way thru welding the inside.


Floor pan converted, and bottom half welded back on, used a pattern part from Denmark, "had to" slice it in 6 pieces to get it to look like the original part. :roll: The pan then had a few hidden rust traps exposed and repaired before being painted in Por15.

Thanks for looking!

jhu Fri Jun 22, 2012 12:01 am

On to the body. I started on the driver side by fixing rust in the front divider wall... where a normal bug has five sheet metal pieces meeting in one point, I found that the super has nine! pieces. Rust fest... It all looked ok from the outside but when you get crunching sounds when you undo the two big bolts underneath you know you have some digging to do! Getting the repairs to look as close to stock as possible is a personal goal for me... no matter how hidden they are. :?


Here I have cut away some of the heater channel and rebuilt the inner parts of the divider wall. Like making a new "cage" for the loose nut in there.


Opening up more to place the weld in nuts


Another angle of the reinforcement for the steering box. Notice the plastic bung closing of a hole, I first thought that it might be the right place for the weld in nut, but no such luck.


Luckily I had a NOS frame rail and quarter panel for a super for another project. And that turned out to be a universal piece, with provisions for bot steering box and rack n' pinion 8) So there is three versions, first the 73-74 (on the right side) then the 75 with only weld in nuts, and the universal (on the left side)

jhu Fri Jun 22, 2012 8:26 am



Cleaning out the reinforcements to get access to both the rust trapped between the frame rail and the outer reinforcement, and to weld in the nuts.


This is the end of the spare tire reinforcement, the 75 doesn't have this and at least the ends needs to be removed to fit the rack and pinion.


Rust repaired and the frame rail extended all the way to the heater channel. I also welded up the holes left by the steering gear, to avoid getting water in there. I also discovered rust behind the legs of the shock tower, so it was cut away and a piece fabricated.


Here is a small piece from a cut up 75... all rusted out.


This is how the 74 frame rail looks after you have removed the spare wheel well reinforcement, the holes have to go before drilling up the needed new ones.


A tricky measurement on the NOS part... measure twice :)


Drilling out the spot welds under the spare wheel well.


A couple of spot welds have to be drilled from the opposite side.


A pair of sandblasted 75 weld nuts welded in on the 74...


From the underside.


All closed up... with a new "leg" in place for the strut tower. At this point I had fixed the heater channel and welded in a new hookies heater channel bottom.



Here is the other side after rust removing and converting, just the closing panel left.


Closed up painted and rack and pinion mounted. 8)


Pretty tight in there... cant quite understand how you could get it in there without notching the frame head. Maybe you save some space by removing the rubber booth, but how wise is that?

jhu Fri Jun 22, 2012 8:50 am


A better picture of the clearances.


Without the rack.


Driver side all done :)


The other parts you need of a 75... the longest of both types are the 75 version. (the others are 74)

Hope this gives some insight in what differs between the 74/75.

Thanks for looking :D

Dubmatix Fri Jan 09, 2015 4:13 pm

After buying a 73 shell to replace my rusty 75 shell, i am doing this work to bring the old shell up to 75 spec. This is a very useful reference without which i might have just opted to retain the steering box that came with the earlier shell! Just got some bits of rust trapped between the panel and strengthener to sort too and then i can put the nuts in. The hybrid panel picture is great, it shows that the box mount spacer gves you the precise fore-aft location of one of the nuts which is a great reference as a double check.

Thanks for posting!

John

VWCOOL Sun Jan 11, 2015 3:41 pm

Good job, explained/shown very well 8)

Metamatic Mon Feb 16, 2015 2:36 pm

Very good job and I thank you sp much for showing and explaining everything in detail.
.
I'm currently doing a total body off restore on my 73 convertible and was thinking of a rack conversion when I have everything off. I am tempted to do it but I'm afraid I'm lacking the courage.

Bugs'n'Pugs Thu Dec 15, 2016 11:59 am

Am I correct in drawing the conclusion that having a Rack and Pinion Steering system such as those found in the 1975-1979 Super Beetle eliminates the need for a Steering Damper and Idler Arm? (I'm just a bit confused because I have seen 1971-1979 Steering Dampers and 1974-1979 Idler Arms advertised.)

Dubmatix Thu Dec 15, 2016 12:09 pm

You are correct, there are no idler arms or damper on the rack versions of the 1303. Indeed the idler arm mount and steering box mounting holes are not present on the rack fitted cars.

DesignBuild Fri Jan 24, 2025 5:40 am

Thank you for posting this as it clarifies how the Volkswagen people laid out the original frame head to install a rack and pinion steering gear between the body and the frame. Your pictures also confirm that the rack is positioned over the track arms.

How did you determine the correct placement of the retaining captive nuts?
Here are some helpful illustrations and part list for the r&p units used on the 1303 models.



H2OSB Fri Jan 24, 2025 5:54 am

This is great info, but to the most recent poster, this thread was started in 2012, and the most recent post before yours was 2016. You may not get a response to your question.

H2OSB

DesignBuild Sat Jan 25, 2025 4:55 am

H2OSB: I am aware that this is continuing an old post but people look to see if there is a recent post if it is something they are interested in.

Do you know of any crash repair sheets or book that would show the location of the rack and pinion mounting holes in relation to some other bolt location on the body? Maybe like this on that is on a '73 body (the bolt location with blue paint above the rack and pinion mounts in the picture).



H2OSB Sat Jan 25, 2025 9:52 am

Unfortunately, I do not. I know Steve Carter would know. Perhaps he'll see this. If you're a member of SuperBeetles Only! on Facebook, Steve is pretty active there. Ask the same question over there. He's bound to see it.

H2OSB



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