suspention pan vs. spot welds?

[Tachin]

The areas where my a-arms bolt into the suspension pan on my '69 are rusting out. I'm considering having a body shop just cut out the two rust areas and weld in a new piece where the a-arm bolts in.

What do you guys think of this approach? Here's my list of pros/cons.

Pros:
* cheaper on labor
* keeps the original factory welds around the pan intact

Cons:
* need to buy the full suspension pan anyway


I'm going to restore rest of the pan so I don't anticipate any more rust occurring .. plus the car does not get out in the rain.

[Fishcop]

I fortunately haven't had to do this with my car (yet), but I've seen a few of our older cars done. I think most will confirm that it is easier to replace the entire part (pan) rather than cutting and shutting (it will be similar labor costs anyway). There is nearly always more rust than you can see once you get into it. You will at least be sure that you have all new and rust free metal in there.

Good luck

[ossiblue]

That is certainly a way to go if the rest of the suspension pan is solid. From what I've seen on these repairs though, once you remove the gas tank support and expose the interior of the suspension pan, the damage tends to be extensive. Doing what you suggest does not require removal of the gas tank support so unless you use a bore scope, you will not know how sound the pan actually is and if the suspension points are rusted through, it's likely other parts are weakened as well. If I were doing it, the least I would do is open the entire area for a close inspection, then make my decision.

Just my humble opinion.

[Rich Lambert]

Originally Posted by ossiblue

That is certainly a way to go if the rest of the suspension pan is solid. From what I've seen on these repairs though, once you remove the gas tank support and expose the interior of the suspension pan, the damage tends to be extensive. Doing what you suggest does not require removal of the gas tank support so unless you use a bore scope, you will not know how sound the pan actually is and if the suspension points are rusted through, it's likely other parts are weakened as well. If I were doing it, the least I would do is open the entire area for a close inspection, then make my decision.

Just my humble opinion.

What he said.

I'm sure the first thought of everyone who's found rust in their suspension pan is, "Can I just replace the rusty part?" It was for me and it would have been a mistake. The only visible rust on my car were tiny little pin holes around the A-arm mounts. I was amazed, and not in a good way, at what was under the tank support. I also had to replace small pieces of the longitudinals on both sides.

[paulgtr]

whenever any body tries to save a few dollars they wind up spending double what they were looking at. better to do it right the first time.

[mpetry]

if you're paying somebody else to do the work, you are money ahead to do the whole thing - replace the front pan and the tank support. The marginal cost of having to go back in and do it "again" is huge - since you have to take the front suspension apart.

Don't mess around. Do it once, do it right.

[Britain Smith]

I agree, cut out the entire pan and replace. This is how mine looked.

-Britain











Make sure you get these peices.

[Griffinroydonal]

Try to replace the panel and follow the factory seams. overlap where you can and weld and reseal so it looks factory. You can order panels here

Restoration Design Porsche Parts

hope this will help.

[Mia911]

there is nothing wrong with changing out the rusty parts but also remember you're looking for strength....so although one side might be rusted out, the other side might have some kind of corrosion , so check for strength , before you decide to just change out the rusty part, i have a friend cut up his new suspension pan to replace out the threaded part and he ended up using the entire thing, it look like a puzzle...lol underneath, yes it might seem cheaper at the time but on the long run it might save you some money....i had mines completely change out due to serious rust, i couldn't save mines.....

[robmog]

from personal experience and as the above photos show, the front suspension points
are a complex layered construction. i think it would be impossible to do it well as a patch.
do it right, replace it.

[Britain Smith]

I actually found that the restoration design parts were missing the small black part that I showed above and did not fit all that great. I actually found that High Performance House in the Bay Area had panels made a long time ago that were really high quality. I went with those.

-Britain

[berettafan]

do it the right way. full pan. well, not exactly full pan....typically you stop part way back and only use the 'front' half or so.

[FrankT]

Tachin- If you decide you don't need to do the entire pan, I can sell you the attachment points so you don't have to buy a whole new one. I'm having to replace the entire pan on my car because the PO did a crappy job replacing it. They even forgot the reinforcement brackets in before putting the gas tank support.

[Tachin]

Thanks everyone for you insight. I'm going to replace the whole pan. There are plenty of shops in the Bay area to do it .. now I just need to find the right one.

[Britain Smith]

Yeaman Auto Body in Palo Alto did mine. Scott, the owner is an awesome guy and he races Porsches. If you go up there, tell him Britain sent ya.

Yeaman Auto Body, Inc. Palo Alto, California

[Tachin]

what are the risks of having an experienced body shop who works on modern cars and high end classic cars do this that hasn't done a Porsche before?

[Walt Fricke]

Tachin

I think it is hard to say. Good body work is good body work. I don't think there is anything all that different with our Porsches.

A racing wreck caused me to cut my SC basically in half - through the A pillars and the floor pan and rockers about at the gear shift. I bought the straight front end of a junkyard wreck, so the two could be joined. A shop which had done something similar on some other brand of car once long ago thought they could handle this if I let them take their time. They did a great job.

But that was sort of a luckily thrown dart, I suppose. They didn't have the Celette Porsche frame bench to make lining things up right easier, etc etc. They were just good and careful in how they measured things (I gave them some pages from the Factory Manual showing the key measurements), knew all about how you weld together multi-layered structures (rockers, A pillars), etc. They worked it in between their meat and potatos insurance work, which kept the cost down (but took longer). I think it was a challenge for the guys, and a break from their usual work.

The pan replacement is hardly trivial, but otherwise not super complex: drill out the spot welds, remove rusted stuff, work hard to position the replacement pieces, weld them in, protect with paint and whatnot. Pretty standard stuff for a decent shop.

Especially the "high end classic cars."

Walt

[logician]

About the torsion bar reinforcement pictured below, is it supposed to be welded to the bolt barrels in addition to welded to the pan? Thanks, -Juan

[Rich Lambert]

We didn't weld those to the barrels as some of the barrels on my replacement pan were not aligned correctly (I guess this is fairly common). To move the barrels you have to grind off the spot welds from the bottom, line up the T-bar brackets & bolts, and re-weld the barrels to the pan. I didn't do that until the pan was welded in as the ER PB bushings on a SWB have to line up perfectly.

[rvanderpyl]

If you don't weld them to the barrels you are not getting most of their benefit since they are meant to provide a top fixture point for the barrels. otherwise they can still move under load and end up fatiguing the bottom metal. The holes they go through are not a close enough fit to provide any support otherwise. If you are concerned about alignment, leave the tank support off until after you have mounted your suspension, then weld up the barrels, and add the support.