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Discussion Starter · #1 ·
I'm going to have to replace my Oil pan gasket this weekend (long story, just the gasket) and am going to encounter the "crossmember in the way" problem. Someone mentioned (forgive me, I don't remember who) cutting out part of the crossmember and welding in tabs to bolt it back in. What a cool idea. I've been searching all night for descriptions and pics with not much luck. Only seen 2 pics. I'm considering this mod but would like more info before I start cutting. Things like... how much is removed? do I need to completely remove the center section (leaving the left and right side still attached or can I just trim off enough to get clearance? Does a mod like this significantly change the integrity of the crossmember? Do I need to weld in nuts or threaded inserts or just run a bolt through one side and out the other? I'm wondering about stuff like that.

Let me have it... :) anything you can offer.

Thanks... Ging's hubby Dan
 

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Hi Dan, the idea came up last week in a thread about oil pressure problems, I think cutting the crossmember to pull the pan is a sound idea unless you put the car in a concours show and a judge notices it. In which case, have the wrong ashtray installed to throw them all off course and they'll be in such a tizzy they won't look at the crossmember :D
My car is still put away for the winter so I have nothing to measure, but I do have the picture I posted in that thread. It looks like you could cut it out about 1-1/2 inches in from the upright tower. My way would be to trash the cutout and fabricate a new center section a bit longer than the trashed one so it overlaps enough to get some bolts in.
Studying the photo it seems all it does is kind of tie the towers together, perhaps if the car sustained a side impact it might help keep the "front frames" apart. But a removable one bolted in solidly would be just as strong.
If I have to pull my pan for a reason that doesn't require pulling the motor I'll hack it out in a jiffy... I think everyone knows I'm not scared to use Sawzall tactics on Speedway GT! :rolleyes:
 

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Nix the Cutting!

It is much less work to just make up a couple of Opel's "Engine Holding Fixtures" Tool J-23098

They are just bits of 6mm X 50mm bar stock made to bolt under the engine mount nut that goes up through the bracket on the motor. They bend down to touch the chasis rail on each side of the motor to take the weight of the motor when the engine suport beam (the one you have plans to cut...) is removed from beneath. After all - how many times do you planto remove that sump? :eek:
Here is a copy of Figure 60-12 from the Opel 1972 FSM:
 

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GT engine cradle

GTJIM said:
It is much less work to just make up a couple of Opel's "Engine Holding Fixtures" Tool J-23098

They are just bits of 6mm X 50mm bar stock made to bolt under the engine mount nut that goes up through the bracket on the motor. They bend down to touch the chasis rail on each side of the motor to take the weight of the motor when the engine suport beam (the one you have plans to cut...) is removed from beneath. After all - how many times do you planto remove that sump? :eek:
Here is a copy of Figure 60-12 from the Opel 1972 FSM:
I think everyone is overlooking one important point. The GT engine is set back much further in the car than in any other model, specifically done to give it better weight distribution . . . you know, as in "Sports Car".

I believe the cradle has dual functions. It is not only used to mount and support the engine, but also to "stiffen" the chassis diagonally at the engine mounting point. This diagonal subframe (cradle) is mounted from the bottom with six bolts that are much larger than required to merely support the engine! I can't see the GM bean counters allowing anything more than what's minimally required for an "entry level" car, can you? Remember, this was the 60's when bean counters ruled GM!

Additionally, the cradle also has two rearward facing tabs on the uprights for two more bolts to prevent longitudinal flexing of the cradle due to engine movement in normal operation . . . you know, the ones that are often forgotten about after cradle removal! They definitely wouldn't have designed it this way unless they were necessary. Check yours! :eek:

I would be very careful about just cutting the cradle center section out without some means of reestablishing the integrity of the cradle. Bolt up center section or FSM braces during cradle removal sound like the most reasonable solutions here. Just wanted to alert everyone of the potential problems with leaving the cut center section out enitrely.

I went through a lot of additional work sectioning and rewelding the cradle in my 2.4 GT to retain this integrity and to clear the awesome Frontera aluminum oil pan, also sectioned and welded to fit my GT. Definitely didn't do it just to make it look pretty!
 

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Just to add what Otto said and my have been over looked or not thought of. The Opel GT is a unibody, the body is part and parcel of the structure to keep everything together. Cutting or removing any part of the structure is not a good thing structurally. The folks that have installed cages for racing applications don't or won't have structual problems removing or modifying the engine cross member. If you have to just drop the oil pan for a gasket leak or similar problems, use a cherry picker and hold the engine up with it. Like it was said, how many times are you going to have to drop just the oil pan for maintenance. How hard is it really to drop the crossmember, engine mount bolts, and 8 bolts including the hanger strap bolts and it's on the ground. Just don't forget where the shim goes when it falls to the ground, if you have one.
 

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GT cradle shims/spacers

namba209 said:
Just to add to what Otto said . . . Just don't forget where the shim goes when it falls to the ground, if you have one.
Ground or shim? :rolleyes:

Actually, it's a pair of them between the cradle and chassis at the inner mounting bolts on each side. ;)

Ever wonder why they're used or why there are two threaded holes facing forward in the cradle just below them? The European, "Lenk style" sway bars replace them to mount their sway bar, very different from our Addco sway bar mounts.
 

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A few good points have been brought up, one I'd like to make is that the removable crossmember done "my way" would be bolted in a lot differently than the one seen in Marcus' photo. I agree it has to be just as strong as before, I think that one is nowhere close.
I like the engine support tool! That's the way to do it if you want to keep the crossmember original.
I wonder how many folks have as much trouble as I did getting the big bolts out of the crossmember to body mounts? My car truly had less than zero rust, believe it or not, compared to others I've seen at gt.com! And those bolts were siezed in there something fierce!
Bolts like those, once they are removed, are good candidates for a good application of Anti-Sieze before reinstallation. I am addicted to that stuff, in fact it infuriates me when I have to work on trucks that have never seen any! That stuff is so good I even like to spread it on Ritz crackers! ;)
Otto's oil sump is neat, I'd like to see more of that car! Obviously I'm not the only one who needs a tricked oil pan. It is really nice to be able to easily inspect the oil pickup!
 

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Discussion Starter · #8 ·
Well I changed the oil pan gasket Yesterday (and finished today). I did not make any mods to the cross member. I thought alot about the comments made and now am a bit (hmm, whats the word)... paraniod? :eek: I don't want to make any changed unless I know it will be AT LEAST as strong as the original design. I do have several ideas. I'll draw up some pictures and post them soon and get everyone's advice. I'll probably wind up adding more weight to the GT but I'd rather it be heavy and safe that lighter and weaker. I'm no welder so I can't fix something I cut and the wife will kill me if I can't put it back the way it was.
I'll keep you posted on the developements.

Thanks for all the good tips and point's view
thanks Dan and Ging... opps, that should be Ging and dan :D
 

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My way of celebrating the new season of Nextel Cup was to pull Speedway GT out of storage and into the shop. How about that Jimmy Johnson!
First thing I'll do is hack that crossmember :eek: and put it back together (removable) stronger than ever, will certainly share the pictures!
I think it would be just really handy to be able to pull a pan quickly.
 

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Discussion Starter · #10 ·
I've got my doubts too ...

The real Ging here ... :p
Daniel and I have been discussing this for a while now and I have the same problems with cutting that cross member that a lot of you have mentioned. I just don't like the idea of compromising the integrity of the support - not only with the cuts but also then boring holes for bolts and basically coming down to bolts bearing the brunt of all the movement, weight, flex, etc. The only possible substitute that I could think of was possibly using nesting pieces of c-channel inside the original (cross member) at the cuts with the bolts connecting these sections of c-channel to the cross member on either side of the cuts. If you understand my meaning. Still, this would be a lot of holes for bolts in a relatively small area on both sides of each cut, blah, blah, blah. It just seems more and more like weakening the metal to a dangerous point.
Frankly, I'm hoping as many of you have said, that the oil pan just won't have to come out much. :D Or anything else requiring the cross member removal for that matter.
Looking forward to seeing what you do Jeff. Someone here always comes up with a new and interesting way to do a project like this and I'm betting you are going to show us one. I'll keep an eye out for the pics.
 

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Racing, maybe . . . street, NO!

jeff denton said:
My way of celebrating the new season of Nextel Cup was to pull Speedway GT out of storage and into the shop. How about that Jimmy Johnson!
First thing I'll do is hack that crossmember :eek: and put it back together (removable) stronger than ever, will certainly share the pictures!
I think it would be just really handy to be able to pull a pan quickly.
For someone who actively races, the operative word being actively, I would agree with you. There are a lot more stresses placed on the chassis during racing, but as long as cradle structural integrity is restored, I don't see any problem.

That said, the opposite is true for most of the rest of us. Let's get real here for a moment. There's something seriously wrong if you have to remove the pan often enough to have to worry about modifying the engine cradle! Better fix THAT problem!
 
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