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Post by tom400cfi on Mar 3, 2010 10:51:11 GMT -7
The reason the engine and suspension have to come out of the car is so that the frame rail from the middle of the driver's door all the way to the front cross member is being replaced as per GM's recommended collision repair procedure. I didn't realize what you were doing either. That is a hell of a lot of work. Whew! What Rudolph said; keep the pics coming. Interesting and cool to see.
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Post by highpockets on Mar 3, 2010 23:15:52 GMT -7
BTW, Vince, your cradle sounds interesting. I'd like to see it. But, since I didn't know about it, I was following the procedure in the factory service manual for removing the engine, and it does have you remove the spring. No problem,you know where I am at. Its just a homemade affair,but since we do so many C5 engine repairs,I had to have one. If you need anything else,shoot me a call,and of course you are welcome to use the cradle if you like during re-assembly.
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Post by Richard on Mar 3, 2010 23:47:17 GMT -7
So, I'll answer the 3 questions that I posed previously. But first, let me say that I'm fully aware that you can disconnect the shocks and release the compression of the spring by letting the suspension go down to full droop. The only problem I have with that is that when I tried it, the spring arched upwards and began pressing on the oil pan which, in a C5, is made out of cast aluminum. I don't know if it could have pressed hard enough on the pan to break it, but I wasn't interested in finding out. I suppose that this might not be a problem with a C4 because it probably has a stamped steel oil pan. A. Why is jacking a car and the use of jackstands on a lift less desireable than on the ground?When I jack a car up on the ground, I get to use this: When I jack a car up on the lift, I have to use this: If I have to jack a car up high enough to get full droop in the suspension, I'd rather use the larger, more stabile jack. Notice also where I positioned the jackstand close to the edge of the lift. This is usually where it ends up when you try to support a vehicle with a jackstand under it's frame. I'm sure most of us have had a car slip off of its jackstand at one time or another. I hate it when that happens to a car when it's on my lift. B. Why is using the lift to lower a car onto a jackstand not a good idea?The resting points for my lift (and most others I have seen) are about 6 inches apart. That means if I use the lift to lower a car onto a jackstand that rests on the ground, in all likelihood, when I have the jackstand holding the part of the car that I want to jack up, the rest of the cars weight will be on the hydraulics of the lift rather than released and sitting on one of the lift's stops. If the hydraulic cylinder slowly leaks, or if a hydraulic hose ruptures, the rest of the car could fall suddenly and have some nasty side effects such as dumping the car off of the lift. C. Why are the ride height adjustment bolts on the ends of the front spring unsecured, and so easy to turn when the spring is compressed with a tool, and yet so hard to turn when the spring is not compressed?If you look closely at the picture of the spring that I posted, you will see that the adjustment bolt has a rubber cover on it's head. When the spring is not compressed with a tool, the rubber head is jammed by the spring into the lower control arm. This makes it very difficult to turn with a 10 mm wrench.
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Post by Crossfire84 on Mar 4, 2010 3:14:09 GMT -7
So, I'll answer the 3 questions that I posed previously. But first, let me say that I'm fully aware that you can disconnect the shocks and release the compression of the spring by letting the suspension go down to full droop. The only problem I have with that is that when I tried it, the spring arched upwards and began pressing on the oil pan which, in a C5, is made out of cast aluminum. I don't know if it could have pressed hard enough on the pan to break it, but I wasn't interested in finding out. I suppose that this might not be a problem with a C4 because it probably has a stamped steel oil pan. A. Why is jacking a car and the use of jackstands on a lift less desireable than on the ground?When I jack a car up on the ground, I get to use this: If I have to jack a car up high enough to get full droop in the suspension, I'd rather use the larger, more stabile jack. Notice also where I positioned the jackstand close to the edge of the lift. This is usually where it ends up when you try to support a vehicle with a jackstand under it's frame. I'm sure most of us have had a car slip off of its jackstand at one time or another. I hate it when that happens to a car when it's on my lift. B. Why is using the lift to lower a car onto a jackstand not a good idea?The resting points for my lift (and most others I have seen) are about 6 inches apart. That means if I use the lift to lower a car onto a jackstand that rests on the ground, in all likelihood, when I have the jackstand holding the part of the car that I want to jack up, the rest of the cars weight will be on the hydraulics of the lift rather than released and sitting on one of the lift's stops. If the hydraulic cylinder slowly leaks, or if a hydraulic hose ruptures, the rest of the car could fall suddenly and have some nasty side effects such as dumping the car off of the lift. C. Why are the ride height adjustment bolts on the ends of the front spring unsecured, and so easy to turn when the spring is compressed with a tool, and yet so hard to turn when the spring is not compressed?If you look closely at the picture of the spring that I posted, you will see that the adjustment bolt has a rubber cover on it's head. When the spring is not compressed with a tool, the rubber head is jammed by the spring into the lower control arm. This makes it very difficult to turn with a 10 mm wrench. APPARENTLY WE ARE BOTH DEALING FROM OUR INDIVIDULE PERSONAL, PRACTICAL EXPERIENCE AND WITH WHAT KNOW. I HAVEN'T HAD THE LUXURY OF DEALING WITH A HYDRAULIC LIFT IN A LONG TIME.IF YOURS IS THAT UNSTABLE MAYBE YOU SHOULD USE ADDITIONAL JACK STANDS UNDER THE LIFT TO PREVENT THE LIFT FROM SLIPPING, If the hydraulic cylinder slowly leaks, or if a hydraulic hose ruptures, the rest of the car could fall suddenly and have some nasty side effects such as dumping the car off of the lift. MY EARLY C4 DOESN'T HAVE THE ride height adjustment bolts on the ends of the front spring AS DOES THE REAR. ONCE THE SPRING PROTECTORS ARE REMOVED THE LOWER CONTROL ARMS ARE EASILY REMOVED FROM THE SPRING WITH THE SPRING REMAINING IN THE CAR. RACEON!!!
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Post by Richard on Apr 7, 2010 15:45:53 GMT -7
The project continues on with the de-engined car on the frame rack, we now weld pull points on the bent sections of the frame: and then hook up the hydraulic ram: and then after welding on a few more points and pulling with 3000 psi pressure: it's starting to straighten out.
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Post by iZabell on Apr 8, 2010 7:40:34 GMT -7
Cool pics of the process, thanks for sharing!
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Post by Richard on Apr 8, 2010 8:02:38 GMT -7
Cool pics of the process, thanks for sharing! Well, I'm just about to the end of my ability on this project. By pulling out the bent section of the frame, I've manage to straighten the rest of the frame to within a quarter inch of the factory measurements. The next part is tougher. Now I need to figure out how to unglue the inner fender well without destroying it, and then I have to cut the mangled section of the frame out and replace it with a new piece. I'm not sure how to go about that. When I weld it together at the center of the door, do I just butt it together, or make overlapping sections? I need to find out if there is a factory recommendation on this type of repair. Or, I need to hire someone who has done this before to guide me.
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Post by tom400cfi on Apr 8, 2010 13:30:04 GMT -7
Cool pics of the process, thanks for sharing! Well, I'm just about to the end of my ability on this project. By pulling out the bent section of the frame, I've manage to straighten the rest of the frame to within a quarter inch of the factory measurements. The next part is tougher. Now I need to figure out how to unglue the inner fender well without destroying it, and then I have to cut the mangled section of the frame out and replace it with a new piece. I'm not sure how to go about that. When I weld it together at the center of the door, do I just butt it together, or make overlapping sections? I need to find out if there is a factory recommendation on this type of repair. Or, I need to hire someone who has done this before to guide me. It sounds daunting to me...and I'm not generally, easily intimidated by challenges like this. The wall thickness of the fram is pretty thin. The frame gets it's strength from shape, rather than mass. I would think overlapping would be better, but I would be concerned about fittment of a new rocker panel over the frame, etc. I guess if I were doing it, I'd treated like a unit body car and butt the pieces together and weld. This is an interesting thread. Interesting challenges.
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Post by Richard on Apr 8, 2010 22:49:26 GMT -7
Little by little, it's starting to look like it can be done. I found a section in the factory service manual this afternoon that answered my question about how to section the rail at the place where it joins in the middle of the door. I was thinking of stepping the rails for a stronger connection, but the approved GM way to do it turns out to be a butt weld with an internal sleeve. I ordered the replacement rail today. When it gets here, I'll be able to figure out where and how to section it so that the rail is exactly the right length. I hope I will, anyway. I'm thinking that the holes on the top of the rail for the door sill mounts will help me get it aligned very precisely.
Also, I set up a shield so that I could heat the rail next to the inner fender well without burning it, and was able to get the glue holding the fender well to release.
So little by little, I'm starting to think that I can actually do this project.
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Post by Richard on Oct 5, 2010 14:31:13 GMT -7
It's been a while, but we haven't given up. I found a guy at a body shop who was certified at the GM school to repair C5 frames. He gave me encouragement to think that I could do it myself, so I'm continuing on with the project. Here's the current state: floor pan removed, and welds ground out from the frame section that's being replaced. This work was all done on my hoist for better access to the underneath. Now it's ready to be moved back to the frame rack and clamped so that the frame section can be removed and replaced
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Post by highpockets on Oct 5, 2010 15:57:58 GMT -7
Looking good ! You never stopped by and got that GM Y-body frame and structural repair manual. Its still sitting in the office if you need it.
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Post by Richard on Dec 9, 2011 0:25:57 GMT -7
It's taken almost two years, but we finally got the frame rail replaced and now are ready to re-install the engine
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Post by highpockets on Dec 9, 2011 7:49:47 GMT -7
Well, at your current rate of repair (ROR,;-)) you should have this car back on the road about 2013 or so. Looks good,nice talking to you the other day,stop by and say hi sometime(even if you ARE in a BMW)
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Post by Richard on Dec 9, 2011 12:35:12 GMT -7
Well, at your current rate of repair (ROR,;-)) you should have this car back on the road about 2013 or so. Looks good,nice talking to you the other day,stop by and say hi sometime(even if you ARE in a BMW) I think 2013 might be optimistic.... ha... remember I have the 2004 to drive when I have a craving for Z06 performance. I'm not sure why I'm even bothering to fix this.... The frame rail went in beautifully. We had accurate measurements for the chassis from Mitchell thanks to a generous Mitchell employee at SEMA who emailed them to me right from the show booth. The moment of truth came when I installed the cross member.. I thought it might take some tweaking if there was any misalignment in the frame, but it bolted right up just like it was made for it... The rocker panel was a nightmare. The crash had broken it into at least 8 pieces. But, we patiently pieced it back together and mended the breaks and it came out fairly straight...... close enough that with a little bondo, it will be hard to tell it was ever pranged. Ya gotta love fiberglass. I called you a while ago... I'm trying to figure out if the torque tube will dip low enough to go in the engine with the cross member bolted on, or do I need to detach the cross member so that I can get the engine in place, and then bolt the cross member on afterwards? I'm not sure whether the frame bolts that go through the cross member will let me get the engine in to place with the cross member on. I think rather than fight it, I'll just support the engine with a cherry picker and unhook the cross member.
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Post by Richard on Dec 9, 2011 22:44:20 GMT -7
That seemed like the right way to go about it... Everything went together just peachy keen...
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