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Frame Sag

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bnw

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What do you do when the frame is sagging enough to effect the door closing? This car was "restored" many years ago and is not a throw away. Thanks
 
I would say, jack it up, make it straight then box the frame with plate. It's never going to be concours now. OR! buy a new frame from Martin.
 
Could also be bad inner and outer sills as those provide a whole lot of structural support for everything and keep the frame from sagging too ! Might check those and you should be able to install new ones with only taking off the wings and doors. Of course that is not a simple matter but simpler than maybe redoing the frame. Or as Vette said, if it is the frame, then reinforce it and drive on !
Good luck,
Mike
 
If your frame is sagging, it is the result of structural integrity disappearing. The first thing to discover is where and how extensive the deterioration is. Mike is correct that the inner and outer sills are a significant part of the Healey’s structure and deterioration in this area will allow the door spacing to close at the top.

If you discover this to be the major area of structure brake-down, I would suggest you replace one sill at a time and consider inserting a box tube inside the sill to increase its rigidity. Also, I would also weld a reinforcing plate onto the inner front fender to attach the forward end of the sill to.

Before making any cuts to any part of the structure, I would use jacks to establish desired door spacing and tack weld supporting braces at the top and bottom of you door openings. The braces will maintain correct door spacing and allow you to install the sills with a greater degree of confidence that the door will fit the opening properly when the installation is completed.

Although this is not a simple task, it is one that many Healey owners have done and many more will do in the future. However, every Healey has its own story and I would not do anything until I have done a thorough investigation and a complete evaluation of all structural areas needing attention.

Good luck,
Ray (64BJ8P1)
 
I agree , you will need to replace the inner and outer sills at least. Repair is as easy as putting a floor jack under the X member in the center and pumping the jack pad up to raise the car from the center, opening the door gaps before you start re welding it . Or you can make this repair incredibly complicated ,its up to you. Of course the car needs to rest with its full weight on its axles while doing this. Kevin
 
Some people say replacing the inner sills and rockers offer strength to the Healey, we have had many customers come to us after attempting this as they have found this approach does not fix their chassis. The problem with the Healey is torsional flexing. The reality is your chassis has lost its rigidity to maintain proper door gaps.
Having to put engine and transmission in the car to set door gaps indicates the chassis is not rigid. The chassis has to be rigid to be driven over railroad tracks and potholes.This type of chassis loading cannot be replicated in your work area. We have seen many freshly restored Healeys put up for sale when the owner is not satisfied with the car because the issue of the sagging chassis was not addressed and the owner is not happy with the way the car handles.
Some of the resolutions suggested may offer a short term solution but the problem will happen again in the not so distant future.
Marty Jansen
 
Marty , if your Healey is just a driver , is it possible to add an additional cross menber brace or steel plates on the side of the frame rails to make the frame more rigid to help with the sagging problem ?
 
Well, there is one other way...

Healey_Rollcage.jpg
 
to add material up each chassis rail would assist in downward loading. Your rail would have to run from the engine mount to at least the X member. You must consider that your X member is a large player in controlling the torsional loading in the chassis. In a monoque design you would use the upper structure to assist in providing rigidity and reduce torsional deflection in the chassis structure design.
Unfortunately, Healey did not achieve this in their structure. Stress loads exceeded the light weight design of the Austin Healey. this is why door gaps close up.
It would be fair to say this is a problem that haunts all Healeys. As I said earlier, some of the suggestion may work but it would be certain the handling and drive -ability will suffer and it is only a temporary solution.

Marty
 
Hi Marty/Rob and others,

About 30 years ago, a friend who often was preparing his car for a race felt he would have a better chance if he could improve the rigidity of his car. Instead of welding reinforcement plates to the frame, he drilled a number of holes in strategic location and filled the frame with foam insulation. He said the insulation would expand and bind to the inside of the frame and produce a similar reinforcing effect as paper on plasterboard.

Although I was tempted to do this to my Healey and believe it will improve frame rigidity over all, I am concerned it may not be safe to repair or attach something onto the frame via welding. Although I don’t know which, I was recently told that this technique was used on a modern high performance car with an aluminum frame.

Although I realize that a replacement, properly designed, frame would be the best solution, for many this is not an alternative. What are your thoughts about filling the frame with foam insulation?

Thanks,
Ray (64BJ8P1)
 
We did have a customer come in that had tried that process and it did not work. We replaced the chassis. In our 28 years of working on Healeys we have seen many attempts on trying to resolve chassis sag. The only successful permanent fix I have found to work is a new chassis which does not replicate the original chassis design.
I would agree it can be an expensive pill to swallow but with this type of fix it is a one time fix other solutions are only temporary.
Marty
 
I visited John Chatham last week, his company is still restoring Healeys and he's seventy five now!

One I looked at was being prepared for racing, all the wings, doors, aprons, bonnet and boot lid had been removed and the car stripped out and dipped to remove all paint etc.

The car had come from the States and the chassis was sound, but he'd made U channels which were welded across under the front cross member and the same going rearwards to the bulkhead. He'd also welded triangular sections between the chassis and the rear of the engine mounts.

Apparently these are areas that can be bust on road cars and often are in competition.

John was friends with Donald Healey and has known the cars since 1952 when his father opened a garage in Bristol.

If anyone is interested and I go back I'll get pictures.

Ash
 
I really appreciate all the feedback I have received on this post. I had a long talk with the folks at Jule and I agree that this a serious problem facing all big healey owners. I am a Triumph guy currently restoring a 57 Smallmouth and I am amazed as to how much stronger this entry level British sports car is to the upper scale big Healeys. This not a dig, just an observation. But back to this Healey in my shop. My customer is not going to spend the 50 or 60K it's going to take to make this car right and all the mods discussed so far do not seem to be overly effective, and in some cases,according to the good folks at Jule, involve some major body/wing modifications. The only problem with this car is in the door openings. So, why not modify the doors to fit the openings instead of modifying the frame/chassis to fit the doors? Only a temp fix, but potentially much less expensive.
 
A quick Google surprised me to find a number of listings that described projects using Catalyzed Ridged Structural Polyurethane Foam in the frame of different classic cars. We are not talking about the stuff Rick buys at Home Depot but a material designed for this type of application. According to Art Goldman, Foamseal's automotive product manager and author of a Society of Automotive Engineers paper on the use of structural foam for the stiffening of automotive structures, and one that has been involved in some of these projects, high density foam could increase structural stiffness as much as 300% in similar applications as our Healeys.

Although I initially had skepticism about the potential of foam filling the Healey’s frame, I am beginning to realize this may have some potential for sagging frames. Although I appreciate and consider a frame replacement as the best alternative, if the cost and extended project time is not acceptable, stiffening a trued frame with foam may be a quicker, less expensive and permanent alternative. For my part, I believe foam frame fill deserves additional investigation.

Ray (64BJ8P1)
 
So, jack it up to achieve the proper door gaps, drill and fill, let it set up, and remove the jacks. I like it and will probably try it. Got a link to the product?
 
I disagree that all big Healeys suffer from this ! Start with a better car ! Once the main chassis rail has been perforated by rust, then water will enter causing rust to form inside the chassis tube the full length of the car, further causing the car to flex and "sag" to a greater extent as the rust progresses internally. Even on a "restored" car , this problem can still exist unless dealt with during restoration by immersing the chassis to strip the rust inside. Sandblasting the outside will not work.

There are many Healeys out there that do not have chassis "sag" and have hundreds of thousands of miles of normal road use on them ! The key is if the main chassis tubes ( rails) have been perforated by rust. If so then water has infiltrated the main chassis tube and rust has begun to weaken the structure.

I have respect for Martin and his work , he has kept many Healeys on the road that otherwise would have been scrapped. However, he is in the business of substituting the original chassis for his "better" chassis. Therefore, he has a financial interest in arguing his point of view exclusively ! By the way , I agree that his chassis is better than the original design, though it deviates from original and may not be the best choice for everyone.

There are original reproductions on the market that are an alternative. Kevin Brinkerhoff
 
vette said:
I would say, jack it up, make it straight then box the frame with plate. It's never going to be concours now. OR! buy a new frame from Martin.
Click to expand...

:iagree: If the car has just begun to sag it is possible to extend the life of the car by plating it from the inside. I've seen this done with 3" square tubing inside the frame. By cutting open the top of the frame from inside the cockpit area and folding it open you can insert a box tube inside, then cut circles about 3/4" round on the original frame then weld the old box frame to the new box frame from the outside around the circles. Then seal up the top opening and you are good to go. It is virtually undetectable unless you look under the car and up the side of the frame. Does any of this make sense?
 
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