TR4/4A Frame Support for Body Repair

[mclaugh]

Roger Williams' book tells me that when doing any substantial body repairs on an IRS TR4A it must be supported on its suspension and loaded with the engine etc. (or equivalent weight properly located), otherwise the doors will not fit correctly. This said to be because: a) the 4A frame is more flexible than a ladder frame, b) the IRS rear suspension mounts are located further forward, or c) both; it's not completely clear.

Does this procedure also apply to my non-IRS car? He doesn't mention the non-IRS option, presumably because non-IRS cars were only for export to the US. It sure would be a lot less trouble to leave the jackstands under the frame as it sits now. Any guidance is appreciated.

Thanks,
-Tom

 

[tdskip]

Good question, do your door gaps change from on the ground vs jacked up and supported?

 

[mclaugh]

That would be a good test. Unfortunately, I have no door gaps. DPO - 1 removed the doors, fenders and windscreen and cut out the floor and sills on the passenger side, then quit and stored the car for 30 years. I could try to measure the difference across the driver's side opening, but I think the lack of support on the other side probably influences that.

 

[John_Progess]

This is good advice whenever you are doing any frame repairs or door fitting. I was told the same thing when restoring my big Healey. I had already removed the drive train so I had to reinstall it. You want this stage of your restoration to be as good as you can get it. After I had completed all my frame repairing/strengthening, I checked the difference in door gaps with and without the drive train and the door gap closed .004" with the drive train installed. I figured I could live with that!

John

 

[charleyf]

Having restored a TR4 I would say yes, to the inner support. I believe that your non IRS TR4A has a similar frame to the IRS models as opposed to the TR3/4 ladder frame. But in all cases it would be very wise to rig up an inner support. You still have the original "settings" on the driver's side of the car. I believe that you can also rehang the passenger door and get it to close on the rear striker plate to establish a distance. This may not be exactly what you had previously, but it will be a whole lot closer than just putting the car back together without any references. Then when you get ready to weld the sill and B post back on that side you should consider hanging the rear fender to be able to see the rear door gap. I believe that the front gap should not be a problem as the A post is fixed to the front body already. The problem is getting the B post ( and the whole rear half of the car) into the correct position before welding it onto the sill.

My method was to do one side at a time. I removed and replaced the floor and sill on one side before I moved to the second side. I also left the support in place on both sides during the whole operation.
Charley

 

[mclaugh]

John, I don't understand your post. Seems to me your microscopic difference in gaps with/without drivetrain installed argues for not bothering.

Charley, yes the TR4A IRS and non-IRS frames are the same, the difference is in the rear suspension. By inner support do you mean bracing the door openings? I plan to do that, but not until I figure out where everything belongs. I think my next step is to hang the doors and evaluate.

Thanks,
-Tom