TR6 DIY TR-6 frame repair feasibility-

OK, guys-I've been driving my 73 for a few years with a flexing frame--the door gaps open and close alarmingly while driving. I know that the trailing arm sections are pretty bad (there's a coupla pieces of (1/4") steel plate sandwiching the frame at the point that the trailing arms mount.), and I suspect that the area under the t-shirt is bad, too--that would explain most of the flex.

I see that the trailing arm sections (TRF lists them, Moss lists 'repair section'?) and the t-shirt plates (TRF, Moss) are available.

It's my intention to pull the body off the frame and see what's really going on.

So--Following along in Justin's thread The start of something big most of the work looks pretty straight forward--but is the trailing arm replacement equally straightforward? It looks like most of the frame is 'flat', so the replacement sections could be set up and verified, with a level, pretty easily.

Any thoughts, cautions, warnings?

I replaced the box section on the trailing arm during the rebuild. BEFORE I cut out the bad section, I took a couple of steel I-beams and clamped them across the frame to keep the frame from twisting. Other than that it was a lot of cutting and grinding to get all the prep-work done prior to welding.

When we did mine, we shimmed the frame off of the very large steel table to get it all level enabling us to make measurements perfect at assembly.
Follow the shop manual diagram measurements. Measure, measure, tack and measure again before final welding.

Thanks--

I've got a nice level floor to work off of, and I intend to put the whole frame up on jackstands and shim to ensure that it is level--then strike chalk lines and use a plumb-bob to mark and measure--as well as using Elliot's method of clamping the frame w/ Ibeams prior to cutting out the trailing arm box sections.

More q's:

Does the Bentley manual have a frame diagram in it? I've got the Leyland 'Repair Operation Manual' that I've always assumed was definitive...But has no frame measurements. :frown:

What gauge steel *is* this frame made of? An internet search reveals that it is 10, 14, 16, or 18 gauge. I didn't see in Justin's thread that the gauge was called out? I assume just plain cold-rolled? I intend to buy some, while waiting for +freezing temps, and start practicing my welds...

The Bentley manual includes very detailed frame alignment info on pages 428 and 429, including "checking for twist", "checking for squareness", and a comprehensive table of dimensional specifications.

Thanks--

I figured that if Bentley has it, it must be in the Repair Operations Manual-- So I went back through my loose-leaf :frown: pile that comprises my manual and found it 76.10.02 (in the body section) for future reference.

Anyone have hints on how best to measure decimal (v/ fractional) inches?

Here in the UK we see an awful lot of TR chassis imported from the USA, and that's been the case for 30 years past. Chances are, if it's been repaired in the USA then either it needs wholesale reconstruction or it's headed for the scrap metal skip.

You can't adequately repair a TR chassis without a pukka chassis jig, simple as that. You can bodge it, and that's about as good as you'll get, a chassis that is not correctly aligned. Just occasionally it might come right, but that will be more by good luck than good judgement.

Diy chassis repair is, I'm afraid, a loser's streak.

Cheers,

Cap'n

That certainly is food for thought.

As well as the first 'don't do it' caution that I've heard, here or elsewhere.

I've seen half-a-dozen sites (including this one) where people have discussed and performed frame repair--not necessarily in depth, but that they've spliced in sections--including the trailing arm mounting section--with no indications that it was either extraordinarily difficult or that it (later) provided alignment difficulties.

I hope that if one exercises caution it can be done...I'll at least pull it apart and take a look. I can always send it off to a frame shop at that point--there's one a mere 120 miles away that indicates (online) that they've had experience with the TR-6. (and that'd be $500 and two months to get it there and back, I'm sure :shocked: ) It appears ( Precision Frame ) that they'd do about what I'm anticipating doing :confuse:

My frame chart doesn't list tolerances--it just provides values. I can't imagine, based on the overall construction of the car, that the original tolerances for the frame were any tighter than, say 1/8"(+/- .125 inches, (3mm)). That's practically <span style="font-style: italic">carpentry</span>, isn't it?

I remember when I used to subscribe to a Brit enthusiast (<span style="font-weight: bold">Popular Classics</span> maybe) magazine in the 90's---they had an article about imported (repatriated) sports cars as they arrived dockside. As I recall, the most of them could (charitably) be described as 'barn finds'. I wonder why they were parked in that barn to start with?

I expect that most of those TRs were parked, originally, due to frame failures--let's face it, mechanical failures are pretty easy to deal with on these cars...then patched/botched (potched?)as their value climbed, and sold on --I can't imagine that 'good' TRs get sold off for export (from the US), are they?

Anyway, thanks for the caution--And you can prepare an 'I told you so', eh? :wink:

Bob,
If you ask around enough you'll probably get a lot of people telling you not to try it, but then you would have gotten at least an equal number of people telling you not to buy an old TR6 in the first place. I, too, have an old TR6 (a barn find) that I'm embarking on a frame-off (body off?) restoration of. Part of the early process includes some significant work on the frame. I have the same Leyland manual as you, and the charts referred to earlier in this thread look pretty good as far as the measurements and critical check points. Based on what I've been able to learn, I can't see why any repairs couldn't be accomplished at home by someone with some welding skill and a good welder. Note those 2 caveats!
I do not have good welding skills, although I will be getting a welder (the Eastwood 135 amp MIG, I think) and learning how to do it. I'm not going to trust my life to my novice frame-welding skills -- I'll learn on the body and other non-critical areas. A friend who is a Journeyman welder also told me not to trust a 110 volt welder to give proper weld penetration on a frame, and I believe him. He also volunteered to do my frame welding in his very well-equipped shop, so it's all good!
Bottom line, as long as the frame is properly set up on jack stands (placed in the right locations!) and the whole assembly is set up dead level both front-back and side-side, it can be done. I also plan to drop my frame off at a local shop with a frame table on the way home from the stripper, to have them take some measurements and pull it back straight if it's too far out. That way it at least starts out reasonably straight, and then the challenge is to keep it that way.
Good luck! Don't be afraid of it. If I can tackle something like this, anyone can.
Steve

Also remember to move around a lot while you're welding to prevent too much heat build-up and the dreaded frame warp. Williams calls it "hogging in his book on restoring the TR6, and goes into some pretty decent detail about the process. If you don't already have this book, it's a good one to add to the library.
Steve

BTW, my TR4A has one of the trailing arm mounts shimmed nearly 1/2", probably originally from the factory. So it isn't like they were using micrometers when building the frames...

Steve69 said:

Bob,
A friend who is a Journeyman welder also told me not to trust a 110 volt welder to give proper weld penetration on a frame, and I believe him.
Steve

Click to expand...

On a modern boxed in truck frame or the like, that may be right, but on our triumph frames, a 110volt mig welder will do everything you need. The frame on a TR6 is only 16 gauge sheet bent into channels and seam welded. This means your fenders are almost as thick as your frame (scarry when you think about it)

In fact the bigger problem that I had with welding my frame was not penetration, but not burning right through the 16 gauge wall I was repairing. I'm a beginner welder myself, but I dont think repair like I did is out of the realm of feasibility for a beginner. If I had to chop out an entire boxed section and replace it, I'd probably have got help however (like doing the trailing arms)

-Justin

Justin,
Good information re: the frame gauge size. In my case I think I'll stick with my friend and his Millermatic, if for no other reason than that he can do more in less time than I ever could (he's restoring a Pantera right now, and had to fabricate from scratch almost every panel under the skin -- it looks awesome right now, and way stronger than new).
I also plan to add quite a bit of gusseting/strengthening material, especially now that I know how thin the frame really is.
Has anybody ever considered adding extra boxed channel pieces from on or near the TA sections in towards the center rails, kind of like crossmembers? It puzzles me that our frames have no real crossmembers at all, and I'd think something could be done to improve torsional rigidity. No?
Steve

Bob_TR6 said:

I remember when I used to subscribe to a Brit enthusiast (<span style="font-weight: bold">Popular Classics</span> maybe) magazine in the 90's---they had an article about imported (repatriated) sports cars as they arrived dockside. As I recall, the most of them could (charitably) be described as 'barn finds'. I wonder why they were parked in that barn to start with?

I expect that most of those TRs were parked, originally, due to frame failures--let's face it, mechanical failures are pretty easy to deal with on these cars...then patched/botched (potched?)as their value climbed, and sold on --I can't imagine that 'good' TRs get sold off for export (from the US), are they?

Click to expand...

Depends upon why they were parked and when but it is usually just a mechanical issue that does sideline these cars. That is usually the original reasoning, followed by lack of motivation or priority to follow through with a repair, 10 years later its still waiting for that simple repair which has now snowballed into more than just a simple repair. I have rarely seen one of these cars initially sidelined due to frame failure, in fact I have seen several that should have been sidelined due to frame failure but are still driving.

The Brits do seem to be more accepting of rough condition and basketcases than most Americans. Most of the production of the TR's came to the US, therefore it is very easy for us, in the US, to look for a better car, the Brits would often have to look here for anything they could find. Some very good TR's do get sold over seas, not just basket cases.

If it flexes enough that you notice it while driving, I would be looking for new frame. They are not that strong to start with. Wouldn't spend time patching one if I was taking the car all the way down. I sold a very solid one last year for $800.

Marv

Steve: Thanks for the encouragement I can weld well enough to <span style="font-style: italic">consistently</span> stick two pieces of metal together . I'll be picking up some 16Ga steel to play with--I think it shouldn't be a problem. I don't have Williams book, but the caution is appreciated.

Darrell: When I did the alignment on mine a few years ago (when part of my job was doing alignments ) I was surprised to find that everything is/was shimmed. Everything is adjustable. That's why I figured that 1/8" tolerance would probably be tight enough to work to. Maybe even 1/4".

Justin: Well, this is all your fault, anyway :wink: You're making it look do-able. I expect that I'll be replacing the sections that the trailing arm bolts to--as I noted above, there is currently 1/4" steel plates sandwiching the trailing arm bracket mounting location. :frown: At least those sections are readily available. I'll be laying in some 16Ga to practice/verify my ability to weld

Swift6: OK, saying that they were parked for frames was a bit hyperbolic :shocked:. But a bad frame will make the value approach zero...and I can understand the temptation to just stick it together good enough to sell, and then stick someone else with it. I've also seen (an e-type) that was parked 30 years ago for an engine issue--and not sold on, because they 'were going to fix it'. A tree grew through it before they decided to try and get rid of it. :frown:

Marvin: I've been looking for frames for a while (on and off--as time and employment allow) and haven't seen one that's local (I can't imagine either buying one sight unseen, or traveling across the country to find/see one) (and then try to ship it, undamaged, back) and in 'good' shape. Plus, even one that seems good may turn up needing work--as Justin found out. I've also been tempted by Ratco--but barring money falling out of the sky, that probably won't happen. :frown: