TR6 I Love My TR6, I Love My TR6, I Love My TR6

[DougF]

Two weekends ago, I went on a club event. We had a nice run and all, but on the way home I heard what has become a common noise coming from the rear end of my car.

I previously mentioned that my frame broke on the way to Watkins Glen. Well, it broke again. This time right above the gas welds that got me home from New York, along with new cracks on the passenger side.

These all started because of a rubber rebound that had disintegrated allowing the tube shock to bottom out, stressing the frame and breaking it at the weld below the shock mount.

This past weekend and a few evenings last week were spent plating in both sides of the frame all around these broken welds. It was a timely adventure as I also decided to install the new adjustable Goodparts trailing arm brackets, along with a different trailing arm.

Now, this is the fourth time this frame has been welded. The first two were performed outside, and the light breeze must have been enough to blow away the CO2/Argon. Lack of penetration in both cases caused failure. Fortunately, this weekend, I was able to get the car back into the garage. But if these welds don't hold, I will be done for the season. To try to grind out old and repair would be a major task. If they do hold, it will take a winter away from the car to forget everything and be willing to drive more than 50 miles from home. For now, I'm just really fed up!!!!

One broken side is bad enough, but when all you had is 1 inch of thin metal holding your shock and the rear diff mounts, you tend to lose confidence in the vehicle.

This is a rust free frame.

I've driven the car less than 10 miles since the repair with no problems. Only time will tell.

On the brighter side, I installed my rebuilt rocker assembly before our club event. The only thing you can now hear at idle is the whirling of the water pump. It's a good pump, so I'm not concerned about the sound....yet!

 

[Tinkerman]

What a bummer! I'm sure that you will get it all worked out. Do you have your own welding rig? Can you weld additional metal on to it to give more strength to the area?

Good luck with the fix, very frustrating to do repeirs over I hate that myself.

Good luck, Tinkerman

 

[DougF]

Thanks.
Yes, fortunately I have a small mig welder. I welded 12 gauge plating all around the suspect areas, this time getting good penetration. I am concerned that the metal may crack again next to the new welds.
I hate doing things twice. This many times driving me nuts. Should it break again, I would have to walk away.

 

[tdskip]

Any pictures Doug?

How big are the plates you are trying to weld in? I've noticed a HUGE difference in the weld quality when a breeze has come along as well.

Is you gas flow OK even when you aren't dealing with a breeze?

Sorry to hear of your troubles.

 

[DougF]

I used 1" width plating. I tried to weld into existing welds where possible. I have no pictures, in fact I will do everything possible to hide my workmanship. Odd angles and tight spaces made for less than beautiful viewing.

When I welded the first couple times, conditions were very light breezes and I thought I was ok. I had a friend, who is a "big steel" welder and more familiar with flux core, dress over my welds. But the moving air was too much. In the garage, the gas flow was very good. The welder is a Lincoln SP100 and has never given me any problems.

 

[BryanC]

You mentioned that the rubber rebound buffer was bad originally but I found that even a good one may not take enough of the load from bottoming out the suspension. I checked this by removing the spring and then raising the trailing arm to see if the buffer hit before the shock bottomed out. I shimmed the rebound buffers up some to help make sure that they were taking the load rather than the shock.

Bryan

 

[tosoutherncars]

How thick is the metal that you are welding? If you're not getting enough penetration, can you get in there with a thin zip disk and chamfer the edges?

 

[DougF]

The rubber buffer that I initially replaced the bad one with was not adequate. Even when shimming it up, it wasn't making contact. When I removed the bad buffer, most of the aluminum threads from the trailing arm came with it. Since I was installing the adjustable trailing arm mounts, I figured it would be easier to swap out the entire trailing arm with one having the proper buffer. The old one would have to come out anyway for a heli-coil(I had thread locked the replacement buffer into position). I didn't have any problems for two years of running tube shocks until the buffer went away.

The plating is 12 gauge. I will estimate that at approx. 3/32". Some of the tight areas on the frame are less than 1". I would have to use a carbide bur which would take a long long time.

For plating, the only thing I could find was galvanized. Even after grinding the surfaces with a flap wheel, welding it still left me naucious. I don't want to have to work with it again.

I just hope and pray that this fix works.

 

[tdskip]

Doug - I'm sure you know but welding galvanized metal produces unhealthy fumes, hence the headache and nauseous feeling. I'm not trying to come off an an expert, since I'm not, but be careful.

I also wonder if the galvanized coating had something to do with the weld penetration. Maybe?

 

[DougF]

I ground the majority of the galvanizing off,but evidently not enough. I am aware of the dangers, but took what I thought would be the necessary precautions. It gave me flu-like symptoms, but food and beer still tasted good.

As far as the penetration problems, they were before the plating entered the picture. The welder penetrated the plating like butta.

 

[tdskip]

Well, I'm out of ideas.

Didn't mean to be preachy, just want to continue receiving the benefit of your coaching! I've heard galvanization and weld are a bad mix...

 

[DougF]

Yes, I am fortunate to sell to a lot people in several different fields of maintenance. I've asked a lot of questions along the way, and have learned a great deal from them. I know just enough to be dangerous at a lot of things. I was told to grind the galvanized surfaces until the abrasive wheel starts throwing sparks. Whether that was sound advice, I don't know. But I didn't get the whitish tan powder residue that results from welding galvanized metals.

Here are my thoughts on the frame problems I've been experiencing. The weld broke because of the rubber buffer. Two bad welds both broke because of breezes resulting in poor penetration and no adhesion. The metal broke above the gas welds either from being hot or from a poor fitting replacement buffer. I tend to lean toward the buffer, as the person that did the welding is a very talented lifelong automotive wizard, imho. The opposite side cracked from the flexing of the suspension and differential while being driven with the other side broken. While driving to Watkins Glen, I thought it was a shock absorber problem and not a broken frame and drove about 200 miles with it flopping around.

No problem, I never considered your comments as preachy.

I drove the car about 25 miles this evening and everything is very solid...knock on wood.

 

[Got_All_4]

Do you know a professional welder that welds frames? If so ask them what to do. Or may your friend knows too. After miging the metal around the welds may become crystallized and my need to be annealed. All you may have to do is get the weld and area cherry red and cool slowly a few times. Been 30 + years since I've studied this so not 100% sure.

 

[tdskip]

Hi Doug - any more driving? How is she doing today? Welds hanging in there?

(sending good vibes from Cali - hey, we're known for this sort of thing...)

 

[DougF]

I'll let you know this evening. I'm going to take it out for a spin in a little while.

 

[DNK]

I'd try to keep the front end pointing straight instead of a spin.

 

[DougF]

No problem there. There are plenty of handling upgrades that keep her going straight. This car doesn't handle like any stock 6. When I get behind the wheel, I always look forward to the adventure ahead. At least until recently.
I went for my drive this evening. Passed a friend of mine, and ended up helping him with the refurbishment of his rental. Sometimes it's better to work with wood than metal. Only drove about 10 miles. The engine is running so well, it almost makes me forget about the frame. It definitely makes me forget about the stereo.

 

[71MKIV]

With your indulgence, may I add something to the conversation?

One other thing to think about when welding stressed components is how your loads are transmitted through your weldment and the stresses you create from your weld. Sometimes you are stronger with LESS weld than with more.

I work here:

www.strasburgrailroad.com

and we routinely weld up cracked frames that carry almost 200 tons. We are currently restoring a late 1880's engine that needs whole sections replaced.

If you weld a square plate onto your frame, just weld the top and the bottom, and resist the temptation to weld the verticle section, you will crack at where the verticle and horizontal sections meet. A stronger repair would be to make the verticles sections of the plate into rounded off "arrows", that way you can weld all the way around and not make any sharp corners for a crack to start.

If I could figure out a way to post drawings I would, but that is not something I have learned yet.

Steve Spangler
71 Spitfire MKIV "Jehu"

now in it's 25th year of ownership

edited to fix my speelking

 

[DNK]

...If I could figure out a way to post drawings I would, but that is not something I have learned yet.Steve Spangler71 Spitfire MKIV "Jehu"now in it's 25th year of ownershipedited to fix my speelking

Copy the drawings to a paint program and save them as a jpg and then your set

 

[IanF]

Gee... I can't believe this thread made it to page 2 before someone mentioned one of these:

https://www.rat-co.com/TRFrames1.html

:smirk:

If I had a TR6, I'd probably be saving my pennies for one... especially if I had sporting intentions in mind...