Caution for Drivers using Auto Restorations T5 Kit
 

I have posted previously about the T5 transmission swap I performed on my Model A, and I mentioned I was was quite satisfied. I have put about 1,200 miles on the car since the swap and have driven the car 55- 60 mph several times with no problems. My feelings changed this past weekend when while driving about 5 miles from home, preparing to get on the highway, when taking off from a traffic light, the driver's side rear radius rod broke apart at the welded section of the backing plate bracket, and fell to the ground. The passenger side was just about to go as well. What a mess. My friend had to tow me home with a rope. I knew when I put the T5 S10 transmission in and removed the original "torque tube", a situation was created where all the driving force would now be placed on the two rear radius rods. But I thought by purchasing Auto Restoration's new heavier duty radius rods, everything would be fine. Well the welds weren't done correctly (see photos) and they failed. Also, I'm now fully realizing that aside from the bad welds this can be a design engineering flaw, and the torque tube is way more important than I ever imagined. This whole thing has to be re-thought, and I'm quite dismayed over it.

I'm no longer comfortable with the idea of no torque tube and I don't like the fact that all the forward force and rear end tilting and twisting action is placed on those rods. Even if the welds are good, and the new steel radius rod stock is bigger, what about possible metal fatigue over time? Maybe I'm just getting ahead of myself. I'm just grateful this didn't happen on the highway at 60 mph. Perhaps all drivers of Model A open drive systems should beware, especially those that have installed radius rods from Auto Restorations, which is now out of business due to illness.

Re: Caution for Drivers using Auto Restorations T5 Kit
 

I did this same conversion on a 29 RPU but did not invest in their radius rods. I have since sold the pickup and the new owner upgraded to a hop'd up B motor. I have not heard of any issues with that setup.

Now thinking about it.........what kind of real world testing was done by Auto Restorations with this setup? I wonder! :)

Re: Caution for Drivers using Auto Restorations T5 Kit
 

Those look like very cheesy welds and should have been double pinned on top of being welded properly. :confused: People don't realize the up and down torque when going to an open drive. But they can be done right and properly. :cool: Those,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,well? :eek:

Re: Caution for Drivers using Auto Restorations T5 Kit
 

That is some of the worst cob job welding and poor engineering I have seen.

I have 2 door with a T5 with an 8 inch rear end, BUT, it doesn't matter what rear end you have the basic principle is the same.
You need radius rods that are strong enough to take the rotational torque from the axles AND the forward driving force.
It is relatively easy to design radius rods that will stand up to just about anything. A pair of 1 inch 4130 tubes with 1/4 wall, hairpin style on each side with mid gussets and both anchored to the belly band. The belly band needs to be 1/3/4 x 3/16 wall 4130 tubing and "K" braced to the rails.
Here is a pic of my front one but the rear is mounted the same.
I have over 50000 miles on this.

Re: Caution for Drivers using Auto Restorations T5 Kit
 

There should slow be a rosette weld where the bar slides into the tube.

Re: Caution for Drivers using Auto Restorations T5 Kit
 

as said, the welds are very poor. Find a fabricator that can fix the mess by reinforcing what is there, it won't take long and it shouldn't cost too much, once done properly it will take all the road miles you throw at it.

Re: Caution for Drivers using Auto Restorations T5 Kit
 

I put the Auto Restoration kit in the '29 ccpu in my avatar at least 10 years ago. I've posted photos here on Fordbarn several times showing how to reinforce the stock radius rods and properly modify the crossmember. In my opinion, the early T-5 kits were crap and I told the owner exactly what I thought of his product. Just saw an ad in SSOS for the kit with a new price of $1395. Inspite of the issues with the kit, the finished project is a joy to drive.

Re: Caution for Drivers using Auto Restorations T5 Kit
 

It appears to me that someone needs to learn how to properly design radius rods and then learn how to weld.

This is a very poor design and the welds appear to be "cold" with no penetration. It looks like they used a wire feed which when done properly can produce good welds but a lot of the time, the operator does not know how to use the equipment and this is what you get.

Fabricated radius rods have been used for a very many years by hotrodders. They are putting many times the torque thru them that our 4 bangers develop. When properly designed and fabricated, rear radius rods are very strong and reliable. Get in touch with a good shop that does hot rod chassis work and they will know how to fabricate proper radius rods.

I would not try to reinforce what you have but to fabricate new ones that are designed correctly.

Last year, I helped a fellow club member who had the very same problem.

My experience and opinion.

Chris W.

Re: Caution for Drivers using Auto Restorations T5 Kit
 

I am not a good welder and do not like welding. However I do most of the welding around the farms. I have worked knee deep in re-cycled grass and water (also known as bull s**t) to make some incredible repairs to cattle pens, gates, etc. So I know that a correctly used wire welder can work wonders, but I know to my cost that they can put down a good looking weld that is absolute crap. When in doubt I use a big hammer to test the weld.

I distrust any welds on vital load bearing components such as radius rods purely y on principal. In fact I had a weld fail on the driveshaft of a new Volvo some 40 years back. Unfortunately most reliable testing of welds is destructive unless you have some sophisticated X-ray or ultra-sonic gear.

Re: Caution for Drivers using Auto Restorations T5 Kit
 

The same twisting force is applied to the radius rods under braking , only much more severe than a piddly 40 HP does to it on acceleration.

Think of it this way...

If you have good brakes, you can lock the rear wheels up and skid to a stop from top speed.

How far would you spin the wheels on take off?

Much much more force applied under braking.

Re: Caution for Drivers using Auto Restorations T5 Kit
 

I would not throw out your investment in the HD radius rods. However, two modifications you may wish to consider: To prevent all of the load being carried by the weld, the yoke (solid steel part) should have a slight interference fit when inserted into the rectangular tubing. It should also extend further into the tubing to eliminate the hinge effect at the weld joint - 10" should get you where you need to be.

A competent welder can easily make both of those modifications.

Re: Caution for Drivers using Auto Restorations T5 Kit
 

Last year we had a vehicle come to us from Kentucky where a Model-A mechanic there talked the owner into installing this kit. In my opinion, this was a real cobble-job.


What brought all this on was there was a huge vibration which we traced to an input shaft adapter that was supplied in the kit to lengthen the input shaft to compensate for the clutch housing length. It allowed the input shaft to spin randomly off center, AND the adapter was too long so it was pressing against the crankshaft (I suspect the crank thrust is not long for this world now!). I just wound-up machining a new one. The rear radius rods on this vehicle had a bow in them too so we straightened them in a press, and then used 26/27 Model-T radius rods cut-down and grafted on so the looked authentic.

Oh BTW, this "Model-A expert" up there convinced the owner that to correct the driveline vibration issue that they should install Float-A-Motor mounts. So now this is a vehicle with a torch-cut center crossmember, and a set of F-A-M mounts. One can only shake their head in amazement!

Re: Caution for Drivers using Auto Restorations T5 Kit
 

The best of all worlds is to use the T5 UNMODIFIED and KEEP the torque tube.
Between the HAMB and Fordbarn I have probably posted the fairly easy solution with pics at least 3 times.
You will have to search for it this time.
My solution does require fabrication skills.

Re: Caution for Drivers using Auto Restorations T5 Kit
 

After careful thought and consideration, I have decided to remove the entire kit and install a Mitchell transmission. Down the road I may consider a Mitchell overdrive as well.

Thanks to everyone for their opinions, suggestions, advice and well wishes.

Re: Caution for Drivers using Auto Restorations T5 Kit
 

Why not go with the Ford 4-speed OD trans. Full syncro, OD and closed driveline.

Bob

Re: Caution for Drivers using Auto Restorations T5 Kit
 

+1 for 4 speed. No frame or mechanical brake modifications,uses torque tube.

John

Re: Caution for Drivers using Auto Restorations T5 Kit
 

I have found the F150 gearbox (3+1) to have rather too low ratios for 1st & 2nd and then there are three overdrive ratios available, Unknowingly, I discovered rather too late that my box has the 41% ratio. Fortunately my improved motor and light body cope with this ratio OK
However, the T5 gearbox is seriously tempting.
Additionally in lengthening and lowering the rear, new spring hangers were welded to the rear of the axle tubes similar to V8s and I think this contributes to resisting the turning moments?

Re: Caution for Drivers using Auto Restorations T5 Kit
 

Yes with all the 3 speed + O.D. kits we have built never that 41% . Our new S10 5 speed kit (as seen in secrets of speed mag) is all CNC machined and includes a rear end to rear trans mount support (or brace) but reinforcing the radius should still be done.

Re: Caution for Drivers using Auto Restorations T5 Kit
 

I have done many thousands of miles with this combination including towing a camper trailer around Australia, some 9,000+ miles. There is a gear for all occasions and with synchro on 2nd, 3rd and O/D, changing is a breeze. I even go from 2nd O/D to standard 3rd gear by moving both sticks at the same time. I heartily endorse your selection.

Re: Caution for Drivers using Auto Restorations T5 Kit
 

It be far safer to just open your wallet and buy the Mitchell synchro transmission and overdrive. WTF you can't take it with you folks... Chevy transmissions do not belong in a Model A....