MTFCA Forum

Bought a Ruxtle rear end totally rebuilt but it is all assembled and has 3 to 1 gears. The question is How can I install the radus rods ? Can I loosen the torque tube by loosen the thru bolts on the torque tube and slide it up enough to slip the torque tube in place. With the 3 to 1 gears the pinon is to large to get out of the diffy hole

I really don't want to split the 1/2's.

tnx
frontyboy

If the radius rods are are the earlier threaded style it may be possible to install the radius rods. Replace the lower thick nuts with thinner jamb nuts and run them all the way down. Then remove the six driveshaft spool bolts. You should then be able to install both radius rods. Good luck.

Done this a few times.
Often, with the earlier radius rods, backing the rearward nuts as far as they will go will be enough. Sometimes, due to the threading being a bit shorter, it may not quite make it. Since your radius rods are not in there (I had to take a set out once to correct another problem and the nuts would not go back far enough), you can look for a set of radius rods with longer threading? Or, you could even run a die over the threads and beyond so that the nut can be run farther back (I did that once also). One usually needs to fiddle with the brake cam arm a bit to slip the forked end around and into place.

One time, radius rods with the nut frozen in place in the back position on the ball-joint end, and I was in a hurry and didn't have the torch handy. I carefully bent the rods curved. The curvature pulled the ends closer together just enough, that I was able to force the rods into place, then I carefully straightened them in place before bolting them into place.

Like Wayne said. I run the back nut up as far as it will go and put the rod end in at the ball end. The Y at the rear end is usually close to fitting, but with a bit of a flex in the rob and a judicious blow with a rubber hammer, it can be driven past any obstruction on the outer cast housing. You might have a couple of scratches to touch up on the paintwork. Once i added a couple of more threads to the rod so the nut could be wound on a little further.

Allan from down under.

I had a thought last night. Instead of thinning down the back nut so the rod would go further forward, you could counter bore the nuts somewhat so that in effect they would go on further but still remain stock looking.

Allan from down under.

Warning Note:
If you are running '26-'27 radius rods with the bumps instead of 2 nuts these ideas will not work.
If you are running the early '26 style with 2 nuts these ideas probably will not work.
The radius rods MUST match the backing plate style or they will not fit.

Up thru '25 bottoming the nut probably will usually sneak in with the nuts bottomed out.

If these tricks do not work then the pinion spool bolts or nuts have to come loose or out.
Watch out for any lube that may be inside, it will make a mess if allowed to.
And PAY ATTENTION to any gaskets in the pinion assembly, they are critical to ring and pinion alignment.
Replace any damaged gaskets with the same number as removed.
There is no need to touch the bolts between the 2 axle halves to install radius rods.
Remember to install seamed radius rods with the seams at the bottom
When you install the rods double check the rear end is "square".

I have had to install radius rods on a finished rear end, it is not the end of the world just some work.
Mike

I Should have mentioned I am using 26/27 radius rods. Just rebuilt and no oil in the diffy.

frontyboy

I have no idea how rare they might be? However, Many years ago, I had a pair of I guess 1926 rear end radius rods. They were too short for the earlier rear end like I was using, and had the longer fork for the later backing plates. They also had the two nuts to adjust the ball joint end, NOT the forged fixed end with no adjustment.
Since I was mostly working on 1920 and earlier Ts, I sold them a long time ago. Certainly, they couldn't have been the only pair like that?
And even if they are so rare that finding a set of original ones like that? I have replaced enough damaged front ends of those, and refit them for auxiliary transmissions enough times to know that changing that threaded end on a later radius rod shouldn't be that difficult so that you can use the tricks discussed above to assemble your rear end.

I usually get a long shank bolt of appropriate size and thread about five to eight inches long (depends a bit on the style of the radius rod how deep you need to replace?). Bend appropriately to fit the angles, open the hollow end of the radius rod and weld into place.
Now you have radius rods you can run the nut back and slip into place.

According to Bruce McCauleys Encyclopedia ("The Bible") here is what he said about 1926-1927 Rear Radius Rods
https://www.mtfca.com/encyclo/P-R.htm
"During 1926 the radius rods were modified to eliminate the rearward nut at the universal joint. The nut was replaced with a forged-in collar which located the radius rod on the U-joint housing."

See the following for pictures
https://www.mtfca.com/discus/messages/4 ... 1409363110

I have an original set of "2 nut" rear radius rods on my December near Christmas 1925 (1926 model) S/N 12,8xx,xxx Touring car.
I suspect that it was a quite early change since these are not really rare, but not also not frequently seen out in the wild.
Maybe a 1 in 20 or less were the early 1926 style?
I suspect that some were also junked by people believing they were "spurious parts" instead of what they really are.

Pop out the pin on the u joint, separate forward of the pinion spool and go from there….., just a little logic.

Henry K. Lee wrote: ↑

Fri Nov 28, 2025 10:33 am

Pop out the pin on the u joint, separate forward of the pinion spool and go from there….., just a little logic.

Head slap! Of course!

I believe I had the same issue once also on a 26-7. Learned my lesson.
I believe I was able to Remove the spool bolts & get enough side movement to get the radius rods into position into the DS then bolt to the backing plates.

Tnx for all the help. I checked out the idea from speedytinc and it worked like a dream loosened the long bolts at spool about 1/2" and was able to slide the drive line up enough to jiggle and press the yoke end of the radius rod in place and slip the threaded end in to the collar.

A hearty thanks to all that responded especially SPEEDYTINC!! his offer was spot on. I did not want to split the housings and start off, his idea saved my hours of time and aggravation.

just sayin'
frontyboy

Howard,
Glad it all worked out!

Ruckstell!

i did n t do goode n enwish .....