Alligning a T rear end with an ohmmeter

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Model T Ford Forum: Forum 2010: Alligning a T rear end with an ohmmeter
Top of pagePrevious messageNext messageBottom of page Link to this message  By Paul Vitko on Friday, December 03, 2010 - 06:16 pm:

For the past few months I have been playing with this project until now I'm confident that it works the way the thought process was started.

My PC skills are lacking so several posts will be used for pictures and explanation.

The T rear end is pushed or pulled with the radius rod nuts 5 thou with every nut flat or 1/6 turn. If one radius rod was bent after production that side of the axel is pulled forward while the other axel would stay straight if it was locked up with the radius rod.

If someone in the past cranked the two outer nuts one turn past finger tight then tightened the inner nuts both axels are pulled forward 30thou. With your fingers you can move the center 2thou each way.

You can diagonal a rear end from the end of the torque tube to the machined corner of the back plate but the problem is the axel could be bent back or forward and still diagonal with an equal measurement

The parts were cut from dry white oak dunnage except for the Ruxtell plug that is CVG dry fir. Brass pipe plugs were installed for boreing in all plugs. Wires are connected to the three plugs used for a standard rear end or a Ruxtell.

By connecting an ohmmeter from the cable to one side of the rear end that side was pushed back in this rear end until there was no continuity, then pushed more until there was continuity. By counting the nut flats between the two then dividing by two the nut was moved back half way.

The outer plugs are bored 1/16" the inner plugs are bored 5/64" about 16 thou larger.

With my experience of one this well used early Ruxtell is within 7 thou vertically and close to dead on horizontally alligned with radius rod adjustment.

The first pictures show the parts made and the 1/16" trolling cable used. 1/16 aircraft cable would work if its 1/16" diameter. You trash the cable once its bent for mounting. Aircraft cable is .18 per foot.

The cable has to be stretched beyond the ends of the back plate because that the way you find the small target to know which way to push the axel.

An outer plug is pulled out until it can be rotated at an angle, which ever way the ohmmeter
loses continuity by being in the target shows as an angle the axel houseing is bent by the angle of the plug.

I started with one ohmmeter but found out that two, one for each side is better because while one side was being adjusted the other side might move into the target and could be locked up.

Alligning a T axel with an ohmmeterAlligning a T axel with an ohmmeterAl


Top of pagePrevious messageNext messageBottom of page Link to this message  By Paul Vitko on Friday, December 03, 2010 - 06:55 pm:

The stretching frame is made from oak dunnage an inch longer legs would have been better. Large holes were bored so the cable could be moved by eye to the center of the hole bored through the outer plug. 1/4" thredded J bolts are used to stretch the cable.

The inner part of the outer plug is chamfered with an angle about an inch into the plug. The reason is when its pulled out to rotate for finding the target it makes it easy.

The method for realignment after the guts are installed will be two flat washers are ground to fit in front of the rear grade 8 nuts, they cannot turn. After allignment the rear nuts will be ran back to the end of the threads, locktight applied then the nuts ran forward tight. The ground flat washer will have one edge bent over a nut flat.

Henry did not take the radius rods from the back plates on a rebuild and the late Ts use a one nut system, I will do the same.

One problem I ran into was the different thickness of split bearing sleaves had to remachine plugs for a smaller diameter.

For some reason my upload is not working!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Paul Vitko on Friday, December 03, 2010 - 07:05 pm:

It was hidden!!aligning with an ohmmeterAlligning a T axel with an ohmmeterAlligning a T axel with an ohmmeterAlligning a T axel with an ohmmeterAlligning a T axel with an ohmmeter


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kenny Edmondson, Indy on Friday, December 03, 2010 - 07:59 pm:

OMG I don't even know where to start.... uhh wouldn't it be easier to use a laser and clear discs with X's on them? What if the rear axle is bent in an up or down direction? I'll think about this some more while having a couple tonight at dinner... Gotta wonder what Henry would think.


Top of pagePrevious messageNext messageBottom of page Link to this message  By John Gelfer on Friday, December 03, 2010 - 08:10 pm:

This makes my head spin. I'm sure it works, but I'm not understanding this at all.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dan Treace on Friday, December 03, 2010 - 08:53 pm:

Guess I'm too inclined to go by the Ford Service manual...set the radius rod castellated nuts on the front till you can enter the cotter pins.

Then run up the rear nuts against the lock washers and secure.

With good used and straight radius rods, this has always worked for me. The outer Hyatts slip right in place with the axle shafts centered in the rear housings..:-)


Top of pagePrevious messageNext messageBottom of page Link to this message  By Paul Vitko on Friday, December 03, 2010 - 09:21 pm:

True Dan IF the axel is straight, what if it is not?? Then how do you do it?

Guess ask Stan what the percentage of bent axels are against straight ones, If the T was used hard as many of them are what then?

The axel done with the pictures was about 100 thou bent forward on the Ruxtell side. The Ford side was also forward but much less.


Top of pagePrevious messageNext messageBottom of page Link to this message  By jack daron-Indy. on Friday, December 03, 2010 - 09:29 pm:

There's more slop than that in the bearings! You are just wasting your talents.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Edward J. Baudoux Grayling Michigan on Friday, December 03, 2010 - 09:37 pm:

As soon as you set yourself in the seat of a T, almost all of the geometry changes. Let alone passengers and luggage. This is why Hyatt bearings are used. They allow for a lot of flexing. I you really are determined to align the rear wheels on a T, scribe a line on the tread of each rear tire by spinning them and holding a screwdriver atop a jackstand. Then use a tape measure and a helper to check top and bottom, front and back.


Top of pagePrevious messageNext messageBottom of page Link to this message  By John Lipa on Friday, December 03, 2010 - 09:39 pm:

Paul - Vey Nice but out of curiousity. How much time did it take you to make up your test rig? I hope this wasn't for a one time use. I would have never thought of doing it this way but it does seem like it will work, though I haven't seen an Ohmmeter like that since I was in the Air Force. I guess using a digitial one on a Model T wouldn't be appropriate.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Norman T. Kling on Friday, December 03, 2010 - 09:44 pm:

That is quite complicated. I use a carpenter's roofing square and a tape measure. I put the square on the driveshaft tube and measure in two places to the axle shaft tube. Both should be equal. So far I have not had a problem. After I get it as square as I can by that method, I do the diagonal from the grease cup in driveshaft to the bolt where the radius rod is connected to the axle backing plate. Both sides should be equal.
Norm


Top of pagePrevious messageNext messageBottom of page Link to this message  By Paul Vitko on Friday, December 03, 2010 - 09:59 pm:

Plain logic tells me that a T rear end out of allignment about 120thou is going to cost me green if I intend to use it. Ruxtells are not cheap, This was done as an alternative to heat shrinking and to settle my mind on the hickups of the many T allignment problems. As far as I am concerned deleat the thred.


Top of pagePrevious messageNext messageBottom of page Link to this message  By kep NZ on Saturday, December 04, 2010 - 09:42 pm:

So how does this work? i am really not that smart and have not figured it out yet. Does it use the cable strung tight through some holes in the wood that have conductors around the holes and when the wire does not touch the holes you know it is alined? Or some better method i have not discovered. Please tell


Top of pagePrevious messageNext messageBottom of page Link to this message  By Paul Vitko on Sunday, December 05, 2010 - 03:36 am:

The cable fits tight to the bored 1/16" holes on the two plugs on the outer ends centered on the bearings.

The two inner plugs have a wire connected to them strung out the drain hole of an assembled rear end. In the pictures its a Ruxtell useing one large inner plug. The inner plugs are bored 5/64" or about 16 thou larger.

The cable is streched tight. By adjusting the radius rod nuts I can put the cable all the way through the rear end without touching the sides of the inner target 5/64" holes.

If the cable touches one of the inner target holes I can tell which side of the rear end because there is a wire conected to each inner target hole. A buzzer, light, or an ohmmeter can be used.

It takes about a half hour to align a rear end after you understand whats happening to unseen targets with the cable strung through them.

This rear end was just slightly high in the center but the cable went all the way through without touching the edge of the target plugs

I will bet that most rear ends are bent in the horizontal with only slight correction needed vertically.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Paul Vitko on Sunday, December 05, 2010 - 04:07 am:

This picture might help it shows the cable through the Ruxtell plug. Before adjusting that side was pulled forward about a 100 thou and its the expensive side to replace. After adjusting I could stick my hand through the shifter hole move the cable in any direction and have continuity from the 1/16" cable to the brass pipe plug with the wire connected to it strung out the drain hole.Alligning a T axel with an ohmmeter


Top of pagePrevious messageNext messageBottom of page Link to this message  By kep NZ on Sunday, December 05, 2010 - 04:37 am:

ok thanks


Top of pagePrevious messageNext messageBottom of page Link to this message  By Bill Stipe on Sunday, December 05, 2010 - 11:47 am:

Paul
I like your setup it's called thinking out side the box. Its kind of like laying cement blocks or bricks with a string line only you can't see inside the rear axle so you do it with continuity check.
Great job,

Bill


Top of pagePrevious messageNext messageBottom of page Link to this message  By willie k cordes on Sunday, December 05, 2010 - 12:57 pm:

I hate to sound like Royce, but I think someone had to much free time. :-)


Top of pagePrevious messageNext messageBottom of page Link to this message  By Paul Vitko on Sunday, December 05, 2010 - 01:34 pm:

Thanks Bill!

Its fun to try another way. Besides building an addition on my shop, Helping Michael Seager with his hanger, and standard upkeep on my home this project went on and off for several months.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Scott Gilham on Sunday, December 05, 2010 - 01:47 pm:

Paul, The more you post the more I like you. You remind me of a friend I grew up with. He's now a Prof. of Math at Purdue. When we were kids I followed and financed a few projects with him. He once built a quadraphonic sound system for a 19.00 dollar record player. He found the plans in a science mag. It was 1972-3 and stereo's with that system were way out of reach for paperboys. I think we spent 6.00 at radio shack. I know he would love your setup! And he could totally baffle me with a lecture on how it works:-)


Top of pagePrevious messageNext messageBottom of page Link to this message  By John Berch on Sunday, December 05, 2010 - 02:38 pm:

Paul, I've always enjoyed you posts. It's very interesting to me to see the scientific approach you take with your projects.

I especially enjoyed your research on the crankcase pan flexing project. Even though I may not drive down the road observing a dial indicator attached to my transmission, or had a clue of what happens when simply stepping on the running board, I've found it extremely interesting. You're research has been the topic of many conversations I've had with my friends when were sitting around talking Model T's.

I'm sure many of us who follow your research and alternative methods don't comment, but really enjoy reading about it. Thanks for your time and trouble.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Paul Vitko on Sunday, December 05, 2010 - 04:42 pm:

Scott, John, Thanks for the positive comments!!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mike Seager on Monday, December 06, 2010 - 01:39 pm:

Paul, You are always coming up with wonderful ideas. Keep up the good work. And thanks for the help on the new hanger and model t barn. Sides are going up now. Mike


Top of pagePrevious messageNext messageBottom of page Link to this message  By Anthony Bennett - Australia on Tuesday, December 07, 2010 - 09:52 am:

Yeah Paul,

Your work with dials and crankshafts has really open my eyes to how incredibly flexible a Ford T is, and how torturous even the simplest of operating conditions can be. I have broken two cranks now, but I can't really begrudge them, your testing proves how hard they work with every turn and every mile.

Thanks again for being innovative and taking the time;) Don't let the bastards grind you down:-)

Cheers

Anthony


Top of pagePrevious messageNext messageBottom of page Link to this message  By Adam Doleshal on Tuesday, December 07, 2010 - 10:46 am:

OMG!

Did you set the axle housings on a surface plate and check them for straightness with a square before you built this contraption? Did you set the axle shafts and drive shaft on v-blocks and check them for straightness? How about the torque tube?

If the center line of the torque tube is square to the mounting flange, and the axle housings are not bent, then you
1)assemble the rear axle, except for the outer bearings.
2)assemble the drive shaft.
3)attach the drive shaft to the rear axle.
4)attach the radius rods, being certain to neither pull them forward or push them back when tightening the front nuts.
5)verify the axle shafts are centered at the outside of the housing. This will tell you that everyting is in correct relation and that nothing is pulled forward, pushed back, or bent.
6)install the outer bearings, washers, seals, wheels, etc.
7)Drive the car.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Paul Vitko on Tuesday, December 07, 2010 - 02:19 pm:

Thanks Anthony.

Wow Adam! First off the longest surface plate I have is 16". something would have to be made to reach about 32" to the end of the back plate. I did try locking up the Ford side virticle with intent to rotate the Ruxtell side on top of it with a dial against the machined back plate but the houseing was warped a few thou and would only rotate 1/4 turn from its assembled position.

Torque tubes are tapered again something would have to be made to do an accurate check.I can tell you after adjusting, the diagonal from the end of the torque tube to the machined corner of the back plate was equal when before adjustment it was about 1/8" off.

I am at a loss how you could check an axel shaft or a drive shaft on V blocks when the middle of them are not machined. I use centers and a lathe and thats not exact.

Anyone with a small lathe could make the parts to do this method. I KNOW it's no more then 7 thou off from the center bearings.

From your posts I respect your abilities but just so far this method has saved me from buying a new or trying to make the Ruxtell side useable.

It appears to me many folks slap the green on the table and buy new when my bride might not agree with the thinking.

To each his own!!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Adam Doleshal on Wednesday, December 08, 2010 - 10:39 am:

Paul, I wish you lived close enough to me that you could drop by and I could show you how to check all these parts. Your method may work, but it is way more complicated than more "standard" methods that are also likely to be more accurate. My surface plate is only 12x16 - you check each housing half individually in the up&down position with a square. The machined backing plate may not be a great reference point. What you need to be concerned about when rebuilding a rear axle is that the bores for the inner and outer sleeves are exactly aligned and exactly 90degrees to the machined faces where the housings bolt together. I should also point out that original "centering holes" in original Model T parts are very often inaccurate and should not be relied on unless steps are taken to verify and/or re-machine the original centering holes. There are simple checks for all the rest of this stuff too. Unfortunately it would take hours to explain, but it can be done.

From your post above, are you saying that your ruckstell housing IS sprung a bit? If that is the case, you REALLY SHOULD either have it properly straightened by someone who understands what they are doing and has done it before, or you should find a better one... You SHOULD NOT put it all together and then try using the radius rods to pull it back into alignment. It might seem like everything is in good alignment, but in this case, things will not be what they seem. With that said, no matter how you do it, it will likely last a couple hundred to a few thousand miles, so if you don't plan on driving much, maybe it will be "good enough". Your system is a neat invention that I'm sure nobody ever thought of before. It took some real thinking to come up with, but there still are more accurate, less complicated ways to do it.

I am greatly in favor of re-using all the old parts you can.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Paul Vitko on Wednesday, December 08, 2010 - 02:11 pm:

I would enjoy liveing closer Adam! Keeping your mind, eyes, and ears open often leads to something good with folks with knowledge.

I am aware of chewed up centers, if I am serious about a part the center will be recut with a four jaw.

The dial on the back of the rear end is not necessary useing this setup, I left it on to show me how much parts moved. There is several parts of this setup left out like finding out two new bearing races from two vendors are differant thicknes and requireing 5 thou under bearing to fit the axel. The plugs work like a go no go gage.

Henry relied on his machineing to allign the rear axel. It was very interesting to find out after this setup was used the torque tube was centered.

I got the idea from a friend who used a simular setup to allign ships drive shaft bearings years ago. he had a special belt driven gage that would set inside the race and turn on an ohmmeter when it touched a music wire. He could see it, on a T rear end you cant.

Pushing the outer end of the Ruxtell back the amout done is not going to hurt it in my opinion, you have to remember it was cold bent that amount forward and not like an exaust manifold heat bent 250 thou and much shorter and smaller in cross section. It does appear the rear end has memory, but just the moisture in the air could change the dial return useing oak to hold the dial.


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