MTFCA Forum

Which is the best one to use ? Original , non adjustable or the adjustable.
Need some input on this.

Personally I stay with original. That means you need a really nice wound hyatt bearing with .003 or hope fully less wear. Tight cage. (hard to come by) Never use the repop solids! Spool must have minimal wear. Thrust side the best surface.(hone to clean) Inner race is easy.(new) But it must press on tight.
If you dont have these good parts - use the timkin conversion.
I would go with the non adjustable. A few years back I worked on one. The 2 piece clamp on collars had moved. At least tack weld them once your gear clearances are set.
Not familiar with the current offerings.

speedytinc wrote: ↑

Sun Jun 27, 2021 5:16 pm

A few years back I worked on one. The 2 piece clamp on collars had moved. At least tack weld them once your gear clearances are set.
Not familiar with the current offerings.

My buddy had the collar slip as well. Sort of his own fault, in a way. Won't go into that now. We got it re-adjusted and re-tightened, but in addition, also added a hard thrust washer between the u-joint and the driveshaft bushing. The usual bushing thrust face had been removed, as many do when using the modern pinion bearing. I would NOT go that route, but instead, fit the bushing as you would a stock T driveshaft set-up. And, also use the u-joint pin.

Pinion Bearings and The Ford Service Manual

The Ford Service Manual is extremely vague regarding the permissible wear in the driveshaft roller bearing bearing (pinion) assembly, and the key word here is assembly. There are three parts in the assembly: the roller bearing sleeve, the roller bearing (which itself is an assembly of rollers, rods and rings), and the bearing housing. All three parts are subject to wear. Ford said to check for wear, cracks and pits in these parts, but never specified allowable tolerances for wear.

The Ford part drawing T-192 specifies the tolerances for these parts when new. The driveshaft roller bear sleeve (T-163 B) outside diameter was to be 1.247”-1.249” or a nominal diameter of 1.248. There are eight rollers in the bearing itself (T-108) and their diameters were specified to be .561”-.563”, or a nominal diameter of .562”. The inside diameter of the roller bearing housing was specified to be 2.374”-2.376”, or a nominal diameter of 2.375”. If all of the parts were machined to their nominal sizes, this would have provided a clearance of .003” for lubrication.

Now take a micrometer and start measuring your parts. The used driveshaft roller bearing sleeve will likely measure 1.246”-1.247” for about .002” wear.

Next measure your used driveshaft roller bearing. You will likely find the diameter of the rollers to be .556”-.559”, and they will frequently taper several thousandths from one end to the other. Since there are eight roller bearings, wear of .004” on one bearing will be matched by .004” wear on the opposite side roller, resulting in a worn tolerance of not .004” but .008”.

Next measure the inside diameter of your used roller bearing. You will likely find its diameter to be 2.378-2.380, or about .004” wear. Now your total tolerance among the worn parts is not the .003” Ford specified, but .014”. In effect, this will cause the pinion gear to wobble .014”. If you set up your differential ring gear for side to side clearance of .006”-.008”, then the pinion gear wobble will result in -.008” to .020” clearance between the gears. This will probably result in a noisy rear axle.

While new driveshaft roller bearing sleeves are available, the new roller bearings are not grooved (the grooves created when winding the roller bearing assisted in moving lubrication between the parts when revolving). New later-style roller bearing housings are not readily available. Consequently, it is very difficult to obtain good roller bearing assembly components that will permit the .003” tolerance that Ford originally intended.

The alternative is to use the modern tapered roller bearing conversion. The conversion eliminates the problems of worn housings, bearings and sleeves. The conversion will result in a pinion that will run much more true relative to the ring gear, and a quieter rear axle.

Respectfully submitted,

Trent Boggess

Due to the lack of quality original parts I have used the Timken conversion kits on both of my T’s. The Locking collar working loose was a worry for me too but I did the “Belt and Braces” approach by using the original style front bush and flange
running on the Universal Joint. This will prevent the shaft moving rearwards should in the unlikely event the collar comes loose.
At John Regan’s advice I went for the Non adjustable version. Alan in Western Australia

I have used modern replacement bearing for many of the rear ends I have rebuilt. I have used the adjustable version but actually found the cheaper none adjustable setup to work just fine. So unless your parts are within new tolerance I would suggest using a modern setup. Looking back I have rebuilt close to 50 back axles including Ruckstell and only had two failure in forty years.
The first failed as at the customers request I used spiral gears for the differential. They failed and ended up cutting the Ruckstell bell housing in half and the whole thing failed. I fixed it for free.
The second was two years ago and the customer wanted a 3,25 ratio so I used a 40 tooth ring gear and a 12 tooth pinion. This required lots of shim, close to 0.1” and it didn’t hold up. It failed in Death Valley with me following him in the Touring. He fixed himself using a standard 40:11 ratio.
Best keep things as simple as possible, though I prefer Timken to Hyatt bearings. JMHO.

I have used the adjustable on 2 of my cars. I believe the only difference between the 2 is the shims. The adjustable comes with a shim pack that allows you to fine tune your pinion depth, while I believe that the fixed comes with a single shim.

Removed by author

Mark Gregush wrote: ↑

Tue Jun 29, 2021 10:39 am

The gasket(s) between the pinion housing and center section are what would be used to adjust depth. Ford did not have a gasket there, not even listed in the parts books. Maybe not as precise as the adjustable setup, but would be fine for most applications. The modern type, still have to fit the upper busing and u-joint and pin same in place.

The gasket is going to decrease pinion depth... The shims behind the pinion gear increase depth.
I set my Ruckstel up without shims and the depth was fine, using the modern style spool bearings.

TonyB wrote: ↑

Mon Jun 28, 2021 11:12 pm

I have used modern replacement bearing for many of the rear ends I have rebuilt. I have used the adjustable version but actually found the cheaper none adjustable setup to work just fine. So unless your parts are within new tolerance I would suggest using a modern setup. Looking back I have rebuilt close to 50 back axles including Ruckstell and only had two failure in forty years.
The first failed as at the customers request I used spiral gears for the differential. They failed and ended up cutting the Ruckstell bell housing in half and the whole thing failed. I fixed it for free.
The second was two years ago and the customer wanted a 3,25 ratio so I used a 40 tooth ring gear and a 12 tooth pinion. This required lots of shim, close to 0.1” and it didn’t hold up. It failed in Death Valley with me following him in the Touring. He fixed himself using a standard 40:11 ratio.
Best keep things as simple as possible, though I prefer Timken to Hyatt bearings. JMHO.

How did it fail?
Was it a RUX? I am also running 3.25 gears. What did you shim? 40 tooth rux ring gear? Been told adding shims can lead to ring gear bolts shearing. Was it a stack of shims or 1 thick one?
Was that what happened?