It seems to me that the one omission in the SKF document is any statement about the variation of end-float/preload with temperature. Given that omission, I would assume that the analysis that they have done is carried out with the bearings at operating temperature. This will vary depending on the application. Given that end-float decreases, and preload increases with temperature, and that excess preload generates a vicious cycle (ie preload results in frictional heating which in turn results in increased preload, and increased heatingâŚ) it would seem important to understand the variation of end-float/preload with temperature in the target application. If it is significant, the recommendation for setup at room temperature should take into account the change at operating temperature. Based on the opinion expressed by those who do this for a living, such as @Dick_Maury, Iâve used a reduced end-float (close to zero) on the rear wheel bearings on my E, but I probably havenât gone as far as some have suggested in preloading them.
On a momentâs reflection, I can see that my blanket statement that âend-float decreases, and preload increases with temperatureâ is probably inaccurate. It must depend on the exact configuration of the bearing installation and materials used. For example, if the bearings are installed in an aluminium housing (as in the rear bearing carriers), the housing expansion with temperature may more than cancel out any expansion of the bearings themselves. Too complex for my feeble brain to tackle right nowâŚ
Brent, I agree that the optimal condition for taper roller bearings is to run with a slight preload.
But that is at operating temperature, and any clearance normally reduces as the temperature rises. And too much preload can be nearly disastrous, as I found out. The problem is, how to set them cold so that they run with the optimal preload when warm, but not have then too tight.
In fact, SKFâs published procedure for setting front wheel bearings on a RWD car are practically the same as those from Timken:-
Bearing adjustment
6. Adjust the bearing to manufacturerâs recommended setting. If this information is not available, follow these guidelines. While rotating thewheel, tighten the adjusting nut until there is a slight bind and all bearing surfaces are in contact.
7. Back off the adjusting nut 1/16 to 1/8 turn, or to the nearest locking hole, or enough so that the wheel rotates freely with .001" to .010" end play.
8. Insert and bend the cotter pin. Replace the dust cover.
I think this subject probably deserves its own thread, considering how important it is.
Iâve been mainly talking about the Front Wheel Bearing configuration when replying to Clive. With the rear assembly housed in an aluminium housing, the End Float does in fact decrease. The housing expands, the cups of the taper roller bearings move to be further apart, thus decreasing the end float.
Hmmm. I thought I addressed that in my previous reply, where I stated that the Front Wheel Bearing system of an E Type does NOT lend itself to being set up in pre-load. The bearings are a running fit on the axle and WILL SPIN for sure if set in pre-load. SKF and others get that and accordingly, describe the adjustment of a system that canât be set in pre-load, but the SKF graph clearly shows that bearing life is maximum when the bearings are in pre-loadâŚ
The bearings are a running fit simply to aid maintenance, in that they are easy to remove. If an interference fit, any time the hubs were to be removed, the inner bearing and seal would be left on the shaft requiring another operation just to be able to reassemble the Hub/Axle assembly.
Different story with a spacer between the bearings. That is NOT being described by SKF and others. There are cars that have the spacer system as standard and they do use the bearings in pre-load.
But getting back to the subject of this Thread, pre-load is called for in setting up the opposing, taper roller bearings of the differential output shaft in the XJS manual of the Salisbury differential; essentially the same setup as the Type 1 diff used in the S1 E Type that called for End Float. The change in thinking Its called evolution.
Came home after full week of work and eagerly checked JL for the latest replies on this post⌠That was a couple hours ago and my head is still spinning
Iâm starting to rehash in my brain DIY vs. Vendor rebuild option and 3.54 vs. 3.07 vs. 3.31!
Time to try and sleep on it while not worrying about blue shafts, bent housings, disintegrating bearings, thermal expansion, Chinese steel, and setup bearings.
No disrespect, I do take it seriously and just having fun. You guys are awesome.
Checked and there is no perceivable end float on either drive shaft assembly. Also, neither had enough preload to register on the deflection beam style inch pound torque wrench. Guessing if I had a accurate digital torque wrench it would show 1 or 2 inch pounds.
Also, neither had a plain washer under the lock washer like shown in the manual.
The locknut took 100 foot pounds of torque to break free and both were the same amount of torque required to break free.
Next step is to press the drive shaft through the flange and bearing housing.
Okay, right side axle disassembled with no problems. Iâm wondering if this type axle was original for this car or if these are replacements as they are different than whatâs in the manual.
Left axle disassembled with no problems also. However, the inner bearing and inner bearing outer race have damage and were destined to fail sooner than later.
Hi Kevin,
What you have there is from a later differential after the bearing system reverted back from the double row, angular contact bearing to opposing, taper roller bearings. Accordingly, not the original equipment for your car.
Dissembled the differential. Bolts were 45 ft lbs per the manual and all internal gears and plates looked good. Next step is to think through reassembly process and order new parts. When bearings arrive, I will measure and see if I can use old bearings as setup bearings.
Guess I need to make sure I know what shafts I have in order to ensure I buy the correct bearings, seals, and O rings.
Just found the answer⌠The final drive is a Series 1.5. The car is a late model Series 1 and Iâm guessing came from the factory with S 1.5 differential output shafts. See pic from SNG.
And all of the Jaguar part numbers for the S1 Final drive that I need to replace are the same as the S1.5 part numbers when I looked each one up on SNG.
I prefer not to hammer a drift if I can find a way to safely use the shop press. I used 2 small strips of steel that were short enough to fit in behind the outer race and then wedged then in place until I could get it in the press and press it with a 1-1/2 inch socket. Pics show how I removed the outer races in the diff output shaft bearing assemblyâŚ
Hi Kevin,
The following picture shows an assortment of pressure plates used in the process of removing and replacing bearings and seal in various assemblies of an E Type Jaguar. The part indicated as Pinion Seal Tool is used to press the pinion seal into position using the Companion Flange nut and the thread of the Pinion Shaft.
The following picture shows the parts stored on a length of Booker Rod, which is also used to seat the bearing cups in the rear suspension aluminium Hub Carrier.and Differential Housing for the Pinion Bearings.
Thx Brent! Will try finding a source for these that fit our needs. I like the storage solution you showed.
The tool to remove the first of two back to back outer races with less than a half inch between them would be nice. If that exists, I would like to see it for future work.
Hi Kevin,
For those, we spray the assembly with Spatter Guard, run a bead of MIG 360degs on the tapered surface of the bearing cup, come back in 5 minutes and they fall out.
Hi Kevin,
In terms of welding, MIG stands for Metallic Inert Gas. Spatter Guard is a substance (normally applied via a spray can) to prevent the unwanted spatter from the welding process, sticking to and spoiling the part being welded.
If youâre not comfortable with buying a bunch of expensive welding equipment and then learning how to use it, talk to someone in your local car club and I guarantee you theyâll be somebody who can weld. Take over your rear end and an adult beverage and I guarantee you theyâll fix you right up.
