Rear end pre load confusion

[BlockBuster]

Quoted from Mr. Tom Endy elsewhere on the Barn…

The two axle housings should be bolted to the banjo with the carrier inside with out any banjo gaskets. The ring gear should lock up when the bolts are tightened. This tells you that by adding banjo gaskets you can achieve a proper preload. If you cannot, then you have to take it apart and add more shims under the carrier bearings. Once it locks up you add banjo gaskets until the proper pre-load is achieved. You should end up with somewhere between a total gasket thickness (for both sides) of between no less than .020 and no more than around .050

I have my carrier bearings locked without use of shims. Do I add gaskets to achieve the 20 in/lbs while also achieving the 30-35 ft/lbs for the 10 axle to banjo bolts? I can't find that written out anywhere, although it may be implied.

Thanks in advance.

 

[BRENT in 10-uh-C]

Quoted from Mr. Tom Endy elsewhere on the Barn…

The two axle housings should be bolted to the banjo with the carrier inside with out any banjo gaskets. The ring gear should lock up when the bolts are tightened. This tells you that by adding banjo gaskets you can achieve a proper preload. If you cannot, then you have to take it apart and add more shims under the carrier bearings. Once it locks up you add banjo gaskets until the proper pre-load is achieved. You should end up with somewhere between a total gasket thickness (for both sides) of between no less than .020 and no more than around .050

I have my carrier bearings locked without use of shims. Do I add gaskets to achieve the 20 in/lbs while also achieving the 30-35 ft/lbs for the 10 axle to banjo bolts? I can't find that written out anywhere, although it may be implied.

Thanks in advance.

This topic is one that is VERY hard to describe in words, but I, Tom or others can physically show you in about 10 minutes so it is not just you that has difficulty with this.

In a nutshell, remember that you will stack gaskets effectively loosening the tension on the bearings until you reach the 20 inch/pounds of rotational drag of the driveshaft. THEN you must check the pinion depth in the ring gear and adjust the location of the gaskets by separating on opposing sides of the differential (banjo) housing to achieve the proper pinion lash. Once you have the proper lash and have installed all the axle housing fasteners into the pinion (banjo) housing, then you can torque them to Tom's 3-35 lb figure. Does this help??

 

[BlockBuster]

Yes, Brent. This helps.
To find the bearing pre-load I ended up with .045" of gasket thickness. Until the above quote from Tom Endy I hadn't seen the .020-.050 figure anywhere and being a complete novice I was under the impression a pair of .010 's and a .005 was gonna get this done. A few hours of trial and error (and another Barn search) showed me the light.

 

[Jim Brierley]

I don't recommend bolting it together without gaskets (shims) as the housings are easily bent out-of-flat. I assemble it all vertically with the right side down. With the left housing just resting on the banjo I measure the thickness required by using feeler gauges. With 3 or 4 feelers (radially) in place I tighten the left housing, removing feelers in steps until I get the pre-load desired. This gives you the total thickness of gaskets required.

 

[PeteVS]

Here's how I held a '48 rear while doing all of the preload stuff. I used an old Rigid "Tri Stand" pipe vise.