Rear end issues

[clhiller]

Well, I got started on the rear end this week. Leaky bearing seals and pinion seal . I also was wanting to put a 3.89 rear end in it if I could find one as it seemed to be a real high revver on the highway. I also felt some movement in the nearside rear wheel when I grabbed it at the 12 and 6 o'clock position and rocked it.
So several things have happened. Looks like I have a 4.55 rear end (41 tooth ring and 9 tooth pinion). No wonder it was such a high revver. (Anyone in the market for one?)
The other thing was the bearing on the nearside wasn't pressed on tight to the axle ring. There is a difference of 1/4" from the bearing face to the shoulder of the taper between the two sides. Far side is 2.25" and the nearside is 2.025". What is the proper distance?
Could this contribute to the movement I felt? The bearing not being pushed on far enough would allow the axle to slide further into the differential than it is supposed to. All the bearings seem tight and smooth, so I don't know where the movement would come from.

As always, all ideas are appreciated!

 

[clhiller]

Hello....anyone? (Lonely cricket chirping)

 

[bernd_st]

Hi,

Wonder what axle or diff you may have. 4.55:1 was never used on an Alpine.Perhaps from a Rapier or Husky? Should be either 3.89 or 4.22 for OD cars. Good 3.89 ones are getting scarce now. Regarding the proper position of the bearing would need to take some measurements. Will check and come back to you...

 

[bernd_st]

I'm measuring 55mm (2.16") from bearing w/o splash shim to taper end. Pls. See picture attached. There might be different bearing thicknesses though. Looks like either your nearside bearing is not fully pressed home or the collar is not properly positioned on the stub axle...


.

 

[puff4]

This doesn’t give specific measurements, but in this thread you can get an idea of the assembly process for the hub, bearing & ring. Prior to this I had been unaware that those rings were not fixed on the shaft.

http://forum.sunbeamalpine.org/index.php?threads/who-knew-the-axle-ring-moves.28039/

 

[bernd_st]

I was aware that the collar rings can be moved under high pressure but normally they don't. Furthermore wonder whether the 0.8 mm in the thread makes much of difference . Have done several rear axles but never changed the collar position -unless the brake drum wasn't positioned properly or the half shaft wasn't engaging well enough in the diff...

 

[clhiller]

I think the diff is out of a Rapier. It is a spherical bevel, not a hypoid bevel final drive. One of my first posts about this car was about the engine and the number stamped on the block. It turned out that the block was originally out of a Rapier II, so I’m thinking that a Rapier was used as a parts donor for certain things during the restoration.
I have sourced a decent 4.22 locally so I will swap that and with the installation of the OD transmission there will be a huge difference in the highway cruising performance. If I can find a 3.89 for a decent price I may swap that eventually.
With the original 1492 engine, maybe the 4.22 would be the best compromise between acceptable acceleration and comfortable cruising.

 

[phyrman]

Once you get the tolerances figured out, I think a 3.70 gear set is available thru Sunbeam Specialties

 

[bernd_st]

A 4.22 with OD should work fine . Fast acceleration in combination with relaxed Highway cruising. At least much better than the current 4.55 you have. Really sounds like an early Rapier donored it's ingredients

 

[Tim R]

The collar on the half shaft MUST be moved if you install new bearings (see WSM). Sometimes people don't do this and you end up with the brake drums not meshing with the brake backplate correctly because things are out of line. I forget the measurements but it is all detailed on The Sunbeam Alpine Channel in the videos that cover replacing Hub Bearings for the various Series. (there is also a video there called 'Raising the gearing' that shows the rpm at various speeds when running a 3.89. The amount that the collar moves is very small but important.
Tim R

 

[bernd_st]

Acc. to WSM Tim's procedure is right. Never paid much attention to it but will check it from now on. However never encountered an issue so far. Rootes tolerances/ Bearing width variations are normally more significant than those 0.8 mm

 

[bernd_st]

Found this in my early Singer Gazelle WSM 117:



Quite interesting. Would assume the Series 2 Rapier must have been quite similar to that Gazelle. So I could imagine that one halfshaft was used from the Rapier donor...

 

[Tom H]

Any idea what a "three spot" bearing is? Is that some hardness code, like the numbers on a bolt?

 

[puff4]

That's a puzzler, Tom. I was guessing there were three bearing surface risers on the races. I find nothing on the web about such bearings, apart from an obscure reference of their use in Triumph motorcycles.

 

[bernd_st]

Well spotted ! My assumption is that the bearing should have a bit more running tolerance because of that "interference fit " on the halfshaft...