Thread: Blown spicer yokes S2B front swivels.

Originally Posted by isuzurover

That is a worry if the yokes are only the same size as a Series 3. From personal experience, S3 yokes are weaker than stage 1, county (and of course 101) CVs.

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That's correct. My guestimate is the design of the front halfshaft and yoke are hangovers from the original Rover design in the 1954 models. They did try to strengthen the system in the F/C by introducing a fine spline that carried onto the SIII 109's and Salisbury. However the SIIB was in production well before the 101 and even the Range Rover so a CV front end was not considered.

It has become an issue for SIIB owners today because NOS front halfshafts are no longer available and hence why Mal Story and I developed the modified the Stage 1 swivel as a direct replacement for the SIIB swivel without any other changes in geometry etc.

Originally Posted by Lotz-A-Landies

It has become an issue for SIIB owners today because NOS front halfshafts are no longer available and hence why Mal Story and I developed the modified the Stage 1 swivel as a direct replacement for the SIIB swivel without any other changes in geometry etc.

Has anyone broken a stage 1 CV in a IIB?

These are an option which may be better:
Extreme duty axles

Originally Posted by isuzurover

Has anyone broken a stage 1 CV in a IIB?

These are an option which may be better:

No - AFAIK I'm the first one in the World to fit them.

Whom made the extreme duty axles and did they make them with ENV splines?

Although, possibly not better when they are being driven by an LT230 constant 4X4 transmission!

Originally Posted by Lotz-A-Landies

No - AFAIK I'm the first one in the World to fit them.

Whom made the extreme duty axles and did they make them with ENV splines?

Although, possibly not better when they are being driven by an LT230 constant 4X4 transmission!

Mercedesrover/seriestrek make them or have them made. They are machined from pre-hardened 1541H blanks, so I doubt it would be much extra effort to put ENV splines instead of rover splines. You could probably also buy some blanks with yokes and get McNamara or Barry at HTE to cut splines in them.

A CV will be a bit smoother in a constant 4x4 application, but UJs aren't too bad. Some models of jeep came as a constant 4x4 with front UJs. With PAS you have some slight steering feedback on corners but that is it.

Originally Posted by isuzurover

Mercedesrover/seriestrek make them or have them made. They are machined from pre-hardened 1541H blanks, so I doubt it would be much extra effort to put ENV splines instead of rover splines. You could probably also buy some blanks with yokes and get McNamara or Barry at HTE to cut splines in them.
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Thanks I'll keep that in mind.

Barry Ward already has a brooch for the ENV splines as I needed to send Mal an ENV side gear for them to make the brooch. Now that they have it they can cut the spline anytime they need, provided there is enough metal on the 1541 blank before they start.

I find this discussion rather interesting, as I installed a 4.4 and Rangie transmission in a series 2b in 1983. This was used as a farm hack for years and regulary carried 4 or 5 cattle in a large tandem trailer, as well as off road work. It has never broken a front halfshaft yoke, so I would suspect that factors other than strength are involved. If you look at the geometry of the swivel pin housing, one very important requirement is that the swivel pin axis should intersect the drive axis at the centre of the universal "cross" If there is any departure from this then the velocity will vary which will produce what could be called chatter in the drive. The best way to observe this occuring is to watch a drive shaft on PTO driven trailed agricultural machinery such as balers while the tractor is turning sharply. The effect is very audible and can smash a yoke very quickly. Even with a uni at each end of the shaft the effect will occur if the pivot point is not EXACTLY in the centre of the drive shaft( midway between unis). If you have the opportunity have a look at the complex coupling when a 101 is used with a driven trailer. The design is to maintain correct geometry as much as possible. If the geometry of our swivel pin setup is upset by either a worn swivel bearing or turning the steering too far then we run the risk of failure. The railco bush is best replaced by a tapered roller bearing, making sure the correct preload is applied. It is also very important to make sure the lock stops are doing exactly that. If the lock stop gets bent or worn then the steering can turn the outer halfshaft too far and binding will occur. If the simple UJ is replaced with a CVJ then some extra lock could be used without the risk of failure. Well that's about it does any one have any further ides? cheers from Storm

Thanks Stormy

I have never broken a front halfshaft, but have 2 X SIIB without the front RHS halfshaft. My personal opinion is that the breakages actually occurred on bitumen roads with the vehicle in 4WD, a consequence of the over complex and often malfunctioning 4WD selector mechanism. With your LT95 the centre diff would not allow the stresses of axle wind up to occur in the front drive train. The only down side is the steering wheel kick caused by the variable velocity of the uni joint swivel. (The stage 1 CVs would solve this aspect of your conversion.)

Regarding your suggestion of taper roller bearings replacing the Railco bushes. I know that Range Rover have tapered roller bearings, but they also have power assisted steering to absorb the shock loads. The very earliest 80" land Rovers also had tapered roller bearings at the top and after various modifications Land Rover settled on the Railco bush. Personally I'm equivocal on this change, a "blue slip authorised" mechanic mate is recommending modifying the system to use tapered roller bearings, but others suggest that without PAS the steering kick from the 9.00 tyres will be excessive, probably requiring upgrading of the steering damper system.

The issue of the swivel pin axis: I have not drawn the axis out technically, however given the negative offset of the SIIb rims (part number 569203) and the 9.00 tyres the centre of the tyre footprint would come very close to intersecting the swivel pin axis. I also believe that the Australian 5 1/2" rims (part number 272309) with 7.50 tyres do not meet this geometry and is the reason the the UK build vehicles changed to the part number 569690 5 1/2" rims.

Would be very interested in seeing any images the engine bay of your SIIB 4.4V8 installation!

Diana

G'day Diana, all OK on the cause of the problem, as for any sort of steering kick the only way I've ever had any adverse reaction was to leave the damper out. I would say that if the damper is in good condition and kockstops OK then no problem should be experienced with the use of rollers top & bottom of the swivel pin housing. I've had bearings for a decade or more and the've been good. I'd love to find a power steering box that would fit without drama, I looked at an early Ford ram type system but it didn't have quite enough stroke. Someone suggested there is a Mazda box that would do. On the swivel pin axis I was really on about how it interacted with the drive axis at the UJ, but the point you raise is very important, because when the axis and ground contact line are away from the centre of the contact patch then it may well introduce steering reaction, especially under braking. The offsets in Australian rims that were made by ROH for series 3s (5 1/2") were in line with the British changes. The OZ rims had the prefix AYG (Leyland part No. I think) and a raised ridge about 25mm wide between the mounting stud holes. There was a big thing about not mixing them with series 2A rims on a vehicle in the army, when the S3 arrived. These rims were called by some in the trade "Spanish" rims. With the 4400 conversion, it was not all straight forward. the 4.4 was wider across the heads than the 3.5 because of the increased deck height. This meant therewas a conflict between the top chassis rail on LHS and the head on that side. the solution was to either move the rail or the engine. The rail won because moving the power plant may have upset the driveline geometry. There was no big deal with engineering back then, it may be different now. Nothing broke over nearly 30 years so the engineering must have been adequate. The left exhaust manifold needs to be a rear outlet that hugs the block to clear the main chassis rail too. There is probably a lot I've forgotten now, but I think if I was to do another I would use a 4BD1T. They just wern't available on the open market then. The one thing the V8 has in its favour is that it is nice and quiet, even though it's sitting right beside you! I do have some photos I'll see if they can be found. Cheers from Storm.