Accelerated wear in sliding joints

[streaky]

What would cause the sliding splines/joints of my front prop shafts to wear out so quickly?

I had some nasty vibrations coming from the front end during over-run at 70MPH...I removed the front prop and noticed alot of wear in the splines of the sliding joint on the front prop.

I replaced the front prop with another one...2nd hand Genuine Rover item but in good nick.

At around 2000KM the vibrations are back and I suspect the sliding splines are worn again.

The truck is lifted 2 inches & has 265/75-16 BFG AT's fitted. The UJ's remain in good working order...no play there.

Any ideas why this could be happening?

Thx,

S.

[David Sparkes]

I'd say it could be a combination of reasons:

1/ How often do you grease it? When you remember?

2/ With the lift the overall shaft length will 'always' be longer than normal, and the spline engagement length reduced.

In this case, length might initially be more important than area, as with a short engagment, as soon as wear takes place the splines can easily become angled, along the length, thus reduceing some more the spline to spline engagement area.

3/ You drive in 'difficult' terrain where you are often putting high torque loads through the shaft engagement area.

I'd say 2 and 3 require you to grease it more often than normal - see point 1.

A longer than standard shaft, or one with more sliding spline engagement (larger diameter also?) will get you back to 'standard' maintenance scheduling (whatever is normal for your driving conditions).

HTH

[western]

Easy Streaky, it all that sand you keep driving in

[streaky]

I know there are guys out there with Disco's lifted higher than two inches...do they have the same problems?

My Disco is a 98 model. The lift was installed in 2001. I ran the same front prop for about 6 years without problems & now I've fitted two in less than four months.

The truck is serviced on a regular basis...so I assumed they greased the props.

I understand what you are saying David regarding the reduced contact area of splines when the props are extended...but they only get shortened by a few mm's....not half the prop length.

Hence I wonder why one prop has lasted dramaticlly less that the original one....9 years verses 4 months!

Thx guys.

Regards.

S.

[rick]

spline wear used to be a problem with free wheel hubs and constant 2wding. It wears the splines only one way, but this wouldn't be a problem with the Disco, so

what type of grease is being used Streaky ?

You really want something with 3-5% Moly in it, it's brilliant in sliding applications, with the best stuff i know of marketed by CAT. They have various grades, usually a Calcium Sulfonate base to resist water washout and salt (not a problem for you ) with some using di-ester (synthetic) oils for extreme temps.

[David Sparkes]

I appreciated I was on 'thin ice' when asking how often it was greased, so thanks for the considered response. It sounds as though that issue could still be open. The sugestion about the type of grease may also be relevant.

"Hence I wonder why one prop has lasted dramaticlly less that the original one....9 years verses 4 months!"

Ah well, nothing like including extremely relevant additional information in the second post to make early responders look wrong footed!!

I don't have any ideas that I really believe in.

Review:

The original (factory?) lasted 9 years.

The second (New? Factory or pattern?) had a short life.

The third (factory, but second hand) had a short life

UJs always OK, so tends to rule out misalignment between UJ ends.

Anything else you want to add?

:-))

[streaky]

All responses relevant and most welcome lads

I'll look into the grease aspect too. Good lubrication must play an important part in the life expectancy of these things. people always quote "sand" ingress when they relate to worn parts in the Middle East. It's not always the case though.

I called up the local Rover parts dealer. They supply both Original and aftermarket parts for my Disco.

The original item was around 230 quid. A Britpart equivelent was around 70 quid.

Next up was a mail to Britpart. Their response has put my mind to rest and I'll be getting the Britpart item. They buy theirs from Hardy Spicer who I know have a very good reputation.

Britpart also suggested a double cardon Disco II front prop with a flange adaptor kit. I like the idea of this too...I've always had a small vabration on the truck which a double cardon should help eliminate.

The trucks in the shop for O2 stuff right now. I'm off to Saudi for the Hail Baja so will have to report back in a few weeks once the work is done.

Thx again.

Regards,

S.

[Astro_Al]

Streaky - couple more points:

if you are driving this thing hard, maybe its overheating the splines (if the suspension is really hammering up and down) - a cooler would help, like this:

(The fins could be smaller radius for clearance).

Also, you could have the splines treated/coated to reduce friction, might help prevent wear.

Cheers, Al.

[streaky]

Crikey...Interesting concept Al... but I wouldn't fancy that thing wizzing around just a few feet from my toes!

The splines are infact already coated with some sort of anti-abrasive PTFE stuff.

Cheers.

S.