me too i would like to know as i just experienced the twitch last night, and yes very un nerving, though i was loosing her
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Hi MikeOriginally posted by Moraystag View Post
You need to grease the rear half shaft splines. These are covered by a rubber gaitor - similar to the steering rack gaitors but smaller. You can either remove the entire driveshaft or, if just greasing the splines, you can remove the four nuts/bolts where the driveshaft connects to the diff output flange and the short end of the driveshaft will pull out of the part connected to the hub. You can then remove this part (which is the female part) from under the car. A good clean up of the spines (male and female) and then use CV grease (my preference) before replacing. Probably worth replacing the gaitor at the same time and securing with new ties/clips. It is a relatively straightforward job. Good luck.
Hope this helps.
Cheers
GrahamComment
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Good stuff Graham that makes sense now, funnily enough I was underneath her last week,
( the Stag I mean ) and I did notice that the splines on the hub side are bone dry.
Next wee job for sure, cheers.
MikeComment
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Mike,Originally posted by Moraystag View Post
You shouldn't be able to see the splines in the shaft without removing the rubber bellows type cover (assuming it has the original shafts and cover). The inside of the hole in thetrailing arm that the shaft passes through is - for some reason - finished as a spline, perhaps it was this you noticed?
I wonder if the original design of the shafts/trailing arm/hub was going to have the hub splined to the trailing arm instead of the six little studs?
John.Comment
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John your right I am getting confused with the spline in the trailing arm. I have however looked through the manual and I now understand where Graham is refering to.
Do you need to grease anything in the trailing arm???.
Do I have to use C.V. grease or can I use something else as I don't have that type of grease at hand??
Could you or someone explain why greasing this joint helps to stop the twitch??
MikeLast edited by Moraystag; 19 April 2011, 16:33.Comment
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Mike,
The trailing arm is a completely 'dry' bit. The hub bearings are greased of course - but in effect sealed, If I needed to do anything there I'd probably buy a reconditioned hub. Your universal joints on the driveshafts might be greasable if they've been replaced with that type during their life.
I think CV grease is usually recommended because it deals with pressure and sliding better than regular grease. If your driveshaft splines are in good condition but desperately need greasing then I'd use regular grease rather than leave them, and then regrease with CV grease later when you've got some. However if they did need greasing that urgently then they're probably knackered anyway!
John.Comment
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Hi Mike,Originally posted by Moraystag View Post
I'll try!
The "twitch" happens immediately after accelerating through a corner and power to the rear wheels is reduced - i.e. foot off the throttle.
Cornering forces change the rear suspension geometry. The stag rear suspension is designed such that the driveshaft must change in length as the wheel moves up and down relative to the centreline of the car.
It was quite a sophisticated system compared to other cars of the time (e.g. the Spitfire).
If the splines lock up through lack of lubrication in the corner and then suddenly release when out of the corner, there is a sudden change in rear suspension geometry. The splines suddenly unlocking is the cause of the twitch. If the splines slide smoothly then the geometry changes gradually and no sudden movements are felt.
If alternatively the splines can't slide at all then as the wheel moves up and down in the arch, forces (and movement) are transmitted to the trailing arm mounting bushes. These provide some "give" as something has to move. As the wheel changes vertical position the bushes exert further forces back on the rear wheels.
I believe it is mainly the splines locking that causes the twitch but adding poly bushes can help mask the problem as they "give" less and put extra force on the splines and in effect make them slide more easily.
Blimey, it's not easy to explain in words. If I could draw you a picture it would be a lot simpler. Anyway, best thing is to make sure you have slidey splines!
Perhaps someone else can give a better description
GrahamComment
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Hi Graham
Russ (Kryten) explained to me what the stag twitch was, and what you said was virtually identical.
Spot on mate.
AlComment
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http://www.stagwiki.com | http://parts.stagwiki.com (Under Development)Comment
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Good explanation, and now I understand. I have had the twitch a few times so I don't welly it coming round round abouts etc, but that's when I do feel it. I'll deffo get these cleaned up and greased and at least that's another job done for the time being. Thanks for info guys and sorry for stealing the thread a bit. But I think that this may help others as well.
MikeComment
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has helped me too, a job for me now as soon as i can round to it, sooner rather than later though
again thanksComment
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Well guys got stuck into it this morning and bought some C.V. grease, ( bloody awful stuff ) LOL. Anyway removed shafts from splines and this is what I found. Passenger side was pretty well greased but did it again anyway, boot was ok and had been secured with tie wraps no damage to gaiter. However drivers side was pretty dry although not completely so removed, cleaned and slapped a load of grease into it. Splines were all in good condition and no broken teath that I could see once I'ld cl;eaned them up.The gaiter was also in good condition no holes no perishing. This gaiter had been secured with thin wire which looked like it had been on for a long time. So I can only imagine that at some point before I bought this car, someone had greased the passenger side but had not checked or greased the drivers side.
Cheers guys for the advice, much appreciated and one less thing to worry about.
MikeComment
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