Hello All!

I'm new to this list so I just thought I'd better introduce myself ... I have just bought a 1200 sedan as a runabout while my CA18 1600 is being fixed. I owned another 1200 a couple of years ago but ended up selling it which I really regret, but I think I'll be keeping this one for a while. It's pretty standard except for the 120Y front disc brakes we put in on the weekend.

Now onto the problem ...

When taking off normally, the back wheels kind of shudder up and down - looking underneath it seems to originate from where the tailshaft bolts onto the diff. There is a little bit of play in the diff but not a heap, and the rear seal is stuffed on the gearbox - would this have anything to do with it? The uni's seem to be fine - no play in them either.

When you give it more revs, and I mean a lot more, and ride the clutch heaps it doesn't do it, but I don't want to have to drive around like that all the time!

Hopefully someone has a solution for me!

Thanks.

do the wheels actually shudder up and down (ie axle tramp), or do you just feel a vibration from the back of the car? I doubt you could cause axle tramp without wheelspin unless there is something seriously wrong back there.

check for:
seized uni
cracked main leaf
buggered shocks (oil leaks / bounce test)
broken gearbox mount

another thing to consider, is it possably the clutch shuddering and your thinking that it is farther back in the car?
a broken main rear leaf spring could cause this, but you should be able to see it. also check for worn or missing spring bushings.

Thanks for your quick responses!

L18_B110...

Yeah the wheels do kind up jump up and down like axel tramp, but no sign of any wheelspin. I'll check out the leafs and gearbox mount cos they sound the most likely, the shocks are good and so are the unis.

rgrinder ...

No I'm sure it isnt the clutch, I drove the car around the yard while my friend hung upside down out of the back window and looked under the car; theres definitely something wrong futher down the driveline.

I'll have a look next time I see the car.

the problem could be even furthur ahead,& be a broken engine mount,or a broken clutch plate spring.had both these happen,with similar feelings in the car.are you sure the shock absorber top mounts aren't loose/broken,as this will cause a similar feeling also.

take your tailshaft off and roll it on the kitchen floor, see if it rolls evenly. MOst of the time they can be out of balance and you dont know it, The kitchen floor only works if it is really bad. I stuffed up my 5 speed with an unbalanced tailshaft, and yeah it made the axles tramp like that. SHould not cost much more than $60 to balance the tailshaft. Probably less.

hope this helps.
mely

Thanks - I'll check out those things as well and let everyone know how it goes. :)

im just imagining my mums reaction to seeing me covered in grease kneeling on the kitchen floor rolling a tailshaft back and forward, probably not a good idea if you live at home!

hahaha good point! luckily i don't live at home anymore but i was hoping the garage floor would do the job just as well...