Do I need new springs?

[67-2door]

The back end of my 2 door saloon crashes badly over bumps, with the kids in the back even the smallest bumps like the 1" high drop onto the road from the end of our drive gives a sharp jolt.
I've had a look under the car with no-one sat in it there's probably 1 1/2" between the rear bump stops & the body, is this too little? Also the springs feel very soft, when I was looking underneath I noticed if I pull sharply down on the bumper mount I can nearly make the bump stop bottom out!
Does it sound like a new pair of springs is required? If so where would anyone suggest getting some? I've read on here that some of the new ones you buy now lose their spring far too quickly.
Thanks for any advice.
Neil.

[mogbob]

Neil
From your description, it sounds as though an overhaul of the rear suspension is overdue.
With a " bounce " test on each rear wing does the car return to it's normal position quickly
or does it carry on bouncing ? ( A leaking shock absorber, lack of fluid ? )
Are the rubbers in the spring eyelets perished ?
Faults in the above will certainly allow you to "nearly make the bump stop bottom out ".
My best guess is that it is the springs.... with one or other /or both other elements above
contributing to the overall poor rear suspension.
I'd recommend polybushes to replace the rubber bushes when replacing the springs and a
top up/ total replacement of the fluid in the shock absorbers when everything is in bits.
Other folks may be able to recommend a source of the springs.

Hope the kids don't suffer from sea sickness too badly !

Bob

[67-2door]

The bounce test shows the car has an incredibly small amount of rear suspension movement (only an inch or two), but it does bounce back up ok without bouncing repeatedly which hopefully shows the shocks are ok (although the passenger side rear shock is weaping slightly), I was planning on removing the shocks, draining them & re-filling with oil before long anyway.
So a new pair of springs & a set of poly-bushes should cure it do you think?

The kids love riding in the back of the Morris, they're forever amused by the sprung rear seat (can see them bobbing up and down in the mirror) & the trumping noises on the over-run always cause them hilarity

[minor65]

My minor occasionlly gave a loud crack noise from the rear suspension over bumps and smooth surfaces. I replaced the springs with all new bushes and checked out and painted the rear axle. The spring leaves where not broken but each leaf had separated at the ends. It made such a difference to the feel and handling and no noises.

[bmcecosse]

Your clearance sounds fine to me - my advice - don't waste money on new springs just yet! You can cut 1" off the tops of the bump stops (leave them tapered if you can) and that obviously gives more travel. And - fill those dampers with SAE 30 (or even better sae 40) oil - that's straight engine oil - NOT 10W40 and certainly NOT 5W30!! The sae 30 is on Tesco's garden shelves (lawn mower engines) - the sae 40 you may need to go to a motorbike place - DO NOT be sold 'fork oil' - it's thin and miserable ! The advice on bushes etc is all good - but if the rubbers look ok - just stick with them until they start to show distress.

[67-2door]

I'll try trimming the bumpstops, thanks. I've got some straight 40 engine oil that I use in my BSA Bantam gearbox, I'll change the shock oil for that to see if it helps.

[bmcecosse]

Ideal oil! You may need to flush the old stuff through a couple of times - and then top up again as the air works it's way out over a couple of weeks use.

[67-2door]

I've taken your advice, trimmed some rubber off the bumpstops. I drained my rear shocks, flushed them with new oil and refilled them with sae 40, it's a long overdue job by the look of it, the small amount of oil that came out was black & stinking!
Took the opportunity to clean the shocks and paint them while they were off too.
Just taken it for a drive and the horrible banging over bumps seems to have gone
Only trouble is while I had the back end jacked up for a few days it seems to have leaked a reasonable quantity of gearbox all over the drive only thing I can think is that it's come from the split pin hole in the bellhousing but wouldn't that mean the input shaft seal has failed? Clutch still works fine. Guess I'll just just check/top up the gearbox & carry on.

[bmcecosse]

Good news on the rear suspension! You may need to top up the dampers after a week or so as air works it's way to the top. Worth doing the same oil trick to the front dampers too. Oil coming out the split-pin hole is almost certainly engine oil - that has come past the rear main bearing labyrinth - but DO check/change the gearbox oil anyway! This is caused by pressure in the crankcase - from piston-ring blow-by - pushing the oil out through the labyrinth. Can often be 'cured' by making sure the engine breathers are clear - and one of them (usually the rocker cover) is connected directly to the intake system via the carb - NOT via the air cleaner, which just clogs the filter with oily mess!

[67-2door]

Odd though that normally it barely leaks a drip from the split pin hole until I leave it nose down with the back end up on axle stands for a few days and then it leaks profusely
Funny thing is though that when I dipped my fingers in it and smelt it (as you do ) it smelt more like gearbox oil than engine oil. But my gearbox is filled with 20/50, the only place I use gearbox oil is in the diff & the leak was no-where near that! Maybe my nose is playing tricks on me.

[bmcecosse]

Normamlly when running the oil would dribble out little by little - and nicely 'rustproof' the underside of the car. Standing/jacked like that - it obviously ran forward and out. Don't worry about it unless it gets dramatically worse.

[67-2door]

I've just checked the levels, engine oil is on the max & gearbox oil is full.
Very strange Maybe it's oil that's just been sat trapped somewhere & having the car at an angle for a few days has encouraged it to drip off?? I'll just keep an eye on it like you suggest.
Thanks for the help.