rear dampers - advice

[dudload]

morning all!

since i bought the moggie 3 years ago i haven't checked the oil level in either the front or rear dampers (as plenty else had to be sorted first). however, after fitting the new engine steady bar, next job is to tackle the shocks and give them some TLC.

was wondering if there's any particular tips on how to remove the rear dampers/if i need new gaskets for any of the nuts etc? i'm assuming the fronts are much easier as i plan on just draining through the easily accessible nuts and "pump" the car up and down until all out, followed by filling with SAE30 oil.

ideally looking for a noddy step by step on the rears and anything to watch out for...

[Trickydicky]

Section L of the downloadable workshop manual details the steps to remove the rear dampers. You may need to replace the drop links as the bushes may be perished.
If there is more than 1/8" play in the arms then it's time to replace them, play usually means the oil has leaked out and the dampers have been running dry. The internals will be worn as a result rendering the dampers unrepairable.

[edd_barker]

Great beginner job to do on a minor! Really straightforward. Do expect to replace drop arms, but when I did mine the new arms available were terrible quality so don't chuck your old ones away! Changing the oil can make a real difference to handling.

dont really need to jack the rear of the car up, but keep one nearby as adjusting weight on the suspension can help when refitting the parts.

Edd

[dudload]

evening all!

got under the car for a good bit today and changed the oil in the rear dampers. good thing was that there was plenty of very old, runny, stinky blue grey fluid in there with minimal play on the arms. Removed the 1/2" of muck and grime off the outer casings and filled up with SAE30. Filling up the things is blooming painful as the hole in the top is so small!!

The drop arms seemed fine as both were quite stiff which suggested the bushes weren't perished, but I didn't have time to take the links off - is lack of movement normally a good sign, or should i really take em off and have a good look next weekend?

[philthehill]

Take the links off and check the ball end - if ok refit and replace the eye bushes with poly bushes.

[Declan_Burns]

......filled up with SAE30. Filling up the things is blooming painful as the hole in the top is so small!!

I use a syringe and some silicone tubing-makes it dead easy and no spills.
Regards
Declan

[dudload]

Well, unfortunately after two long drives to Cheltenham and back this weekend the rear dampers are now leaking through the link arms. Looks like two new ones from esm - does anyone have any experience of the uprated ones or refurbished that they stock?

[don58van]

I'm no expert on the dampers... but...

It seems to me that it would be wise to leave an air gap when refilling with fresh oil.

My logic is:
* the dampers generate heat when they operate. This arises from oil being forced through small valves (this is how the damping is achieved)
* the bumpier the road, the more heat
* the oil would expand a little when heated (inside the dampers cylinders and reservoir)
* if there is no air gap, the increased volume of oil would tend to be forced through spaces where it is not intended to go instead of compressing the air space.

So, overfilling could give the impression that the dampers are clapped out as evidenced by leaking.

What do you think??

Don

[BLOWNMM]

Section L3 of my MM manual states 'The interior of the body should be filled with fluid to within 3/8 inch (10 mm.) from the top of the cover'.
Also done with damper removed.
Bob

[Trickydicky]

Well, unfortunately after two long drives to Cheltenham and back this weekend the rear dampers are now leaking through the link arms. Looks like two new ones from esm - does anyone have any experience of the uprated ones or refurbished that they stock?

There was a recent thread were a op bought a pair of reconditioned dampers and they were fine. The uprated ones have the advantage of being new but if you wish you can tweak them by replacing the oil with a heavier or lighter oil to suit your preferred ride.

In answer to the other two replys, yep you do need an air gap otherwise the damper would just lock up as there is no place for the oil to move between the two bores.
Generally the reasons the dampers fail is because in normal operation the small amounts of movement wear the bore of the lever arm oval, couple that with over the years of operation and the crud that acumilates around the location of the seal it fails and thus they leak. They never leak from the rear as the end cap is a good fit. Then you have the problem after the oil has leaked out the dampers run dry. This the wears away the bearing surfaces of the link pins and other bearing surfaces and creates the wear you can feel in the arm (detailed in the workshop manual)
Don, I do get your theory on the oil getting hot but here in Blighty it's too damm cold most of the time

[dudload]

well, i think the problem is that i've overfilled it. i stupidly filled to just below the cap level, so i've probably caused excess pressure. i guess the question now is if the leaking will make things go back to normal, or if i've now gubbed the seals due to me causing the additional pressure

[myoldjalopy]

Well, if they aren't OK, I can confirm I got reconditioned dampers and fitted them about five years ago and they are stilll fine.......

[don58van]

Bob said

Section L3 of my MM manual states 'The interior of the body should be filled with fluid to within 3/8 inch (10 mm.) from the top of the cover'.

Bob -- I should have checked the manual before putting up my previous post. I think it is pretty clear now that overfilling has the potential to cause leaking from the seals.

Dudload -- Your dampers might be perfectly OK once the air space issue is addressed. I think it would be worth cleaning them up and watch to see if the oil already lost is enough to provide the necessary air space hence cessation or reduction in leakage. Ideally, I would suggest draining a very small amount of oil from them (say, a teaspoon full).

Don

[BLOWNMM]

It is important to remove the damper as the manual states and have it level, otherwise it is difficult to gauge the amount of air in the body if the damper is at an angle.
Bob