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2+2 rear suspension

PostPosted: Thu Feb 17, 2011 11:21 pm
by tim22
I would be grateful for some advice: my Lotus is an Elan +2 with standard rear suspension.

I noticed when I last drove off a clonk beneath the car and the handling felt wrong so I immediately turned back and parked up. I then saw that the body is leaning over to the driver's side by about 45mm. I have taken off the wheels and found that the passenger side spring is about 35mm longer than the spring on the other side - 200mm between spring retainers driver's side which fits with the 211mm compressed spring length in the manual but 235mm on the passenger side . Distance between the perch plate and bearing carrier is the same both sides and looking through the holes below the parcel shelf everything seems the same on both sides at the top. No evidence of a broken springs and the car seems to bounce fine on either side - it passed its MOT the day before breaking down! I am planning to take to get the car on a friend's ramp tomorrowfor a better inspection but wondered if anyone had any ideas what to look for.

Whilst looking around I noticed a few other things. The bottom of the passenger side spring perch is badly corroded and the inner link of the wishbone is distorted - see pictures - and there is a small amount of vertical play (enough to feel but no noise or heat notice earlier) in the wheel bearings both sides. Are either of these first two repairable - should I buy a new wishbone and if I buy a new tube (available from SJS but not cheap) is this a DIY job to fit to the hub carrier or would it be best to go for adjustable narrow spring conversion and remove the rusted perch plate? I am also planning to fit a solid drive shaft conversion (from Sue Miller) so the suspension needs to come apart in any case - would appreciate a full list of suggestions for what to look for when the car is on the ramp in order to do a 'proper job'?

Many thanks

Tim

Re: 2+2 rear suspension

PostPosted: Thu Feb 17, 2011 11:32 pm
by jimj
Tim, sorry to state the obvious and pass bad news but, judging by the photos, the whole rear needs some big money spending. The diff. is leaking, the wishbone is bent, then there`s the corrosion. What else must there be. I think you need some professional advice and not from the lax MOT garage.
Sorry,
Jim

Re: 2+2 rear suspension

PostPosted: Fri Feb 18, 2011 9:51 am
by Elanintheforest
I agree with Jim completely. If some parts of the rear suspension are knackered, then the chances are it will all need doing. But there is good news!

A lot of Plus 2 cars have been broken for parts over the past few years and getting hold of servicable rear struts and even rear wishbones is pretty easy in the UK if you need them. You should be able to get all four bits for ?200 - ?300. They'll have to be overhauled of course, and that diff does need to come out.

Mark

Re: 2+2 rear suspension

PostPosted: Fri Feb 18, 2011 1:20 pm
by ardee_selby
Tim,

What Jim & Mark have said, except I wouldn't have said "lax" exactly. If he has been your regular guy, I don't think he has been doing you any favours.

But where are you? I'm sure if someone on here is in your area they'd we willing to look & advise. No shortage of help on here, from my experience.

May be prudent to hang fire on the solid driveshafts until the rest has been assessed?

Good luck & cheers - rd

Re: 2+2 rear suspension

PostPosted: Fri Feb 18, 2011 5:54 pm
by gerrym
Be very weary about using 2nd hand wishbones. They were built pretty thin/weak to begin with, may have been bent or straightened, be worn out (where the bushes are pressed in ) or corroded.

If you can stand the damage, go for ajustable toe-in rear wishbones. Spyder or Kelvedon do them

Gerry

Re: 2+2 rear suspension

PostPosted: Fri Feb 18, 2011 10:32 pm
by alexblack13
As Gerry says. Be very carefull with second hand. It is not difficult though (as Mark said) to obtain good secondhand as there are a few +2's being broken for spares .. God only knows why but there you go! If and when you do get hold of some secondhand just make sure they look right. No visible damage is good and they must not be rusty. You need to make sure they are nice and thick metal wise and weight helps. Tap them gently with a small hammer and listen. They should ring and talk to you. If in doubt..Buy new. The adjustable ones are nice but you could live without them ok.

The tubes in the Chapman struts need to be carefully checked for rust too. Make sure you have plenty of metal left. Again any doubts = get some new (or good s/h) If the ally parts are in Good nick you can have the tubes replaced. Then if it were me I would fit the adjustable perches and the smaller dia springs.

That just leaves your diff'. A good overhaul with seals and bearings and a good check of the diff itself will see it ready to do a few more years. They do last well in the Elan if reasonably well cared for..

Watch those brake pipes.. And are the Calipers all OK? Handbrake OK?

Its no big deal... I had 10 months MOT on my car when I bought it and I could bend the rear A frames (wishbones) over my knee. They were almost rusted through. It will all refurb' fine. Trust me! :wink:


Keep us all posted as to your progress and remember we are all here to help.

Alex B...

Re: 2+2 rear suspension

PostPosted: Sat Feb 19, 2011 9:25 am
by tim22
Thank you for your replies.

It sounds like I should take my time and get everything sorted out in one go (funds permitting!) although the immediate problem is to find out why the car is leaning over and to replace a damaged doughnut so that at least it runs.

I have been replacing dougnuts at a rate of more than one per 2,000 miles and one went suddenly in the past, so I bought the solid driveshafts a few months ago with the intention of fitting them in the summer. I also bought a set of polybushes from Autobush - generally I prefer to replace parts to the original specification and although I'm a bit reluctant about these changes they seemed necessary from my experience that any new rubber components don't seem to last - any views to the contrary could still persuade me to switch to rubber bushes? I live in Central London so use the car infrequently but it is my only car - mileage is only about 3,000 miles per - so I aim to maintain it as a road car and try to build in as much reliability as possible for a Lotus! My friend's workshop is near Lingfield.

I will update and probably ask for more advice after I get a chance to inspect properly.

Tim

Re: 2+2 rear suspension

PostPosted: Sat Feb 19, 2011 9:51 am
by Peter +2
Tim,

If it's of help I have a spare pare of rear wishbones, they are not perfect but are sevicable if you send me a Private Message I can send you pictures. There yours for ?60 the pair and I am in SE3.

Peter

Re: 2+2 rear suspension

PostPosted: Sat Feb 19, 2011 10:53 am
by Craig Elliott
Tim - It's well worth doing this properly even if it does take time. Sounds a bit like one of the springs has sagged more than the other but check that there aren't any chassis problems to add to the woes. I replaced the bushes on my suspension with polybushes (superflex in my case) and fitted new lower rear wishbones and it made a very positive difference to the handling and the way the car drives. Generally if feels a little bit "tighter" and more responsive and a good improvement over the rubber bushes without feeling too harsh. When you do sort the suspension out it's also worth checking the rear toe-in as this can also make a big difference to the handling.

On the topic of rear uprights and rust spring seats, it may be worth giving Spyder a call as they may have second hand spares knocking about. Which side are you looking for or are both gone?

C

Re: 2+2 rear suspension

PostPosted: Sun Feb 20, 2011 10:04 am
by mikealdren
Tim,
there's a rear arm on the 'for sale' section.

Mike

Re: 2+2 rear suspension

PostPosted: Mon Feb 21, 2011 8:24 am
by kstrutt11
In an ideal worls you would rreplace everything worn, but being pragmatic.

In order of priority, firstly you need to sort out the spring seat, if that lets go the spring will jam into the tyre and you will end up in a ditch or worse (at the same time you need to sort out the list to one side (hopefully just a failed spring or top mount).

If there is no rust in the A arm it will be fine for a while, the longitudinal arm is not that stressed comparred with the others, and it's function is doubled up by the chassis, at a push you should even be Ok straigthening it.

The wheel bearings should not have any play, these can be replaced easily if you have access to a press, I have even done them on the car using a collar behind the spinner to push the hub off and then a tubular drift to knock the shaft out (you need to remove side shaft first). If you leave them too long the shaft begins to spin on the bearing and is also ruined (or at least needs metal spraying and re-machining). The other thing to keep an eye on is the wheel clearance to the outer A arm bolts, these are very close and any bearing play causes them to foul.

The oil leaks from the diff are probably just age hardening of the seals, the side ones can be easily replaced in situ (remove side shaft, remove circlp and use slide hammer to pull out), I have found it's best to replace the bearing as well though), in the short term you should be able to get away with just regularly topping up the oil. The front seal is a bit more complicated, accoring to the Ford proceedure you are supposed to strip the diff and fit a new collapsable spacer, in reality I have always got away with paint marking the nut and doing it back up to the same location.

Kevin

Re: 2+2 rear suspension

PostPosted: Mon Feb 21, 2011 11:05 am
by tim22
Thank you all for your replies.

Had a chance to inspect from underneath and found the reason for the car listing to one side is actually the front end - a failed thread in the offside trunnion.

Agree with Kevin that the spring seat is a priority and once this is sorted out will straighten out the wishbone as otherwise both seem reasonably OK. The diff only needed a slight top up so will clean around the shafts and keep an eye on this for now. Once the driveshafts, bushes and spring seat are up to scratch, the plan is to get the whole arrangement (bearings, geometry and roadholding) tested professionally to advise any further work - during the longer evenings!

Apologies for misleading start to this thread - the ride height was most pronounced at the back but a good excuse to start another thread!

Tim

Re: 2+2 rear suspension

PostPosted: Mon Feb 21, 2011 12:12 pm
by ardee_selby
tim22 wrote:Thank you all for your replies. Had a chance to inspect from underneath and found the reason for the car listing to one side is actually the front end - a failed thread in the offside trunnion.Tim

Tim,

1.0 Do you mean the threaded part of the upright has failed at the top? Could it now look like the attached? (in this case, an example from a Triumph).

Have a look Gerry's interesting thread on the subject of fitting new, un-drilled uprights.

(elan-f15/front-suspension-uprights-lube-oil-drilling-t22088.html)

2.0 Dismantling of the rear hub assemblies can be "problematic". The archives show so many folks who have run into trouble. From the method of hub removal, shaft removal thru to final re-assembly stages, there are many traps for the unwary who haven't done it before.
There are SO MANY threads on how to do it in the archives, it's difficult to point you to a single one. Just don't be lead by the workshop manual. If in doubt, ask.

Cheers - rd

Re: 2+2 rear suspension

PostPosted: Mon Feb 21, 2011 2:15 pm
by tim22
RD

The thread of the trunnion got wrecked so that the upright jumped out. The thread on the upright might still be serviceable but I guess I won't know for sure until I screw the new trunnion (Stanpart from Sue Miller) onto the thread? I think I was lucky as this happened turning slowly out of a parking spot and must be the 'clonk' I first heard before the car tipped over to one side. Thinking back I noticed during the summer that I couldn't force oil into the trunnion but put off further investigation / renewal - bad move!

I have spent some time researching how to strip and assemble the rear hub - there is a lot of information to absorb but it is a fantastic resource.

Thanks again

Tim

Re: 2+2 rear suspension

PostPosted: Mon Feb 21, 2011 4:49 pm
by ardee_selby
tim22 wrote:RD The thread of the trunnion got wrecked so that the upright jumped out. The thread on the upright might still be serviceable but I guess I won't know for sure until I screw the new trunnion (Stanpart from Sue Miller) onto the thread? I think I was lucky as this happened turning slowly out of a parking spot and must be the 'clonk' I first heard before the car tipped over to one side. Thinking back I noticed during the summer that I couldn't force oil into the trunnion but put off further investigation / renewal - bad move! I have spent some time researching how to strip and assemble the rear hub - there is a lot of information to absorb but it is a fantastic resource. Thanks again Tim


Crikey Tim!...from the degree of wear you describe I would be surprised if it was all in the "sacrificial" bronze bit!
You MIGHT be able to fit another trunnion on the old thread and get away with it, but seriously doubt it.
But, MORE IMPORTANTLY, look at the pic of the failed upright. It doesn't appear to be lacking lubricant (leaving any talk of what lube 'til another day). The fatigue failure can be seen quite clearly, so ANY thought of re-using your uprights should concentrate on crack detection at the area prone to failure, even if they appear to have re-useable threads. (elan-f15/crack-testing-uprights-t20576.html) Also, note the replacement of the bottom pivot parts. Seizure there doesn't help the cause at all. (elan-f15/help-trunnion-trouble-t14101.html)
Most accounts of these failures seem to be at parking speeds, anything else doesn't bear thinking about!

Good Luck - rd