Technical Rear banana arms

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Technical Rear banana arms

DoIDon'tI

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For a while now, I've been hearing a clunk/rattle from the rear of the car, and suspected that there was some play somewhere in the rear suspension. When I changed my wheels over for winter I noticed a considerable amount of play at the top of the rear wheels. The outer joint in the upper suspension arms (banana arms to the Vectra-C folks) has developed some play, with the MoT looming something had to be done.

So, a couple of days ago I found myself crawling under the rear end of a Croma on axle stands (I jacked the car under the lower suspension arms and put the stands under the mounting points for the trailing arms - sunstantial structure). I'd read up on how to do the job by looking at the Vectra-C forum so felt fairly prepared.

Little did I know that the Vectra floorpan isn't exactly the same as the Croma one...I spent a while scratching my head before coming up with a way to get the job done. The way I found easiest is as follows:-

1. Remove the two bolts holding the rear caliper on and move the caliper out of the way.

2. Undo the 21mm nut (use a 16mm socket to hold the other end of the bolt still) and remove the bolt holding the upper arm to the hub. Put a jack under the lower arm as the hub will drop when the bolt is removed.

3. Unclip the wiring loom from the upper arm but leave the clips attached to the arm for now.

4. Now for the good bit. The inner end of the arm is held in place by a Ribe bolt with the head facing the rear of the car, and an 18mm nut at the front. Access to the front is limited, but if you have the correct Ribe bit then it's not too difficult to get a combination of extensions to allow you to get to the bolt head.

5. The problem is the nut - it's very tight and you can't really get a ratchet handle in there. In the end I discovered that my extandable wheelbrace (an example of which can be found here) with an 18mm socket was just about right, and with a bit of fiddling around I was able to get the nut loose enough to undo it using the bolt head.

6. Once the bolt's been removed, the arm can be removed upwards and outwards. The wiring clips are much easier to change over when the arm's out of the car.

7. Fitment is the reverse of removal (!) but take care to position the arm in the middle of its travel before tightening the bolts - again, use a jack under the lower arm to help.

The car no longer rattles from the back and feels a little more planted on the road, so job well done I reckon. The best bit - the arms cost £30 inc P&P from ebay so at least the parts were cheap. The car's done nearly 71,000 miles so that's not too bad really.

Anyway, hope this helps someone.
 
Yup, good description. I had the left side changed about two months ago and watched the mechanic working on it.
 
I changed both arms last weekend to stop the knocking from the rear end.
I must say DoIdon'tI was a great help. I opened up the sealing boots and there is no dirt inside and plenty grease. Seems like the same problem with the driveshaft joints, crap metal.
 
I have just changed the rear springs on my 06 Croma - corrosion has made them snap off at the bottom coil. I noticed that the outer ball joints on the upper control arms (Banana arms) are worn the same as you describe this also explains the thumping noises coming from the rear. Thanks for the post describing how to go about it. I am now off to look on Ebay for some new arms.
 
I replaced the nearside arm last weekend with the help of my 15 year old son. It really is tight in there. It took ages to undo the nut a fraction of a turn at a time. So I scoured eBay for a 72 tooth ratchet spanner to do the other side and came across this bargain:

http://www.ebay.co.uk/itm/181119710138?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

It came within two days and made speedy work of removing the nut. A bargain at under £6 delivered and a usefull edition to my toolkit. The quality seems excellent but I still used the wheel brace method to loosen the nut initially. Another useful tip is to be very careful that you don't drop the nut! It WILL drop into the hollow subframe and roll out of sight and reach. It took 20 mins, an inspection mirror, magnet on the end of a cable tie, a torch and two pairs of hands to extract it!
 
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Although now an ex Croma owner I have an interest in this thread, I too changed my rear upper control arms and thought I had found a bargain on Ebay having picked up a pair of arms for abour £37 for the pair, this proved false economy and within 6 months they were knocking again, I had to change them again but this time I used Vauxhall World parts to supply me with a pair of Febi Bilstein parts which are of much better quality, they cost about £80 for the pair but still much much cheaper than the £165 per part I was quoted by my local Fiat dealer. Be warned cheaper isn't always best!
 
My bargain was the spanner, not the arms!
Yes I agree, that's a good price for a fine toothed ratchet. When I did mine I used a Snap-On impact drive universal joint which is a ball type rather than the usual double hux joint type, this coupled to the longest 1/2 inch drive extension in the world enabled me to get at the inner bolt head quite easily, I still managed to drop the nut into the subframe though. :bang:
My Croma is now plying it's trade in Ipswich so I hope the roads are less potholed there than here in the West Midlands and the arms will last longer.
 
My bargain was the spanner, not the arms!
Yes I agree, that's a good price for a fine toothed ratchet. When I did mine I used a Snap-On impact drive universal joint which is a ball type rather than the usual double hux joint type, this coupled to the longest extension in the world enabled me to get at the inner bolt head quite easily, I still managed to drop the nut into the subframe though.
My Croma is now plying it's trade in Ipswich so I hope the roads are less potholed there than here in the West Midlands and the arms will last longer.
 
Hi All, Great write up for changing the rear upper control arms. Thanks DoIdon'tI

This was an MOT failure for my 2005 1.9JTD. I have managed to remove the arm on the exhaust side. But am completely lost at gaining access to the bolt head which seems to be obscured by the fuel filler pipe on the otherside. I have read the fiat workshop manual, for this process and is doesnt mention how to access the bolt head to undo or move it, and doesnt mention any special tools needed either.

Does anyone have any hints or tips on getting this bolt undone, and with replacing the arm on this side.?

BTW, The work is being carried out on axle stands, if this makes a difference for access.

I have 30 + years experince with automotives, and do all my own maintenance, but after hours lying under the Croma, I am still unable to figure it out.:bang:, . What am I missing?

Thanks,

Bigzed
 
is it inverted torx socket for that bolt?

dunno if these pictures will help but still
 

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Hi folks,
(y) I figured it out, I had to move the fuel filler pipe, upwards and use a wooden wedge to keep it propped up and out the way. Doing this creates just enough access between pipe and subframe to insert the E18 socket to hold the bolt head. With the use of wobble extensions, universal joints, more extensions etc. was even able to use a ratchet to relatively quickly unscrew the bolt from the nut.
Now all I gotta do is put it back together with the new arms.

Flisko , thanks for the pics of the sub-frame, wish mine looked like that.:)
 
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