Changing rear coil over damper units

ALAN COCHRANE · Post by **ALAN COCHRANE** » Sat Jan 09, 2016 3:28 pm

Happy New Year everyone

I'm in the process of changing the coil and damper units in the IRS. I've measured the length of the existing units cup to cup and they're 9&3/4 inches long. The SNG Boge units are a whisker over 10 inches. Can I clamp these in a vice and screw them down the 1/4 inch to match the old ones?
I don't want to try this before consulting the more learned heads on here.

Cheers

Alan

MarekH · Post by **MarekH** » Sat Jan 09, 2016 4:05 pm

Dear Alan,

It's the length that they settle at once in the car which matters. That'll depend solely on the springs. Only once that is known, can you reach any conclusion about how to adjust the ride height by altering the distance between the eyelet and perch.

The fully extended length will likely only ever be a factor if you have taken off over a hump backed bridge at speed.

For safety advice, look at a previous thread on the subject showing how not to do it.

kind regards
Marek

Post by **mgcjag** » Sat Jan 09, 2016 5:16 pm

Hi Alan......i have the combined Boge unit from SNG fitted them a few years ago.....there is no adjustment on them.....unless you have something different?....the springs are under tension on the damper, do not put them in a vice and try to twist them, you run the risk of the spring flying off......try measuring them center to center of the mounting eyes....

David Oslo · Post by **David Oslo** » Sat Jan 09, 2016 5:59 pm

Quoting the age-old advice : "fit & forget"

You'll never notice a 1/4" on the fully expanded length once they're in the car, and the important length is the semi-compressed state once loaded by the car self-weight (as mentioned by Marek).

ALAN COCHRANE · Post by **ALAN COCHRANE** » Sat Jan 09, 2016 6:45 pm

Yes I soon realised that it's the eye to eye measurement that's important and they're the same.
Now for the next questions-the top bolts are fitted from the inside of the IRS cage facing out to the bodywork on both units. I'm hoping this is the correct way round? I seem to remember that someone mentioned there was a right and a wrong way to fit the bolts.
Anyway the nyloc nut on the rear upper mount appears to need a very long 11/16th ring spanner to remove it-is this right or am I missing something obvious?
Finally should I remove both units to allow the suspension to drop fully and then refit the new ones together, fit the top bolts first and then raise the suspension and line up the lower mounts-is this the correct sequence or not?

Thanks in advance.

Alan

David Oslo · Post by **David Oslo** » Sat Jan 09, 2016 7:05 pm

I'm looking forward to the next replies on this thread, the PO of my car has fitted the Boge's upside down (shroud at bottom), so I need to flip them around. Not figured out bolt clearance to body - my top bolts are installed with nut's facing each other, e.g. bolt heads on the outermost sides of the assembly.

Post by **mgcjag** » Sat Jan 09, 2016 7:18 pm

Hi Alan.....top bolts should fit from the inside and nuts on the outside.....yes a long spanner but you may fit a ratchet to the bolthead from the inside....remove both shocks....fit top end of both...raise suspension and fit bottom....but various ways what ever is easier for you...sorry David..you may need to hacksaw of your bolt head on the outside and remove from inside...

andrewh · Post by **andrewh** » Sat Jan 09, 2016 7:23 pm

ALAN COCHRANE wrote:Yes I soon realised that it's the eye to eye measurement that's important and they're the same.
Now for the next questions-the top bolts are fitted from the inside of the IRS cage facing out to the bodywork on both units. I'm hoping this is the correct way round? I seem to remember that someone mentioned there was a right and a wrong way to fit the bolts.
Anyway the nyloc nut on the rear upper mount appears to need a very long 11/16th ring spanner to remove it-is this right or am I missing something obvious?
Finally should I remove both units to allow the suspension to drop fully and then refit the new ones together, fit the top bolts first and then raise the suspension and line up the lower mounts-is this the correct sequence or not?

Thanks in advance.

yes the bolts can only go in one way when the IRS is in position well for sure on the rear, namely that the bolts can be withdrawn to allow the coil/damper to be withdrawn. I guess if you have removed them in situ you just need to put them back the same way. Nuts to the bodywork.
It is a bugger to get at the top nylon but doable and just need a bit of manipulation to get on it. Really you need a flattish ring, not a big kink on the spanner but enough to get on the nut and stay on. I would remove one nut on the bottom shaft and remove fully using a brass drift, then fit the new shockers and lift up the lower wishbone and feed the shaft back into the new shocker bottom.

Alan

ALAN COCHRANE · Post by **ALAN COCHRANE** » Sun Jan 10, 2016 12:26 am

Steve/Andrew

Thanks for the confirmation. E-types are never straight forward even for the straight forward jobs. I've kindly been loaned a long 11/16th spanner by a fellow E-Type owner, but guess what it's not long enough. Roll on Monday and a visit to my local friendly garage. Failing that Ebay.

David

I feel your (upcoming) pain. I can't see how you can have enough space to cut the bolt head as Steve has suggested. I fear that dropping the IRS is your only option or you could put a contract out on the PO. It won't solve the problem but might give you some satisfaction.

Alan

Post by **mgcjag** » Sun Jan 10, 2016 2:02 pm

Hi Alan.....you may find it a tad easier if you tape the nut into the ring spanner to slide it up into place and hold it whilst you fit the bolt

ALAN COCHRANE · Post by **ALAN COCHRANE** » Sun Jan 10, 2016 2:30 pm

Steve

A bodge has been revealed on closer inspection. A PO seems to have had trouble lining up the rear most upper bolt so has resorted to fitting a smaller bolt altogether. Brilliant idea when combined with the fact that said smaller bolt has a very shallow hex head which prevents a socket gaining any purchase. Take a bow PO.
So the upshot is that my trusty Dremel has been called into action to cut off the offending bolt head. There's enough space between the cage and the bodywork to drift through the shank of the bolt and nut-good news for David Oslo.

I'll let you know the next developments in due course-because I'm certain there will be some.

Alan

ALAN COCHRANE · Post by **ALAN COCHRANE** » Wed Jan 27, 2016 9:05 pm

This job is turning into a bit of a marathon, not helped by a skiing holiday in between.
I've now fitted the driver's side rear units. I've checked the workshop manual and can't find any mention of a torque setting for the nyloc nuts-is there one or should I just tighten them to about 50lb/ft. Rather alarmingly the old nuts were not tight at all.
I replaced the rear top bolt with one 1/2 an inch longer and added two 1/4 inch thick spacers. This meant that the nut is clearly visible between the IRS cage and the body.
I ended up buying an old single ended open spanner off Ebay to allow me to tighten this nut. I had to bend it to offset the shaft and stick it into a hollow pipe-et voila!-special tool number 461. I now have so many of these that I should be labeling them.
I also noticed that the cage seemed to contain a lot of grease. The culprits turned out to be the two grease nipples on the driveshaft. I could turn both by hand. The PO must have been manfully pumping the grease into the nipples only for it to spew back out at their bases. I never cease to be amazed.

Cheers

Alan

Post by **mgcjag** » Wed Jan 27, 2016 9:26 pm

Hi Alan....re the nuts...i just tightened them up.....nb dont forget the metal sleeve that goes through the top bush on the shock

ALAN COCHRANE · Post by **ALAN COCHRANE** » Thu Jan 28, 2016 1:02 pm

Steve

Yes I've remembered to include the spacers before fitting the new units.
It's so much easier to fit the lower eyes after I discovered that you could drift the threaded mounting shaft through the lower suspension tube. Maybe I should read the Workshop Manual before starting these jobs.

Cheers

Alan

ALAN COCHRANE · Post by **ALAN COCHRANE** » Sat Jan 30, 2016 9:55 am

Next question-is there a trick to removing the grease nipple cap on the hub carrier. It looks like you would lever it off with a screwdriver, but I don't want to damage it unnecessarily.

Cheers

Alan

Post by **mgcjag** » Sat Jan 30, 2016 10:52 am

Hi Alan.....Hi Alan.....Just prise it off.......its all in the manual

ALAN COCHRANE · Post by **ALAN COCHRANE** » Sun Jan 31, 2016 11:55 am

Thanks for the info Steve.
I've now discovered that the car has two different sized driveshafts. The driver's side is approximately two inches in diameter between the UJs and the passenger side is only 1&1/4 inches in diameter. They both look like they've been there for a long time. Although I suspect the passenger side is the original because I seem to remember a Forum discussion on this very subject. The early cars, like mine had the smaller driveshafts, or am I having a senior moment. Info please.

Cheers

Alan

PeterCrespin · Post by **PeterCrespin** » Sun Jan 31, 2016 12:10 pm

Driver and passenger descriptions are confusing on an international forum. All cars have a left and right side, however, even single seaters...

In this case it makes no difference as your half shafts should be the same. Early were fabricated tubular, later were solid forged. 62 was changeover year so it depends when it was built.

Post by **mgcjag** » Sun Jan 31, 2016 12:15 pm

Have a look here Alan viewtopic.php?t=4596&highlight=driveshafts

ALAN COCHRANE · Post by **ALAN COCHRANE** » Tue Feb 02, 2016 1:06 pm

Pete

My car was built in October 61 so the larger diameter fabricated drive shafts would have been the original factory fits.
Thanks for the link Steve.
Yes I seem to have the same set-up as the original post. Since it's not causing any problems I'll leave well alone. I may keep an eye out for one or other of the drive shafts on the usual auction site. I've no doubt at some point in the future I'll be removing the IRS cage so then would be the ideal time to change it.
Another E-Type owner local to me is intending to remove his IRS this winter so I volunteered to give him a hand. What better way to learn all the tricks with none of the dangers!
I finally managed to remove the hub carrier dust cap with a pair of mole grips. I didn't realise it was just a hole underneath giving direct access to the hub itself.
I've now discovered that the front dampers did not come with a set of lower bushes-so these have now been ordered.
I've also read the workshop manual in advance this time. So I'm aware of the danger of necking the steering rack ball joints and the need to tighten the damper bolts only with the full weight of the car on them. I'm getting better.
Anyway the dampers will all have to wait until next week-another long weekend skiing in France looms-life's such a bitch!

Cheers

Alan

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