DUMMY SHOCK BOLT CENTRE TO CENTRE SPEC (Rear Ride Height)

[Gohn 68]

afternoon,

 

I have just fabricated a dummy shock, but havent drilled it because I don't know what to drill it to

So I need the dummy shock setting for the rear ride height.

BOLT CENTRE TO CENTRE MEASUREMENT

hopefully for each of the different thickness Torsion Bars:

19mm, 21mm and 23mm

I've got 19mm with no plans to change, but at least if its collated, others with the thicker ones can refer to it also

 

As I understand it, after working on the 205 rear suspension any peugeot mechanic wanting to reset it to original spec would

- with the car unloaded/jacked up, insert a dummy shock set to the recommended length (bolt centre to centre)

- install the torsion bar for the Left side

- remove the dummy shock 

- install the shock absorber in its place, but don't tighten bolts up

- repeat for the Right side.

- then lower the car down and tighten up the top and bottom shock absorber bolts

 

- The Haynes book does not go into resetting rear ride height, says its too hard for your bogstandard duh-herrrr DIYer

(instead it just confuses the issue by recommending 288mm for the bolt centre to centre with weight on, which is NOT a ride height setting,

its just a setting to prevent the shock absorber bushes being over rotated during use and shredding)

 

- past discussions have suggested shock bolt centre to centre anywhere from 312, 315, 318, 320, 322, 325, and 330mm ! 

but I've no idea which is correct

 

- contacted local Peugeot but no response so far..

 

cheers

 

 

 

 

 

[dcc 855]

Remake it with a length of threaded bar and tube, weld a nut on the end of the tube then you can set it to what ever length you like

 

from memory I think the workshop tool we have is 8mm threaded bar (so 13mm nut)

 

what ride height are you after? What springs are you running on the front (i.e. lowering or standard)?

 

 

 

[speaksgeek 5]

9 minutes ago, dcc said:

Remake it with a length of threaded bar and tube, weld a nut on the end of the tube then you can set it to what ever length you like

Or, cut a slot in the outer tube, and tap a thread into a hole in the inner tube, and then it will slide.

 

No comment on the specific lengths.

[petert 588]

That looks very similar to mine. I'd say:
23mm - 290mm

21mm - 210mm

19mm - 325mm

[Gohn 68]

7 hours ago, petert said:

That looks very similar to mine

A poor imitation I'm sure Peter, but as close as I could make it!

Your own looked too impressive to not make one up

Found the M14 ends in a shocky boneyard, took a few goes to get the right RHS blanks, but good now

 

thanks for the measurements, and the inspiration

 

8 hours ago, dcc said:

then you can set it to what ever length you like

 I already can

 

front and rear are all regular peugeot shocks and Im just looking for an easy way to set standard ride height the same way the factory does

before they rolled off the line, the rear ride height was set by a tool like yours or the one I copied from Peter

from there I can lower it by rotating the torsion bar one spline (-50cm) or

increase the ride height by rotating the torsion bars one spline the other way (+50cm)

rather just leave it though

 

got any pictures of your fabled workshop tool ?

8 hours ago, speaksgeek said:

then it will slide

 it already does

the steel bars are hollow and telescope in/out

 

..any further 'suggestions' will be forwarded onto PeterT, proceed

 

[welshpug 1,657]

the dealer tool has a 12x1.0 thread pitch with a lock nut, so half a turn = half a mm.

 

I would agree with Peters numbers as a very good starting point, but be prepared to tweak a little to match whatever you have up front as there is quite a variance with all the different spring manufacturers, engine weights etc.

[calvinhorse 870]

I’ve just rebuilt a 205 Xs beam and it was 330mm centre to centre

 

i believe every 1mm at the shock absorber = 3mm at the wheel 

[Gohn 68]

right so the different settings reflect the torsion bars being run AND the engine

so a TU and XU would set the dummy shock to a different length, to target a different ride height even if they had the same torsion bars?

 

17 hours ago, calvinhorse said:

every 1mm at the shock absorber = 3mm at the wheel 

so is this the same thing?:

if 325mm is my standard ride height setting, and if rotating the torsion bar 1 spline gives plus or minus 50mm in ride height

wouldn't the next useable dummy shock settings be 275mm or 375mm ?

any settings in between wont work cause the TB splines wont slot in ?

 

maybe that's overcomplicating it

[petert 588]

You're definitely overcomplicating it. If you have 19mm bars and want std ride height, set the dummy shock to 325mm. Try to insert the torsion bar. Keep rotating a spline at a time, until it slips in. Lock the bar and remove the dummy shock. Job done. Repeat with the other side.

[calvinhorse 870]

The splines are different on either end of a torsion bar 

 

you remove the bar entirely, set the ride height using the dummy shock, then put the torsion bar back rotating it until the spline line up 

 

I’ve managed it and I’m proper thick 

 

 

[309SRiguy 15]

Gohn, your first and second paragraph sum it up nicely. 

If we are talking about standard 19mm torsion bars at standard height Haynes does not give any help. The manual I downloaded does not give a measurement that I could find.
The Haynes by Comber for the 309 has a little more. Apart from a wider tube and bars the rear suspension geometry is the same as 205.
It does mention twice that the dummy shock spacing is 288mm between centres.
The ride hide is 330mm measured from a flat section on the chassis "rail" to the ground. Does the 205 have a similar flat?

 

After chewing over all the info from a recent discussion I still didn't understand why there was no real conclusion. How could Haynes and Comber get it wrong? I searched around and couldn't find anything to clarify the issue until I found this comment:

>>>>>>>>>>>>>>>>

 

"Sorry if this sounds boring/technical but having just readjusted my beam yesterday ( to take account of the extra load of camping gear for the EuroTrip) I found that on std length rear dampers the travel from bump to rebound is 75mm. So to have the damper piston sitting at the centre of it's travel and therefore equal amounts of bump and rebound - the bolt centre distance at static deflection(i.e. four wheels on the ground with half a tank of fuel and spare wheel and whatever you normally carry on board) should be 277mm.

That's half way between 315mm (fully extended) and 240mm (fully compressed).

The obvious problem when lowering is that you are reducing the amount of otherwise available bump travel and be on the 'bump stops' a lot of the time; if you're going to lower the ride height, get appropriately shortened dampers to suit.

We've mostly all been there and yes it does look good, but the ride is greatly compromised unless done properly. My car now looks like std, which I always thought looked too high but, the ride quality overall is worth it in my opinion.

 

Edited April 9, 2009 by fangio "    

( 205gtidrivers.com/forums/topic/104122-is-standard-ride-height-330m )

 

>>>>>>>>>>>>>>>>

That is the best measurement of half travel that I have seen. It makes the manual's figure of 288mm seem correct. Is the 10mm difference to allow the bump stop to give 10mm of compression before the shock piston bottoms out at the end of its travel?

The 288mm spacing on the dummy shock ( nice work Gohn and PeterT ) will help align the correct splines for the factory ride height (which should measure 330mm from chassis to ground). 
fangio's comment has me thinking that the factory/manual stated 288mm is the only way that the torsion bars are unloaded at half travel and acting with equal twist either way from full compression to full extension. Ditto for the shock bushes.

I hopes this helps rather than confuses.

Bryan

 

[jord294 92]

From experience these bars are getting on a bit now, so I'm setting std height more than 325mm. Otherwise the cars seem to be squatting at rear

[Evo Smith 0]

I'm rebuilding a 309 gti beam on my work bench at the moment (off the car).

What shock absorber bolt centre distance should I be using to set the beam for standard 309 GTi ride height with standard 309 GTI torsion bars then.

Too many differing measurements now being written about.

[Ozymandis 97]

3 hours ago, jord294 said:

From experience these bars are getting on a bit now, so I'm setting std height more than 325mm. Otherwise the cars seem to be squatting at rear

A number of times, I have had to make the drivers side ones a bit longer than the passengers side as the drivers ones have sagged a bit more than the presumably less loaded passenger side.

 

I think a screw adjustable dummy is a better idea than set distances, it is getting so some of these now ancient bars sag a fair bit and the book figures dont work any more.

[Gohn 68]

there's a bit of forum confusion goin round

 

Evo, get a caliper and measure your torsion bars

Then use Peter's numbers (there's a typo in there) which should read:

torsion bar thickness - distance between shock bolt centres:

19mm - 325mm

21mm - 310mm

23mm - 290mm

Yours being a GTi they will probly be 21mm, similar to the 205GTi

So set your shock bolt centres unloaded at 310mm apart , but dont torque up the nuts yet

When its built, bolt the beam onto the car as a complete unit and drop the car off the jacks

Now with weight on, get under the car and torque up the nuts when the shock centres are at 288mm apart. Put things in the boot to weigh it down if needed. This measurement is nothing to do with ride height, its just to prevent the shocky bushes from shredding during normal operation, over bumps and down ditches.

if anyone has some actual 309 set distances post em up

 

bryan, 280mm ground to outer rail, just in front of the rear jack point. only as you asked, but this is not to be confused with the ride height setting dimension

 

41 minutes ago, Ozymandis said:

a screw adjustable dummy is a better idea than set distances

dan thought so too

not disagreeing, but the design I followed is pretty good, it has two faces to drill many different length settings, and its hardly even cold yet

if anyone has a picture of one they've bodged up, or even the peugeot tool, that would be good to see, throw up a photo

 

[jord294 92]

205 gti torsion bars are 19mm (18.9mm if being fussy) 

309 gti are 20mm as std

205 vans i believe had 21mm torsion bars.

[petert 588]

Once you have a dummy shock, everything is new and the splines are lubed up, it takes 10mins to change the ride height with beam in the car. Once you’re happy, fit the shocks and job is done.

[Ozymandis 97]

Heres mine Andrew. Its some threaded bar, nuts and some scrap

[Gohn 68]

thats a bit bloody good jay

very neat indeed !

 

I'll go with the current Mk1 dummy shock for now, but can see a Mk2 update in the future

 

[welshpug 1,657]

On 4/17/2021 at 2:05 PM, jord294 said:

205 gti torsion bars are 19mm (18.9mm if being fussy) 

309 gti are 20mm as std

205 vans i believe had 21mm torsion bars.

probably a very rare option as the ones Ive had apart have been 18.9mm and a skinny roll bar

[greenclaws1975 4 1 Cars]

On 4/15/2021 at 6:43 PM, calvinhorse said:

I’ve just rebuilt a 205 Xs beam and it was 330mm centre to centre

On 4/15/2021 at 6:43 PM, calvinhorse said:

I’ve just rebuilt a 205 Xs beam and it was 330mm centre to centre

 

i believe every 1mm at the shock absorber = 3mm at the wheel 

Hi Calvin, was your car standard and  fitted with a TU engine?