Need some information about suspension height.

Post by **JimK** » Mon Oct 09, 2006 9:25 pm

Could a two-door owner tell me how far it is between the tip of the suspension bump stops and the surfaces they strike against?

My car is lowered (or the springs are knackered) but I don't know by how much. The front suspension arms are roughly horizontal.

How are cars usually lowered? I guess the front is done by adjusting the torsion bars in their mounts, but the back? If I want to keep it at this height but want more than half an inch of travel, am I stuffed?

Ta.

Post by **flying** » Mon Oct 09, 2006 9:40 pm

i actually mesured this last week for when i replaced a panel...one side was 4 inches and the other was 4.6...but this is with out the bumps stops on

Post by **jonathon** » Mon Oct 09, 2006 9:46 pm

The back is lowered by fitting a lowering block, usually about 1"-1-1/2". If this has been done then simply remove it to restore the ride height. There should be around 1-1/2"-2" between the top of the rear bump stop and the bump stop plate on the chassis leg. If the ride height is still low with the blocks removed then the springs are worn and will need replacing. The same goes if there are no blocks fiitted and the car still being too low. If your springs are flat between the front and rear hangers and the axle mounting then they are worn and need replacing.
You are correct about the front being lowered/raised on the torsion bars. If you like the low front then you could just cut down the bumpstops.

Post by **JimK** » Mon Oct 09, 2006 9:56 pm

Ahhh, just had a brainwave. Checked the workshop manual, and it has a section on fitting new torsion bars. It says that the difference in height between the inner and outer pivot pins should be 4.1cm.

*thinks* If the arms on mine are more-or-less horizontal and there's a 2cm gap between bumpstop and plate, that means the gap when properly set is only about 6cm.

Does that sound right? It doesn't sound much.

Post by **alex_holden** » Mon Oct 09, 2006 9:57 pm

This is how you're supposed to measure the front suspension height according to the official workshop manual.

Post by **alex_holden** » Mon Oct 09, 2006 9:59 pm

So I just went and scanned that in and you already have the workshop manual?

Post by **JimK** » Mon Oct 09, 2006 10:06 pm

jonathon wrote:The back is lowered by fitting a lowering block, usually about 1"-1-1/2". If this has been done then simply remove it to restore the ride height.
There should be around 1-1/2"-2" between the top of the rear bump stop and the bump stop plate on the chassis leg.

That's what the back has for a gap, the front is lower. The car tilts slightly forward, as though it's going to pounce

I think the back is OK.

You are correct about the front being lowered/raised on the torsion bars. If you like the low front then you could just cut down the bumpstops.

I like the way the line of arch and tyre are arcs around the same centre, but I'm thumping into the bumpstops on almost any lumps in the road. I guess I need stronger springs? I'm happy to have a firm ride, but the combination of little damping and little travel is not a good one.

Expect an incoming email about suspension options...

Post by **JimK** » Mon Oct 09, 2006 10:09 pm

alex_holden wrote:So I just went and scanned that in and you already have the workshop manual?

Sorry

I have a PDF of a scanned manual, anyway. Handy for printing out odd pages to take outside.

I'd really like a text-searchable version, if anybody knows of such an animal.

Post by **jonathon** » Mon Oct 09, 2006 10:34 pm

Jim, what size wheels do you have. As a rule of thumb, if the wheels are of the right offset you should be okay if the gap between the top of the tyre and arch is 2" any less and you can experience trouble.If you have 13's or 14's with low profiles then this will not help.

Post by **bmcecosse** » Tue Oct 10, 2006 7:27 am

You need more gap at the front bump stops - if it's hitting the stops it will soon smash it's way through the inner wings - have a look now - I bet there is some cracking/bulging there already. You should crank it up at least one spline on the bars. I think it is a very bad idea to cut down the front bump stops - they are short and hard as it is ! You will also find that the lower arms smash into the engine bay floor if the car runs too low. The secret is to increase the damping - by fitting tele dampers in addition to the standard lever arms - and I like to fill the lever dampers with thicker oil although some on here don't agree!! Usually causes a wee burst of debate - I've been doing it for many many years with excellent results and no problems.

Post by **jonathon** » Tue Oct 10, 2006 8:10 am

Jim , if the rear is okay then just raise the front by one spline, and see if this raises the car enough to miss the bump stops. If it doesn't then raise another spline, if this puts it too high esthetically but well clear mechanically then re trim down using the adjuster on the cross member end of the torsion bars. Likewise if it is almost correct by turning one spline then adjust up on the x member end.
There is no problem in shortening the bump stops, it is common practice with lowered cars.
Telescopic dampers will improve the damping, but your issue here is ride height so unless you wish to upgrade (different kettle of fish) then the torsion bar/spring is the first port of call.

Post by **JimK** » Tue Oct 10, 2006 8:48 am

jonathon wrote:Jim , if the rear is okay then just raise the front by one spline, and see if this raises the car enough to miss the bump stops.

Previous owner told me last night that he lowered the front by one spline when he fitted the new front brakes. The back is untouched.

If it doesn't then raise another spline, if this puts it too high esthetically but well clear mechanically then re trim down using the adjuster on the cross member end of the torsion bars. Likewise if it is almost correct by turning one spline then adjust up on the x member end.

If I raise the front by one spline it will be back to original.The springs are in fine fettle, having only covered maybe 40k miles.

Telescopic dampers will improve the damping, but your issue here is ride height so unless you wish to upgrade (different kettle of fish) then the torsion bar/spring is the first port of call.

If I want lower ride height I need to stiffen the damping, I think. An upgrade to damping would be good, but the apart from the wheels and front brakes the car is original and unrepaired and I'm not sure about doing things that can't be reversed. Unless your telescopic kits (with or without coil springs) can be fitted without permanent modification, I'm reluctant to go down that route.

I looked for markings on the wheels to find about offset. They are Mintator, say "14J" between a couple of spokes, and there's another marking I can't read - looks like it could be where some letter blocks are inserted into the cast?

Post by **minor_hickup** » Tue Oct 10, 2006 12:48 pm

My car used to be 2 splines below factory height and I actually had the rear of the bump stop break through the top of the wing. I'm sure lowered cars are fine around town but on potholed roads they don't do well. I would also be very reluctant to cut the bump stops fr the same reason.

Post by **bmcecosse** » Tue Oct 10, 2006 1:10 pm

But if the damping is increased - the car will ride the road more evenly without plunging up and down - and crashing onto the stops. but top priority is more clearance - then sort out the damping later. You say 'new brakes' - is it new drums - or discs ?

Post by **JimK** » Tue Oct 10, 2006 1:16 pm

bmcecosse wrote:But if the damping is increased - the car will ride the road more evenly without plunging up and down - and crashing onto the stops. but top priority is more clearance - then sort out the damping later.

I'll raise the suspension because I can do that now. Well, at the weekend. How long did it take you the first time you ever did it?

You say 'new brakes' - is it new drums - or discs ?

I'm not sure I should tell you...

Post by **minor_hickup** » Tue Oct 10, 2006 1:26 pm

JimK, dose the splines in plus gas now then!

BMC, that happened while using dampers a la ecosse (if you know what i mean)

Post by **bmcecosse** » Tue Oct 10, 2006 1:28 pm

Oh go on - do tell!! I'm not sure about 'first time' - I certainly had it down to a fine art at the end when I sometimes had to do it at the start of rallies when word went round that lots of 'white' roads would be used !! It's an easy enough job if the nuts and bolts come undone without a struggle. You need a couple of jacks - or one jack and a block of wood - which is not so easy. Trick is to leave the front half of the lower arm connected and just move the back part back enough to clear the spline - lift the car slightly and tap it round one and then shove it back on. If the last owner lowered it - at least the bolts and splines should be free of rust and grot!

Post by **JimK** » Tue Oct 10, 2006 1:43 pm

bmcecosse wrote:Oh go on - do tell!!

OK, *whisper* they're discs.

It's an easy enough job if the nuts and bolts come undone without a struggle.

It was only done about 18 months and 200 miles ago, so they should be OK.

You need a couple of jacks - or one jack and a block of wood - which is not so easy. Trick is to leave the front half of the lower arm connected and just move the back part back enough to clear the spline - lift the car slightly and tap it round one and then shove it back on.

The workshop manual talks about removing the tie rod and the front arm, where you talk about leaving the front on.

Can I move the rear torsion bar lever around while leaving the front end stuff all together?

I need somebody to point at bits while explaining...

Post by **RogerRust** » Tue Oct 10, 2006 3:17 pm

I don't understand the method BMC could you give me some more details. I usually disconnect the whole wishbone am I missing a trick?

Post by **bmcecosse** » Tue Oct 10, 2006 6:51 pm

You only need to move the back part - so leave the front in place and just separate the two - you obviously need to take the remaining twist in the torsion bar on a jack (or wood block) as it comes away from the trunnion - then lift the car until it has no twist left. Then slide it back 'just' off the splines move it down one and slide it back on again. Seriously - with practice it can be done in 20 mins each side. Well done with the discs - uprated brakes are required if you intend to uprate engine later. I have nothing against discs - it's the conversion cost that puts me off!