MY series vs L series front end geometry

Silverbullet · Post by **Silverbullet** » Sun Sep 14, 2014 1:40 pm

So instead of clogging up the "what did you do to improve your subie" thread with this discussion here is a new thread dedicated entirely to the issue.

There's been a bit of discussion in various threads in the past regarding swapping L series front brakes on to an MY vehicle (Brumby, wagon etc) It was suggested the L series brake caliper will bolt straight onto the MY steering knuckle (The big cast iron lump with the wheel bearings in it) but I have since found this is not possible at least on my wagon. The two 17mm bolts that bolt the calliper to the knuckle have different bolt spacing between MY and L series. L series having a larger spacing. I was trying this on a 1981 wagon using 1987 Vortex turbo parts.

So the next question is; why not just use the L series steering knuckle? All problems solved right? Well maybe not; it was my understanding that the L series knuckle had a different camber built into them, since L series vehicles have a wider track width and longer control arms (this is what I always thought, I may be wrong here) And certainly other members have had massive camber problems when putting L series brakes on, other members state they've had no problems at all.

Again I've always thought to use L series steering knuckles you would also need to use longer L series control arms to correct the camber. Then you would also need the slightly longer L series drive shafts, modified radius rods and would also need to modify the front sway bar as the ends would no longer line up. This would also increase the front track width, making it wider than the rear. Again, I could be wrong on this!!!

Now will somebody who's actually done this please chime in and dispel some myths??

Are the L series control arms actually longer? Do the knuckles have different camber? I will make a move to figure this out for myself by bolting up the L series/Vortex knuckles I have onto my wagon with MY control arms, drop it on the ground and see the camber difference...but mine has no weight in it so probably not the best indicator. Too bad I don't have any L series control arms to hold up to the MY ones and compare.

There seems to be alot of confusion around this issue, maybe I've had a part in contributing to it

nncoolg · Post by **nncoolg** » Sun Sep 14, 2014 2:54 pm

When I had my Touring Wagon it was before I owned a digital camera so I couldn't afford to be as snap-happy as I am now so I been able to find photos of the individual parts, but I did find a picture of my car...

RX turbo brakes all round.

Silverbullet · Post by **Silverbullet** » Sun Sep 14, 2014 3:09 pm

Certainly no camber problems there, sits really nicely on those big wheels

And you think you used the L series knuckles? Well you must have done, unless there are 2 different bolt spacings for L series callipers.

Okay then, looks like I need to experiment myself and put those Vortex knuckles you gave me onto the wagon and see how it sits, that will be next weeks job while I have the front end up for putting the front lift blocks in.

nncoolg · Post by **nncoolg** » Sun Sep 14, 2014 3:27 pm

Yep, L series turbo Knuckes, backing plates, rotors and calipers.

Please note though, that while my memory is foggy as it was about 13 years ago, I remember the inner wheel bearing seal was different L series to MY.
From memory I had to spin-up an adapter ring to fit the MY inner seal (smaller O.D.) into the L series knuckle. This was due to a different size or shape of the MY CV and the MY seal had to be used.

I think I also had to use L series tie rod ends for some reason, which is why I sent those alog with your parts.

If you do play around with this, please take some photos so we can all put this topic to bed.

Remember too, the higher you let these cars sit, the further the wheels tuck in.

Silverbullet · Post by **Silverbullet** » Sun Sep 14, 2014 3:55 pm

Thanks for the pic, lets see if I get the same when I bolt those bits up on mine

Also my car has absolutely zero engine or running gear in it, no weight. So whatever I get camber wise will be worse than when it's fully loaded. As you say, when the front goes up the camber gets worse.

nncoolg · Post by **nncoolg** » Sun Sep 14, 2014 3:57 pm

found another :

steptoe · Post by **steptoe** » Sun Sep 14, 2014 9:45 pm

AWD18L - nice plates

cool unit

If I can recall how to gat into my imagehack account - must be a pic of MY and L knuckles I took......

phil nelis · Post by **phil nelis** » Mon Sep 15, 2014 8:11 pm

L series control arms are roughly 50mm longer.

steptoe · Post by **steptoe** » Mon Sep 15, 2014 10:28 pm

L Series 4WD front CV shaft axles are 45mm longer than MY 4WD

Silverbullet · Post by **Silverbullet** » Sat Sep 20, 2014 1:39 pm

Well the jury is still out on this one for me, seems there is not so much difference as I thought. I've swapped one wheel over to the L series knuckle, below are some before and after pics and a comparison of the two knuckles. When I held them up side by side I immediately thought there was a difference in the angle between the strut socket and the bearing housing. But when I bolted everything up and dropped it on the ground again I have to say I could not tell the difference

Keep in mind there is no weight in the engine bay, it hasn't been driven to settle everything down etc etc. But to my eye when comparing it to the other side (still original) the other side actually looks worse camber-wise than the L series side!

Maybe the difference I thought I saw in the side by side comparison was just my imagination playing tricks

In any case, I'm still on the fence with this one. So I will leave the L series knuckle on that side while I get on with other things like lift kit, engine+gearbox etc etc and as the weight builds up I'll keep an eye on the stance. But more weight can only mean less camber I think. If I decide to go the L series knuckle route and put them on the car for real, I will have to buy another set of bearings for each side (dang

) I think the front bearing kits are the same between MY and L series, will double check. nncoolg mentioned something about the inner seals being different, but if the bore is the same size between the two different knuckles I could always press an MY seal into the L series housing, since I will still be using MY drive shafts.

I guess I should be glad; if this all works out I can use the big L series ventilated discs and big beefy callipers, woo hoo!

Before:

After:

MY vs L series knuckles ( MY on the left)

steptoe · Post by **steptoe** » Sat Sep 20, 2014 6:37 pm

leave it 50/50 and take it in for a wheel alignment

It is interesting to see the midway result.

I'll have to delve into my parts to sit the two different ones on something, take the graphic photo to show you what i found ....

nncoolg · Post by **nncoolg** » Sun Sep 21, 2014 7:20 am

What is the verdict with the tie rod ends, did you need the l series ones?
Also did you check the inner bearing seal for the fitment issue I couldn't remember properly?

Subydoug · Post by **Subydoug** » Sun Sep 21, 2014 10:33 am

Inner seals are different between MY and L series.

Silverbullet · Post by **Silverbullet** » Sun Sep 21, 2014 11:06 am

nncoolg wrote:What is the verdict with the tie rod ends, did you need the l series ones?
Also did you check the inner bearing seal for the fitment issue I couldn't remember properly?

I don't know about the tie rod ends yet, I don't even have a steering rack at the moment

Saving up for a reconditioned P/S rack. Also I havent checked the inner bearing seal yet since I thought I'd be pulling this all apart again

But Doug says they are different;

Inner seals are different between MY and L series.

I imagine it would just be a difference in diameter between the two?

Subydoug · Post by **Subydoug** » Sun Sep 21, 2014 11:28 am

From memory when I tried to use MY seals in my vortex, the outer ones were fine and the inner ones were too small OD, rock in a milo tin.

Thats as far as I got because I just put it all aside and ordered the correct seals. The bearings fitted fine.

Regards

Doug

Post by **TOONGA** » Sun Sep 21, 2014 11:34 am

The outer MY CV cup is a different size and shape to the outer L cup

Finding true images of the joints is proving difficult.

You will need to make shafts that use the L outer CV.

TOONGA

steptoe · Post by **steptoe** » Sun Sep 21, 2014 9:43 pm

or do what nncool did and 'just' spin up some reducer adaptor to fit inside the L hub to take MY inner seals ....

Silverbullet · Post by **Silverbullet** » Sun Sep 21, 2014 10:15 pm

Well I do have the skills required, would just mean staying late at work but I hate doing that. It's a shame I can't just use L series shafts since I'm having an L series g/box as well but that extra 45mm might cause some headache. I know a place that could make the custom shafts, might be easier if I go that route.

Matt · Post by **Matt** » Mon Sep 22, 2014 6:53 am

Where can you get custom shafts made? I am running MY hubs and brakes with L Series Control Arms. The Outer CV is different between the pair, however a quick trip to the local Bearing Specialist with the hub and CV and just get the right size bearings to run the MY Shaft on the L Series Hub

steptoe · Post by **steptoe** » Mon Sep 22, 2014 8:18 am

and of course, in your excitement you did not keep the numbers to share with anyone else, or for repeat needs for yourself ?

You meant to type 'seals' rather than 'bearings' ?