Limited slip differential and rear subframe

[Dudeland]

10 hours ago, 0257 said:

From here two hours?  If you have a cheap cheesy Horrible Freight tranny jack on hand you just might get it in under the wire.  I’m with JGerock, you could have some good fun along the two-week way!  There’s nothing all that technical about the job.  And the feeling of satisfaction when you’re done?  Timeless!

If I am dropping the rear subframe, I am getting adjusters installed on the trailing arm mounting points. 

 

 

[tech71]

This is all assuming you actually find a shop willing to even touch an 02 with a ten foot pole... Most wont, easier profit elsewhere.

2 hours? Please..In a perfect world perhaps but on a 50 year old car of unknown history/mechanical condition? Highly unlikely.

 

Edited February 19 by tech71

[rjd2]

13 hours ago, 0257 said:

From here two hours?  If you have a cheap cheesy Horrible Freight tranny jack on hand you just might get it in under the wire.  I’m with JGerock, you could have some good fun along the two-week way!  There’s nothing all that technical about the job.  And the feeling of satisfaction when you’re done?  Timeless!

 

question for ya: do you have the spacers on the diff end of the half shafts? does it matter? i installed the spacers on the wheel end of the half shafts....also, is there a way to verify that the geometry of the new axles is functioning properly? I did the whole E21 axle/mix n match CV joint thing, and before I actually put the car under load, I'd really like to know that the cages and bearings are all, you know, happy and shit. I'd hate to have to do this again in the near future....

[0257]

3 hours ago, Dudeland said:

If I am dropping the rear subframe, I am getting adjusters installed on the trailing arm mounting points. 

 

 

At the time I did that work my knowledge of suspension setups was way too limited to do the work, much less the mods.

[0257]

52 minutes ago, rjd2 said:

 

question for ya: do you have the spacers on the diff end of the half shafts? does it matter? i installed the spacers on the wheel end of the half shafts....also, is there a way to verify that the geometry of the new axles is functioning properly? I did the whole E21 axle/mix n match CV joint thing, and before I actually put the car under load, I'd really like to know that the cages and bearings are all, you know, happy and shit. I'd hate to have to do this again in the near future....

Wish I could provide authoritative advice, but I just did what seemed most practical at the time. When I redid the subframe I was still running my open diff.  I then replaced just the diff (with the LSD) and since the diff end of the axle was detached, that’s where I put the spacers. I think it’s less a question of geometry (the CVs will function across a range of angles) than a matter of making sure your axles are bedded as deeply as possible in the ends.  If you have the narrower e21 diff casing and don’t use the spacers, there’s a good chance your axles will separate from the ends, shredding both in the process.  Related to that, I have picked up via various posts that the spacers, because they add an extra joint, create an opportunity for uneven forces that don’t exist otherwise and that can cause your allen bolts to come loose.  So generous application of blue loctite recommended.  Others may have more authoritative advice.

[rjd2]

cool;-great explanation. I am not too concerned with the spacers being on the wheel end. I guess at some point I'll just need to drive the car and see what happens!

[jimk]

If you can't slide the axle shaft side to side with the wheel off the ground so the shock is fully extended, spacers are needed.  That's when the joint get's pulled off the axle end (breaks off the circlip groove end).

[TobyB]

Quote

If I am dropping the rear subframe, I am getting adjusters installed on the trailing arm mounting points.

 

This is just my experience, and I do not float in the deep end of the pool, so take it for what it is-

 

the stock, unbent, as-it-came-from-the-factory rear 2002 subframe with no adjusters is just fine.

It doesn't NEED adjustment, unless you are 

a- pretty deep in the weeds in suspension sweeps, and have gotten to the rear end, or

b- offended by what's about the right amount of camber for the track on your boulevard donk cruiser stantsmobile,

 

When I bought the first race car, it had no rear adjustment- and on radials, lowered to 5" at the rocker,

I got pretty even tire temps once I learned how to drive it hard enough to matter.

With the 'street' car on the track, I found similar.

 

The stock subframe gives just a bit of toe- in, for stability,

about a degree of camber at stock ride height

(which isn't enough on modern tires, BUT)

as you lower it, you can get up to 3+ degrees of negative camber, which, if you're running

a radial tire of appropriate width and sidewall for a normally- aspirated M10, is pretty good.

If you take much of that out for street, then there's a real danger of trailing throttle oversteer

if you DO decide to really push it, and then pucker at just the wrong time...

 

So, yeah, if you're running 10" rims 'wrapped with'  30 profile 205 tires lowered to 2", it's not going

to work so well.  Or for rally, if you're running a 7" ride height, same problem- you'd need more

rear camber, and maybe some toe- in for tarmac- or toe- out if you can't use a rear cutting brake.

 

But for a regular street car that might do a lapping day or 10 a year, front camber for sure, 

but the hassle of the rear adjusters and the expense of putting them in and then finding someone

who can and will align it- meh?  I'd say, only if you plan on doing it yourself and aligning it yourself

and if you think you might have fun fussing with rear changes.  Because they're hard to make,

and hard to be precise with.  And the precision required is in the 0.20 mm range*, once you really

start digging into it.  Which you can't get with serrations, and it can be annoying even with eccentrics.

 

t

* not sub- micron, Elmo.  And only for toe.  For camber, the serrated adjusters seem like a fine idea.

I saw a DeLorean the other day, on the way in to work.  It looked far better than the Elmobile.

Edited February 19 by TobyB

[0257]

Instant quintupling of my knowledge in this area.

[2002iii]

On 2/18/2024 at 6:44 PM, rjd2 said:

 

question for ya: do you have the spacers on the diff end of the half shafts? does it matter? i installed the spacers on the wheel end of the half shafts....also, is there a way to verify that the geometry of the new axles is functioning properly? I did the whole E21 axle/mix n match CV joint thing, and before I actually put the car under load, I'd really like to know that the cages and bearings are all, you know, happy and shit. I'd hate to have to do this again in the near future....

If you did the e21 hybrid axles you don't need the spacers.