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Sierra rear axle widths
RogerM - 17/3/05 at 05:08 PM

Anybody got a sierra rear axle complete they could measure for me???

(disk brakes but as I think they are the same width it shouldn't matter)

Basically I want to know what the width across the two wheel mounting faces are when the faces are parallel (and both perpendicular to the floor too ...)

The reason I am asking this is that the I threw away the arms and tube ages ago but forgot to measure them first. Need to know what the standard across faces width is to build my jigs for rear end on my car. As I intend to shorten the shafts I need to know what the width was to start with so I can work out how much to shorten each shaft by.

Cheers for the help in advance.


Liam - 17/3/05 at 08:00 PM

Haynes says 1468 rear track...

Add 38x2 for wheel offset and you get...

1544 wheel mount to wheel mount (which of course includes the thickness of the brake discs since the wheel mounts on them).

Rear track is listed as 1458 for estate and there are doubtless other small variations accross time and models (which is OK since each shaft has about 40mm of plunge).

My CAD drawing of my locost gives about 1547 accross the mounting surfaces and my real thing is pretty damn close to that (well it ought to be).

This concurs with another measurement i remember taking of a complete rear axle taken off a car of about 1500 accross the discs. The discs have the 'bell' sticking out about 25mm from the disc surface so again we get about 1550 accross the wheel mounts.

Hope that helps,

Liam

[Edited on 17/3/05 by Liam]


chrism - 17/3/05 at 08:20 PM

According to the design of the MK DeDion that is on the Locost CD, the distance between the hub mounting faces is 52.5".
I currently have the IRS rear on my locost set to this and with the drums on gives me about 1530mm between wheel mounting surfaces. Rescued attachment general layout2.gif
Rescued attachment general layout2.gif


RogerM - 17/3/05 at 09:19 PM

Thanks guys, that all seems to make sense and sort of rings a bell.

If anybody could actually run a tape over one I'd be greatful .... measure twice, cut once and all that!!


James - 18/3/05 at 11:19 AM

You sure you wanna go the short track Sierra (chopped Sierra drive shafts) route?

Luego abandoned this with the Velocity. Rumour has it that the handling was screwed up.

Cheers,
James

[Edited on 18/3/05 by James]


robby - 18/3/05 at 12:06 PM

can measure my back end (!) tonight if you like, sierra, standard shafts. had a wee bit bother getting wheels with correct offset that would go under rear arches, so shortening shafts would help there. (no problem if you're using 6" rims, but i wanted wider.) can give you rough measurements of suspension, worked it out masel though, so it might be dodgy!


RogerM - 18/3/05 at 12:12 PM

I don't have much of a choice over axle width. Car was orginally designed to run with a Mk1 Escort axle and rear body section all one piece.

Not too happy with widening arches a lot as it's all compound curves and the body set is the first new one to be produced in 20 odd years!!!

Have previously run with a Capri axle (1375mm) and fwd offset wheels under standard body work.

AS for ruining the handling it's all a matter of mating the front and rear geometry in terms of roll centres, camber changes etc.

I am confident it will be more than just alright (professional automotive design engineer .... suspension was my speciality for final year).

I would still appreciate any measurements possible as I don't fancy crawling around in the oily mud at my local breakers .... especially with the amount of work left on my chassis!!!

Cheers guys.


NS Dev - 18/3/05 at 12:51 PM

quote:
Originally posted by James
You sure you wanna go the short track Sierra (chopped Sierra drive shafts) route?

Luego abandoned this with the Velocity. Rumour has it that the handling was screwed up.

Cheers,
James

[Edited on 18/3/05 by James]


Ehhhhhhhhhhhhhhhh??????????????????????

Driveshaft length screwed up handling??????????????

If you narrowed a car using sierra rear arms complete it may have an effect, but not just using the hubs and shafts!!!

The reason people use std width stuff is it's cheap and easy!!!


Liam - 18/3/05 at 01:03 PM

Well I didn't do my CAD drawings from guess work!

I think what you can gather from this thread is that you wont get anything more precise than what is already offered since there is so much variation and it's also not an easy dimension to physically measure acurately on an assembled car.

Just under 1550 is pretty much bang on for disc/lobro style shafts and chrism's pic suggests maybe smaller drum/tripode sierras are a little narrower at around 1530. Take your pick somewhere between that. Call it 1540.

I wouldn't worry too much cos you literally have up to 100mm plunge in the two shafts.

Liam


RogerM - 18/3/05 at 05:09 PM

Thanks guys, I'll take it as read.

Liam, thanks for all your input especially, It wasn't that I doubted you ... just that I don't even trust my own measurements until I've done it from both ends so to speak!!

Cheers again.