E30 Zone

can anyone enlighten me as to what i need to swap my rear drums to disks on my 316i?


need to check before i phone a zone member to buy the bits i need, cheers

I'm not 100%, but I believe you need to change the complete trailing arms if you want to fit the rear discs.

Ian.

I had my BMW specialist do the same for my 320i, so I don't know the details, but I recall they just replaced the whole rear subframe with one from a 325i. FWIW, they tought it was an easy job.

I wonder why you'd need rear discs on a 316i though....

yep as above

complete trailing arms including everything

full subframe is easiest by far
and dnt forget to rebush everything while you have the chance

the way i see it if you want to go faster, as it's the m10 is should

1st upgrade brakes
2nd uprgrade suspension
3rd invest in forced induction

that way i can go fast safely, i like twisty roads ( i live in the lake district), fast in a straight line is boring

Complete rear frame is the way to go, as you get the chance to renew the rear frame bushes and sort the rear metal brake lines at the same time.
You need different handbrake cables as well.

Right Not sure how much you know, so appoligises if you already know this:

There are 2 types of casing Small and large (read wider)

AFAIK all 325i's had large case diffs be it slip or non slip

I imagine your 316 has a small case diff (thinner)

The driveshafts on the large diff cars are shorter (to allow for the wider case)

When I did the rear disc conversion on my old 318i I used the 325i driveshafts (short) with the 318i diff (thin).

This worked fine apart from it used to leak oil because the shafts were not sat in place fully.

Soon after I fitted the 325i diff (still 318i at this time) and this didn't really make a noticable difference to acceleration, but ment that top end was slightly higher (Got an INDICATED 130mph on the clock once! )

Hope this helps!

Andy

Andy325i wrote:The driveshafts on the large diff cars are shorter (to allow for the wider case)

When I did the rear disc conversion on my old 318i I used the 325i driveshafts (short) with the 318i diff (thin).

Not true, all E30 driveshafts are the same length, the distance between the output flanges on all e30 diffs is the same. The small case diff uses long output shafts and the large case diff uses short output shafts to give the same measurement.

My E30 was a standard 320iSE with a small case diff but now has a large case diff whilst using the original driveshafts.

Have a look in the tech articles here http://www.e30zone.co.uk/modules.php?na ... htrail.htm for a breakdown on the conversion.

Cheers,

Iain T

Diffs are directly interchangeable, shafts are same length.
Strictly speaking 325 is a medium case diff. Large case diff is fitted to large engined 5 series and 7 series etc.
Only non E30 diff that will directly fit an E30, AFAIK, is the E25 525 one, which fits with a swap of output shafts and rear cover.

Templ8e30 wrote:

Andy325i wrote:The driveshafts on the large diff cars are shorter (to allow for the wider case)

When I did the rear disc conversion on my old 318i I used the 325i driveshafts (short) with the 318i diff (thin).

Not true, all E30 driveshafts are the same length, the distance between the output flanges on all e30 diffs is the same. The small case diff uses long output shafts and the large case diff uses short output shafts to give the same measurement.

My E30 was a standard 320iSE with a small case diff but now has a large case diff whilst using the original driveshafts.

Have a look in the tech articles here http://www.e30zone.co.uk/modules.php?na ... htrail.htm for a breakdown on the conversion.

Cheers,

Iain T

Hmmm Maybe I have it wrong then Will have to check, but was sure that there was a gap between the output flange and where the driveshaft would normally sit (about 1/2" IIRCA) Hence changing the diff for the 325i Item soon afterwards.

Andy

v.helpful guys.

thnks for all the input