So the plan was to stick with the 4.10 ratio differential from the automatic setup, I thought I’d like the quick shifts through first and second… and I did, but not so much the 3500rpm at 60mph hahaha!
So after a lot of pleading on forums and Facebook E30 groups I managed to track down a relatively rare 3.45 Limited Slip Diff from a late E36ti. Its a straight swap into an E30, exactly the same diff but you just have to swap the output flanges over.
So… cleaned the diff back to bare metal removing all the corrosion, replaced the two output flange seals and the swapped the output shafts from the 4.10 diff over to the new one.
A nice paint job and an oil change over to Redline 75w85 (is there anything on EARTH that smells worse than old Diff oil!?!) and it was time to fit it in the car which is a bit of a balancing act on your own.
The four top bolts are a bit of a pain but I got there in the end, I honestly can’t believe how good the car is underneath… even the drive shafts look like new!
A quick test drive and it was night and day, still plenty quick enough but first and second are now actually usable and on the run back it was sat at 1800rpm at 65mph which is about the same as my new diesel F30 daily… totally transforms it to a very usable and civilised car for long runs now.
Next up I had noticed an issue with the fog lights, fronts were fine but the rears didn’t work.
Check the bulbs and the harness, all fine. Pulled the switch… ahhh!
Lots of electrical contact cleaner later, re-assembled and it works perfect now, rear fog lights lit right up.
I decided to treat it to a genuine BMW leather gear knob too, after all the hard work doing the auto to manual swap the plastic one felt a bit cheap.
New clips for the front ”IS” lip
Glass polished the fogs with the DA
Noticed the Air Con was cool but not cold so took it in to be re-gassed. Turns out the recovery was 29g of gas and refilled with 800g’s.
Must be almost a decade since it was re-gassed so I’m amazed there was anything left in there to be fair haha!
An finally the only piece of the car that needed a bit of paintwork was the lower front valance… there is no rust it was just looking a bit grey after 30 years of deflecting road dirt.
Booked it into BM Refinishing who did some great work on my other BMW, the F30, and its come out looking absolutely spot on… gleaming Alpine white II… very happy!
The Mighty E30 Blog 