Project Weißer Regen: 91 318iS Restomod

[Jordan]

Hey Jordan,

I am about to rebuild my whole rear end and rear axles have been shot for some time. I want to rebuild diff. Would you recommend the rebuild is something that can be done diy if the kit is purchased? Not sure if special tools are required. Thatcher kit is what you recommend?

TIA

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The rebuild kits that Thayer motorsport // bimmerdiffs.com sell (same company) are everything you need to refresh a diff with good working bearings. No special tools are needed to change the clutches.

If the bearings are smoked Thayer sells those too, but that job is best left to professionals. The bearings in these diffs don't go bad often unless they are run out of fluid.

[bradnic]

See? I'm paying attention!

Me too. Love the work. Constantly learn something here.

[monty23psk]

The rebuild kits that Thayer motorsport // bimmerdiffs.com sell (same company) are everything you need to refresh a diff with good working bearings. No special tools are needed to change the clutches.

If the bearings are smoked Thayer sells those too, but that job is best left to professionals. The bearings in these diffs don't go bad often unless they are run out of fluid.

Thanks and will look into it. Was already searching the internet and was already looking at those 2 sites plus some DIYs.

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[ThatOneEuroE30]

When I replaced the bearings on my medium case diff. I got them from rockauto. They were timken bearings and for all the bearings and races it was like 80 bucks which is far cheaper then Thayer. I did get their clutch kit though. Bearings are easy but Need to be done with great care. Just cut the inner races off with a Dremel being very careful and then press the new races in. The bearings are fun to install. Just put pieces in freezer and keep the bearings out. Heat up the inner race of bearing and they just drop on effortlessly since they expand and say the pinion shrinks from being in the freezer.

[Jordan]

Yeah… Physical installation of the bearing is the easy part setting the preload in the gear mesh pattern is a different story which it sounds like you disregarded all together.

[ThatOneEuroE30]

Yeah… Physical installation of the bearing is the easy part setting the preload in the gear mesh pattern is a different story which it sounds like you disregarded all together.

I set the preload/ gear mesh. I will agree that was a pain. Gotta buy 2-3 crush sleeves cause you will mess up at least one cause it goes from being under the correct preload to be wayyy over in like a 1/64 of a turn. If you dont mess with any of the shimming. Then really all you need to do is set the preload and go but its always a good idea to do the mesh just to be safe.

[Jordan]

Assembled the majority of the front and rear suspension last night. Hardest part by far was installing the new front swaybar bushings... mother of god those were tough to get the bolt started on.

[Mwishlist]

I thought it was just me on the sway bar bushings. The first thing I did (well second after brakes) was refresh all my suspension and the sway bar bushings took forever. I had to get a clamp to hold the bracket in place enough to get the bolt started, what a PITA!

[pandaboo911]

Get some screws 5mm longer? Lol

[Mwishlist]

It's not the screw length, it's the angle. Getting the brand new bushing squeezed down to get the bracket parallel enough to get the bolt started was the problem.

[alistairolsen]

Looking really good in an understated/OEM way. Are you leaving the bottom of the balljoint cups bare? They tend to flash rust very quickly.

Are you still keeping a running tally of your hours so far?

[Jordan]

It's not the screw length, it's the angle. Getting the brand new bushing squeezed down to get the bracket parallel enough to get the bolt started was the problem.

I used a screwdriver to force the bracket forward into alignment as I closed the gap with a large pair of channel locks. I seriously considered reusing the squashed old ones as they fit so easily. It was really a two man job but I managed to get the first thread started and then they sucked down easily enough.

Looking really good in an understated/OEM way. Are you leaving the bottom of the balljoint cups bare? They tend to flash rust very quickly.

Are you still keeping a running tally of your hours so far?

I'd not really given much thought to that, as it is how Lemforder supplies the new arms. I haven't looked at any OG original arms lately, most cars don't have them anymore. The factory left the bottom of the balljoints them selves bare, and they are zinc plated so that is OK. the machined area for the balljoint to seat on the other hand may very well flash over though. It would be easy enough to mask and do a little blow in spray job on that area.

I'm surprised no one has asked lately, but yes I still keep fanatical track of time and money into this project. For the purpose of accountability I am "paying" myself $40/hr on the build, which is what I charge when I do sidework.

Here is my to this moment accounting of the time & money, I built a pretty slick multi paged excel spreadsheet that updates automatically.

[keine30]

Just goes to show that the most expensive part of restoring one of these is the hundreds of hours that go in. Not many people tally up their hours spent, but on your chart it becomes readily apparent!

[mike.bmw]

Such good work! This definitely serves as an inspiration.

I am jealous of your diff. I've been looking for a small-case 4.10 LSD for a while.

[Jordan]

Not a whole lot going on this weekend. I had a business marketing / shop management seminar all day Saturday. I wasn't aware ahead of time but it was actually headed up by Bogi Lateiner of Velocitys "All Girls Garage" fame. Great all day course on the professional side, and then some of us including Bogi went for Mexican food and mucho margaritas while shooting the shit about shop culture and life experience. Super rad.

Moving on to today which was my only day this weekend to work on the E30 I mainly spent the first half of the day reorganizing the shelving units, pruning items that have since been purchased new, and choosing the best examples of the duplicates on used parts that would eventually see reuse on the car.

The weather was nice enough today that I wanted to tackle a small project, which was reconditioning the side moldings. In case you don't know several sections of the coupe six piece side molding set are now NLA. I wouldn't want to mix pieces of varied patina so for me the best choice was to refinish the best six pieces of the two sets I had.

Between the two sets I have all the clips I need to make one good set (the clips on the back of the quarter and fender trim are not sold separate!)

Here is the first piece next to an average old piece:



...and some time later, the full set:




I hope to be able to pickup the rest of the parts from being vapor blasted this week, my Stromung exhaust should show up soon, and if all goes well the chassis should roll back over to the body shop this coming week.