Steering rack rukus, seeking knowledge of the rack.

So, I went about trying to get the engine in my project car last night, and boom, with the trans on there, the bell housing now hits both the steering box and the slave pitman arm on the passenger side. In the spirit of cut and weld until it works, I'm looking into fitting up a rack and pinion.

To keep the geometry as close as I can, I need a rack that has a center section around 555mm or slightly less, and tie rods around 330 mm. I'm about to make a trip to the junkyard here in a bit. The goal with this one it to make something that will work decently. Eventually, I will be redoing the front end with a geometry designed for a rack and so I can move the engine back a little more.

That is not in the cards right yet, unless I really make it. Anyone know of a rack of that approximate size? Manual or power, that doesn't really matter. It would be nice if the ratio is not terrible. The weight of the car shouldn't be too much of a problem with most modern cars. Probably a VW Rabbit is a bit too light, but other than something like that we are ok.

The car is a W108 Mercedes (1972 280SE), the lower A arms don't really lend well to a rack and pinion swap, but I think I can get it done with the room I have thanks to the oil pan design on the newer engine. If this doesn't work, it is off to the books to learn me a little more about suspension geometry and I'll make a new front end for the dang thing. I was hoping to get the car on the road for a while before I went and redesigned everything.

So to recap, rack and pinion, ~555 mm center (just under 22 in), and ~330 mm tie rod ends (almost exactly 13 in). Preferably with a ratio that does not really suck.

Thanks for looking.

Huh huh knowledge of the rack...

Swap the spindles R to L and make it a front steer?

Can't do that. Oil pan is in the way. Mercedes engineers were experts at filling available space in the 90's.

You can always use a Saab rack with the tie rods attaching in the center and use it to drive a center link. That can give you some flexibility for how the center link mounts.

I just so happen to have a TR7 rack here ready to go in. End of inner tie rod to end of inner tie rod is 22". Arms and tie rod ends are 13". Total length as this one sits is 48" but there is adjustability in the ends. Mounting blocks are fixed at 14" apart and are centered on the solid part of the rack. Inners stick out of the rack and into bellows. Steering rod connects sort of above but slightly outboard of one of those mounting blocks, so you will need a rear sump pan because the steering arm will end up located about where the front edge of the oil pan is. Using it with my LS engine install in a TR8 and there is zero fitment issues. I have several others. Manual racks, 3.9 or 4.5 turns lock to lock, but the 3.9s are hard to find because they only came in the early coupes. Then they realized woman drove these cars too. I also heard some 80s Toyota racks were popular with street rodders.

Thanks for measuring yours out. I ended up with a GM rack out of an SUV. It is slightly off on the measurements, but I think the adjustability will cover that. Plus I like how it mounts, and it is a slightly better ratio.

It is funny you mention the 80s Toyota rack. I had an 80's Corolla manual rack, but ended up selling it when I didn't need it. They are rare around here and everyone in that scene wants one.