First, I've already pm'd Gene (50Dodge4X4) and he was good enough to answer some questions for me, based on what he knew. He didn't know how to answer this question, however. Gene, and several others, used the early Cavalier rack and pinion which has the tie rods pivoting from near the center of the rack housing. Apparently, at some later time, mid 90's?, they went to a more conventional r&P which has the tie rods pivoting off the ends of the rack gear. This model appears to be more readily available now and is the one that Fatman uses with his kit, I think. Does anyone have experience with this r&p? Does it match up to the pivot points of the Mopar front suspension? I'm thinking about putting one on my 41 Plymouth while I have the body off the frame. (If I'm ever going to do it now is the time.) Any recommendations on which model to use? Also, has anyone ever actually tried looping the hydraulic ports and just using it as a manual r&p? Thanks Rock
ROCKABLE I have used 2 of the center pivit style and looped the lines to make manuel both work just fine.
Sherm II...I've wondered about that loop trick. A power rack has a small torsion bar as part of the assembly and it allows the input shaft to go beyond the rack pinion position a bit as the wheel is turned, to actuate the valve and let hydraulic pressure do the work as you turn. With no pressure on the lines the steering wheel should have additional free play as the shaft has to flex the torsion bar to reach the stops and give solid input to the pinion. (No hydro pressure to assist) I've never tried the loop trick so I'm wondering if the additional flex reveals itself as additional freeplay in the wheel? Rockable...Someone on here mentioned that Cavaliers only had power racks but Pontiac versions had a manual rack available. Not sure if it works in the later years too but it might!
every now and then someone who has done this conversion comments about a loss of turning radius. For those that have done it, just how much turning radius is lost?
I shortened by steering arms, so I'm not really concerned about loss of turn radius. Hackerbilt, that is the reason I asked who had tried it. Anyone tried the version with the tie rods at the end of the rack? What year did that start and does it match up with the front suspension ok?
FWIW Fatman setup uses the center pivot rack which is available in both manual and power versions, as well as "Sport" quick steer and standard ratio. I used the power version "Sport" style rack on my '38. I think the radius on a full 180 degree turn is ~10 feet bigger. It is noticeable, but mostly in parking lots where you end up doing more 3-point turns. (Which fortunately are easier since you have power steering...). I'd use the regular ratio rack instead of the quick steer next time. Rock Auto shows many versions of the center pivot rack to choose from.
My wife's daily driver is a 2002 Cavalier and I wouldn't put that rack and pinion setup in a go kart, but to each his own I guess.
What is the spline on the Cavalier racks? I'm using a manual rack, if that matters. It is a round spline shaft with a flat on one side. Definitely, not a Double D. Thanks Rock
This article was written when swapping the Cavalier Rack into a Pontiac. Not a Mopar, I know, but it has some good info. http://www.crankshaftcoalition.com/wiki/Swapping_to_rack_and_pinion_steering Good Luck
I put a '91 Pontiac Sunbird rack (same as Cavelier) on my '40 Plymouth Coupe about 8 years ago. Used a kit from Plydo, disk brakes too. Had adapters for some Jap pickup tie rod ends (don't remember which ones, but I have it filed somewhere.) whch fit to the Mopar steering arms. I've had no trouble at all with the system. No, it doesn't turn as sharp pulling out of the driveway, but it's no short car either, 117" wheelbase. You just turn a little wider, like in a pickup. I used a U joint to adapt the rack to a GM tilt column.
I believe it's 17mm or some such, IIRC Borgeson has a U-joint with the correct spline on one end. I'm not quite sure what kind of joint the GM J-car uses on the end of its column. I did some playing around fitting this rack on a (not quite HAMB-compliant) '60s product but went a different direction in the end. I think I have a Borgeson U-joint around here, with the J-car spline on one end, 3/4DD on the other, and their 'vibration reducer' in between...let me see if I can find it. The '94-03ish Saab 900/9-3 uses a slightly different flavor of the same rack design ('94-95 Saab racks were ZF and '96-up Delphi) and I expect the Saturn L-series does too (they're both a J-car/Vectra platform) but the input shaft on the Saab at least is a slightly different size - same spline diameter but the flat is wider (the pressure cylinder's also a different diameter than the US J-cars, which means the mounts are a little different.) In theory (and I'm not familiar with your Mopar application) you could get your steering lock back by using shorter steering arms (which speeds up the effective overall ratio) then using the slower-ratio version of the rack. - update - was wrong on two counts, first the Saab Delphi rack has a 19mm (3/4in) double-D input shaft, but the flats are wider than the conventional US double-D shaft and a 3/4 DD U-joint would have to be shimmed to fit it. Secondly, the spare Borgeson joint is 3/4 DD at both ends.
Rock, Do you have any pics of your rack install? I'm thinking of putting on in my '51 dodge to gain exhaust room and cost of a-body manifolds. Did you shorten the radius arms? (at least thats what name is popping in my head for the items the tie rods connect to the spindle by, sorry) In order to gain the turning radius back. If so how did you do it? thanks, 'spike
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