Strike3

I have a 92 coupe with base suspension. It's getting tired and I am in the planning stages of a complete rebuild of steering/suspension.
While looking at replacements for the rack and pinion, I noticed there are no options for the later year C4's like there were for the early C4's. Such as Z51 suspension etc. I also noticed that my 92 was at the end of a run where they had used the same unit (part number) since 88. The next years unit ran from 93 thru 96. However, the 88 -92 unit and the 93 - 96 units appear interchangable. Same mounts, hoses, etc, Often NEWER equals IMPROVED. Is that th case here?? Is there any compelling reason to stay totally original or go with the newer unit? Were there improvements in the later design or just cost cutting changes?

Joe C

i really can't help you on the decision making thing here, but i can recommend the AC Delco rebuilt units. i bought one years ago from the last detail for my 85, and never had issues with it. it's a job you don't want to do twice - it's a royal PITA! if it were me, i'd stick with the correct assembly for the 92.

have fun swapping out the rack - - just keep saying "i love my corvette, i love my corvette, i love my corvette..."

finally, i don't know if you have them in your toolbox, but get the correct size flair nut wrenches for the power steering hoses - not sure of the exact sizes, but i'm thinking one is an 18mm, the other - ???

good luck - have fun!

rodj

ZO7 was the late model version of Z51 "perf handling pkg " ; came with a faster rack than base car but apparently not as fast as pre '89 Z51 units.
http://forums.corvetteforum.com/1566156772-post2.html

Externally racks are the same ; IIRC ,you can even use a early rack in a late car if you change the tie rods ( Mounting points are the same )

RWDsmoke

I bought one from advance auto. A month later it dumped all the fluid on the garage floor. They replaced it under warranty but it was a pain changing it again and back to the alignment shop. The second one didn't leak but had too much play. I finally got it adjusted so it is not too bad. I would try to find a local shop that will rebuild the old one.

WW7

My 89 has the quick (2 turns stop to stop) rack in it.. These are harder to find then the ( 2 1/2 turns stop to stop) racks.You could have yours rebuilt...WW

coupeguy2001

about 10 years ago, I got a rebuilt from Autozone. I just replaced it again. no hassles, lifetime warranty, and it takes about 4 hours from start to finish.
It's not bad, take your time, use a LARGE 3/4 inch tall drip pan about 2 feet X 3 feet, and it catches everything. Just you will have to take the car to have it aligned, and then to the car wash to hose off the residual fluid that creeps everywhere.
measure the best you can the dimensions of the rack, then measure the tires to the fender.
Best is if you use masking tape, put some on the steering wheel, and some on the column. Then draw a line across both tapes.
When you go to line everything back up again, the tapes' line will be in the same place, and the tire to fender measurement will be there, and you screwed the tie rods back to the same measurement, so it will be close.
The toe will be 1/8 " from true straight, so no way can you get that by guess and by gosh.

Strike3

Thanks guys!! Great info.

samsonb

I've read you measure where the tie rods are at on the rack. Then screw the tie rods on the new rack to the same measurement. Or is it more complicated than that to get it mostly correct?

PLRX

This is the one you would love to have

I have it in my 96...good stuff

samsonb

Napa sells two racks. One is 2 1/4 Turns Lock to Lock, and the other is 1 3/4 Turns Lock to Lock. Nice thing is it says on the site they come with new tie rods. But don't know if that is accurate.

glava2876

If you get a rebuilt rack, be sure and bench test it lock to lock and also that the rack is centered.
If you search, you'll see my NAPA 84 Z/51 rebuilt rack story -the NAPA HD version is for the 84 Z/51. I had a problem and they replaced it with no problem, but I still had to do the work and pay to have it aligned twice.
The Z/51 should have APPROXIMATELY 2 turns lock to lock, so from center you should have about 1 rotation right and about 1 rotation left -this was confirmed when I finally spoke with the NAPA tech people and they let me talk with the rebuilders.
The first two rebuilt racks that I had were only about 1 3/4 rotation lock to lock, which may not seem bad, but from center it had 1 rotation left and only 3/4 rotation right -no issue at speed, but at low speeds it was hard to pull into a parking spaces etc.
No matter which rack you use, I just want to save you the hassle of doing this twice -so check this out before you install.
The NAPA rack that I ended up with is working great and has no leaks.

2012 coupe

I just replaced my rack with a GM/Delco unit through a GM dealer, $307.57 with core. I got the Z07 one. You can find them cheaper, but I prefer to stay with GM stuff for the important parts. Make sure you get one for a 1992 year vette.

mtwoolford

went through this a few months ago. "fast", "standard", "sport" really come down to two things. either they are 13:1 ratio or 16:1 ratio, "fast", "sport" or "standard" respectively. The 13:1 will also be described as a "2 turn" lock to lock; in the real world, installed it will be slightly more than two turns; the 16:1 is the "2&1/2 turns" lock to lock; again once installed it will be slightly more than 2 and half turns.

the important thing is that most racks are 16:1; 13:1 is uncommon.....so....if you want to upgrade from standard to fast, check out your new unit on the bench; you can simply measure how far the rams move in and out per one turn of the input shaft. compare it to your stock unit.

you don't want to wait until the unit is installed in your car to find out what you thought was a fast rack is indeed a standard rack. one, you don't want to have to take it out; and two, you probably won't be able to exchange it at that point anyway.

good luck

WW7

I don't know about other years, but the 89 Corvette came from the factory with the (2 turn) rack installed as stock...WW

coupeguy2001

The one I installed is 2 1/4, and in the car, it is 1 turn and a little bit, like an inch and 3/4.
The 1 3/4 turn rack like the previous poster says, is 1 turn left, and 3/4 turn right if you do not have the correct steering shaft. THe indices on the Z51 car are in a different place.
So if you go to the short throw steering from the regular steering rack, you have to change the shaft as well. The problem with that is the steering shaft on the rack has a groove the bolt slides through to keep the shaft slip-proof, and the shaft bolted to the steering column has a hole that the bolt goes through. If they are not the right combination, the steering rack is not really centered, even though the steering wheel is centered, and all looks great and the car goes down the road straight. It just won't turn equally in both directions till you switch shafts.

samsonb

It is hard to find the correct rack. Autozone just has them as "Standard" or "Sport". Advance has them at "w/16 Whl." or "Exc. 16 Wheel."

Napa has them 2 1/4 Turns Lock to Lock, and the other is 1 3/4 Turns Lock to Lock.

Do you know which rack at Napa would be correct for an 89?

glava2876

Josh, I'll look at the NAPA PN on my reciept, but my 84 Z/51 used the1 3/4 rotations. I don't know for sure about other years.
I actually had to call the NAPA Tech line 1-888-876-6272 after getting (2) racks that were the correct PN & rotaitons lock to lock for the Z/51, but could not be centered correctly ... they finally bench checked one for me to be sure that it turned the same rotation right to left off, off center.
They sent that to my local NAPA store and it was correct.

93Rubie

Wow, way too complicated.

Just center steering wheel and lock in place.
Pick the same tread block on either wheel. Measure distance apart (with tape measure) in front of wheels. Then using same tread block measure distance on back of wheels. Compare measurements to determine if it is toe in or out. Adjust it so you have about 1/4" more measurement in front than in rear. Keep the steering wheel level.

I just did this on my DD, by golly the wheel was almost perfectly straight. I replace the inner and outer tie rod ends on one side.

Tools Needed: Wrenches, Tape Measure, Your Brain.
Maybe a Helper (to hold tape) and a Creeper.

Might take 30 minutes tops.

This will be more than adequate to get you to an alignment shop.