1991 ZR1 - Rack and pinion assembly
 

Good day all,

First time vette owner here, I just picked up a 1991 ZR1 here in Canada. Honestly this community and seeing the support around for the ZR1 played into my decision to pick it up.

Unfortunately, it didn't pass inspection; there is a tiny bit of slop between the rack and pinion assembly and tie rod end (couldn't even notice it on the steering wheel).

I have a couple questions for you folks:

-It looks as is the regular C4 vette assembly is the same as the ZR1? Here is the one I am looking at ordering:

https://www.rockauto.com/en/moreinfo...t=7388&jsn=917

-Is there any DIY around on pulling this out and is it much different with the LT5 vs the regular vette engine?

-I assume the 1991 Corvette shop manual applies to the ZR1 as well? Not sure if there would be anything on doing the rack and pinion assembly in that? I seen there was a seperate LT5 one as well, I will likely just order both.

Any help/suggestions is appreciated!

Trevor

Re: 1991 ZR1 - Rack and pinion assembly
 

Welcome. Yeah the helms manual details everything you need to do the job

Re: 1991 ZR1 - Rack and pinion assembly
 

You can always send your steering rack out to Turn One and they will rebuild it for you. Many of us in Wazoo have done this and are very pleased with the results. https://www.turnone-steering.com/

Re: 1991 ZR1 - Rack and pinion assembly
 

Thanks for the replies!

Is the helms manual the same as the 1991 Corvette service manual? I just ordered that one on a thumb drive along with the hard copy LT5 manual.

I think shipping it to the states and back is likely just as costly as ordering a new one (not sure how good a new one will actually be though compared to the original).

Re: 1991 ZR1 - Rack and pinion assembly
 

I will always take rebuilding my OEM part rather than some replacement designed and manufactured in Asia.

Re: 1991 ZR1 - Rack and pinion assembly
 

Thanks, I just done a bit of research and found a spot within Canada that seems to be reputable; spoke to them on the phone and seems to know their stuff. Likely end up being around the same price as the Asia one.

Re: 1991 ZR1 - Rack and pinion assembly
 

Sorry, just so I?m clear - the play is in the rack itself and not caused by a worn inner or outer tie rod? Racks do have to be rebuilt from time to time but the wear item is more commonly the tie rod. Just asking because you mentioned the play is between the rack and the tie rod end. I may not be thinking about it correctly.

Re: 1991 ZR1 - Rack and pinion assembly
 

According to the mechanic who done the inspection he figured it was in the rack and not the tie rod. When he showed me in the garage with the front in the air I think they moved a wheel a bit and got me to feel a tiny bit of slop in the tie rod, which I did feel I tried to repeat with it in the ground in my garage and couldn?t feel it. I?ve actually booked another inspection at another garage to see what they come back with and do some more troubleshooting myself before pulling it; just preparing for it if I have too.

I just drove the car 1,300 kms from where I picked it up and everything was solid, there may have been a couple times when going around long right turn then turn the wheel to the left I felt a little tiny notch, never happens often at all though, it was tight otherwise. So I guess we shall see, only 83,000 kms on the car.

Re: 1991 ZR1 - Rack and pinion assembly
 

So I got my second inspection done, this time they came back with the rear shocks and rear wheel bearings (rear wheel bearings came back on the first too).

I can buy into more so than the steering rack, I tried to repeat the slop in my garage jacked up and could not get it to happen and otherwise drives tight. The right rear shock was pretty stained up (worst wheel bearing too) and left somewhat. The fronts were clean

I found this shock its called B6 (not FX3) with selective ride, I assume this is the like for like replacement? Just want to confirm prior to ordering. Part # 20070014

Also one final question; looks like the last owner ran Pennzoil 10w30 non-synthetic. Do it matter just to do a straight up oil change to synthetic? Been looking at 5w30 Mobil synthetic (much more easy to get) or possibly the Amsoil 10w30 synthetic.

Thanks for the help!

Trevor

Re: 1991 ZR1 - Rack and pinion assembly
 

Trevor,
Most likely the rack is fine and the play is within the inner tie rod that threads onto the rack. Rockauto DORMAN IS200PR.

Rear wheel bearings usually make noise but not uncommon for them to fail early. Mine are replaced with
Rockauto. MOOG 513013

if the shock is not leaking fluid it is fine. If the rubber bushings are worn out they can easily be replaced. I have done it. If you need bushings let me know and I will search for the supplier I used. I have no opinion on full replacement.

Oil. Plenty on that subject but you cannot use any modern oil off the shelf. Change it. The oil must have higher quantity of zinc. I use the following and get it from Amazon for $100
PENN GRADE 1
71506, Synthetic Blend High Performance Oil SAE 10W-30, 1 Quart (12 Pack)

The following oil filter has minimized the typical start up up rattle.
WIX 51324

You have done the best thing in getting the 1991 Chevy service manual with LT5 supplement. Spend some time to get familiar with it.