Corvette Forum : DigitalCorvettes.com Corvette Forums banner

1963-1982 Steering Box Rebuilding

92K views 145 replies 54 participants last post by  gtr1999 
#1 · (Edited)
Ok this is another one of my favorites. Not to sound arrogant but I build the best saginaw steering boxes on the market. Not because I'm a super genius but simply I put the time into them and the extra work requred to make them better then the day they were new and certainly better then some I've had shipped to me that were "professionally rebuilt" I have one coming in now out of a 63 SWC that was "done" by a vette shop. The guy is my brother in law so I know he had paid the shop big $$$ to go through the car yet it was all over the road.

What you need to know about these boxes:

1- Do not attempt to adjust the lash unless you have a dial in/lb wrench and the box is out of the car. I know there are guys who will tell you to use the fish scale procedure in the car, they will also tell you that vette boxes are NG and to buy a new one- big mistake.

2- Forget about adding grease as the book says, not accurate. If you overfill the boxes they will leak. They are not vented and heat will expand the grease and either blow out a seal or the oil in the grease will weep out. Even properly filled this may happen. Plus a lot of times you'll get a false reading as the old grease creates a caked up dam preventing the new grease from getting to the bearings. I believe I have some pictures of just this situation with a box sent to me.

3- The 63- 69(69 manual only) used a full 360* spline while the L69-82 used a coarse spline with a flat milled into it. The rag joints from 63-66 were the same and are $$$$ now, the Tele joints were different and I have not seen one. The 67-E69 rags are also different and the L69-82 are all the same. USE a GM rag if you need one. Pay the $100 or so and get it, forget about those repair kits I think they're junk. Remember I don't care what a vendor says this is coming from a restorer, owner, driver. NOTE: I no longer recommend ANY Rag joint from ANY supplier. I found the current GM rags have changed. They no longer are grounded and material isn't the same. They are not as rigid as they were a year ago and I suspect the supplier is not making them in the good ole USA anymore- I could be wrong but the ones I got in from my local GM dealership are not the same anymore. If you can find a NOS GM rag look for the wire mesh molded into the rag and red ink on the material. Hopefully someone will come up with a quality rag joint like the GM rags I used to buy but I wouldn't count on it. I have a couple left but will be holding on to them.

4- The pitman arms for a power car are different then a manual car. The PS arms have 383 as the last 3 digits in the arm. The manual arms are 451.

Ok here we go:

This is what they look like when I get them in. Yours is probably the same. If your car has been sitting a long time then the grease get acidic and attacks the ball screw in the worm assembly. Be aware when looking it over.






The first thing you have to do is remove the pitman arm. Some of these suckers are on there pretty tight so I hit them with the propane then PB Blaster. I use a puller and spacer to protect the threads on the shaft. Use an impact gun to pop it off just be sure to have the arm turned in the right direction so it doesn't free wheel into the end of travel. Remove the lash nut and turn the lash screw out a little. Remove the 3 cover screws and screw the lash screw in to back off the cover. I have a 3/4 socket set that I use to loosen the side adjusting nut and lock ring.

Here is what an old box looks like with the nut off.


Here are the 2 inputs, full spline and the milled one.


Remove the parts and wash them. Here they are broken down.


I made some tools up to do these all the time but for you one timers here's the trick to removing the bushings. In the cover use a burr and once it cuts through the bushing will spin it out and you can use pliers to remove it. The 2 in the housing require a homemade tool. Get some washers the diamter of the bushings and bolt them together. Then grind a flat on one side so they can be fit into housing and lay flat on the bushing then you can drive them out one at a time. I made a tool to install them. They are soft so you need to radius the ID like you would a cam bearings and install the same way.

The kits sold are not all the same. The quality does vary now compared to a few years ago. They usually come with bushings and those are ok although I never use them. You can use them and have a vendor type build - BUT if you want the best built box you will have to machine up and fit your own like I do. This takes time and you need a lathe. Is it worth it for a 1 time job, that's your call.


Here is a stock bushing


If the gears are still good- they can be set to 11-12 in/lbs and there is no heavy pitting then you can rebuild them with 54 new balls. I take the shaft and polish it before fitting the bushings to it.



Here are those ball guides, follow the GM manual on rebuilding the box here.



Look at the ball screw for pitting. If bad then you have to replace the gear set. I can not get the parts separately.



When I get the gears back and new races in place I dry set the gears to see where they run.



This is another spec to check, the gap has to be between .0015-.002" Shims in the kits will get you there or you have to machine up some.



When all is good, preload set to 4-5 in/lbs, lash goes to 11 -12 in/lb ok then you can add grease, leave room for expansion. UPDATE 8/2010- I no longer use Mobil 1 grease. It's a good grease but had issues with the oil separation with it. It separates more then other greases and will sometimes lead to the oil from the grease weeping out past seals. Maybe only a tablespoon of oil will weep but there are other greases out there that work better. ALSO some rebuilders will not tell you want they use or will tell you they use a special grease. This is total BS they just want your cash and will use tactics to try and sell you something. Any quality grease will work, the key is using one that will not separate like the Mobil has. Even though the red grease weeps it will stop, all the grease is not going to leak out. On the other end of the spectum I found "rebuilt" boxes without any grease! No leakage there, a couple of new seals,a paint job, old bearings,bushings,and gears and they charged the guy $150-$200. Real nice.

Here it is, done and ready to bolt in. If you add the arm torque it to 150 ft/lbs. I also witness mark the set points so you can see if an alignment shop helped you out and adjusted it. Then you get to set it up all over again. This has happend more then a few times so pay attention.




This is more involved then it looks and it is not a ebay $150 special. It's your vette- do it right! If you want the best and don't want to do it let me know.
 
See less See more
13
#9 ·
Thanks Gary. Mine is going in the mail to you tomorrow.
:cheers:
 
#10 ·
#11 ·
Mine is on the way to you Gary. You should have it by Friday.
Thanks!
SP

:cheers:
 
#13 ·
Thanks Gary. You're the man! Wow that was quick. :thud:
 
#14 ·
I just got a chance to open the box tonight Gary. It looks fantastic. Thank you so much.
 
#16 ·
I received some calls recently on how I torque the pitman arm on the shaft off the car. You don't want to load the ball nut inside the box by torquing the pitman arm nut to 150 ft/lbs or you'll damage it. I put a brass rod in between the arm and my bench vise so all the load while torquing is going against the rod and not the ball screw in the box.



 
#19 ·
I have Paul's 70 box in to check. One of the first things I do is to check the lash setting and see if there is anymore room to adjust the original gears. Paul's was sloppy as most are but I was able to adjust the lash in the range I wanted. There wasn't a lot of adjustment there but they were borderline for reusing.

Then I opened up the box and took a look at them and didn't like what I found. The ball screw on the worm assembly was badly pitted, the chrome was flaking off and it was pitted. So even if the lash range is good you have to look over the parts. With the combination of high temp and old grease, the box was an acid bath on the parts. Over time it took it's toll on them.

There was an attempt in the past to regrease this box too. This is a good example of why I would remove the box to regrease- against all those that said I was going beyond needed service. You can decide for yourself. In the pictures of the grease you can see where the "new" red grease was added and then just how much was pumped inside. Not enough to make any difference and may have been too late anyway.

Here is the box with the cover off, 1st time. See the red grease in the corner.



You can see here just how much was in the box.




Here is the end of the ball screw and a close up. Not what I wanted to see.




 
#23 ·
Gary,

I'm going to be machining up some bushings for mine soon, really want to try and get the best possible setup and keep the "slop" to a minimum. I'm interested to see just "how good" this agricultural old system can be made to work ;-)

I'll be taking some measurements obviously when the time comes, but out of interest what OD do you turn your home-brew bushes to, for a light press fit in the bore? I see you run their ID at .002" clearance to the shaft - do you think there's any benefit to going tighter at .001"? Perhaps not worth it to invite binding when hot?

Cheers
Theo
 
#28 ·
Well I was just at Carlisle this past weekend and a fellow corvette owner stopped at the tent with a C2 box in his hand. I looked it over and asked if it was a core as it was in poor shape and the gears were shot. To my surprise he told me this is how it was shipped to him from a vendor. I advised him to go to that vendors spot and exchange it for another one.

He came back later with a sealed cardboard box with a newly rebuilt C2 box in it. We took a look, see for yourself. Keep in mind this guy already exchanged 3 previous rebuilt boxes with this same vendor, his original box was better then any he received.


The box lash from lock to lock was 5 in/lb - 20 in/lb in 1 turn, then off the scale at 30+ in/lbs, then dropped back down to 20 at the other end. This was supposed to be a ready to bolt in box. This is just bad work guys I can't see any other reason for it other then to make a quick buck at a fellow vette owners expense.

Here is the box as I got it, looks pretty good huh.




Cover off, grease looks good.


Cleaned up the parts and found the bushings were the original grooved ones,certainly not the common new oilite bushings used. The rack on the ball screw was installed upside down to tighten the lash I guess or the rebuilder just didn't know what he was doing. I suspect he did and didn't want to install new gears for this worn out set.











This post is presented as a fellow service to corvette owners.Be very careful on what you buy and do not let price govern your decision. This box was assembled wrong, greased,painted and left so far out of adjustment it was unsafe to use. (Paul this was the guy you asked me about, just happened I was given one of his boxes to fix.) Pretty sad.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top