Page 1 of 2

Worm gear for a 68 2000

Posted: Thu Aug 13, 2009 8:57 pm
by Ted928
At some point I would like to tighten-up my steering. When I adjust the box to take all the slop out while pointing straight ahead, the steering binds when I try to turn it. I think that means that the worm gear is worn.

What are my options to repair or replace?

Thanks

Re: Worm gear for a 68 2000

Posted: Thu Aug 13, 2009 9:03 pm
by dbrick
Best option I know of is to swap it to a type B box, recirculating ball type but a bunch of parts are needed, U joint, lower shaft and maybe the idler box. Getting the whole assembly from a parts car is the best bet.

You could try re-adjusting the existing box a bit looser to find a happy medium and using 140 wt conventional gear oil, thicker film of oil may help a bit, unless it's excessively worn on center. A wheel alignment afterward will make it track better, so the play may not be as annoying.

Re: Worm gear for a 68 2000

Posted: Fri Aug 14, 2009 11:20 am
by sfdaugherty
There's a writeup on updating to the recirculating ball type in WIKI section. These came out mid to late 1969 but, according to the article, you will need the u-joint (which is smaller), a steering box, and will have to bend some metal. I don't think you need more than that if you have the late model, two-piece steering column.

Although I'm not having problems with mine, the rebuilt boxes and parts to repair them are getting VERY costly so I bought two boxes on ebay (one of each kind for my 68 and 69) and some extra u-joints (just in case I decide to upgrade my 68).

Shannon

Re: Worm gear for a 68 2000

Posted: Fri Aug 14, 2009 9:23 pm
by Ted928
Is rebuilding the ball type much cheaper or is it that they do not wear out?

Re: Worm gear for a 68 2000

Posted: Fri Aug 14, 2009 9:41 pm
by dbrick
The multiple balls in the system spread out the wear, so they last longer and stay tighter. I would watch for a box from a low mileage rustout. As long as there's oil in it, they weather well.
I'm 99% sure you need the lower shaft to change to the late box, different spline count.

I was thinking, as long as you don't drive in very cold weather, you may have nothing to loose by filling the box either 50/50 or 100% with STP oil treatment, thick and very slippery, but it flows. If you decide to drain it out, might take a few days to all run out.

Re: Worm gear for a 68 2000

Posted: Sat Aug 15, 2009 9:58 am
by sfdaugherty
I'm 99% sure you need the lower shaft to change to the late box, different spline count
Dave: I'll compare mine and see if that's true. If so, I'll need one more part to do the swap.

Ted928: I thought that one of the vendors sold new worm gears but, when I looked I couldn't find it.

Shannon

Re: Worm gear for a 68 2000

Posted: Sat Aug 15, 2009 10:16 pm
by 23yrRebuild
I upgraded to the RCB in my '67. IMHO, it was a worthy upgrade and I like it alot. 8)

Re: Worm gear for a 68 2000

Posted: Sat Aug 15, 2009 10:55 pm
by garth
Ok. I've got the newer RC box. Where can I get the matching U joint? I understand it is one of the hardest parts to replace. I asked Ross today if he had one. "Nope, got 40 of the older type though" Not very encouraging!

So if anyone wants to part with one, please pm me.

Re: Worm gear for a 68 2000

Posted: Thu Aug 27, 2009 10:47 pm
by sfdaugherty
I'm 99% sure you need the lower shaft to change to the late box, different spline count
Dave: You were right, the worm gear splines are much larger than the RB splines. Rats! Now I have to keep an eye on ebay for the lower steering section if I ever want to do the swap.

Here's a couple shots of the two different boxes. The older worm gear style is the one with the bolts in it still.

Shannon

Re: Worm gear for a 68 2000

Posted: Tue Mar 23, 2010 6:37 pm
by Ted928
Has anyone tried to weld repair their worm gear????

Re: Worm gear for a 68 2000

Posted: Wed Mar 24, 2010 12:10 am
by garth
Ted,

When I discovered my worm gear had a chunk missing out of the "worm" I took into the weld shop where I worked to see if a weld repair was possible. I cleaned it up and did a dye penetrate test which revealed numerous cracks that would have to be repaired in addition to building up the missing chunk. Diagnosis complete: Not worth repairing. Even without the cracks, building up the damaged area would require some special welding techniques and post heat treatment to restore hardness, both expensive and risky processes. The worm gear faces are case hardened steel for the extreme loading steering forces generate.

Repaired steering mechanisms are likely to fail at the worst possible circumstances similar to repaired braking systems. Be safe and find an alternative solution.

BTW I was at Ross Mullen's tonight picking up some parts and I noticed 8 or 9 damaged worm gears sitting on a shelf beside several used steering units so its a common failure and repacement as the common fix.

Re: Worm gear for a 68 2000

Posted: Wed Mar 24, 2010 10:28 pm
by Ted928
Unfortunately, you make a lot of good points. What are the options?? What do all the racers use for a steering box?

Re: Worm gear for a 68 2000

Posted: Wed Mar 24, 2010 10:43 pm
by dbrick
garth wrote:Ok. I've got the newer RC box. Where can I get the matching U joint? I understand it is one of the hardest parts to replace. I asked Ross today if he had one. "Nope, got 40 of the older type though" Not very encouraging!

So if anyone wants to part with one, please pm me.
They basically don't exist. I tried to get them fabricated a few years ago, got a sample of the new one, and they kept the stock one I sent them, which I borrowed from Michael Spreadbury. Took me 2 or 3 years to find a replacement to send back to him. Sample is my spare, but would need to be tack welded in.

Best solution would be a sleeve or a yoke to enable using the old style larger joint on the later box. I forgot which is the smaller shaft size.

Craig Halstead just listed one, nice part, but it's not cheap. http://cgi.ebay.com/ebaymotors/Datsun-1 ... 0376710047 See if he has a lower shaft if you contact him.

Re: Worm gear for a 68 2000

Posted: Wed Mar 24, 2010 10:44 pm
by Dcyco1
sfdaugherty wrote:
I'm 99% sure you need the lower shaft to change to the late box, different spline count
Dave: You were right, the worm gear splines are much larger than the RB splines. Rats! Now I have to keep an eye on ebay for the lower steering section if I ever want to do the swap.

Here's a couple shots of the two different boxes. The older worm gear style is the one with the bolts in it still.

Shannon

I have the one on the bottom, the smaller shaft, sitting in my gararage.

Re: Worm gear for a 68 2000

Posted: Wed Mar 24, 2010 10:55 pm
by Ted928
Dcyco1 wrote:
sfdaugherty wrote:
I'm 99% sure you need the lower shaft to change to the late box, different spline count
Dave: You were right, the worm gear splines are much larger than the RB splines. Rats! Now I have to keep an eye on ebay for the lower steering section if I ever want to do the swap.

Here's a couple shots of the two different boxes. The older worm gear style is the one with the bolts in it still.

Shannon

I have the one on the bottom, the smaller shaft, sitting in my gararage.
pm sent