Steering not right

[DerekJ]

Dave, you are right about DWR not showing it as a part. I called them up to discuss the subject and said “I don’t suppose you just sell the arms do you” and they said yes we do. It was a good price too, so I was very satisfied.

 

[red57]

Re: Steering not right - follow-up steering worm damages

Hi All,
Not sure if this should be a new thread but I chose to add it here since it is the same project, and connected.

So, since I had identified the problem with the rocker shaft, I went ahead and put the steering together for the final time (all the earlier part of the thread was with the old tie rod ends and outer links because it was coming apart/back together so much I wanted to save the new parts for a final assembly so everything would have nice paint and such).

Once I had the springs in and all the rods connected and everything ready to drive (car is not but steering was), I set about trying to dial-in the steering box free play. As other threads here have discussed, there can be a lot of trial and error getting the things as tight as possible without binding.

I fully expect to do more of that when I finally get it running but I started noticing an odd thing - as I turned it to the right, past the 'tight spot there was a bit of variable resistance to the turn (rumbly) but going the other direction, turning to the left past the tight spot, it was as smooth as ever. I kept turning it back & forth and adjusting but no matter how much I loosened the set screw the same slightly rumbly feel turning right and smooth turning left. So I finally decided something wasn't right and took the box out of the car to check it out.

All the ball bearings and races are still perfect and I was feeling the worm when I noticed a slight deviation near the center of the travel. So subtle I had not noticed it when I had the box apart to put in new balls and races a while ago.

In the accident the pitman arm was bent to the left and the pitman shaft was twisted to the left - I don't remember any particular strain in my hands from the steering wheel but there must have been a lot to twist the shaft and bend the arm and that all translated to the peg so obviously a great load on the worm. This load hammered a deflection into the side of the worm groove and cracked the worm - I couldn't see the crack until I rubbed it with a Sharpie and wiped off the surface (cheap home-brew die-penetrant test ). I had replaced the pitman shaft and the peg and needle bearings but missed the damage to the worm (BTW, there was no sign if damage to the peg, I just had a new one so I used it).

At least this explains the weird feel when turning the steering wheel.

Here are pics of the worm - it was hard to get pictures to show what I'm describing - took it outside into bright sunlight and hope you can see the damage, I put

blue sharpie marks on either side of the damaged area and crack​

.



Obviously a new worm is called for. Even though I wish I was done with the steering, I'm real glad I tore it apart again and found the problem. At least I know I really need to spent the money on this one.....
I doubt it could have resulted in any sudden catastrophic failure but you never know and steering is kinda important.

I decided to post this as a follow-up in case anyone is rebuilding a wrecked or accident damaged car, you may want to examine the worm closely.... I though that, except for the ball bearing races, these worms were pretty indestructible - now I think not!

Dave

 

[Jack T]

Re: Steering not right - follow-up steering worm damages

Dave,

Excellent job of finding and diagnosing that issue. That could easily have been overlooked by someone else working on your car just interested in getting it out of the shop.

Jack

 

[steveg]

Dave,
So are you going to buy a new worm or go the whole box?

 

[red57]

Steve,

I haven't fully researched it yet but probably just worm & shaft - don't think I want to spend $1500-2000 for a complete box.

I already have a new rocker shaft w/new peg & needle bearings and new ball bearing races and balls . And I've reworked my box by increasing the bushing bore up into the box high enough to have two bushings, one above the other to give a much broader bearing surface to help reduce side movement of the rocker shaft, with new bushings and new seals. So, with a new worm & shaft, I should be as good as new, for a lot less than a new box - in theory anyway.

This evening I opened up the two spare boxes I have here and found both have pitted ball bearing races so will most likely be buying something new.

So far the best price I've found for a worm & shaft is AH Spares for a little over $300 + shipping. I'm wondering if anyone on here has purchased one from them and might have any comments on quality/fit?

OTOH, a complete new box might give me more satisfaction/driving pleasure??? I'm going to try to make a decision over the weekend so I can get something ordered the first of the week.

Dave

 

[steveg]

Dave - how did you bore out the bushing area to accept the second bushing?

That sounds like it would go a ways to making a superior box.

I wonder if the worms sold by the usual suspects are all made by the same sub in the UK. On the other hand, maybe with CNC making a worm is easy and they all do it separately.

 

[red57]

Hi Steve, The rework for a second bushing was pretty simple. I had a local machine shop do it back in 1996 when I was preparing the car to go racing and it has been a worthwhile upgrade IMO.

All I had them do was to continue the counterbore of the bushing area diameter up into the floor of the box. We then pressed one bushing all the way up to near the floor of the box and the second one up to where it would normally which left a gap if about 3/8" between the two bushings. The shaft is the same machined diameter for it's entire length so bushings of the same bore can be placed anywhere. This gives a little over 3" from the top of the top bushing to the bottom of the lower bushing. I was trying to spread the load as far as possible for the best wear and stability.

I did this because there is only the one replaceable bushing - the upper end is just a bore in the iron box and if there is wear, there is no way to repair it. In my case there was wear and I decided to try the extra bushing to see if it would help and it did. I've never used anything but 75-90 gear oil. I use the thin double seals and the seals didn't start to weep for about 15 years. And I still haven't replaced the bushes, they are still a very nice fit on the shaft.

Some pictures (my camera doesn't allow manual focusing so trying to get pics turned out to be a circus)
1st one shows the top of the upper bush just below the floor of the box
2nd form the bottom of the shaft hole
3rd from then top of the shaft hole
last is top of box showing how thin the side of the iron bore is.
​

The best solution would be a bushing at the top of the shaft but as you can see in the last picture, it is very thin walled on the worm side and I was afraid I would weaken the box too much if I tried boring that part out and putting in a bushing.

I have since heard about a fellow named Steve Day of British Car Ranch http://www.british-car-ranch.com/index.html . I've never met him but he is a sponsor of the Cascade Healey club here in Washington and I've read that he does a box upgrade with a bushing at the top - maybe a thinner walled bush? anyway, NFI but he has great reviews in general by the club members and is very active in the club so I thought I'd include contact info (nothing on his website about steering box upgrades so if interested you will have to contact him)
If his method doesn't weaken the box too much, it is probably a superior way to go.

Dave