Manual steering rack play?

[RoadRacer]

My 33 HR steering rack has some play in it - what is normal?

I can rotate my 13" steering wheel 1.5"-2" before the rack moves, which seems a lot to me. There's no discernible play in the column.. the very last joint at the rack moves exactly in relation to the steering wheel movement.

But the tie rods (and hence wheels) don't move at all until those 1.5-2" of slack has been taken up.

For reference, I found this (https://www.howacarworks.com/steering/checking-rack-and-pinion-steering): "It should not be possible to move the rim of a 15in (380mm) diameter steering wheel more than 1/2in (13mm) without the front wheels moving."

[sread]

A big part of the problem is the steering rack is fairly flimsy. Watch the inner tie rods when you turn the wheel back and forth - they deflect quite a bit because there is no support for them . And with the number and operating angle of the numerous u joints in the steering shafts any free play at all becomes pretty noticable.

[sread]

Just remembered one more thing - the free play in the rack itself is adjustable. I had to tighten mine up. Its pretty easy - just loosen the jam nut and turn in the adjuster till snug, then back it off about 1/4 turn - you can fine tune it some by feeling how tight it gets.

[edwardb]

Coincidentally, I just assembled the steering assembly in my Truck build yesterday. I believe it has all the exact components as the 33 HR. I'm a little disappointed that I too have a slight amount of free play in the steering wheel as well. But it's only just over 1/8". I can feel just the slightest movement in each of the U-joints when I turn the wheel. With five of them (!!) I guess I shouldn't be surprised. It adds up. I'm hoping it's OK and will leave it for now and see how it drives. I don't detect any issues with the steering rack itself. Your 1.5"-2" before the rack moves is clearly way excessive and the setup is capable of much better.

[RoadRacer]

Thanks all. Yes I’ll go through it all again at the weekend and see what I can do. The last uj by the rack used to be a problem but I had previously jbweld’d that one to the rack.. which was surprisingly very effective and is still rock solid.

[33fromSD]

Thanks all. Yes I’ll go through it all again at the weekend and see what I can do. The last uj by the rack used to be a problem but I had previously jbweld’d that one to the rack.. which was surprisingly very effective and is still rock solid.

I love JBweld!!

Jim

[RoadRacer]

I love JBweld!!

Jim

Well it was your idea :D

[33fromSD]

Well it was your idea :D

Good stuff, lots of uses. I actually just used some last night on the neighbor's girl's toy. The Mom came over knowing I do a lot of mechanical stuff and wondered if I could fix her little girls toddler car since the wheel was wobbling. The problem was the plastic housing broke on the wheel where the axle slides through, so I pulled out the JBweld and voilà, wheel no longer wobbles. You would have thought I just saved the planet, the Mom was singing praises to the other neighbors the rest of the night. Her husband came over and asked where to buy some, Kind of funny ;)

Jim

[johnnybgoode]

Not sure what set screws are used in the U-joints but mine were SS which I replaced with black oxide steel ones that I was able to tighten more without stripping the Allen key. I also blue Loctited them all. Got rid of 90% of the slop. Scott

[edwardb]

Not sure what set screws are used in the U-joints but mine were SS which I replaced with black oxide steel ones that I was able to tighten more without stripping the Allen key. I also blue Loctited them all. Got rid of 90% of the slop. Scott

I also used blue Loctite. Used the provided set screws and was able to put serious torque on them with no issues. The slight amount of play I'm seeing is between the u-joint sections. Not in the attachment to the shafts.

[RoadRacer]

Yeah I used blue loctite too on the joints, and none of them seem loose right now. The very last one was not tight on the rack spline though - and wouldn't tighten with the grub screw. Super wobbly, although won't come off due to the layout & design. But to remove the wobble I JBweld in that side of the UJ, and shoved in the spline, then screwed back up. It set super solid and hasn't deteriorated in 3000 miles so far.

But I'm heading out there now to see if sread's idea helps.. been too long since I put that rack on.

[RoadRacer]

Ha.. never trust your first impression. Check everything, even things you're "sure about".

First though, I don't see (or perhaps understand) where there's any adjustment on the rack?


Just remembered one more thing - the free play in the rack itself is adjustable. I had to tighten mine up. Its pretty easy - just loosen the jam nut and turn in the adjuster till snug, then back it off about 1/4 turn - you can fine tune it some by feeling how tight it gets.

150859

I'd love to hear more, please!

Anyway, even though I was sure that there was very little slop before the rack.. I undid every grub screw+nut and tightened them all back up. It didn't feel any different, but now when I measure at the steering wheel I have 1/2" of play. So something had gotten loose, even though I didn't find the culprit. They all "broke loose" of the loctite. So we'll see if that translates to the road manners in any way.

[RoadRacer]

P.S. I still wish I could afford the helicopter joints I used once - on a money-no-object build when I was younger and dumber I used a couple of these and OMG they were wonderful. Not sure what they're like internally, but they seem to have zero play in them.

https://www.pegasusautoracing.com/productselection.asp?Product=1490

150863

[sread]

It has been a while since I dealt with mine so I had to go out and look at it again to refresh my memory. You really can't adjust it with the rack in place. Look at the rack and there is a cap on the bottom with a hex head on it - probably has a paint mark on it. Well, that cap is actually 2 pieces - the large outer portion is the jam nut and the center with the smaller hex head is the adjuster. Underneath the adjuster is a spring. When you loosen the outer jam nut, you can then turn in the adjuster to compress the spring - essentially compressing it to the point of coil bind. Then , back off the adjuster 1/8 to 1/4 turn or so and then tighten the jam nut to hold it there. When you take it apart it is very easy to see how it all works.
The only reason I know all this is because mine was extremely loose - I'm talking made my heart skip a beat during go -karting type loose. I had to take it apart to see what was going on. Mine was so bad it actually caused some abnormal wear to some of the teeth on the pinion.
There are many videos on youtube and threads on various car forums showing how it works also. While they aren't exactly similar, they all work pretty much the same.
And the truth is, the whole rack is a very light duty piece. Really was probably never intended to control tires the size that most guys run. I think the only reason it works as well as it does is because the car is so light. Seriously, with the weight on the wheels, turn the steering wheel back and forth and watch how much the inner tie rods deflect before moving the front wheels.
I read somewhere that Tim Whitaker once made some type of support bushings for the inner tie rods to help with the issue but haven't gotten around to asking any more about it.

[cob427sc]

I have experienced several of the set screws loosening up even with Loctite and extra torque on the screws, especially the one at the rack spline. did them all again and finally tack welded the last joint at the spline. Now I have less than the 1/2" wiggle at the wheel.

[RoadRacer]

Yep, tightening up all grub screws made a huge difference. Over an inch better at the wheel - about 1/2" now - that's huge at 100mph on an uneven highway. Felt much more stable.

Never touched the rack in the end. Now that the car is built, I am tempted to see how the steering can be simplified, given that I'm not personally needing a generic solution that copes with coyotes etc. Gonna play with some round tube one weekend and see what can be done in a straight line, lose a joint or two...

[33fromSD]

Yep, tightening up all grub screws made a huge difference. Over an inch better at the wheel - about 1/2" now - that's huge at 100mph on an uneven highway. Felt much more stable.

Never touched the rack in the end. Now that the car is built, I am tempted to see how the steering can be simplified, given that I'm not personally needing a generic solution that copes with coyotes etc. Gonna play with some round tube one weekend and see what can be done in a straight line, lose a joint or two...

Probably sounds crazy, but I have used JBweld as a thread locker in the past and it worked really well. I had a go-Kart I built for my son where the set screw on the drive pulley on the axle kept loosening up no matter how many times I used thread locker so figuring I had nothing to lose I used JBWeld and I never had to touch it again for the next year and a half when we sold it.

Jim