Jump to content
SAU Community

Recommended Posts

Hi guys,

At the last DECA I was giving the car a workout and found that the steering developed an intermittent dead spot in the centre. I had the passenger grab the wheel at one stage to prove I wasn't going crazy.

The car is an S13, CA, and I'd assume it's the original rack, it certainly doesn't look reco'd. I'm assuming rack as the tie rod ends looked fine, no bends, threads are good, no free play that I can easily get to happen up on stands. Rack mounts and bushes "look" OK to me but I'm no steering specialist. I topped up the power steering reservoir and thought it got better but then it came back, it seem to be when loading the car up hard side to side on the skid pan, which to me implied a hydraulic issue in the rack. The boots on the end of the rack aren't filled with fluid so I'd say the seals at the end of the rack are good, no leaks that I can see.

At it's worst there's probably a good 20-25 degrees dead space in each direction from centre.

I had 235 semi's on it at the time, -2.5 deg camber. Can't recall toe/castor settings right now.

Thoughts?

you need to determine where the freeplay is exactly. jack it up and get some one to turn the wheel in the freeplay back and forth and check everything,

what colour is the powersteer fluid? is it burnt?

It's on stands at the moment and I'll be doing that but when it was intermittent and seemed relative to lateral load on the car durnig cornering.

Fluid is standard colour, didn't look any different to what came out of the bottle when I topped it up and didn't smell burnt.

I'll be getting under it in the next few days.

OK here's what I found.

Car up on stands, me lying on my bak with the leadlight, GF turning the wheel.

Mechanically I can't see any free play, I had the GF do fast and slow turns full lock in both directions with and without me providing enough resistence on the wheels to stop her being able to turn the wheel in the cabin.

I also had her hold the wheel hard while I tried to make each wheel turn, no freeplay there.

What I did find is that one rack boot has a split in it and inside I can see brown grease. Without cmoparing to the other one I'm not sure if it should be that colour or not. If it shouldn't be covered in crud then I suspect that when the rack has a lot of pressure on it there may be fluid getting past the outer seal and into the boot, however the boot didn't show signs of large amounts of fluid - maybe early days for the leak.

I also noted that the inner part of the tie rod where it joins the rack has been bent back, I'd say from hitting the rack on full lock turns too hard.

I also note that the outer tie rod ends/pins that connect to the wheel hub assembly have split boots on both sides. I'm a bit vague on terminology, sorry.

Thougths? Mechanically it looks and feels ok. A mate was telling me there's a valve where the steering column knuckle joins the top of the rack and they are common failure points just for something extra to consider.

Thanks so far guys :D

A bent rack end will cause that, as it spins around it can play havok, but unlikey due to your diagnosis.

If you don't know how to diagnose problems its hard to rule anything out.

There are only a few links in the steering (5 if you count the rack bushes)

Jack it up, grab the wheel at 3 and 9 o clock. Keep steering the tyre back and forth by hand, If you feel any freeplay, your getting somewhere. Get a mate to do the same while you watch closley at each steering part to see whats got free play.

To me it sounds like the rack is stuffed, Ive never heard of the gears loosing a tooth, but it might be possible.

Could also be a caster rod bush/bearing gone, it might be binding the steering.

To test your rack bushes put it on the ground, get 5 fat mates to sit in the engine bay, then you get under the car and watch the rack while your girlfriend steers left to right throughout its whole range.

5mm of movement is normal, any more or abnormal movement is a bad sign, as under load with semis the problem compunds.

Really its impossible to diagnose over the internet.

This leads me to believe the outer seal in the rack is weeping under pressure? I assume this requires a rebuild?

Bad side

post-23873-1283656656_thumb.jpg

Good side

post-23873-1283656694_thumb.jpg

Edited by ActionDan

also, check the drivers side rack bush. it is usually covered in oil and perished. with the car on the ground jiggle the steering wheel. you will be able to see the rack move side to side if it is worn.. this can feel like freeplay when driving.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Have a look at that (shitty) pic I posted. You can see AN -4 braided line coming to a -4 to 1/8 BSPT adapter, into a 1/8 BSPT T piece. The Haltech pressure sender is screwed into the long arm of the sender and factory sender (pre your pic) into the T side. You can also see the cable tie holding the whole contraption in place. Is it better than mounting the sender direct to your engine fitting......yes because it removes that vibration as the engine revs out 50 times every lap and that factory sender is pretty big. Is it necessary for you......well I've got no idea, I just don't like something important failing twice so over-engineer it to the moon!
    • Yup. You can get creative and make a sort of "bracket" with cable ties. Put 2 around the sender with a third passing underneath them strapped down against the sender. Then that third one is able to be passed through some hole at right angles to the orientation of the sender. Or some variation on the theme. Yes.... ummm, with caveats? I mean, the sender is BSP and you would likely have AN stuff on the hose, so yes, there would be the adapter you mention. But the block end will either be 1/8 NPT if that thread is still OK in there, or you can drill and tap it out to 1/4 BSP or NPT and use appropriate adapter there. As it stands, your mention of 1/8 BSPT male seems... wrong for the 1/8 NPT female it has to go into. The hose will be better, because even with the bush, the mass of the sender will be "hanging" off a hard threaded connection and will add some stress/strain to that. It might fail in the future. The hose eliminates almost all such risk - but adds in several more threaded connections to leak from! It really should be tapered, but it looks very long in that photo with no taper visible. If you have it in hand you should be able to see if it tapered or not. There technically is no possibility of a mechanical seal with a parallel male in a parallel female, so it is hard to believe that it is parallel male, but weirder things have happened. Maybe it's meant to seat on some surface when screwed in on the original installation? Anyway, at that thread size, parallel in parallel, with tape and goop, will seal just fine.
    • How do you propose I cable tie this: To something securely? Is it really just a case of finding a couple of holes and ziptying it there so it never goes flying or starts dangling around, more or less? Then run a 1/8 BSP Female to [hose adapter of choice?/AN?] and then the opposing fitting at the bush-into-oil-block end? being the hose-into-realistically likely a 1/8 BSPT male) Is this going to provide any real benefit over using a stainless/steel 1/4 to 1/8 BSPT reducing bush? I am making the assumption the OEM sender is BSPT not BSPP/BSP
    • I fashioned a ramp out of a couple of pieces of 140x35 lumber, to get the bumper up slightly, and then one of these is what I use
    • I wouldn't worry about dissimilar metal corrosion, should you just buy/make a steel replacement. There will be thread tape and sealant compound between the metals. The few little spots where they touch each other will be deep inside the joint, unable to get wet. And the alloy block is much much larger than a small steel fitting, so there is plenty of "sacrificial" capacity there. Any bush you put in there will be dissimilar anyway. Either steel or brass. Maybe stainless. All of them are different to the other parts in the chain. But what I said above still applies.
×
×
  • Create New...