Steering Judder At Slow Speeds

[Guest mrtcotton]

Guys,

 

I have a non-standard setup so may not be easy to identify.

 

Firstly, i have just rebuilt/serviced the Diff with new plates and cross pins. I have new wheel bearings, new wishbones & bushes.

I have just rebuilt & serviced my Bilstein Coilovers.

I also have new driveshafts.

I have original PAS which has NOT been rebuilt - car has done 98k miles.

 

The problem : -

 

At manoeuvring slow speeds, my steering clonks very loudly and aggressively. It almost feels like someone is whacking the wheels with a sledgehammer whilst i am turning it is that bad. It can be heard from inside and out.

I believe that from outside, you can see the wheels clonking about - almost as though the diff is unlocking itself.

 

However, at speed and whilst competing/driving hard, the steering and diff are perfect together.

The problem was there before hence needed to replace the cross pins in the diff, but now it is a LOT worse.

 

I suspect there is a weakness in the PAS somewhere personally, and that the tight diff has exaggerated the problem.

What do you guys think? Could it be the ram cylinder, could the pump be worn and thus weak at slow speeds??

 

Thanks,

Justin.

[James_R 3]

Inner CV's under the load do that, once the diff's broken in it improves, grippy tyres too??

[Daz_C 8 1 Cars]

I would guess its the Diff mate. I have no idea why but have read on here of people with this issue. I know 16v205 and he has/had this with his, I also have a friend with a MkII Escort and the same there.

Not much help i know but I think I'm pointing you in the right direction

[Guest mrtcotton]

Inner CV's under the load do that, once the diff's broken in it improves, grippy tyres too??

 

Yes. But seriously can't be right. I'm aware these plate diffs are aggressive, but it really makes you wince when it does it.

I have only replaced the long driveshaft, not the short one.

 

I reckon it damaged the cross pins in the diff and caused premature wear on the ramp reaction ring. I showed it to the guy at Tran-x and he said he had never seen damage/wear like it before.

 

I have all the pics if needed.

[James_R 3]

Did you do the slow figures of 8 with the diff to break in the plates? I had that when I first got mine, and it sounded pretty bad, but just ignoreed it and after the irst trackday it was silent, unless I'm on full full lock when it does it a small amount now.

 

On slicks its worse though.

 

I also changed both shafts, just small amounts of lock caused what you described till I changed both, I did the long one and it made a small difference, then a short shaft then it was a million times better.

[Guest mrtcotton]

Did you do the slow figures of 8 with the diff to break in the plates? I had that when I first got mine, and it sounded pretty bad, but just ignoreed it and after the irst trackday it was silent, unless I'm on full full lock when it does it a small amount now.

 

On slicks its worse though.

 

I also changed both shafts, just small amounts of lock caused what you described till I changed both, I did the long one and it made a small difference, then a short shaft then it was a million times better.

 

 

Didn't do the figures of 8 but i have just competed in the Horiba Rally last saturday. 55 competitive miles. Apart from the slow speed turns around the bales it was fine.

The horrendousness appeared just when i stopped and made my wasy back to service park. The 3 point turns in the service park were practically unbearable.

 

So you think its the short driveshaft possibly?

[James_R 3]

That sounds familiar, I did a full day at donnington, circa 160miles of track abuse, I'd start with the short shaft yeah, if you feel any play in it then it will be no good, get a GKN new one rather than a recon. the inner CV has to feel "tight" no play in it.

 

I still wouldn't do 3pt turns by choice, it's just the diff doing its job as the wheel speed varience is enough to set it off, if it stops doing it to an extent then it's not working anymore

[Guest mrtcotton]

Thanks, where do you go for GKN shafts?

 

I was just going to disconnect and drain the PAS system and go around the block to see if it improved.

[Chris H 10]

This sounds like a fairly normal noise from a newly rebult tran-x, it will be getting worse during a rally as it gets all hot and bothered.

What oil are you using? I allways use total BV 75/80 and it seems fine and works better than so called competition oils in my opinion. If it feels fine at speed i'd say its ok...if its really severe...maybe drop the diff out and check there is no contamination between the plates....i had this once and it was very bad judder.....it was caused by the diff touching the housing and ally particles sticking between the plates increasing the preeload

 

GSF do the GKN shafts...but make sure you particularily ask for the gkn ones or you may be given cheaper, lower quality shafts.....it took me a couple of attempts to get a pair recently...in the end my branch faxed head office to make a special request for a pair of GKN shafts to be sent to them.

[Guest mrtcotton]

This sounds like a fairly normal noise from a newly rebult tran-x, it will be getting worse during a rally as it gets all hot and bothered.

What oil are you using? I allways use total BV 75/80 and it seems fine and works better than so called competition oils in my opinion.

 

I use the Millers hi-synth 79/90 i think it is. As recommended by Dan at Tran-x.

So you wouldnt be concerned with it then?

Its not just a noise, you can FEEL it across the whole car. I'd love someone to drive it and tell me its ok, then i can stop going on about it and move on

[Chris H 10]

I use the Millers hi-synth 79/90 i think it is. As recommended by Dan at Tran-x.

So you wouldnt be concerned with it then?

Its not just a noise, you can FEEL it across the whole car. I'd love someone to drive it and tell me its ok, then i can stop going on about it and move on

 

Well if you want to pop down to daventry on sunday i'll give it a spin for you...i know i'm not exactly local...but the offer is there.

 

I was using the millers 75/90 and find the Total BV seems to give better shifting when hot.

 

I know what you mean about the shudder in the diff comming through the steering. Do you know what setting your diff is on? Heavyweight full friction surfaces or lightweight, paired friction surfaces?

 

I've just got used to my diff making this noise and judder.... i run mine on the heavyweight setting and its fine when driving properly on the stages and locks up when you break a shaft and has kept me in 2 rallies but allowing me to finish the stage on one shaft.

[SPGTi 2]

Have a search on the British Rally forum for Trans-x in the technical section. There was quite a long thread about them started by a guy based in Aberystwth who used to work for trans -x. My mate went and bought a gearbox etc off him and said he was very helpful and knowledgeable. He might be able to help out.

If not, from your location I presume you are a member of WSSCC. Go and see Mark Gamble at Jam Motorsport (also WSSCC member) in Wombourne, he should be able to help you out.

 

Steve

[philfingers 5]

Sorry Justin I should have realised. if you go back far enough (about 5yrs!) in the threads of various forums you'll find me saying the same thing! I use Comma Sx semi 75 oil. Car was fine when cold and then when it gets warm snatches and clunks like a B&*^&**((! Even 5 miles of gentle road driving would warm it up enough. Lost count of the times people have looked around in the street to see what the noise is, the folks who told me 'you're CVs away mate'.

I too went down the route of stripping it in case anythign was wrong, nothing. Mine was a new unit too.

Then a few folk said 'oh they all do that'

You're welcome to drop it down to Halesowen or I may be able to drop by on Sunday eve on the way back from wales and you can take me a run up the road in it. Sounds just like mine tho! Mine was on lightweight 45/45 settings

The guy in wales (whose name escapes me) had just moved there and was really helpful too.

I've got some stuff on the tranx, I'll mail it to you

[Guest mrtcotton]

I've got it on the less aggressive 30/60 ramp as advised by Dan at Tran-X.

I am running a high preload, individual plates (not paired).

 

Think its the 65/70 setting.

 

So, there may be nothing wrong at all then as everyone keeps telling me.

It's the previous damage that tells me something isn't right with my setup.

See the attached pics below.

 

 

 

Obviously, the cross pins have been replaced with new.

I reckon its the clunking/lock-on lock-off that has caused this.

Although, the diff has done about 4 years service i reckon before ever being stripped.

[philfingers 5]

possibly material incompatability or lubrication issue?

There was talk on BritishRally of Tran X having quality control problems but I shouldn't think this is an issue with yours as you've had it so long. Makes me wonder if I should whip mine out of the old 309 box. It's done about 10000 miles and 10-12 events. the one in the 205 was in it when I got it so haven't checked that one out yet. Should stop collecting engines and boxes really!

 

Phil

[Guest mrtcotton]

possibly material incompatability or lubrication issue?

There was talk on BritishRally of Tran X having quality control problems but I shouldn't think this is an issue with yours as you've had it so long. Makes me wonder if I should whip mine out of the old 309 box. It's done about 10000 miles and 10-12 events. the one in the 205 was in it when I got it so haven't checked that one out yet. Should stop collecting engines and boxes really!

 

Phil

 

If you need a buyer for one, let me know.

Thanks for the email btw.

[philfingers 5]

I tend to collect stuff! But looking to sell the 8v engine. Gp A cam, LAD head, finished mull 61st and 63rd so some reasonable results for an 8v on std injection

Offer stands if you want me to have a look at your car on Sunday

 

Phil

[Alastairh 47]

A friends diff did this in his 306 which i experienced as a passenger whilst out at the ring last year. He had rebuilt it not long before, and i know what you mean, it was quite anoying.

 

But my TranX is apparently 6 years old and done a fair bit of use and never done it, so it seems like it needs a few miles on it

[Guest mrtcotton]

I'm going to give it all a check over this weekend.

 

I think i'll replace the short driveshaft now, just to even them up as it appears that any play/wear in the shafts would be exaggerated by a nice new tight diff.

I do also think it probably needs more miles.

 

Its done around 180 now at the most.

Must admit though, that when you do press on with it, i love it!

[tony perks 1]

My 205 rally car does the same, but only when hot on a rally usually when turning in or out of our service "bay" i too thought shafts but no they are fine i run 45/45 fully loaded and yes you really fell it though the whole car and it sounds terrible.

[Guest mrtcotton]

So i guess i should get used to it then.

I havent even so much as got the car out of the garage yet, i fancied a week off.

 

I will give everything a check-over, but i think if all is ok, i will just live with it and put some miles on it.

 

Thanks everyone & thanks for the offer Phil!

 

Justin.