slight amount of free play on rear suspension....any ideas?

[Buggybloke]

After a few handling problems,on my Blitz2, recently, I've replaced all of the swivel-joints, (front and rear, top and bottom), also the front rack and track rod ends, together with the rear rack(locked, and used as a suspension locator), and track rod ends, I've also replaced the o/s/f, and n/s/r wheel bearings...... but oddly I still have a little amount of free-play in the n/s/r wheel, as if the track rod end is u/s..... ie the wheel appears to rock slightly when I put my hands in quarter to 3 position (imagine wheel is a clock-face!), with wheel on ground there is approx 2.5mm movement, at edge of tyre, and with wheel jacked up, about 3-4mm. I can see the track rod moving, ever so slightly, with the hub pivoting along the axis formed by the top and bottom swivel joints,... but I don't understand why this should be, since all the parts are new, and where possible, they are shimmed correctly.
When test-driven, a very slight, almost undetectable amount of torque-steer can be felt, and again on braking/accelerating alternating.... which develops into a slight weave....I am racking my brains as to what the cause is.... does anyone have any ideas?

 

[Phaeton]

I've found there will always be a small amount of play as the standard Mini bushes are rubber, you can minimise this by using Poly bushes. The quality of track rod ends could be another issue, I've found that even brand new ones have some play. Another place to look could be the bearings either not tight enough or you can sometimes get play in the bearing to hub. You might also want to get the backend tracked, if you have slightly different toe angle across the wheels it can cause a nervous rear.

Alan...

 

[wurzell]

Suggest that you also check the two Steering Arm to Hub bolts, as these have a nasty habit of working themselves loose..
I have always used Cooper 'S' heavy duty Steering Arms, together with longer uprated heavy duty UNF bolts (preferably 12.9 grade),to fully utilise the depth of thread within the actual Hub casting, and drilled & wirelocked together the bolt heads.
You can also still use the original locktabs together with thread locking compound, and torque them up carefully to 45 ft/lbs.
Even then, sometimes they'll still work loose, the bigger the wheels & tyres you run, and the more grip you have, the easier they seem to come undone...
Certainly recommend checking regularly...

 

[Buggybloke]

thanks guys!.... on the 'Standard Mini rubber bushes', subject, ... I've already upgraded to the purple and black Minispares upgrade for the Tie-rod bushes, and the difference felt under hard braking is phenominal!..... I feel it's defineatly a track-rod type issue, and now it's been raised, I'll re-check the torque of the steering arm bolts as I replaced them and the hub and bearing on the offending wheel-station, in July this year, if it's not the bolts, then I'll try another track-rod end,.... and it can be said I do often drive it to it's limits of handling...(on tarmac!!! ). and on the harder compound Dunlop SP-3 Mud and Snow rear tyres, (at 6ply rating!), drifting seems to be the order of the day especially in the wet or the cold/icy conditions we are currently experiencing....in my neck of the woods.....

once again thanks guys, oh!,... anyone had much experience in using adjustable suspension bit? -bottom arms and tie rods? as mine are standard, and with my oversize wheel/tyre combination, (185/70/13), I'm starting to see pronounced wear on outer edges of front tyres, and the camber does appear to be a little 'positive', but I'm thinking it's the very soft rubber compound of the Kingpin Mud+Snow front tyres, that are accounting for the truly tenacious grip I have in cornering.....What would you say is the ideal camber angle for the fronts and rears? There's nothing mentioned in the Blitz2 Build Manual about camber, only Front Toe-in of 1.5 deg, and rear toe-out of 1.5 deg, it seems to handle well(-ish) like this, bends tighten predictably as you back-off the power, and widen, eventually into a nicely controllable drift if you power it into a suitable bend more,.... as for on smooth grass, wet or dry does amazing doughnut/figure of 8, effortlessly, all the way up to 3rd gear!!! ;D ;D

 

[Phaeton]

I have also considered getting rid of the track rods ends & replacing them with rose joints. Drilling out the arms to take a 1/2" bolt which you would then pass through the arm & rose joint but just got concerns that the rose joints would have enough free movement in the horizontal plane.

Or you could go with these my only concern with these are that it's the thread going through the arm & not a solid bolt.

Alan...

 

[Mini Mad Max]

One thing aboout rose joints though is they don't take very kindly to offroading. It is a good idea to put the most heaviest of duty ones you can get on with rubber boots to keep grit out and reducing wear. They are better on road and on track where there is less repetitive shock and load put on them. But as long as you maintain them and replace them once in a while i don't see why not
Max

 

[Phaeton]

Just to muddy the water Max, I was told not to put boots on, their reasoning was if you put boots on then the grit is held inside the boot to do damage to the rose joint, if you don't put a boot on then washing with water gets rid of all the grit so not damage to the joint. Not saying they were wrong or right just another take on it.

Alan...

 

[Buggybloke]

slightly wobbly nsr wheel,...-the ongoing saga! ???.... ok, this afternoon, I got a little assistance from onre of the MOT men from our works garage, and got him to look at the rear hub whilst i rocked the wheel..... after a few mins of wobbling it this way and that, he deduced that the free-play was between the steering arm and the hub! After I got it home I had another look at it, with the wheel out of the way, and sure enough there was about 1.5mm of 'looseness' caused by a fracture in the special tab washer, which links the 2 bolt heads together, so one bolt had worked slightly loose . I removed both bolts, checked the thread for damage, and refitted it all back together, this time with liquid threadlock, and large spring washers..... unfortuneately the Haynes 'bible' for Mini's does not mention any torque settings for these bolts :-\, so I called Minispares, for advice. The man said 'as tight as you can and use threadlock, don't worry, you won't strip the threads....', so I cautiously :'( tightened them with a torque wrench, until any movement was decreased to a level that was undetectable, due to the tyre flexing when I tested for movement, and arrived at a torque figure of 70-75 ft/lbs. With it all back together, I took it for a quick blast round the block, all the 'nervous' wet-weather skittishness has completely gone,.... HOORAY!... I'm gonna keep an eye on the bolts and get a new tab washer asap. ;D