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Rs250 cup stability issues

JohnVerv

Member
Hi guys, can anyone recommend a starting point for common frontend issues on the rs250?
Still under warranty but the Cotech has been unable to find any major/obvious issues...

History:
Originally had a bolt snap on the front engine mount (I think) which is apparently common. Bolt was replaced, but the vehicle has degraded ever since. Now it may be related or not, can't say for sure.
Have had both lower control arms replaced along with shock mounts, and gearbox + torque link and cambelt side engine mounts (only the top one left to do I guess)

Explanation of issue:
So the car does some strange things:
-when pulling off, there is a noticeable lunge as the car rocks, especially once clutch bites and the engine torques, have almost eaten the steering wheel afew times.
-when pulling off at anything but dead centre, there is a jump laterally, especially pulling off to the right
-when doing a circle at low speeds, the car seems to jump/alternate between the left and right wheels, not constant/stable like it was originally
-noticeable torque steer on anything but straight line, slightly uneven roads send the car on random direction changes
-leaving the car to drive in 1st gear off throttle previously was rock solid, car now lunges as soon as the slightest change of throttle used (increased or decreased throttle); noticeable lunges when cruise control is used on highways as it adjusts throttle
-on an uphill as the weight is biased to the rear the frontend is very erratic, the smallest steering inputs while accelerating send the car sideways

Other info:
-So the car is a cup, hence it has the LSD, I guess play in the front axes will be EXPONENTIALLY more visible as the diff tries to steer the car in random directions.
-being an RS, we have the perfohub, so potentially its not the steering axis at fault but rather the other axis (what to call it?!?)
-hub carrier has all the anti rotation black magic stuff on it, maybe something there broken/missing/bent/loose
-I believe there are some serviceable bushes in the rack which are known to degrade?

Car is now just over 100,000km but issues started at around 60,000km...
Yes maybe been too patient with the techs...

So if anybody has any idea where to look, I am concerned we are making things worse with unnecessary trial and error part swaps.

Thank you all in advance for any suggestions!
 
Maybe check your other mounts, particularly on gearbox side. Start with a good visual examination. Get a socket or spanner on all the mount bolts and check they havent snapped too. Sometimes all can look well, but a bolt thats sheered inside a mount is not obvious until youve given it a tug.

Other i would try, bonnet up and get someone to engage clutch and look for any excess movement anywhere
 
The jumping when turning immediately suggests a knackered driveshaft to me, or worst case scenario diff fault. Possibly damaged when mount failed & engine dropped? Check all the engine mounts again thoroughly.
 
That was my first thought but after reading it all it seems very extreme for a shaft issue.
I'm not versed on the perfohub though so i'm going to wait for @Red21 to show up an unleash that encyclopedic brain of his :D
I can suggest anything & every thing but with out seeing and experiencing the actual issues at first hand it would be a blind shot as the cause.
 
Thanks all

No collisions/kerbs this far...
No noises as such, no cv clucking, no noises when doing circles etc
There is a vibration when idling, revving which was there after the initial bolt snapped, this is why the other three mounts incl gearbox were replaced under warranty as part of Renault's troubleshooting, but still there.
I also suspect a mount, but Renault says they all look good...

Alignments been done numerous times.
I did have a gearbox seal replaced as there was some leakage, could this be an indication of a gearbox/driveshaft/diff issue?
Vibration, stability, traction, all could be affected by drive train issue?
 
I'll have to book it in again and get them to check all the mounts, I've almost collected the barrier twice...

What would you say is a good estimate on damper replacement mileage?

Sent from my GT-I9300 using Tapatalk
 
Most damper manufacturers say that most dampers are past their best at around 40000 miles mark (60000Km) and sooner if worked hard.
Derogation of dampers is a progressive so drivers tend to get use to them up to the point of failure then they curse.
 
Indeed, I have been told some rs250 cups are on 160000km with orig front dampers, but have changed rears, other guys say the rs250 'hides' it very well if a damper is buggered as you can't really inspect them...
So I'm stuck in trial and error, and possibly trial and pay...
I'd expect the dampers on a tracked car tho, not a daily...

Thanks for the input in any case guys
 
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