| Author |
Message |
Phil Hughes (Ferrarifixer)
Member
Username: Ferrarifixer
Post Number: 252
Registered: 7-2003
| | Posted on Tuesday, October 28, 2003 - 3:11 am: | |
Check tyre pressures and sizes(diameter) and mounting for correct direction of rotation/assymetric on each side.
Check wheel alignment. Total toe not too important, but ensure rear is following front with as close to zero thrust angle as possible (under 1mm or about 15min'). Check castor is symmetrical.
Also check all four shock stepper motors are working properly and connected to the shocks correctly (they can jump off if the spring clip is poorly fitted).
Make sure handbrake or a caliper is not binding one side, or a wheel bearing tight/slack.
Jack rear of car up and firmly apply handbrake. Then select 1st gear and load the drive train slightly on and off to observe any suspension movement from slack joints etc.
Check for broken road springs. |
Stanley DiGuiseppi (Standig)
Junior Member
Username: Standig
Post Number: 107
Registered: 5-2002
| | Posted on Monday, October 27, 2003 - 6:27 pm: | |
What you are describing is torque steer. It is normally caused by uneven half shafts.
Badly worn or mismatched tires I found can cause a similar problem.
Make sure alignment is in spec. Make sure tires match and are not badly worn.
I had a similar problem with my 87 TR. New rear matching tires solved the problem.
Always start with basics.
I am assuming your car is stock and not modified.
I have a 90 348 ts and replaced rear tires that matched the fronts which were original. No pull. I later replace the fronts. No pull.
|
Danny R. West (Dan_west348ts)
Junior Member
Username: Dan_west348ts
Post Number: 225
Registered: 3-2001
| | Posted on Monday, October 27, 2003 - 2:55 pm: | |
This sounds like torque steer. Rotate the rear tires and see if the pull changes. I had a simular occurance on my 348ts. I am using P-ZEROS. It is a problem caused by mismatched tires or tires that are not close enough in circumference (size).
Dan |
Steve Holden (Sf348s)
New member
Username: Sf348s
Post Number: 6
Registered: 10-2003
| | Posted on Monday, October 27, 2003 - 1:41 pm: | |
Thanks guys , i'm back to UK in 3 weeks (just in time for the icey roads!)i'll only have 2 weeks to sort it so at least i have some where to start, hopefully Tal has saved me 18 months! |
James I. Movich (77_308gt4)
Junior Member
Username: 77_308gt4
Post Number: 57
Registered: 2-2003
| | Posted on Monday, October 27, 2003 - 11:33 am: | |
Jeff,
good advice. i happen to be replacing with exact same tire, so all tread will be identical all the way around. |
Tal Withington (Tal)
New member
Username: Tal
Post Number: 10
Registered: 3-2003
| | Posted on Monday, October 27, 2003 - 11:17 am: | |
Hi Steve,
I had a similar problem but my car pulled to the left. I had a full four wheel alignment carried out by a dealer. This made no difference. They then said change the tyres. So I changed all four, this made no difference. They then said that I had a bent shock absorber. They changed it then put it back as it was not bent. They then said it must be a wish bone, but could not tell me which one. I then let a friend of a friend look at it who used to work for Jordan F1 team. He took it out checked tyre pressures then swapped the wheels over from side to side. The car then pulled to the right. he then checked the wheels and two of the wheels were slightly out of true. I swapped these and now the car travels straight.
This was all over about 18 months.
Good luck as this becomes very frustrating |
Jeff B. (Miltonian)
Member
Username: Miltonian
Post Number: 656
Registered: 12-2002
| | Posted on Monday, October 27, 2003 - 10:49 am: | |
James: While I can't say for certain that my problem was that I replaced only the rear tires, I CAN say for certain that the problem was NOT with the car, it was with the tires. Either defective new rear tires, or the fact that I had not replaced the fronts with new matching tread tires. From this experience, I would now strongly recommend that the tires be replaced only in sets of four. If the car was handling properly before the tires were replaced, and the wear pattern was normal, and the pressures are set correctly, chances are that the suspension/steering/alignment is fine. |
Fred (I Luv 4REs) (Iluv4res)
Member
Username: Iluv4res
Post Number: 583
Registered: 8-2002
| | Posted on Monday, October 27, 2003 - 8:38 am: | |
Check the suspension. |
James I. Movich (77_308gt4)
Junior Member
Username: 77_308gt4
Post Number: 56
Registered: 2-2003
| | Posted on Monday, October 27, 2003 - 7:25 am: | |
Jeff, your old thread states that you could not be sure that the problem was related to replacing only the rears.
i must replace the rears on my 348 this week. the tires are on order. i had a split in the sidewall on one and so am replacing both. they are only ~20% worn. shame.
i will let you guys know how this goes, and because of this, i will be alert to changes.
|
Jeff B. (Miltonian)
Member
Username: Miltonian
Post Number: 653
Registered: 12-2002
| | Posted on Sunday, October 26, 2003 - 11:34 pm: | |
Steve: I learned the hard way that it is NOT a good idea to replace just the two rear tires on a 348. See
http://www.ferrarichat.com/discus/messages/112/315127.html |
Rob Schermerhorn (Rexrcr)
Member
Username: Rexrcr
Post Number: 856
Registered: 11-2002
| | Posted on Sunday, October 26, 2003 - 6:32 pm: | |
Steve, post the old thread. I think I responded, or did to a similar post. |
Ernie (Ernie)
Member
Username: Ernie
Post Number: 868
Registered: 11-2001
| | Posted on Sunday, October 26, 2003 - 1:30 pm: | |
Alignment, alignment, alignment. Get it done the same day that you put new tires on the car.
I'm just guessing but have you had the ride height checked out. It possibly could be that the adjustable coil overs aren't all even. Kind of like when you sit in a chair with one leg that is not level and it tips to one side. So I would think that if the cars suspension isn't set right that it could be causing you car to pull. Just a guess. |
Steve Holden (Sf348s)
New member
Username: Sf348s
Post Number: 5
Registered: 10-2003
| | Posted on Sunday, October 26, 2003 - 10:43 am: | |
For any of you guys with a great memory, i had a problem i posted in february about my 348 (lhd)pulling to the right under acceleration & pulled back into line again when i let off, i changed the rear tyres as they had uneven wear, but it's still happening.i remember someone had a similar problem with Mondial & was due to visit a dealer but that was as far as i got , anybody have any ideas? |