A sideways RMC

stiffy · #1 (**permalink**) 08-07-2007, 06:21 PM

I need some assistance,,,,,,,,

My car has over the past 6 Months been behaving badly when I step on the gas. 1st is OK but halfway thru 2nd when the torque comes in, the car
snaps sideways (at about a 100k's). It has gradually gotten worse.

The shocks are new, LSD 3.54 Ratio, Sumotomo 315x17x35 ( 2 years old)
I have just replaced the trailing arm bush's (they were warn) with the Nolathane units, this is what most people thought the problem was. Well I finished the job last night, this mornings run to get the mail, same problem

any ideas ?????????????????????

SCARED STIFFY

stephen low · #2 (**permalink**) 08-07-2007, 07:05 PM

I thought that was your normal mode of travel, herr stiffness??

400TT · #3 (**permalink**) 08-07-2007, 07:17 PM

Have you checked the shock absorbers?

CHANMADD · #4 (**permalink**) 08-07-2007, 07:22 PM

Firstly,you have got to get the alignment right!!
You need at minimum 1 to 1.5 degrees of toe in on the back wheels.The rear hubs have a habit of wearing the fulcrum shafts just a little.When you jack the car up try to wiggle the wheel from front to back (like feeling a wheel bearing),if its got play its the fulcrum shaft (cheap to replace).Check the bolts on top of the diff,they may have come loose.Also I put track rods (radius arms) running backwards to solve the same problem,they can be made long enough so as not to effect the toe when travelling up and down.

Rebel1 · #5 (**permalink**) 08-07-2007, 07:50 PM

Stiffy, does it always snap the same way. ie.always snaps to the right or to the left or does it snap to both sides?

stiffy · #6 (**permalink**) 08-07-2007, 08:03 PM

400TT,

The 4 rear shocks are new ( 2 years old) 10k in total

Rebel1,

ALLWAYS the same way to the left (gutter side) I am getting use to it ( so to speak) BUT its still scary.

CHANNMAD,

I will check what you said tonight

STIFFY

Aussie Mike · #7 (**permalink**) 08-07-2007, 08:09 PM

Could the camber of the road be pulling it left or does it do it on a flat surface like the drag strip?

When the engine torques over it lifts the passengers front side of the vehicle and transfers weight to the drivers side rear tyre. Aussie Drag racers have been building left hand drive vehicles to take advantage of drivers weight to help preload the chassis. They often run more preload on the right rear spring or use a stiffer right rear spring. It'd be interesting to find out what your corner weights are.

Cheers

stiffy · #8 (**permalink**) 08-07-2007, 08:15 PM

Aussie,

Flat road, Drag Strip anywhere.....

The front of the car lifts as one, then it just moved sideways.....

STIFFY

justbetter · #9 (**permalink**) 08-07-2007, 08:59 PM

Mate i've told you before about that, stop picking up the FAT CHICKS, they really up set the balance of a Cobra, obviously your problem

richardferguson · #10 (**permalink**) 08-07-2007, 09:29 PM

How fat is FAT, Garrett? Would a tight little size 18 put me sideways?
Richard

Rebel1 · #11 (**permalink**) 08-07-2007, 09:53 PM

Check left hub pivot bearings as CHANMADD said. If you do normally have toe in then a worn left hub pivot bearing will toe out pointing both back wheels to the left.

Usually the left hub bearings fail first as that's the wheel you drop off the road more often.

Check lower control arm inner pivot bearings......not often they go because their is bugga all movement but lack of attention over time may cause one to fail.

Powerlok diff clutch pack gone on one side?

Just thinking out loud. Prolly something simple just gotta find it.

cheers

PCC · #12 (**permalink**) 08-07-2007, 10:59 PM

Stiff,

Mine pulled to the left at a similar speed especially on an uneven road (most annoying!).

Suspension / alignment was my first and second thoughts, but turned out to my tyres (Falken worn 50%). Partly gripping then as the torque came on the car wandered to the left (front end lifting - poor traction)

Now with the Toyos on the front it sticks like glue and total confidence has returned.

Maybe wrong, but worth trying someone elses front wheels to see

acecob · #13 (**permalink**) 08-08-2007, 03:16 AM

If it pulls sideways violently you'll find it's your diff letting go in one clutch pack, if your suspension was worn or had movement anywhere the car would steer croocked under heavy acceleration. the reason it turns violently simply is slippage in one of the clutch packs in the diff, a lots of guys also make the mistake of using oil additives (friction modifiers etc) which causes clutch packs to slip when they should be running straight lsd oil .

My car does the same occationally (nine inch) and it sure isn't the suspension.

thats my 2 cents worth anyway and lots of years of experience

iva bigan · #14 (**permalink**) 08-08-2007, 03:30 AM

Stiffy

Check that the lower link (dog bone) is not cracked where it has been shortened in length and welded back together.
This did happen to a friend of mine and was discovered early enough to avoid a major disaster. He had the same symptoms as yourself ,bar the premature ejaculation.
Good luck with your projects

stiffy · #15 (**permalink**) 08-08-2007, 05:18 PM

It could be the wheel bearings, the left wheel has some movement from 12 to 6 O'Clock but none from 9 to 3 O'Clock.
The right has movement everywhere

This could be the problem.......

I am off to Supercheap to get a bigger shifter (I will ask for an imperial one

)

Maybe I could ask JUSTBETTER for his tool kit!! thats right I modeled mine after his

STIFFY (no fat chicks) SMITH

BigBlockRob · #16 (**permalink**) 08-09-2007, 12:29 AM

hey stiff, how old is your RMC? and how many K's has it done?

stiffy · #17 (**permalink**) 08-09-2007, 03:54 AM

BIGBLOCKROB,

It was regestered in 1988, as you would know most of the parts would have been secondhand. I replaced the single spinner with a LSD about 2 years ago.

The bearings are a bit warn (especially the drivers side) i gave them a tighten tonight but they will have to be replaced next week.

STIFFY

BigBlockRob · #18 (**permalink**) 08-09-2007, 07:08 AM

yeah, thats an oldy, sounds like you should go over the entire thing and make sure its all good. the early RMC's had a few front end issues.

stiffy · #19 (**permalink**) 08-12-2007, 05:16 AM

Did some laps at Winton on Saturday, the car was better after the nip up, but they are still going to be replaced.

I took them apart today, I am no mechanic (the Vic club will testify to tha) and they look pretty sloppy.

STIFFY

Tony Cram · #20 (**permalink**) 08-12-2007, 06:05 AM

Rohan,

If you think the bearings need replacing make sure you get someone to reassemble them and check them. They will need to be shimmed up to the right preload or you will have similar problems. It may need some shims machined to the correct size to get the preload.

I would get your preload checked on the hub / bearing before you replace the bearings. They may still be OK.

If you cannot preload them then new bearings are probably needed. Get Don Stafford to have a look at them. He fixed mine a few months ago and they only needed some re shimming.

Cheers

TC