Centro C4.1 pulling to the left under acceleration

[cornishboy176]

I am wondering if anybody can help me please,

Just got a Centro and everytime I put the power down it wants to shoot off to the left,I am running on grass,it might just be me but it just doesn't seem right

Thanks

[neallewis]

Chassis tweek possibly. Is the chassis bent?

[NeilRalph77]

Is it one you've built or bought? You may have a slightly tight bearing on one side either diff outdrive or hub bearing this will cause drag or binding and allow the opposing wheel to spin up quicker. If its going left i would suggest a bearing on that side as the right wheel will be trying to pivot round it. I pressume you keep your car reasonable and it's not just a little twine wrapped up somewhere or bad tracking?

[Burty248]

Best way to find out is to open it up and have a look. like Neil said could just be something simple that is causing drag.

[cornishboy176]

I bought it second hand and so far fitted nearly all new parts on it got new outdrives coming as the one on the right is chewed up badly so it might even be that,we will see?

[adey]

If it was mine I would rebuild the entire car checking that nothing is bent, has excessive play or wear and put the chassis on a flat surface to check it. I had a similar issue with a car and it turned out to be worn driveshaft.

[cornishboy176]

After closer inspection we found that also there is alot of sideways play in the diff which will need shimming up to eliminate that,I have stripped most o it down and rebuilt it just mainly the drivetrain to go thru now,I think it would have been cheaper to buy a new kit!!

Oh well never mind,you lives and learn!!!!

[steveproracing]

Check the shocks are the same length side to side.
Half a mm out on 1 shock will cause the problem you describe.

[Chrislong]

What Steve says above is important.
Also, if you lift the car so shocks are at full travel, just as the wheels leave your bench the car should not rock corner to corner.

If it does, first measure the shocks off the car - they need to match, wind in the shock bottoms to achieve this. If they match and the car still rocks then check - bent shock mount screws, twisted chassis, bent hinge pins.

Next, also important (all of this is important), are the shock springs and preload is all perfectly equal, also the rebound too. If your springs are old - change them, they do degrade. If unsure how to check this - buy the Losi shock tool, its worth having defo.

if all the above is equal, and it still does it. Tighten your diff a tad and try it, and beyond that your looking at checking the corner weights and weight balance.... and that is getting deep into fine detail (this is what wins races afterall!)

[Gaz_Stanton]

Originally Posted by cornishboy176

got new outdrives coming as the one on the right is chewed up badly so it might even be that

Highly likely if it's just one side very worn. Binding up the suspension one side under acceleration could cause issue described. Get this sorted before going into too fine tuning.

[neallewis]

Is it worn on the cup that the dogbone sits in, or the bearing face? has the outdrive bearing been ceased and the outdrive been turning in the bearing seat?
As Ralphy mentioned, this would cause problems.

I had a gummed up outdrive bearing recently. It ran straight, but would spin out and donut on some loose corners when trying to get the power down.
But I also had a diff and tranny full of black gunk, which I know wasn't helping as the diff felt crud.

Have you checked your chassis for straightness on some glass?

[cornishboy176]

Right I have got some ideas,gonna sit down and have a look tonight,thanks everyone

[zoaman]

hi there i had this problem the other day as i change the rear spring. when i changed them i thought i had 2 pairs of silvers.but it turn out to be a pair of silver and a pair of greys.it wasnt until i looked on the net and found you can have grays as well.upon inspection i had 1 of each on the car.very simple thing but very hard to see the difference.got a post on here about it.

[hit5005]

Cheak wheel bearings if thay seizing that will do it

[cornishboy176]

All sorted now,after changing diff outdrives which were worn where the dogbone fits and where the bearing sits,I rebuilt the diff and there was 3 of the Thrust bearings missing,and the grease in the gearbox was non existent,i have also fitted new springs fr and rr,new hinge pins all round and all new fr and rr Arms,C hubs (25 degree),new steering blocks,new hub carriers,cleaned all bearings and fitted new bearings in the rear hubs,and also fitted the Chassis Braces,so it is basically a new car now!!,tried it out yesterday and it is so easy to drive and accelerates away straight,i am really pleased with it so far,all that needs doing now is to race it but with the sh**e weather we are having i just got to wait

Thanks for all your help lads much appreciated

Iain

[Chrislong]

Where's the 'like' button.
Good work!