Hard to select 4th from 5th
Discussion
Got the new R400 about a month ago, and it was always a bit notchy going from 5th to 4th (6 speed box).
Did a trackday at donington yesterday, and towards the end of the day it got very hard to select 4th.
First thought is to check the clutch pedal stop isn't too high.
Any other thoughts or tips?
Did a trackday at donington yesterday, and towards the end of the day it got very hard to select 4th.
First thought is to check the clutch pedal stop isn't too high.
Any other thoughts or tips?
Forth gear usually isn't too bad. I'd check the clutch as you say and change the oil. If it is not using Reline MTL already, then try that. Also worth checking the gear stick spherical bearing is not stiffening up. But if all that fails, your probably looking at an overhaul.
[edit: if it is a new car, then back to Caterham. my first gearbox didn't last a 100 miles]
[edit: if it is a new car, then back to Caterham. my first gearbox didn't last a 100 miles]
Edited by DCL on Saturday 6th June 14:26
Edited by DCL on Saturday 6th June 15:11
I had the same thing with my new 6 speed last year, It was quite bad going up and down through 4th gear.
It did work for a short while until it got worse again, Instead of shipping it back to the UK I decided to strip it myself and have a look.
So off came the rear tail housing that 3rd and 4th gears are in, the problem was the lack of clearance between the synchro and the 4th gear cone it engages on when changing gear.
Mine had been binding and worn grooves in the cone from the synchro rubbing on it all the time, then with the grooves getting deeper the synchro failed to grab the cone properly when changing gear.
The clearance was increased by grinding the cone about 0,15mm and fitting new Caterham synchros, its been back in for 8 months now and works great.
I did send several emails with pictures to Caterham and was promised a new 4th gear cone and synchro from the SA Caterham importer for my trouble.
Time wise it took 3 days, out and stripped on a Sunday afternoon ground and reassembled on Monday evening then back in the car on Tuesday evening.
I hope this helps and Caterham should know what to do with your box, all the parts are CNC machined so I am sure mine is not the only one that would have had the problem and I recall there was someone in the USA with the same problem last year.
Chris.
It did work for a short while until it got worse again, Instead of shipping it back to the UK I decided to strip it myself and have a look.
So off came the rear tail housing that 3rd and 4th gears are in, the problem was the lack of clearance between the synchro and the 4th gear cone it engages on when changing gear.
Mine had been binding and worn grooves in the cone from the synchro rubbing on it all the time, then with the grooves getting deeper the synchro failed to grab the cone properly when changing gear.
The clearance was increased by grinding the cone about 0,15mm and fitting new Caterham synchros, its been back in for 8 months now and works great.
I did send several emails with pictures to Caterham and was promised a new 4th gear cone and synchro from the SA Caterham importer for my trouble.
Time wise it took 3 days, out and stripped on a Sunday afternoon ground and reassembled on Monday evening then back in the car on Tuesday evening.
I hope this helps and Caterham should know what to do with your box, all the parts are CNC machined so I am sure mine is not the only one that would have had the problem and I recall there was someone in the USA with the same problem last year.
Chris.
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