crunching gears

[BigCol]

My 7 is currently having its 1000 mile service at Caterham In Dartford.

 

I asked them in addition to look at the gearbox as often I crunch the change from 1st to 2nd and frequently it is awkward to get into 1st and/or reverse, requiring a double-declutch.

 

Whilst I didn't get a TADTS response, I was told "The technician was happy with its operation during road test. It may be technique and it may ease for you with use. If you should have continued problems we would be happy to revaluate at a later date."

 

I know I often lack finesse when driving but don't think the frequency with which I get the change wrong is down to me, especially when changes between other gears are fine. This is by far the worst gear change of the 20+ (most new) cars I have had.

 

Any thoughts as to the cause and/or how I should handle it when I see the people at Caterham tomorrow?

 

I am told it is a brand new, standard 5-speed MCP 'box.

 

[Jonathan Kay]

Ask if the technician can do a road test with you watching and listening?

 

Getting that marker down about looking at again in the future is good: put it in writing in an email.

 

Jonathan

[Martin J]

Do you have the clutch stop fitted through the footwell?

When mine became a bit awkward selecting reverse especially I found winding it in a couple of turns to give more clutch travel made a huge difference.

[BigCol]

I commented about the 'box early doors and it was suggested that I wait and have them look at it at the first service.

 

The marker about my disquiet has been both verbal and in writing via email. James at Caterham confirmed it is appropriately noted (though they say nothing's wrong with the gearbox!) and offered for me to go out with a technician tomorrow when I collect the car (as there's also an annoying rattle that they couldn't hear too!)

 

I adjusted the clutch stop, so with the pedal fully down and car in gear, it goes nowhere... is that the incorrect way to set it? Would happily wind it back a bit but what might I be straining as a result?

[Klunk]

It sounds like the clutch stop is correct but to be sure it is not the issue just remove it for the time being.

 

If you're having to rev match to get into second from first I would say there is something up with the synchro. This is definitely not a case of TADTS. As Jonathan says, go on the test drive and make sure he is changing gear briskly and at high revs (i.e. 5k not 2k).

 

Just another thought, you haven't changed gear with the main case lid off at some point have you?

 

Regards,

Giles

 

Edited by - Klunk on 29 Aug 2013 20:13:54

[BigCol]

Have only changed gear with the 'box in the car and with its lid on...

[Klunk]

That's good news. Will it select all the gears easily with the engine off and the clutch down?

[shn7]

To check for clutch drag jack up the back end and start the engine. With the clutch depressed do the wheels turn when in 1st gear?

 

If they do then the clutch isn't fully disengaging and will cause poor changes especially noticable in low gears including reverse.

[BigCol]

funny you should say that... given this post I made during the build:

Sanity Check

 

but what needs doing to fix it...?

[shn7]

Richy gave a possible answer in that thread. I'm sure in my Sevens the wheels would not rotate.

[shn7]

Though none had hydraulic clutch. Wonder if u could swap to cable operation.

[Grim Reaper]

What is the problem with changing gear with the lid off the box?

[7 wonders of the world]

If you go changing gear with the lid off you risk the detent becoming jammed as it is retained by the lid, and locking the box in 2 gears, that's why gearbox builders have a dummy lid with the detent retaining portion present but the rest cut away.

 

 

[Stationary M25 Traveller]

If it is a Sigma with internal hydraulic clutch ... wonder if there is some air in the system ?

[charlie_pank]

From your description it sounds very much like the clutch is not fully disengaging. That causes the symptoms exactly as you describe, 1st and reverse are the worst and the rest are fine (of course they are, it's possible to change up through the box without using the clutch at all!).

 

You need to find out why the clutch plates aren't disengaging fully. Is the pedal travelling far enough? Are you making sure that your foot is all the way to the stop before attempting a gearchange? Is the release arm too short or bent? Is the cable stretched or is there a bubble in the fluid? etc...

 

 

C

[BigCol]

Just back from Caterham with the car...

 

Went for a protracted drive with a technician, Mark, as passenger and whilst I only had one noisy/embarrassing gearchange, it was confirmed that I'm not a numpty when it comes to changing gears 😳 and that 1st/2nd are very much stiffer and harder to select than 3rd, 4th or 5th.

 

Mark said he'd checked the clutch ahead of my visit (had emailed the thoughts of Blatchat in advance!) and it was fine. He also reckoned that this sort of thing is more usually seen on race cars and more often manifests itself on 3rd and 4th gears rather than 1st and 2nd.

 

Either way he says the 'box isn't right and has got James to agree that they'll sort me a new gearbox; though the timescales for this are unknown and possibly protracted.

 

So am happy that we have a solution (even if it will be another two half-days to get the car to/from Dartford or a day if I can wait whilst its replaced). Thanks to all for their thoughts!

[shn7]

Glad to hear they have agreed there is a problem to be sorted.

 

Interesting they are saying the problem is with the gearbox and not the clutch failing to fully disengage.

 

Can you say on what basis this has been determined?

[Jonathan Kay]

Well done

 

Jonathan

[BigCol]

on the test drive the technician said he was confident that the clutch was OK based on his inspection of it prior to me arriving (and before you ask, no I don't know exactly how he came to that conclusion!) and felt the awkwardness of selecting gears was down to the 'box... we'll see... if I've the same issues with a new gearbox, then his diagnosis might have been wide of the mark!

[BigCol]

I dropped the car off at Caterham in Dartford on Monday and picked it up yesterday.

 

It now has another gearbox. There's a marked improvement (though the 'left hand' gears, ie R, 1 and 2, still feel stiffer than the 'right hand' ones, ie 3,4 and 5) so I'm a happy bunny.

 

They also attended to a brake issue which I mentioned when I dropped the car off.

 

Both jobs were done under warranty with no charge at all for parts and labour (just the cost to me of my time, fuel and train fares to get the car and myself to/from CC)

 

Given the frustrations suffered by others with Caterham, it is only fair to say I got the overall result I wanted without too much "assertiveness"!

 

(It could be argued with some compromise... with my other car, I would have pushed for a loaner, collection and delivery back etc but the dealer is closer and much less of a cottage industry. Plus, of course, acceptable compromise is what negotiation is all about!)

[Garry7]

Big Col,

Your overall experience ties in with mine - acceptable compromise is the way to work with them. I have alway found Mark to be very good (he has his own kit built R400D - so must have felt a bit of our "pain").