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Clutch & Gear change issues on a TD5

Posted: Mon May 23, 2005 9:52 am
by Mick G
Have just had my master slave cylinder changed and have noticed the following problems with my Manual S2 TD5 which has done 113,000 klms and has a remapped Bruce Davis ECU fitted - not necessarily related problems.

Problem 1. When depressing the clutch whilst changing up through the gears, the throttle sticks and keeps going for a second or two - reving a fair bit and when the gear engages, the car obviously lurches forward. Nearly shot me down a steep hill at the weekend whilst in low range so it does it in both high and low range. Seems to happen sometimes and not others and have noticed it doesn't matter if the engine is cold or hot.

My theory - Hopefully this is simply a slicky accelerator cable which is easlity fixed (by someone who knows what they are doing!!)

Problem 2. Gear stick is cacthing when changing from 2nd to 3rd. You really need to zig zag into 3rd where as before it simply slid up nicely.

My theory - Don't have one but hope it is not too expensive and can be fixed easily. Maybe something to do with tthe "H" plate??

Problem 3 (while I'm at it) - Occasionaly when changing gears, the process of the engine engaging is a bit cluncky. i.e. you put your foot back onto the accelerator and a second later the engine engages and kind of kicks in with what feels like the whole engine moving inside the bay.

My theory - engine mounts?? Expensive to replace? Anyway to make the up and down change smoother so not as much lurching.

I am NOT a nmechanic by any stretch of the imagination and will be taking it to the mechanic I use soon, but want to gain a bit of knowledge first before I have to spend money getting it fixed. All tips or suggestions are appreciated and I will be posting this on a couple of other sites as well.

Cheers

Posted: Mon May 23, 2005 9:59 pm
by Bush65
I haven't any experience with TD5, but my understandin is that they are fly by wire. This means that the accelerator cable is replaced by electrical sensors somewhere on the accel pedal that provide the pedal position to a computer that controls the fuel injection pump. So it is not a sticking accel cable.

I wonder if there is a sensor on the clutch pedal that plays some role with the accelerator!

When taking off from a stop, when does the clutch start to engage and is it different to before when it all worked properly? When the clutch is only let out a little (ie pedal close to the floor) or only when the pedal is nearly all the way up?

With the gear stick catching. Is this a mechanical/physical catching, on the gear lever, or is this your explanation of a gear grinding type phenominum from poor synchronising of the gears? There is no H-plate.

Has the gearbox oil been changed lately? Incorrect gear oil can affect the gear change. It should be MTF94 or an equivalent GL4 manual transmission fluid, not automatic transmission fluid and definetly not gear oil which is too viscous.

The R380 gearbox tends to run too hot and the heat has been known to affect the gear lever. From memory the TD5 should have an oil cooler for the gearbox. The cooler consists of a thermatic valve in a housing bolted to the lh side of the gearbox and a steel piping that runs to the front of the vehicle and back (the steel piping is the cooler). If you are only having problems with the gear lever when the box has warmed up, there may be a problem with the thermatic valve.

I dont know anything about the engine mounts on a TD5. From memory when I looked under one, the were different to those used for 300TDi's and v8's.

Posted: Mon May 23, 2005 10:08 pm
by rovernut
Well i can answer one of your questions regarding you sticky throttle cable and let you know that all TD5's have a fly-by-wire throttle which means that you dont actually have a cable. The throttle position is fed to the computer via a sensor then relayed to the ECU, so your sticky throttle could have something to so with the chip you had installed??? just a theory.

Good luck. Matt

Posted: Mon May 23, 2005 10:19 pm
by Slunnie
I think the clutch does have a sensor in it for the cruise control.

ECU

Posted: Tue May 24, 2005 5:07 pm
by Mick G
Seems that the problem might lie with the upgraded ECU. Bruce Davis is on the case and hopefully will have it sorted out soon. As for the sticky gear box, turns out a spring has gone inside which means the gear stick rests between 1st & 2nd and not in the middle between 3rd & 4th.
Will be checking the engine mounts soon although I think it is simply the slight lag in the throttle which makes the engine kick when engaging. It's not too dramatic but I'm just a perfectionist and like things to work as they are intended.
Anyway, thanks for all the input.

Mick

Posted: Tue May 24, 2005 6:47 pm
by Bush65
Yes, forgot about the spring problem with the gear lever. Sometimes the mounting plate for the springs fails. Neither the springs nor the bracket are inside the box BTW.

Posted: Tue May 24, 2005 8:56 pm
by Woop
There is a pressure switch installed in the line from the master cylinder to slave cylinder that drops the engine revs when it senses a pressure rise in the line--ie whilst depressing the clutch. This switch can go faulty giving the symptoms you describe

Nick

Posted: Tue May 24, 2005 9:53 pm
by Mick G
Woop wrote:There is a pressure switch installed in the line from the master cylinder to slave cylinder that drops the engine revs when it senses a pressure rise in the line--ie whilst depressing the clutch. This switch can go faulty giving the symptoms you describe

Nick


Cheers Nick

Will make sure I check out this possibility if the ECU is not to blame.

Mick