Odd Gearchange
 

Over the last few days I've noticed my transmission doing something odd only when under hard acceleration.

As it accelerates the revs rise normally and all seems fine but as it changes up to the next gear it momentarily hesitates, the engine note flattens out and the car ever so slightly decelerates then it goes into the next gear and carries on accelerating as normal. This odd fluctuation takes just a split second but it feels and sounds horrible.

I've looked through some other transmission threads on this forum for something similar but there's just too many to look at. So if anyone has any idea what is happening it'd be very much appreciated.

WEll from what i have been reading that is just a tranny starting to wear out.

but you can try this i am sure this will stiffen the shifts up for you.

http://www.smallcar.com/svx/tsk.htm

the shift kit from them.

well hope this helps.

I hope the tranny isn't on its way out; it was rebuilt by the previous owner only 18 months ago at a cost of £2000 (about $3000).

As for the Shift Kit; by coincidence one of them came through the post and landed on my mat this very morning courtesy of smallcar.com. I shall hopefully fit it this weekend.

Any other ideas what the problem could be and how it can be curred without major expense? I had hoped to get 50,000 miles out of it at least before I have to dip my hand in my pocket.

Re: Odd Gearchange
 

Gid'ay Monzta, Tell us more about it. Does it happen between all gears or just between two? Is it the same on light throttle or full throttle?. Hot or cold?.

Harvey. ;)

Harvey,

Watcha mate! It happens between all gears and at all temperatures but only so far under severe acceleration......when I'm having a bit of a play. :D

But generally I find my 'box has a few foibles. It hunts backwards and forwards between 3rd and 4th when doing about 80mph on motorways......which is kind of annoying.

Also, it sometimes changes between 1st and 2nd with a bit of a thump which is why I bought the Shift Kit from smallcar.com.

Basically, my tranny is a delight in all gears just not so good swapping between them.

As the 'box was rebuilt recently could it be more of a ECU problem, something somewhere sending bad messages to the transmission?

No I dont think it is in the box, have you checked the throttle position sensor to see if it shows 0.5volts with the throttle closed. Have you fitted the shift kit yet? or is this happening without it.?

Harvey. ;)

N.B. your TPS may show the correct voltage when closed and be set correctly but may be all to hell through the full extent of travel.

This would be the most likely cause of the problem you correctly suspect i.e. " bad messages to the ECU " and or TCU . You should remove it and check and clean it. Not difficult and details you will find in the " How Too " section. Intermittent contact between the wiper and resistance element within the TPS has been recorded as a common fault

Harvey,

I haven't fitted the shift kit yet and haven't checked the voltage as I don't own a tester as I'm a bit of a Luddite when it comes to that sort of thing. I think I'll have to invest in one though and teach myself how to use it.

Trevor,

I've read your 'How To' on adjusting and cleaning the TPS, will try to give it a go when I get a chance.....will buy a voltmeter first though.