'Snatchy' transmission

[Paranoid android]

Bongo trouble / transmission?
 
Gearbox ‘snatchy’, erratic gear changes especially at low speeds and when cold. Sometimes very smooth from the off but sometimes ‘very’ not. Worst case seems stuck in low gear/s and vehicle can lurch forward a foot or so from stationary. Occasionally can hear it trying / deciding to change. Its not over revving when problem occurs (revs seem fine).
 
About month ago had a flashing hold light and intermittent Speedo. Did not continue to drive as 2 years ago had flashing hold and no gear changing + high revs. That resulted in a new transmission valve / solenoid chest.
 
This time we had a transmission fluid change (as it has only ever been toped up since solenoid set change). Although fluid looked clean on dip stick mechanic advised there was swarf in the fluid and it was greyer than should be. He also said he checked vacuum hoses, transmission connector blocks and all seemed ok.
 
This made no difference to intermittent hold flashing and after some miles (50 or so) speedo eventually died altogether. No problems with gear changing obvious.
 
Tried running diagnostics, technician said there was no signal out from diagnostics box so no information on fault.
 
Reading up on Bongo Fury found could short mid and lower right hand terminals on diagnostics to get hold light to flash code. Code 7 was displayed indicating fault with speedo sensor on back of transmission.
 
Had speedo sensor substituted with a new one, no change / intermittent hold flashing, no speedo.
 
On investigating further found that when the vehicle was imported speedo and odometer conversion included a Kph to Mph via a ‘SpeedM8’ (011030) box. This was connected between loom and speedo connector with 5 wires (black, red (power), grey, white and orange).
 
Was advised that this may be faulty. Ordered a replacement in form of a ‘KBTV’ speedo converter and fitted according to KBTV instructions (removing SpeedM8 of course). KBTV is 4 wire chip. Two power and divert of signal wire (pin 3L from speedo connector).
 
When fitting noticed 4L was not connected to anything.

Speedo returned but gear changing problems and hold light flashing still occurring intermittently.
Described problem to KBTV (very helpful) and he suggested wiring as original out of factory to establish if speedo chips affecting problem.
 
Have rewired as original (out of factory / no chips) including reconnecting 4L
 
•No hold light flashing so far (50km done since)
•When shorted, diagnostics still read fault code 7
•Speedo (odo) working fine (in Km!)
 
…but gear changes still intermittently indecisive and transmition is still‘snatchy’ - not a happy Bongo and transmission problems getting worse!
 
Any help / advice gratefully received


 
 
 
 
 

[Northern Bongolow]

hi and welcome.
by your very good description of the faults occuring i would have gone for the speedo chip myself, as this is now out of the loop and the speedo is reading correctly, you are sure its working correctly?, i would look at the alternator output. ive had several recently that have been looking like they have been working ok but when measured carefully they have had faults which have been affecting the gearchanging,i am pretty sure the two were linked.
check the output of the alternator for under or overcharging. what ampage is the alternator, check the plate,and what colour is the painted band around the field coil area on the pulley end ? (black or green).
the other thing that can do wierd things to the g/box is the fan switch (driverside of the head, near the rear). if this is faulty it can send odd messages to the ecu and maybe then to the g/box, the end should not be wobbly where the plug fits in.
try these cheaper options first, then it may be time to check the g/box itself again.
if you want your speedo to read in miles you can fit a speedo out of a mazda car (626), it has GA5R written on the face plate, this is a straight fit with no magic corrector box needed.
hope its a cheap fix,come back and let us know if any of this helps.

[teenmal]

Hi,
Did not like the sound of((Swarf in the fluid and Grey (ish) colour of the fluid.

The gear box expert Alacrity,should be along shortly,if not give him a PM.He is a very nice and helpful man..

Cheers.

[Paranoid android]

Hi, thanks for tips - looks like my weekend will be under the bonnet (or seats). I'll let you know outcome.

Cheers

[Alacrity]

'Snatchy' shifts (especially 2nd) when cold are, more often than not, down to poor engine performance when cold. If you are having to put your foot down a lot when cold the shifts will be late & firm. Is it OK when warmed up?

A lot of people get worried when they see grey 'sludge' & fine swarf in the sump. Clearly if there is a vast amount of it or if the swarf is large then you have a problem, but grey sludge is common in all transmissions as is a degree of fine swarf - especially when new of after a rebuild when you may have new bushings etc. that will polish up with us & can deposit fine material in the oil. I am more concerned about your comment of topping up the oil - you shouldn't need to unless you have a leak somewhere.

A TPS at fault could be your problem although you have no code for it but they can mess about without setting a code. Is the speedo fault code an old one from the old chip problem, i.e. did you clear the code after you read it? Other causes could be speed sensor on the transmission.

It needs diagnosing correctly to establish if the problem is inside the transmission (Unlikely (but not impossible) is my gut feeling) or, as I suspect, external to the transmission.

You don't list your location so it is difficult to put you in touch with someone who may be able to help.