Bad gear change

[Earlfez]

Gents and ladies,i have a 2.5wlt 4x4 auto bongo. When it is cold the change from 1st to 2nd is sharp, sudden and just feels like something is going to break. I also get a lag sometimes after selecting drive.
When everything is nice and warm it changes gears smoothly and the lag is less noticeable.

I have changed the gearbox transmision fluid and this has made no difference. Any ideas before i start randomly investigating?

[Northern Bongolow]

is the tick over nice and even, or does it occasionally raise and dip slightly. what age and milage has it got on it.

[Earlfez]

tick over seems smooth, I haven't noticed it dipping. Will pay more attention however the engine seems to run sweet.

It is year 2000 and it has 127k km on the clock. Generally in very good condition. No starting problems. Just the really bad gear change from 1 to 2 when cold and a slight lag on selecting drive.

When I changed the transmission oil it needed it but the fluid wasn't the worst I've seen.

Amy ideas?

[Earlfez]

Checked and have been paying lots of attention. Tick over is smooth and consistent. No hunting or dipping of the revs.

[Northern Bongolow]

is the oil level the correct level.

this is checked when the engine is running and in park etc, are you aware of this. did you top pump the oil out or did you drop the sump and do the filter. sounds like a oil supply/solenoid problem, suggesting the filter as the oil will drop into the sump so when cold and freshly started up there may not be enough oil in the gearbox solenoids or pump to work things properly.
a good auto gearbox place should be able to pressure test the system and check the solenoid pack.

[cmm303]

Because the oil was quite bad and changing the oil only replaces about half of it, would it be worth doing another change? Just asking!

[Earlfez]

Good stuff. I took the Bongo to my local garage where one of the guys is an ex Bongonaught. He dropped the sump to do the transmission oil change. I would like to think he knew what he was doing when he checked the oil level afterwards. mmmmmm I will check the oil level with the engine running and in park again tonight. If it is still okay i will take it for another oil and filter change.

Thanks for the advice. Will post what i find

[mikeWalsall]

The valve block filter is a fine metal mesh screen that can be washed in solvent .. (I did mine in the dish washer) ..

There is a magnet on the bottom of the sump that any metal particles stick to .. the debris on this .. the filter screen and fluid condition may give an indication of the general condition of the boxes internals ..

There have been reports of the solenoid pack inside the box giving problems .. it was actually a factory recall many years ago ..

[cmm303]

The valve block filter is a fine metal mesh screen that can be washed in solvent .. (I did mine in the dish washer) ..

There is a magnet on the bottom of the sump that any metal particles stick to .. the debris on this .. the filter screen and fluid condition may give an indication of the general condition of the boxes internals ..

There have been reports of the solenoid pack inside the box giving problems .. it was actually a factory recall many years ago ..

There is a good thread with pictures here
Interested in how you get on, mine is also a bit lumpy changing 1st to 2nd when cold.

[Earlfez]

Well, have tried most things now with no effect. Now starting to get what sounds like a screeching thrust bearing when going from 1st to 2nd, fault developing fast. I dropped it off at ADS (bongonaughts) in Bristol for them to give me their opinion. General consensus is it's a problem in the gearbox (probably a bearing or accumulator issue (?)) itself... dagnabbit.

New or refurb unti required. Got some wild quotes for refurbs so have decided to go for a unit from a breakers. Will then keep hold of the old unit and strip it.

If I find anything interesting I will post it on here.

Thanks for the help

[Earlfez]

Okay, so it looks like I may have been a bit of a muppet.

I took the sump off the gearbox and found lots of stuff. Clearly a bearing was in it's death throws in the box somewhere.

So I went for a second hand Auto 4x4 box. Honest John said it was a good runner. Replaced the box today and then after doing the hard bit (old box off and new box on) I noted some of the connectors were different. Not too much problem to swap the odd bit. There is one hall effect sensor which has three wires on the box and only two on the connecter on the vehicle.
So that's not connected yet. Any suggestions. (the old one is not a match to fit)

Engine starts, I move through all of the gear positions, and the D doesn't illuminate but all other selections do illuminate. There is no drive in any position in any direction.

Help please before I go out of my mind

[Northern Bongolow]

i would have a friendly chat with these guys, bongospares2012, tell them exactly what you have done, they will have come across it before im sure, or will know a way round it.
the above presumes you didnt buy it from them and they already know.

http://www.bongospares.co.uk/

[Alacrity]

Electrics CANNOT cause a no drive situation. Fact.

All the electrics do is make it change gear & control the pressure the transmission runs at. If you have no drive then the transmission has an issue, it is either a duff unit - always a risk when fitting 2nd hand - or the pump has been broken when fitting, VERY common when units are fitted by folk who have little or no experience of fitting automatic transmissions. Did you bolt the converter to the flex plate before you fitted the gearbox or was the converter in the bell housing?

There are two types of 'early' transmissions, both the Jatco R4A-EL but they have significant differences. I recently fitted a 2nd hand one for a friend to a 2.5td 4x4 & found that out the hard way. Differences are (at least):- converter, pump, maincase, range switch & extension housing. We got it to fit & it drives fine but it was a performance. Get the right one (by I.D. no). The later (post '98?) Jatco JR405E unit I have had little experience with having only ever done 1 Bongo & a couple of Isuzu's (same trans but different before anyone asks).

As others have said a 1-2 thump is common on these units when they have done a few miles, both mine have done it. Oil changes wont effect it. Oil changes are preventative maintenance the same as with an engine, you wont cure a transmission fault by changing the oil (or if you do it wont be for long) any more than you will cure an engine miss-fire by changing the engine oil.

[Earlfez]

Okay, well the end to my little story was a trip to the gearbox refurb chaps in Bristol. Gloucester road gearboxes. The 2nd hand unit was not in good working order the original unit was refurbished and the van is now driving sweet. The Gloucester road gearbox guys say that the inside of the old box was a bit of a mess and i was lucky i hadn't suffered a catastrophic failure with the amount of 'wobble' in some of the bearings.

Anyhow, i now have another nice new shiny piece on my bongo that no-one will ever see,,,, that is not unless they are lying under it.

I did notice recently i seem to have a little oil starting to make it way out past the cylinder head gasket,,,,,, Is that normal on the 2.5 TD wlt?

[wonkanoby]

sure you dont mean rocker cover,as that often leaks